How to improve your digestive health

A healthy digestive system is fundamental to a healthy body. Optimal digestion is the foundation of optimal energy. Digestion allows the body to get the nutrients and energy it needs from the food.  The digestive system is basically a tube of 25 and 30 feet long running through the body from mouth to anus. The digestive tract and the accessory organs of digestion make up the digestive system. The organs of the digestive system include the oral cavity (mouth), oesophagus, stomach, small and large intestines, rectum and anus. The accessory organs of digestion include the salivary glands, teeth, liver, gall bladder and pancreas. Over a lifetime no less than 100 tons of food passes along the digestive tract and 300,000 litres of digestive juices are produced by the body to break it down. Digestive juices flow from the walls of the stomach and small intestines, pancreas and gall bladder. Enzymes, bile and bacteria break down the food.
Facts on digestion
Digestion is a function of an organ system which involves a series of processes.  There are 5 processes that are involved with digestion: eating, breaking down food into simpler chemical compounds, absorption, assimilation and elimination of waste. Digestive organs can become disturbed for a multiplicity of reasons: poor diet, irregular eating habits, physical and mental strain, viral or bacterial or fungal or parasitic infections, allergies, toxicity and drugs. Digestive discomfort can express in many forms: stomach pain, bloating, indigestion, constipation, diarrhoea and foul smelling gas.
Statistics
More than 80 million Americans live with and suffer from chronic digestive problems. It is estimated that 4 million Americans have constipation and 60 million Americans have acid reflux. Approximately 12 million people in the United States suffer from food allergy. One-third to one –half of all populations have digestive illness. It is estimated that 25 to 50% of all digestion- related ailments can be prevented and / or modified by proper eating, exercise, natural medicines and lifestyle modifications.

Definitions

The digestive system comprises a group of organs that break down food and absorb the nutrients used by the body for fuel. The digestive system begins with the mouth and extends through the oesophagus, stomach, small intestine and large intestine, ending with the rectum and anus. The most important roles of digestive system include ingestion, propulsion, mechanical digestion, chemical digestion, absorption and defecation. Gastroenterology is a branch of medicine concerned with the function and disorders of the digestive system.

Digestion refers to the breakdown of food into smaller molecules that can be absorbed and assimilated by the body. The process of digestion occurs as the food you eat travels through the digestive tract. The food is kept moving by muscular action called peristalis. The main work of our digestive system is processing the food we eat to obtain energy and nutrients.

Good digestive health is the ability to break down, absorb and use nutrients and to eliminate waste products from foods and beverages in a way that optimizes one’s health and vitality.

Importance of the digestive system

The digestive system represents not only the physical ‘engine’ of the body, but also the center of emotions and the seat of subconscious.  Two-thirds of our immune system is located in and around our digestive system. According to Dr. Michael Gershon in his book The second Brain (1998), all of the neurotransmitters that are found in the brain are also found in the digestive system –hence the term ‘second brain.’ The digestive system actually has its own nervous system called the enteric nervous system (ENS) and over 95% of serotonin is made in the gut (Gershon 1998). The enteric nervous system functions without the direction from the brain. The activity of the digestive system is regulated by the rich network of nerves found in the enteric nervous system (ENS).

Factors in good digestion

The factors that promote good digestion include timing, manner or eating, quantity of food, condition of the food, quality of the food and appropriateness of the food to your body.

·         Timing – when you eat;

·         Manner – how you eat;

·         Quantity – how much you eat;

·         Condition of the food –raw, cooked, warm or cold;

·         Quality of the food – fresh, clean and pure;

·         Appropriateness of the food – whether the food is compatible with your digestive capacity and relevant to your nutritional requirements.

Four R's gut healing program

Digestive problems are part and parcel of our life. There is a 4-R’s program with the following steps: Remove, Replace, Re-introduce and repair. In the first step, remove the things that are causing the problem such as bacteria, parasite, Candida or yeast overgrowth and potential food allergens and toxins. Then replace the diet with healthy food, dietary fiber and pure water for regular elimination. In the third step, re-introduce the gut with dietary probiotics or supplementary enzymes. Lastly repair the gut lining, so food and germs do not get through to the blood stream and cause a bad reaction called ‘leaky gut syndrome.’  It is reported that leaky gut syndrome is thought to cause all kinds of problems from food allergies to irritable bowel syndrome and colitis.

Herbal and nutritional healing of digestive disorders

Traditional Chinese medications use concoctions of kiwifruit as  a tonic to find relief from indigestion. Kiwifruits have substantial amounts of prebiotics, phenolics, dietary fibers and vegetarian digestive enzymes. Chamomile is an all –around stomach soother. Bitter herbs like dandelion can help improve digestion. Bitter herbs are great helpers for optimal digestion. Deglycyrrhizinated licorice root may reduce heartburn, acid reflux and gastritis. Licorice protects the mucous membranes that line the digestive tract against the damaging effects of stomach acid. This effect can be very helpful for those with heartburn. Slippery elm is another herb that acts as a barrier against stomach acid which again is important for those with heartburn. Aloe vera reduces mucosal inflammation, prevents acid reflex and improves gut healing. The herb milk thistle may be a useful supplement in the case of constipation caused by a lethargic liver. Digestive enzymes found in tropical fruits such as bromelain from pineapple (which reduces tissue irritation) and papain from papayas (which soothes the stomach) can provide help in digesting proteins as well. Tomatoes keep the digestive system healthy by preventing both constipation and diarrhea. A healthy complement of intestinal flora (the digestive bacteria acidophilus, bifidus and lactobacillus) is essential to good digestive health. Dietary fibers help promote regular defecation and prevent constipation. Fiber –rich foods include berries, greens, beans, apples, pears, oats and flaxseeds. The daily recommended intake of dietary fibers is 20 to 35 grams per day.  Lubricant foods and herbs help the stool move through the digestive tract called demulcents. The demulcents include okra, flaxseed, oats, kelp, cactus, natto, toasted seasame oil,olive oil, acacia and chia seeds.

Digestive level of foods

Some foods are harder to digest than others. Proteins are the hardest to digest. Protein digestion requires an acid medium (hydrochloric acid) and the enzyme pepsin for its digestion. Starch digestion requires an alkaline medium and the enzyme ptyalin for its digestion. Starchy foods are easier to digest. The non-starchy vegetables are very easy to digest. The easiest food of all to digest is fruits.

Food combining for better digestion

Do not combine protein foods with acidic foods or fats or starch foods or sugars. Do not combine two concentrated protein foods at the same meal. Do not combine starches with sugars or starch foods with acidic foods. Eat one concentrated starch food at a meal. Do not eat acid fruits with proteins. Do not combine sweet fruits with proteins, starches or acid fruits. Acid fruits may be used with sub-acid fruits and sub-acid fruits may be used with sweet fruits. Combine fruits only with lettuce and celery. Salads combine very well with proteins or starches. Do not consume melons with any other foods.

Foods for healthy digestion

A healthy diet consists of a good balance of macronutrients (proteins, fats and carbohydrates), prebiotics and probiotics, essential fatty acids, minerals and vitamins.  A healthy diet is one that helps to maintain or improve health by providing appropriate amounts of nutrients. Super foods for healthy digestion include yogurt, high fiber whole grain bread, rice, whole grain cereals, tofu, miso, tempeh, dandelion green, sunflower seeds, sea vegetables, flaxseed oil, papayas, garlic and sage leaves. Our food choices play a significant role in the quality of our digestion.

Tips to improve your digestive health

1. Eat a balanced and varied diet with fresh fruits and fresh vegetables. Eat four to six light meals per day. Eat more foods containing complex carbohydrates and fiber. Avoid over eating, only eat as much as you need.
2. Take small bites; Eat slowly and mindfully. Don’t eat before bed and walk after each meal.
3. Eat right type of fats and eat foods containing complete proteins, but in moderation.
4. Get enough fluids.
5. Give up caffeine; eliminate alcohol and nicotine.
6. Exercise is crucial to good bowel health.
7. Reduce depression and anxiety.
8. Listen to your body; be cautious about constipation, gas or upset stomach – it’s a sign you need to make changes in your dietary habits.
                           The digestive impulse is the life of your stomach

Health benefits of dietary phytoestrogens

Phytoestrogens are non-steroidal plant – derived phytochemicals with estrogenic activity. The common biological roles of phytoestrogens are to protect plants from stress or to act as part of a plant’s defense mechanisms. The name ‘phyto’ means plant and ‘estrogen’ comes from estrus (period of fertility for female mammals).  All phytoestrogens are diphenolic compounds with chemical structures similar to natural estrogens and antiestrogens. Phytoestrogens are made up of more than 20 compounds and can occur in more than 300 plants such as fruits, herbs and grains. Three major subclasses of phytoestrogens have been identified and chemically defined as Isoflavones, lignans and coumestans. The best studied dietary phytoestrogens are the soy Isoflavones and the flaxseed lignans. Phytoestrogens cannot be stored in the body and can be easily broken down and eliminated. Dietary phytoestrogens have weaker estrogenic effects than human estrogens. Human clinical trials suggest that phytoestrogens may potentially confer health benefits related to cardiovascular diseases, cancer, osteoporosis and menopausal symptoms.

The soy hypothesis

Historically, Asian countries have had low incidence rates of breast cancer compared to Western countries. Soy, a dietary staple in many Asian countries may protect women against breast cancer. Anticancer effects of soy Isoflavones may be attributable to their structural and functional similarities to estrogens.  Epidemiologic studies in Asian and Asian-American populations support the hypothesis that early exposure to dietary soy may decrease breast cancer risk, while exposure in adulthood may not be positive. A regular intake of soy foods appear to be protective. This is evidenced by Japan, for example only 25% of menopausal women suffer hormone withdrawal symptoms as compared with 85% of women in the U.S (Notelovitz 1989). In menopausal women, dietary phytoestrogens can help compensate for the hormone deficits and thereby moderate the hormonal withdrawal symptoms.

Phytoestrogens – a definition

Phytoestrogens are defined as “any plant substance or metabolite the induces biological responses in vertebrates and can mimic or modulate the actions of endogenous estrogens usually binding to estrogen receptors” (MAFF UK, 2003).

Estrogenic potential of phytoestrogens

Phytoestrogens have biochemical structures similar to those of mammalian sex hormone estrogen. The estrogenic activity of phytoestrogens has been related to their ability to bind to the mammalian estrogen receptor (ER). The phytoestrogens such as genistein and coumestrol were shown to have higher binding affinities to estrogen receptor(ER). Dietary phytoestrogens have weaker binding affinities when compared with the female endogenous estrogen β-estradiol. Isoflavones are best researched and most common form of phytoestrogens.

Dietary sources

The main dietary source of Isoflavones (e.g. genistein and daidzein)  for humans is soybean, while flavonoids (e.g. apigenin, naringenin and luteolin) are found in several different vegetables, fruits, berries, herbs and green tea. The soy foods contain approximately 0.2 – 1.6 mg of Isoflavones/ g dry weight.  For Coumestans( e.g. coumestrol), the main sources are sprouts of alfalfa and various beans. Lignans (e.g.entrolactone and enterodiol ) are not present in our diets as such, but precursors are converted to lignans by the gut microflora. Lignan precursors are present in fibre- rich foods such as flaxseed, unrefined grain products particularly rye and some berries. Flax seeds are one of the best sources for lignans. Dietary intake of phytoestrogens is greater in vegetarians than in non-vegetarians. Asians, Japanese, Koreans and Chinese consume more phytoestrogens than the people of Western countries including Americans.  It is estimated that dietary phytoestrogen intake is up to 30 times higher in Eastern Asia than in Europe and North America.

Dietary reference intakes

The total phytoestrogen consumption in Eastern population or in adults taking phytoestrogen supplements may be approximately 60 to 75 mg/day. Therefore an average 60-75 kg adult would consume approximately 1 mg phytoestrogens per kg body weight (bw). Many Asian populations that exhibit low incidence of prostate and breast cancers consume 20 and 80 mg/day of the isoflavone genistein mainly from soy foods. The mean daily isoflavone intake in Asian populations has been estimated to approximately 30 mg/day. It has been recommended that dietary phytoestrogens sources containing 30 to 120 mg of Isoflavones can be given daily for relief of post menopausal symptoms. The dietary intake of phytoestrogens can affect the menstrual cycle and the concentration of reproductive hormones in the blood of premenopausal women. In 1999, the U.S. Food and Drug Administration (FDA) approved the health claim that a diet low in saturated fat and cholesterol that include 25g of soyprotein per day reduce the risk of heart disease. A meta-analysis study concluded that an intake of an average of 47g soyprotein / day lowered total cholesterol and LDL- cholesterol. This was supported by studies in the monkey indicating that isoflavone increased HDL-cholesterol, enhanced vasodilation and decreased atherosclerosis.

Therapeutic properties

Several health effects have been hypothesized for phytoestrogens: they can be estrogenic or antiestrogenic, antioxidative, antiproliferative, antiviral, antibacterial, insecticidal or fungistatic, cardioprotective, antiatherogenic, hypocholesterolemic, bone maintaining, cancer protective and anticarcinogenic (Branca F and Lorenzetti S, 2005). Phytoestrogen such as genistein affect the blood vessel wall to inhibit atherosclerosis by binding to hormone receptors. Phytoestrogens exert a cardiovascular protective effect by regulating blood lipid levels. Isoflavones and other phytoestrogens have been considered to exert anticarcinogenic actions mainly through antiestrogenic, antiaromatase or antiprolifertive mechanisms. Isoflavones can have a beneficial effect on balancing male hormones and the risk of prostate cancer. Dietary soy supplementation has been shown to increase bone mineral density. Sufficient dietary intake of soyprotein relieves hot flashes in post- menopausal women. The lignan phytoestrogens provide the building blocks of cell walls in plants and in humans. Lignans have the ability to inhibit fungus growth and kill various bacteria and viruses.

         Soy estrogens (isoflavonoids) play beneficial role in menopausal health

Health benefits of dietary phytosterols

Phytosterols are steroid alcohols (triterpenes). Phytosterols (plant sterols and stanols, saturated form of the sterol) are chemically like cholesterol molecules. Phytosterols are related to cyclopentaphenanthrene with four condensed rings of 28 or 29 carbons. Phytosterols present a diverse group of more than 200 different compounds found in various plant and marine materials. They are essential structural components of the plant cells and membranes. Phytosterols regulate membrane fluidity of plant cells. Sitosterol, campesterol and stigmosterol are the most abundant phytosterols in plants. Stanols such as sitostanol, and campestanol are saturated plant sterols. Phytosterols can be converted into phytostanols by chemical hydrogenation. Phytosterols are not synthesized by the body and an estimated 200-300 mg phytosterol is obtained daily from the diet. In humans, intestinal absorption of Phytosterols is low (0-10%) compared to the >40% for cholesterol. The phytosterols and stanols are naturally occur in a variety of foods such as nuts, vegetable oils, seeds and cereals. The prime function of phytosterols is to inhibit the intestinal absorption of cholesterol. Human body uses the Phytosterols to produce the hormones it needs. Phytosterols are not synthesized in human body, are poorly absorbed and are excreted faster from the liver than cholesterol.

Definitions

Phytosterols encompass plant sterols and stanols, are steroid compounds similar to cholesterol which occur in plants and vary only in carbon side chains and/or presence or absence of a double bond. Stanols are saturated sterols, having no double bonds in the sterol ring structure (Wickipedia.org).

Phytosterols are plant –derived compounds that are structurally similar to cholesterol. The compounds may lower blood cholesterol levels, particularly LDL cholesterol and may have uses as immunostimulants and in treating benign prostate enlargement.

Phytosterols and cholesterol

1. Phytosterols are not synthesized in the human body.
2. Phytosterols have their intestinal absorption much lower than that of cholesterol and
3. Large doses of Phytosterols in diet diminish the absorption of cholesterol.

Mechanism of action of phytosterols

Cholesterol absorption is a very important physiological mechanism that regulates cholesterol metabolism. Phytosterols have been shown to inhibit the uptake of both dietary and endogenously produced (biliary) cholesterol from intestinal cells. Such inhibition results in a decrease in serum total and LDL-cholesterol levels. Levels of HDL – cholesterol and triglycerides do not appear to be affected by dietary phytosterol consumption (AbuMweis et al 2008).

Food sources

Plant sterols are found in all foods of plant origin. Foods rich in phytosterols include unrefined vegetable oils, whole grains, nuts and legumes. The main sources of Phytosterols are vegetable oils, vegetable fat spreads and margarines, cereals and cereal products (bread) and vegetables. These sources contribute to 50-80% of the total phytosterol intake (Klingberg et al 2008,Valsta et al 2004). The fruits contain about 12% of phytosterol. The content of phytosterols in most vegetable oils ranges from 1.0 to 5.0 mg/g of oil. Wheat germ oil contains 17-26 mg/g of phytosterols. Lower amounts of phytosterols are found in palm oil (0.7 – 0.8 mg/g ), coconut oil (0.7 -0.8mg/g ), and olive oil (1.4 – 1.9 mg/g ). The phytosterol content in Finland rye, wheat, barley and oat are 1.0, 0.7,0.8 and 0.4 mg/g respectively.

Health promoting properties

The most important function of phytosterols is their plasma cholesterol –lowering effect through inhibition of intestinal cholesterol absorption and enhanced elimination of cholesterol in stools. Maximum cholesterol – lowering benefit is achieved at doses of 2-3 g/day (Hallikainen et al 2000, Jones et al 2000, Maki et al 2001). Several recent studies indicate that the consumption of 2g/day of sterols or stanols could result in a reduction in the risk of heart diseases by about 25% (Law 2000, Jones and Raeini – Sarjaz 2001, Hicks and Moreau 2001). The potential health effects of phytosterols include the prevention of inflammation caused by rheumatoid arthritis, control of blood sugar in diabetes, the reduction of the risk of various types of cancers and the prevention of inflammation caused by atheroscelerosis. Phytosterols protect against colon cancer by slowing down the reproduction of cells in the large intestine.  The phytosterols have been shown to effectively reduce prostatic hyperplasia (Berges et al 1995, Berges, Kassen and Senge 2000) and colon cancer (Bouie and Lamprecht 1999). The phytosterols have limited antioxidant activity.

Recommended dietary intakes

Dietary phytosterol intakes have been estimated to range approximately 150 mg/day to 450 mg/day in various populations. Early human diets were rich in phytosterols providing as much as 1 g/day. On average, most Americans get between 2 and 4 mg/day of the phytosterols. Natural health practitioners believe that we actually need to consume between 30 and 50 mg/day of phytosterols. The United States Food and Drug Administration (FDA) recommended an amount of 800 mg of phytosterol per day on a consistent basis for increased health benefits.  Typical consumption of plant sterols in the diet is approximately 200-400 mg/day (Aparna Kuna et al 2011).

Functional use of  dietary phytosterols 

Phytosterols and phytostanols in free or esterified form are added to foods for their properties to reduce absorption of cholesterol in the gut and thereby lower blood cholesterol levels. Phytosterols are currently added as an esterified form to wide range of food products such as margarines, yoghurts, salad dressings, milk and snack bars. Phytosterol and phytostanol esters are used as a fat replacer in margarines and spreads. These esters can provide a crispy texture (prevents sogginess) to cereal products by coating the product surface. Both phytosterol and phytostanol esters give an enhanced creamy texture to low fat dairy products (yoghurt / drinking yoghurt). They may also improve the taste of food products by masking bitterness and hence reduce the amount of sugar or sweetener required to obtain a pleasant taste and mouth feel (e.g. soy drinks).The phytostanol and phytosterol esters are microbiologically inert during the fermentation process used to produce yoghurt. The phytostanol and phytosterol esters added to various food products show excellent stability at different pH levels during long term storage (upto one year). The phytostanol and phytosterol esters are also stable in milk and fermented milk products with viable bacteria like yoghurts and yoghurt drinks.
                Dietary intake of phytosterols lowers the absorption of cholesterol

Therapeutic nutrition

Diet plays a major role in curing diseases or restoring the health by supplying the needed nutrients. Diets are composed of nutrients: macronutrients (proteins, fats and carbohydrates) and the micronutrients (vitamins, minerals and trace elements). Special dietary measures may be required to maintain lives of patients, who have chronic heart, kidney, liver and gastrointestinal diseases. These diets must also consider and supplement the effects of medications on nutrients. The regular diet is a normal unrestricted diet and is the food a person eats every day. The regular diet is well balanced and has a variety of foods from the food pyramid. A therapeutic diet is usually a modification of a regular diet. Therapeutic diet is formulated to optimize the nutritional needs of a particular patient. Therapeutic diet differs from a regular diet in the amount of one or more nutrients or food components for the purpose of treating or healing a disease or illness. The therapeutic diet is also called ‘special diet’ or ‘modified diet.’ A therapeutic diet is made under a physician’s guidance.

Therapeutic diet have modified for nutrients, calorific contribution, texture or consistency and /or food allergies or food intolerances.  For example, a cardiac diet is low in fat or cholesterol. A diabetic diet is low in sugar and fat. A clear liquid diet may be used to maintain hydration during gastro-intestinal illness such as nausea, vomiting and diarrhoea. Calorie – controlled diet is served to residents who are overweight. Sodium – restricted diet is served to residents with heart or kidney disease. High fiber diets (30g or more) are believed to help prevent diverticulosis, constipation, haemorrhoids and colon cancer.

Definition of diet therapy

Diet therapy is the use of any diet for restoring or maintaining optimal nutritional status and body homeostasis. The purpose of diet therapy is to restore or maintain an acceptable nutritional status of a patient.

Therapeutic nutrition

Therapeutic nutrition is broadly defined as the use of nutrients such as vitamins, minerals, amino acids, essential fatty acids, co-factors, enzymes, antioxidants and phytonutrients to support the body’s immune and healing systems, thereby altering the course and outcome of a disease process. It can be used as a preventive or can be used as a therapy. The goals of therapeutic nutrition include the supply of appropriate, bioavailable nutrients, the reduction of inflammation and the enhancement of elimination of toxins. Therapeutic nutrition is concerned with the treatment of patients by prescribing the right type of diets in order to meet their nutritional requirements.

The role of therapeutic diet

1.       To correct dietary deficiencies

2.       To maintain the patient in good nutrition state

3.       To formulate diet to meet the need of the patient.

4.       To educate the patient and family.

Types of therapeutic diets

Simplest therapeutic diets – are mechanically altered diets.  Mechanically altered diets contain foods that are pureed, chopped/ ground or soft for patients who have difficulty in chewing or swallowing. Mechanical soft diet is produced by simply grounding or chopping the food so it requires minimum chewing. For a pureed diet, the regular food is pulverized to a pureed consistency using a food processor.

Liquid diets – the diet is liquid at body temperature. Liquid diets may clear liquid or full liquid. The diet includes fruit juices, water gruels (strained and liquefied cooked cereals). This diet may be used after surgery. This diet can replace fluid lost from vomiting or diarrhea.

Soft or bland diet – it consists of easily digested foods that do not irritate digestive tract.

Restricted residue diet or low residue diet – it eliminates or limits foods that are high in bulk or fibre. It is used for patients with digestive and rectal diseases.

Hippocrates diet – is a natural diet of unprocessed and unchanged food as it is found in nature. It consists of fruits, vegetables and greens; fresh fruit and chlorophyll juices, sprouted seeds, grains and legumes; nuts and seeds; fermented foods and small amounts of raw honey.

Palaeolithic diet – it is also called caveman diet or stone age diet or hunter- gatherer diet. It is basically a high protein, high fibre eating plan. The diet includes a lot fresh lean meats and fish and vegetables and healthier fats.

Vegetarian or  neutral  diet – the vegetarian diet is sourced from plant products, plus dairy products and egg.The neutral diet is diet that contains the least amount of contaminants, pollutants or allergens. A vegetarian diet is the healthiest diet. A vegetarian diet reduces the risk for obesity, coronary artery disease, high blood pressure, diabetes and certain types of cancers. A diet rich in animal fats is the least healthy.

Vegan diet – consists of fruits, vegetables, legumes, grains, nuts and seeds. No eggs, cheese, yogurt, ice cream, butter or other milk products are eaten.

Raw food diet – consists 70% of raw fruits and vegetables and 30% of grains, nuts, dairy products and meat. Eating fresh, organic raw fruits and vegetables will increase the vitamins and micronutrients in your diet.  The raw foods have high levels of antioxidants with health promoting and disease preventing compounds.

Gluten free diet – Gluten is a protein found in wheat, rye, barley, triticale and oats. People with celiac disease (a digestive disorder) are sensitive to the presence of gluten in the diet. Gluten free foods include meat products, fish, dairy products, fruits and vegetables, pasta and noodles, rice and potatoes.

Calcium rich diet – calcium is absolutely critical nutrient in regulating acid/alkaline balance in the blood. Calcium plays another critical role in maintaining structural integrity of our skeleton. Excess calcium can deposit in blood vessels and kidneys. The diet includes dairy foods, sardines, collards, greens, spinach, sesame seeds and scallops.

Iron rich diet – Iron is an essential nutrient required for the synthesis of haemoglobin which carries oxygen in the blood. Iron deficiency anaemia is a worldwide health problem in young women and in children. Iron rich diet consists of broccoli, soybeans, bok choy, lentils, dark green vegetables, meat, poultry and fish.

Protein restricted diet – The average person needs between 40 to 65 grams of protein each day. People with chronic liver or kidney disease should limit protein intake. Proteins contain 16% nitrogen, which the body eliminates in the urine as urea. In cases where liver or kidney function is impaired, urea, ammonia or other toxic nitrogen metabolites may build up in the blood. To control protein intake, foods such as starches, sugars, grains, fruits, vegetables, fats and oils should be eaten at levels sufficient to meet daily energy needs. The purpose of a low protein diet is to prevent worsening of kidney or liver disease.

Mediterranean diet – consists of food mainly plant sources such as vegetables, fruits, cereals, legumes, garlic, nuts, olive oil, moderate amounts of fish, chicken, yogurt, red wine; low in cheese, eggs, saturated fats, sugar and red meat. A study has reported that this diet lowers the incidence of secondary heart attacks by 70% - a 70% reduction in deaths from all causes.

Detoxification diet – a diet of fruits, raw vegetables, water and yogurt to eliminate toxins absorbed from the environment or caused by poor digestion or poor excretion waste products.

The Atkins diet – It is a high-protein, low carbohydrate diet developed by Robert Atkins during 1960s. It is the most famous weight loss diet. It is based on the simple premise of a diet high in sugar and refined carbohydrates causes weight gain and ultimately leads to obesity. There are four phases to the Atkins diet: induction phase, ongoing weight loss, pre- maintenance and lifetime maintenance phase.

The macrobiotic diet – was developed in the 1920s by George Ohsawa. It consists of a simple diet of brown rice, miso soup and sea vegetables. Whole grains such as brown rice, barley, millet, oats, corn and rye makeup the bulk of the macrobiotic diet. This diet encourages the consumption of vegetables such as cabbage, broccoli, cauliflower, kale, bok choy, collards and mustard greens. Beans, tofu and sea vegetables should be eaten on a daily basis.

Zone diet – was developed by Barry Sears. The zone diet proposes a dietary ratio of 40% carbohydrate, 30% protein and 30% fat.

Benefits of therapeutic diets

It is essential or life saving treatment in the case of coeliac disease, phenylketonuria and galactosemia. Therapeutic diets are used to replenish patients who are malnourished in the case of cancer or intestinal diseases. Therapeutic diets are used to produce a negative nitrogen balance in obese people. Therapeutic diets are used as an alternative or complementary treatment in the case of diabetes or hypertension. Therapeutic diets are used to provide standard condition for diagnostic tests in the diagnosis of food sensitivity.

     Diet therapy restores or maintains an optimal nutritional status of a patient.

Cancer preventive dietary antioxidants

An antioxidant is a nutrient that helps inhibit or delay oxidation reactions caused by free radicals (free radical scavengers). Dietary antioxidants are compounds that reduce oxidative damage to the body by free radicals. Dietary antioxidants can safely interact with free radicals and terminate chain reaction of oxidation before vital molecules are damaged. Cell damage caused by free radicals appears to be a major contributor to aging and diseases like cancer and heart disease. Overall free radicals have been implicated in the pathogenesis of at least 50 diseases.  Antioxidants prevent the free radical damage to the delicate lining of one’s blood vessels, to the brain and nervous system and the DNA molecules. Antioxidants repair the cell damage associated with neurodegenerative conditions. They protect human body cells from the ravages of inflammation. Inflammation is known to be associated with increased levels of lipid peroxides and free radicals. Antioxidants play important roles as anti-disease agents and anti-aging agents.The dietary antioxidants such as vitamins A,C and E; carotenoids(i.e., beta-carotene, lutein and lycophene); polyphenols; the mineral selenium; and endogenous antioxidants such as glutathione-elevating agents (n-acetyl cysteine and alpha – lipoic acid), co enzyme Q10 and L-carnitine are essential for cancer prevention.

Definition of antioxidants

The USDA defined antioxidants as “compounds that protect biological systems against the potentially harmful effects of processes or reactions that can cause excessive oxidations.”
The Food and Nutrition Board of the Institute of Medicine (IOM) defined a dietary antioxidant as “a substance in foods that significantly decreases the adverse effects of reactive species such as reactive oxygen and nitrogen species, on normal physiological function in humans.”
The normal functioning of cells is dependent on a proper balance of pro-oxidants and antioxidants. The pro-oxidants promote the release of oxygen to provide energy needed for functioning of normal cells. However antioxidants protect the body from free radical damage. Antioxidants donate electrons to the free radicals and stop the chain reaction.

Reactive oxygen species (ROS)

Reactive oxygen species which encompasses all highly reactive oxygen molecules including free radicals. Free radicals are incomplete, highly unstable and reactive compounds or molecules. Free radicals contain one or more unbound or unpaired electrons. Due to the presence of unpaired electrons, free radicals show considerable degree of reactivity. Free radicals have the potential to attack critical molecules in the body by changing their chemical structures and affecting their functions. Free radicals are like robbers which are deficient in energy. Free radicals attack and snatch energy from other cells to satisfy them. The toxic of reactive oxygen species include the hydroxyl radical, hydrogen peroxide, the superoxide anion radical, nitric oxide radical, singlet oxygen, hypochlorite radical and various lipid peroxides. Reactive oxygen species and free radicals attack cells and lipoproteins to induce oxidation of lipids, proteins, sugars and DNA, which results in membrane damage, protein modification, enzyme deactivation, DNA strand breaks and base modification.

Oxidative stress

Oxidative stress is caused by the imbalance between pro-oxidants and antioxidant mechanisms. Oxidant exposure and antioxidant depletion are general phenomena that together are described as “oxidative stress.” Oxidants occur in various forms.Both chronic and natural and both acute and catastrophic events contribute oxidative stress.  Normal cells maintain a balance between reactive oxygen species (ROS) generation and antioxidant defense mechanism. Any disturbance of this balance produces oxidative stress which damage cellular components and even leads to cell death. Oxidative damage to DNA, proteins and other macromolecules may lead to a wide range of human diseases. The excessive oxidative stress can be due to the impact of several environmental factors such as exposure to pollutants, alcohol, medications, infections, poor diet, toxins, radiation etc.

Types of natural antioxidants

Natural antioxidants may be classified according to their nutritive value or their solubility. The hydrophobic (water hating/ lipid soluble e.g., vitamin E) and the hydrophilic (water loving/ water soluble e.g., vitamin C) is important both as nutrients and as antioxidants. The nutrient antioxidants include vitamins A,C and E, minerals copper, zinc and selenium. The non-nutritive antioxidants can subdivided into lipid soluble (e.g., carotenoids) and water soluble antioxidants (e.g., polyphenols). The examples of lipid-soluble antioxidants are vitamins A and E, carotenoids and lipoic acid. Water -soluble antioxidants include vitamin C, polyphenols and glutathione.  The antioxidants, which can be produced by human body include glutathione, alpha-lipoic acid and CoQ10 (ubiquinone).  
Antioxidant –rich phytochemicals are micro-constituents in plants and agriproducts. They differ from proteins, carbohydrates and lipids, which are macronutrients that are abundant in plants and food products. The type and quantity of antioxidant phytochemicals vary significantly from source to source. The antioxidant capacity of fruits and vegetables depends on the total concentrations of phytochemicals mainly ascorbic acid, phenolic compounds and carotenoids.

Physiologic mechanism of antioxidant activity

The physiologic activity of antioxidants may be divided into 3 categories: preventive antioxidants, chain breaking antioxidants and repair and de novo compounds. The preventive antioxidants are those compounds that reduce the rate of initiation of free radical chain reaction e.g., the selenium – dependent enzyme glutathione peroxidise. Chain – breaking antioxidants interact rapidly with the free radicals after the chain reaction is initiated, converting free radicals to stable forms e.g., vitamin C and E. Vitamin E has been referred to as Nature’s best chain – breaking antioxidants. Vitamin C can be a double-edged sword, where on one edge it is essential for health and acts as an antioxidant and the other edge it promoted pro-oxidant reactions. Repair and de novo compounds include enzymes that directly restore altered molecules to their original state or degrade them to non-functional compounds (catabolic reactions). Β-carotene is an important singlet oxygen and free radical scavenger.

Antioxidant Vitamins

Vitamin A and beta-carotene -Diets high in vitamin A and beta-carotene, the plant form of vitamin A that the body converts to vitamin A, appear to have cancer preventive properties. Those who have diets low in vitamin A and beta-carotene seem to have an increased risk of developing cancer. Both smokers and chewers of tobacco have low levels of vitamin A and increased precancerous cells in the tissues of mouth, throat and lungs. According to the Academy of nutrition and Dietics , carotenoids – rich foods may help prevent prostate cancer.

Vitamin C – Vitamin C has the ability to render harmful free radicals harmless. Vitamin C seems to block the conversion of nitrites in processed foods to nitrosamines, which are thought to be carcinogenic to the stomach, colon and bladder. Vitamin C helps in the formation of collagen and it also takes part in the formation of interferon, a naturally occurring antiviral agent. It regenerates damaged vitamin E to an active form of vitamin E.

Vitamin E – Vitamin E has been promoted as a cancer preventive vitamin because of its apparent ability to stabilize cell membranes and reduce free radicals. Its derivative vitamin E succinate exhibits potent anticancer activity. Vitamin E reduces inflammation and stimulates immune function.

Alpha –lipoic acid – it is a more potent antioxidant than vitamin C or E. It is soluble in both water and lipid; therefore it protects cell membranes and water soluble compounds. It regenerates tissue levels of vitamins C and E and markedly elevates glutathione levels.

Antioxidant mineral

Selenium is the only mineral that functions as an antioxidant.Selenium is a component of the enzyme glutathione peroxidase and is involved in the removal of harmful peroxides. It converts  hydrogen peroxide in the body into water.The sites of action include the blood vessels (endothelium), kidney, liver and erythrocytes.   According to the Academy of Nutrition and Dietics, selenium may reduce cancer risk and promote heart health. The richest sources of selenium include Brazil nuts, meat (particularly liver and kidney), mushrooms, seafood and other protein foods. The RNI for selenium is 75 μg/day for men and 60µg/day for women.

Antioxidant endogenous enzymes

The endogenous antioxidant enzymes include catalase, glutathione peroxidase, and superoxide dismutase. The minerals that are critical components of antioxidant enzymes include copper (as superoxide dismutase), zinc (as superoxide dismutase) and iron (as catalase).

Antioxidant amino acids

There are three amino acids which have antioxidant activity include cysteine, glutathione and methionine. Vegetable sources of proteins such as  nuts, beans and grains are not only provide amino acids but additional nutrients such as fibre, vitamin A and C.

Antioxidant phytochemicals

Antioxidant phytochemicals generally possess one or more hydroxylated aromatic or phenolics rings which contribute to their antioxidant activity e.g., phenolic phytochemicals. More than 800 phenolic substances have been detected in plants.   Protocatechuic, Caffeic, coumaric and chlorogenic acids are phenolic acids found in abundance in fruits and vegetables. Ferulic acid is a phenolic acid commonly found in grains especially in grain bran.Polyphenols are a group of flavonoids, which are divided into anthocyanins, Isoflavones, flavones, flavonols, flavanols and flavanones. Anthocyanins are present in high levels in berries (e.g.,blue berries, black berries, straw berries) and Isoflavones are abundant in beans. The flavonol quercetin is largely present in apples, while catechin, a flavanols, is found in teas and coffees. Grapefruits are rich in flavanones such as naringenin. Tannins are a group of polymerized polyphenolic antioxidants present in berries and red wines. Some antioxidant phytochemicals in grain germ and bran such as tocols and oryzanols are lipid soluble.

Antioxidant mechanism of flavonoids

1. Direct radical scavenging – Flavonoids may act at any stage of free radical formation. They may trap hydroxyl free radicals.
2. Down –regulation of radical generation – Flavonoids react with peroxy radicals to slow their propagation and delay the onset of lipid peroxidation.
3. Elimination of radical precursors – Flavonoids proactively work to eliminate the precursors to free radicals such as hydrogen peroxide thus eliminating them before the initiation of a problem.
4. Metal chelation – Flavonoids prevent radical formation by chelation of transition metals such as iron, preventing iron-induced lipid peroxidation.
5. Inhibition of xanthine oxidase – Flavonoids inhibit pro-peroxidant enzyme xanthine oxidase which prevent the formation of superoxide radicals.
6. Elevation of endogenous antioxidants – Flavonoids elevate body concentration of endogenous antioxidant such as SOD (superoxide dismutase) which themselves eliminate free radicals or their precursors. 

Food sources of antioxidant phytochemicals

Fruits and vegetables are rich in antioxidant nutrients. They are recognized  as important sources of vitamins and mineral micro-nutrients.The green leafy vegetables like spinach, kale and collard beans are loaded with antioxidants such as vitamins C,E,A and selenium. Nuts like almonds, cashews and walnuts are rich in fibre, phytonutrients and antioxidants vitamin E and selenium. Olive oil is very high in phenolic compounds which act as powerful antioxidants. Red wine contains polyphenols that reduce cholesterol, prevent blood colts and lower blood pressure. Turmeric has antioxidant, anti-inflammatory and cholesterol- lowering properties.

Health advice

For optimum health, people should consume on a daily basis at least five portions (80g/portion) of fruits and vegetables (World Cancer Research Fund 1997; Department of Health 1998) or a pound of vegetables a day (World Health Organization).

Some anti-cancer foods

Berries, Beans, Onions, garlic, Cauliflower, Broccoli, Carrots, mushrooms, Grasses like wheat grass, barley grass and fruits like Durian, cranberries.

Benefits of antioxidants

Antioxidants protect our genetic material (DNA) from the attacks of free radicals.  Some antioxidants stop cancer growth or induce cancer cell death (apoptosis). Antioxidants can regulate your body’s gene expression and increase your natural immunity. Certain antioxidants prevent metal radical chelation and toxification (e.g., mercury, arsenic). Antioxidants can repair damaged biomolecules like DNA.

Summary

Polyphenols scavenge carcinogens and mutagens. Carotenoids and ascorbic acids (vitamin C) quench free radicals. Sulphur – containing phytochemicals stimulate DNA repair.  Antioxidants do not have a long half-life in the body and should be maintained and replaced daily. Antioxidants work synergistically in giving protection against free radical damage, so it is better to take smaller doses of several different antioxidants than a large amount of only one.  Antioxidant nutrients work best when they are used consistently and preventively. Antioxidants are naturally occurring in fresh fruits, vegetables and certain spices.

The Glycemic Index ranking of dietary carbohydrates

High carbohydrate foods are the basis of diets around the world. Both the quantity and quality of carbohydrate intake are important in optimal nutrition. In Asia, where rice is a staple food, carbohydrates provide as much as 80% of the fuel in the diet. Carbohydrate makes up more than 50% of the energy in a typical American’s diet. Carbohydrate provides energy for the brain, central nervous system and muscle cells. The sugar glucose is the most important carbohydrate. It is as glucose that dietary carbohydrate is absorbed into blood stream. Normal blood glucose levels are about 80 to 120 mg per 100 ml of blood. This level is regulated primarily by the hormones Insulin and glucagon.  Controlling carbohydrate intake plays a central role in maintaining normal glucose level (normoglycemia). Eating too much carbohydrate at one time can raise blood glucose too high stressing the insulin – producing cells. Eating too little carbohydrate can lead to abnormally low blood sugar (hypoglycemia). The diets high in carbohydrates have been blamed for everything from obesity to diabetes. The reason for this is related to the types and sources of dietary carbohydrates.

The glycemic response

A rise in blood glucose levels can be detected shortly after eating carbohydrate – rich foods. The impact of different foods on the magnitude and duration of the rise in blood glucose after a meal is called glycemic response. A rating system known as the glycemic index (GI) is developed to classify foods according to their relative glycemic response.

The glycemic index (GI)

The glycemic index (also glycaemic index, GI) is a measure of the extent of the change in blood glucose content (glycemic response) following consumption of digestible carbohydrate, relative to a standard such as glucose. The glycemic index was developed by David Jenkins, Thomas Wolever and colleagues at the University of Toronto in 1981. GI ranks the quality of individual carbohydrate – rich foods on a scale of 1-100 by measuring how glucose levels rise in blood after someone eats an amount of that food containing 50grams of carbohydrate.

The GI measurement

The glycemic index is a numerical index that ranks carbohydrates based on their rate of glycemic response. In the first step about 50 grams of available carbohydrates have been consumed and the blood sugar levels are measured over a period of 2 hours. The changes in blood glucose over time are plotted as a curve (glucose response curve). In the second step about 50 grams of two control foods, either white bread or pure glucose have been consumed. Once again blood sugar levels are measured over a period of two hours. Another curve is plotted and the glucose AUCs or “area under the curves” are compared.  The glycemic index is calculated as the area under the glucose curve after the test food is eaten, divided by the corresponding area after the control food is eaten. The value is multiplied by 100 to represent a percentage of the control food. For example, if a person consumes a starchy vegetable like green peas and the glucose AUC is 48%. In this case the GI for green peas would be calculated at 48% of 100 or simply 48. Glycemic index uses a scale of 1 to 100 with high values given to foods that cause the most rapid rise in blood sugar. The glycaemic index is influenced by the amount of carbohydrate, nature of the sugar components, and nature of starch, cooking / food processing and other food components such as fats, proteins, dietary fibres, anti-nutrients and organic acids.

Definition of Glycemic index

For a given food, glycemic index is defined as the incremental area under the glucose response curve 2 hours after consumption of 50 grams of carbohydrate from a test food relative to the same amount of available carbohydrate from a control food (either white bread or pure glucose). It reflects the rate at which the carbohydrate in the food is digested and absorbed into the blood stream.

The Glycemic index ranking system

The glycemic index is a ratio of the blood glucose response to a given food compared to a standard (pure glucose or white bread).Glycemic index uses pure glucose as its control food and rates all other carbohydrates in relation to it. It measures the rate and degree of blood sugar elevation following the consumption of a single food carbohydrate. It provides a numerical, evidence -based index of postprandial (post-meal) glycemic response. The glycemic index’s ranking system is only for carbohydrates and not for fats or proteins.

Carbohydrates are broadly categorized by the glycemic index as high (70 or greater), medium(56 to 69)  and low glycemic (0 to 55) rating system. High glycemic carbohydrates enter the blood stream quickly and readily available for the body. Low glycemic carbohydrates enter the blood stream slowly and help maintain stable blood sugar levels in an extended period of time. Lower glycemic eating  improves overall health, maintain lean body mass and reduces the risk of cardiovascular disease, type 2 diabetes, metabolic syndrome, stroke, depression, chronic kidney disease, formation of gall stones and cancers of the breast, colon, prostate and pancreas.  The glycemic index helps as a useful guide for persons with diabetes to help keep their blood sugar levels in the healthy range. The GI index is also used for weight loss and weight management.

GI classification of food carbohydrates

High GI foods such as white breads, white rice, cornflakes, baked potatoes, chips, rice crackers, muffins doughnuts and popcorn score between 70 and 100. Medium GI foods scoring between 55 and 70 include whole-grain cereals, brown rice, quick oats, some cakes and cookies, table sugar and energy bars.  Low GI foods scoring between 0 and 55 include all vegetables, most fruits, oatmeal, barley, nuts and seeds and most whole-grain products. Eating food with a glycemic index of 75 or above causes irritability, mood swings and excess weight gain. Eating foods with a glycemic index below 60 tends to conserve insulin, energy and moods, balances hormones and adds to our anabolic capacity.  We should select our daily foods with a glycemic index of 60 and below.

The Glycemic load, GL

Walter Willett and colleagues at the Harvard School of Public Health created the concept of glycemic load (GL). Glycemic load combines both quality and quantity of a carbohydrate in one number. It is an excellent way to predict blood glucose values of different types and amounts of food.

Glycemic load = (Glycemic index value X no. of grams of carbohydrates per serving)/100.

The glycemic load of a food is calculated by multiplying the glycemic index by the amount of carbohydrate in grams provided by a food and dividing the total by 100. Dietary glycemic load is the sum of the glycemic loads for all foods consumed in the diet. The average range in the glycemic load is lower than the glycemic index.

High Glycemic load = 20 or more; Medium Glycemic Load = 11 – 19; Low Glycemic load = 10 or less.

A glycemic load of 0-10 is considered low (slow, steady conversion to blood sugar), whereas a high glycemic load is 20 and more (sudden spike in blood glucose, tough on health and body homeostasis).

How to follow glycemic index diet

The glycemic index of foods is of primary importance for keeping blood glucose under control. Our management of blood glucose over time appears to depend on our regular food choice and life style. Try to start the day with a great breakfast of low glycemic index foods. Eat a balanced diet with a variety of nutrient – dense foods every day. Try to choose whole – grain foods over processed foods. Try  to have at least one food from the lower glycemic index list at every meal. Do choose foods that are high in fibre to prolong your digestion time. Do choose a diet rich in fresh vegetables, fruits and beans. Don’t mix too many foods together. Don’t over-eat or take too large portions. Over eating encourages insulin resistance, which leads to weight gain. Choose foods with little added sugar or calorific sweeteners. Be cautious of the types of fats that you choose. Use in moderation of unhealthy items such as salt, caffeine or alcohol. Try your best to make small changes in your dietary habits. Remember even the small changes are still changes.

Benefits of GI awareness

Glycemic index helps anyone making the best choices of low glycemic foods.Knowing the glycemic index foods, one can virtually eliminate the risk of contracting diabetes. Eating   low glycemic foods protects our insulin response from becoming overtaxed, which in turn keeps our heart, brain and other organs healthier. Over consumption of high glycemic index foods encourages the risk of heart disease and strokes. Focusing on food from low glycemic index list will significantly improve one’s heart health. By following the glycemic index, one can choose low glycemic foods which helps to lose weight and reduce the risk of developing diabetes, will also help to lower one’s level of blood cholesterol, which in turn will eliminate the risk of several chronic diseases. The low glycemic index eating is life – style friendly and keeps our sugar and insulin levels on a healthy and constant plateau.

Health benefits of dietary fibres

Dietary fibre is considered to be an important ingredient of a healthy diet. The term “dietary fibre” was coined by Hipsley (1953) to denote indigestible plant cell wall material (CWM). In the olden days dietary fibre (DF) was known as 'roughage or bulk'.  Now dietary fibre is referred to as non-starch polysaccharide (NSP). It is resistant to digestion and absorption in the human small intestine. It undergoes complete or partial fermentation in the large intestine. Fibre is thought to exert significant effect on faecal volume, laxation, intestinal transit time, flatus production, bacterial metabolism and output of short chain (or volatile) fatty acids(VFA). Fibres help us clean our digestive tracts("Your Body's Broom").  Plant cell walls are the major source of dietary fiber. The major fibres of foods are cellulose, hemicelluloses, β- glucans and pectins. Gums and lignin  are minor fibres of foods.  The recommended dietary allowance for fibre is 25 grams.

Definition

“Dietary fibre is the edible parts of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine. Dietary fibre includes polysaccharides, oligosaccharides, lignin and associated substances (Anon 2001, adopted by American Association of Cereal Chemists, AACC).

The dietary fibre hypothesis

Dietary fibre hypothesis was based upon the pioneering observations of physicians and epidemiologists (Burkitt  and Trowell 1975, Burkitt 1983).It is postulated that a high intake of fibre – containing foods is directly related to or is associated with a low incidence of many disorders and diseases common with a western lifestyle (e.g., chronic bowel diseases, diabetes, coronary heart disease, obesity and colon cancer). Dietary fibre intake is inversely associated with the risk of both cancer and adenomas.

Analytical fibre fractions

Total fibre – it is the aggregate amount of fibre in a food product. In other words total fibre is the sum of dietary fibre and functional fibre.

Functional fibre – it consists of isolated or purified nondigestible carbohydrates that have beneficial physiological effects in humans. It is also referred to as “isolated” or “novel” fibre mostly from animal  sources. Cellulose, chitin, beta glucans, gums, inulin, oligofructose, fructoligosaccharides, lignin, pectins, psyllium, and resistant starches are forms of functional fiber when added to foods. 

Crude fibre (CF) - It is the residue of plant food left after extraction with solvent, dilute acid and dilute alkali (Williams and Olmstead, 1935). Crude fibre is only 1/7 to ½ of total dietary fibre.

Total dietary fibre (TDF) - refers to total amount of nondigestible (unavailable) material naturally occurring in foods and mainly of plant origin and it includes fiber from foods such as whole legumes, vegetables, fruits, seeds and nuts, undigested products, and undigested biosynthetic polysaccharides, whereas crude fiber is the material that in chemical analysis remains after vigorous treatment with acids and alkalies (Mehta and Kaur 1992).

Kinds of dietary fibres

Dietary fibres are usually classified as soluble or insoluble based on their solubility. Plant foods contain both types of fibres in varying amounts, according to the plant’s characteristics.

Soluble fibre (SF) –It partially dissolves in water to form gel like texture. It helps to slow down digestion. It can help lower blood cholesterol and glucose levels. Soluble fibres are found in oats, rye, barley, legumes (peas, soybeans, and beans), fruits (berries, plums, avocados, bananas) vegetables (broccoli, carrots, sweet potatoes, onions) and nuts (almonds).

Insoluble fibre (IF) – It does not dissolve in water and passes through the gastrointestinal tract without being changed. It has positive water-attracting properties that help to increase bulk, soften stools and shorten stool transit time.  Whole – wheat flour, wheat bran, corn bran,  nuts, seeds,  beans and vegetables such as cauliflower, green beans and potatoes are good sources of insoluble fibre. Insoluble fibres are gut –healthy fibres which are metabolically ferment in the large intestine (“the colon’s portion”) and can be prebiotic.

Chemical composition of dietary fibre

Dietary fibre is made up of 3 components.  The largest component consists of polysaccharides or plant fibres such as bran, pectins from fruits and vegetables, various gums and beta-glucans  from oats and rye. The second – largest component is lignin, which is made up of polyphenylpropane molecules and found in stalks and stems of plant products. The third component includes resistant starches and nondigestible oligosaccharides. The heterogeneity of dietary fibre is the primary reason for the diversity of its physiological effects.

The non-digestible fructo-oligosaccharides (FOS) fibres help keep the digestive tract healthy by nourishing and promoting friendly bacteria (Bifidobacteria, Lactobacilli).  These microbes use some of the "prebiotic fibres,” in the food as fuel for their own growth, and through their own metabolism produce molecules called short-chain fatty acids (SCFA). SCFA production by these microbes has been associated with a decrease in cancerous colonic cells, reduction of serum cholesterol, and maintenance of healthy blood sugar levels and healthy intestinal tract cell walls. Natural food sources of FOS include onions, garlic and asparagus. FOS helps to heal irritable bowel syndrome by exerting a regulatory action on bowel movement.

Recommended dietary intake

The American Dietetic Association (ADA) recommends an intake of 20 to 30 g fibre/day for adults. The World Health Organization (WHO) recommends an upper limit of 40 grams of dietary fibres a day. Experts hypothesize that primitive diets contained between 80 and 250 grams of dietary fibre/ day (Sobolik 1994, Dreher 2001), whereas the mean dietary fibre intakes of the present are only 13 – 18 g/day (Institute of Medicine, 2002). The average daily intake of fibre in the United States is about 12g/day. The average daily intake of dietary fibre in the United Kingdom is around 12g/day in both men and women. In the developing tropical countries, the dietary fibre intake of people eating rice as a staple food (India, China, South America) are similar to Western intakes. Dietary fibre intake in the Asia – Pacific region and in most industrialized nations in Europe are also far below the recommended levels (Galvin et al 2001). The adequate intake (AI) of total dietary fibre for children, adolescents and adults was set to 14 g dietary fibre / 1000 kcal by the Institute of medicine, National Academy of Sciences, USA. The National Cancer Institute recommends an intake of 20 – 30 g fibre/day because it helps to reduce the risk certain types of cancer.

Food sources of dietary fibre

The fibre content of different foods varies greatly, e.g., cereal products 2.0% (white rice) to 42.0% (wheat bran); dried vegetables, 2.0% (chickpeas) to 25.5% (beans); dried fruits and nuts 5% (walnuts)to 18.3 (figs); fresh fruits, 0.5% (most fruits) to 3.0% (pears); and green vegetables, 1.4% (most vegetables) to 5.3% (garden peas) (Thebaudin et al., 1995).All plant – based foods contain mixtures of soluble and insoluble fibre.  Legumes, whole grains and nuts are generally more concentrated sources of fibre that fruits and vegetables. Eating fresh fruit is better than fruit juice because most of the fibre in fruit is damaged when it is squeezed to make juice. It is better to get fibre from natural foods rather than from fibre tablets, power or other supplements. There is no fibre in fish, meat, shrimps, eggs and milk.

Foods high in soluble fibres

Oats, barley, oat bran, psyllium husk; Legumes –peas, beans lentils; fruits-apple, orange, passion fruit, pear; carrots, broccoli.

Foods with insoluble fibres

Brown rice, rice bran, whole wheat, wheat bran; seeds and nuts; green leafy vegetables, cabbage, tomato; fruits – cherries, grapes, melons, prunes, berries.

Health benefits

Dietary fibre intake provides many health benefits. Because dietary fibre retains its ‘bulk’ as it moves through the digestive system, it creates a sense of fullness and satiety.   The promotion of satiation, lower calorie intake, and more feelings of fullness play a positive role in preventing obesity. Dietary fibres even control the rate of digestion. Dietary fibre decreases the absorption of macronutrients and minerals.

Being indigestible and hydrophilic, dietary fibres add to the bulk of stool and soften it. It improves large bowel function and elimination (“Nature’s laxative).   High fibre intakes promote bowel health by preventing constipation and diverticular disease.  Dietary fibres positively modulate the colonic microflora and increase colonic fermentation.  The production of volatile short chain fatty acids is used by the microflora to derive energy or for inhibiting pathogens. Viscous fibres such as those found in oats and legumes can lower serum LDL cholesterol levels and normalize blood glucose and insulin responses.

Dietary fibres bind to bile salts and they are valuable in the treatment of recurrent gall stones. The binding of dietary fibres with bile acids is integral to cholesterol homeostasis and fat absorption. Dietary fibre tends to absorb the intestinal toxins or carcinogens that build up in the large intestine and carries them out of the body.

High fibre intake is recommended (20-30g/day) in irritable bowel syndrome, haemorrhoids, diabetes mellitus and hypercholesterolemia. High fibre intake has a 40% lower risk of heart disease. Some researchers found that increasing fibre intake decreases the body’s need for insulin.

Some disadvantages of high fibre intake

Some people experience abdominal cramping, bloating or gas, when they suddenly increase their dietary fibre intake.  Too much of fibre intake may lead to malnutrition and decreased absorption of minerals. Another  disadvantage of foods rich in fibres is that they contain a large amount of phytic acid. Phytic acid hinders the absorption of calcium, zinc and iron.

The art of mindful eating

Eating is an activity that plays a central role in our lives. We eat food for getting energy and the building blocks of various body chemicals. Mindful or conscious eating involves setting an intention before we eat, becoming aware of the process of choosing what to eat and eating consciously with a full attention. Mindful eating is a set of skills that anyone can learn.  Mindful eating fosters concentration and helps break emotional eating habits. Mindful eating helps to reduce cravings, controls portion sizes, enhances the eating experience, and improves digestion and overall health. Mindful eating creates an increased awareness of one’s physical hunger and satiety cues to guide the decision of when to begin or stop eating. Mindful eating promotes balance, choice, wisdom and acceptance around meals, body and eating. “The quality of one’s life depends on the quality of attention” writes Deepak Chopra in Ageless Body, Timeless Mind.

Meaning of mindfulness

Mindfulness is the practice of paying attention (or attention training or attention regulation). Mindfulness is practiced by paying attention on purpose non-judgementally and with a welcoming and allowing attitude. It means turning toward present- moment experience based on three human qualities: patience (Invitation to wait for a mindful response), openness (opening one’s senses to the flow of experience) and compassion (feelings of empathy).Mindfulness is not always easy to achieve or to sustain. Practicing mindfulness requires effort and patience. Mindfulness is an opportunity for anyone to discover the inner space, stillness and simplicity that are our natural heritage as human beings.

Steps in eating with awareness

1. Start small- choose one meal each day and try to focus on mindful eating of the meal.
2. Do nothing else while eating –avoid any distractions and pay attention to the meal.
3. Observe the food – notice its shape, colour and texture and appreciate its appearance.
4. Honour the food – express gratitude to be worthy to receive the food.
5. Focus on each mouthful – think about the flavour, texture and even sound of food in your mouth.
6. Chew the food – chew your food slowly and thoroughly.
7. Taste the food – notice the sensations of sweet, salty, sour or bitter.
8. Swallow your food – sense your body being nourished by the food.
9. Engage all six senses during eating – feel its aroma, shape, colour, texture and taste.

Benefits of mindful eating

1. Reduces overeating
2. Increases enjoyment of food
3. Improves digestion.
4. Being satisfied with small portions.

Types of foods

Calorie – dense foods – these foods are rich in calories and deprived of valuable nutrients. It is best to minimize your daily consumption. Examples include fried foods (French fries, potato chips), foods high in fats (red meats, cheeses) and foods high in refined sugars ( candy, white breads, refined pastas).

Nutrient – dense foods – these foods are packed with essential amino acids, essential fatty acids, vitamins, minerals, phytonutrients and necessary fibre. Nutrient density refers to the amount of essential nutrients for the given volume of food.Nutrient density is a simple way to connect nutrients with calories. Nutrient dense foods provide more nutrients for the fewest amounts of calories. Fresh fruits and vegetables and whole grains are excellent examples of nutrient - dense foods. 

Empty – calorie foods – empty calories are the calories from solid fats and added sugars in foods and beverages. These foods add to total calories but provide no vitamins and minerals e.g., soft drinks, candies, cookies, fatty meats and stick margarine. Reduce the intake of calories from solid fats and added sugars.

Fiber – rich foods – dietary fiber is a vital component of a healthy diet. Fibre is a diverse group of compounds including lignin and complex carbohydrates that cannot  be digested by human enzymes in the small intestine. Fibre tends to absorb toxins that build up in the large intestine and carries them out of the body. The American Dietetic Association (ADA) recommends an intake of 20 to 30 grams fibre/ day for adults from a variety of food  sources. All plant – based foods contain mixtures of soluble and insoluble fibre. Legumes, whole grains and nuts are generally more concentrated sources of fibre than fruits and vegetables. High – fibre intakes promote bowel health by preventing constipation and diverticular disease.

The 2000 dietary guidelines  with “A-B-C” or

 “aim-build-choose sensibly” steps:

Step A : 1. Aim for a healthy weight; 2. Be physically active each day.

Step B : “Build a healthy base” with the following:

1.       Let the food pyramid guide your food choices.

2.       Choose a variety of grains daily especially whole grains.

3.       Choose a variety of fruits and vegetables daily.

4.       Keep food safe to eat.

Step C : “Choose sensibly” through the following:

1.       Choose a diet that is low in saturated fat and cholesterol and moderate in total fat.

2.       Choose beverages and foods that limit your intake of sugars.

3.       Choose and  prepare foods with less salt.

4.       If you drink alcoholic beverages, do so in moderation.

Healthy – eating guidelines in “The Balance of Good Health” by

The Health Education Authority, UK (1997)

1.Enjoy you food;
2. Eat a variety of different food;
3. Eat the right amount to be a healthy weight;
4. Eat plenty of foods rich in starch and fibre;
5. Eat plenty of fruits and vegetables;
6. Don’t eat too many foods that contain a lot of fat;
7. Don’t have sugary foods and drinks too often; and
8. If drink alcohol, drink sensibly.

Quote for personal reflection

Mindful eating...

"Mindful eating is not a diet. There are no menus or recipes.

 It is being more aware of your eating habits,

 the sensations you experience when you eat and

 the thoughts and emotions that you have about food.

 It is more about how you eat than

 what you eat."      - Susan Albers.