Tuesday, August 12, 2014

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) vitamin E (α-tocopherol) and the hydrophilic (water loving) vitamin C (ascorbate) is important both as nutrients and as antioxidants.  The non-nutritive antioxidants can subdivided into lipid soluble (e.g., carotenoids) and water soluble antioxidants (e.g., polyphenols). 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
Durian fruit.


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 are naturally occurring in fresh fruits, vegetables and certain spices. Antioxidant nutrients work best when they are used consistently and preventively.

Friday, August 8, 2014

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.

Monday, July 28, 2014

Foods for better brain health

The brain is the most delicate and complex organ of the human body. Human brain is unique, electrochemical supercomputer which is far greater in complexity, speed and sophistication.   Isaac Asimov quoted, “The human brain then is the most complicated organization of matter that we know”. According to a saying, the brain is wider than the sky and deeper than the sea. The brain is the command and control centre of human body.  The brain is the seat of intelligence, emotion and memory.  The brain is the organ of one’s personality, character and intelligence. The brain receives, registers and processes information.   The brain initiates movements and behaviours. Neurons are the basic building blocks of the brain. The human brain contains more than one hundred billion neurons (nerve cells).  Each of the neuron has about 60,000 to 100,000 synaptic connections and has a total number of synaptic connections of about 1027 . The human brain is connected to 30,000 miles (50,000 kms) of nerves.  The neurons are arranged end to end and the neurotransmitters transfer signals across the gaps (synapses) of 0.02 to 0.05 microns. The brain is a dense web of interconnecting synapses. Neurons communicate using electrical impulses. The neurons actually make up less than a tenth of the cells in the brain. The other 90-98% by number is glial cells, which are involved in development and maintenance. The human being has the highest ratio of weight of the brain to the total body weight.  The human brain weighs about 1.5 kgs, about 2 percent of body weight. The brain requires 15 percent of the blood, 40- 50 percent of the oxygen supply and 25 percent of the calories we consume. A 15 sec blockage of blood to the brain will result in unconsciousness. The brain cells are sensitive to oxygen availability. The brain needs a well-balanced, low-cholesterol and low- saturated (animal – fat) diet.

Brain chemicals

Neurotransmitters are the chemicals in our brains that regulate our feelings and emotions. Different neurotransmitters perform different functions in the body. There are 183 currently known transmitters.The neurotransmitters are primarily synthesized in nerve terminals. The master neurotransmitters are serotonin and the catecholamine group which consists of dopamine, norepinephrine and epinephrine. Neurotransmitters are made from amino acids. For example epinephrine and dopamine are made from phenyl alanine. Serotonin is made from tryptophan. Amino acids are generally abundant in high protein foods such as dairy products, eggs, legumes, fish, meats, nut, poultry and soybeans. Amino acid therapy is the use of supplemental amino acids to help balance body’s normal supply of amino acids and should be undertaken under the supervision of a doctor.
Acetyl choline is a neurotransmitter that is believed to play a crucial role in memory. Gamma amino butyric acid (GABA) (natural tranquilizers) inhibits message transmission and helps to control brain overload. Serotonin is a neurohormone that acts on the overall operations of the brain. It is our natural anti-depressant and sleep promoter. It helps to control the general states of alertness. Catecholamines are our natural energisers and mental focusers.  Dopamine is a neurohormone that helps to control physical movement.  Endorphins are neurohormones (feel – good chemicals) that serve as a source of pleasure and reward as well as a means of reducing one’s awareness of pain and irritation.

Brain cell death

A process called oxidation destroys brain cells and creates free radicals as a by-product. Free radicals are killer molecules that kill cells including neurons and destroy neurotransmitters – which are the chemicals that transmit electrical messages from one brain cell to another.

Brain glucose

 The human brain is metabolically most active organ of the body.  It uses about 20-30% of a person’s energy intake at rest. Glucose is the brain’s sole source of energy.   The tight regulation of glucose metabolism is critical for brain physiology. The brain functions such as thinking, learning and memory are closely dependent on glucose levels and how effectively the brain utilizes glucose. If glucose becomes inadequate, neurotransmitters are not synthesized and communication between neurons breaks down.

Brain water

Human brain is very soft and composed of 80% water, which means that the most important requirement of good brain health is hydration. Dehydration causes shrinkage of brain tissue and expansion of fluid filled cavities in the middle brain. Dehydration can impair short term memory, visuomotor functioning and psychomotor functioning.  Extreme dehydration can results in delirium which causes confusion, inability to speak or think coherently, disorientation and hallucination. Dehydration is a major contributor to increased production of free radicals and premature aging.

Brain fats

The brain is composed of about 60% fat and brain cells is about 70% fat. The fats we eat directly affect the structure and substance of the brain cell membranes. About 20 % of the fat in our brain is made from essential fatty acids omega-3 and omega-6 fatty acids.  The balance between omega-3 and omega – 6 fatty acids seems to be critical for the brain’s structure and function. Human brain has special requirement for fatty acids. DHA (docosahexaenoic acid) accounts for up to 20% of total fatty acids in the grey matter and is the most abundant PUFA in the brain. DHA insufficiency affects membrane fluidity, serotonin transport, gene transcription, and inflammation and energy metabolism in the brain.  DHA exerts a neuroprotective action by preventing oxidative damage and inflammation.
Many nerve fibres are surrounded by myelin sheath, which speeds up the transmission of nerve impulses. Myelin is made up of various fats, fatty acids, phospholipids, cholesterol and protein. In fact 75% of myelin comes from fat. Choline enhances memory and promotes clear thinking.

Brain vitamins and minerals

The brain needs vitamins and minerals. B-vitamins help to maintain and build healthy brain cells. Vitamins B1, B6 and B12   play a valuable role for good brain health. Vitamin B1 (thiamine) helps in the conduction of electrical impulses within the brain.B6 (pyridoxine) is needed for the production of the neurotransmitter serotonin, which improves mood and B 12 (cobalamin) which is a constituent of the myelin sheath. Mineral ions such as sodium, potassium, calcium and magnesium must maintain in critical balance.


Brain healthy foods

Physical exercise is most important food for the brain. Foods that have over 90% water content like grape fruit and water melon contain essential nutrients and electrolytes required to maintain proper hydration and optimal brain function.  Drinking beverages like coconut water and fruit juices effectively maintains optimal hydration and electrolyte balance.
Since glucose is the fuel for the brain, the blood glucose level has to be properly maintained. Complex carbohydrates are the best brain foods. Complex carbohydrates like whole grains, vegetables, beans or lentils – take longer to digest and slowly release potential energy.  Refined starch (white breads, white rice and pasta) impairs mental function.
Human brain needs oils and fats to function. Two essential fats especially critical to the brain are the omega – 3 and omega – 6 fatty acids. Foods high in omega- 3 fatty acids are important to maintaining brain health. Certain fish including salmon, mackerel, herring, sardines, tuna, anchovies, white fish and sable fish are good sources of omega – 3 fatty acids. Bad fats (saturated fats) inflame the brain. Trans fat is labelled as potentially the risk for Alzheimer’s disease by almost 50%.
Vitamins B 1 can be obtained from whole grains, nuts, meat and eggs. Vitamin B6 can be obtained from eating fish, poultry, eggs, whole grains and nuts. Vitamin B 12 can be obtained from meat, fish, dairy products, eggs and yeast extract.
Foods rich in vitamin C, Vitamin E and beta- carotene appear to reduce cell damage including brain cells. Vitamin C is found in citrus fruits, broccoli, Brussels sprouts and straw berries. Vitamin E is found in vegetable oils (corn, canola, sun flower, soybean and olive oils), nuts and leafy greens. Beta – carotene is found in sweet potatoes, carrots, kale and spinach. Folic acid is an essential ‘brain food’, which is critical for normal nerve function. Folate works with approximately 20 different enzymes to build DNA. Folic acid is found in leafy green vegetables, bananas, orange, and straw berries.
Iron – rich foods improve mental alertness and energy levels. Lean sources of red meat, poultry, spinach, beans, dried fruits and whole grains are excellent sources of iron. Selenium is linked to balance of moods, which is available in whole grains, rice, meat and sea weeds.

Essentials of brain health

1. Be physically active
2. Eat a healthy and balanced diet
3. Avoid saturated fats and caffeine
4. Listen to your body
5. Keep your mind active
6. Maintain good heart health and healthy body weight
7. Protect your head from injuries.
8. Calorie restriction can enhance learning and memory.


Monday, July 21, 2014

Leadership lessons from Abraham Lincoln

Abraham Lincoln was the sixteenth president of the United States. He was born on the 12th of February 1809 in rural Kentucky (USA). He served as president from 1861 to 1865, during the American Civil War. During the Civil War, Lincoln was determined to maintain the "Union” of American States at any cost.  He fought the war bravely and declared, “A nation cannot exist half free and half slave.” He won the war and kept his country united. Almost all historians judge Lincoln as the greatest president of American history because of the way he exercised leadership during the war. Lincoln had very little formal education, but had a strong passion for books and self-learning. His primary means of education was schooling at home using borrowed books and the Bible. As a legislator, he had a reputation of eloquent opponent of slavery. Lincoln married Mary Todd in 1842 and they had four children.  He was elected as a president of the United States in 1860, re-elected in 1864 and served from March 4, 1861 until his death. As president, he built the Republican Party into a strong national organization. He is remembered for his character, his speeches and letters and as a man of humble origin whose determination and perseverance earned him the nation’s highest office. Lincoln is often admired for his Gettysburg address, which is considered one of the greatest speeches in American history. He is a symbol of racial equality. Lincoln was assassinated on the 15th April 1865. His life reveals not only dreams and desires but also his habits of strong direction, dedication and determination.


Leadership lessons

Focused ambition 
Lincoln had a desire to become a great orator. With this aim, he approached his teacher, Mater Graham. The teacher advised him to learn grammar. Lincoln borrowed a grammar book and memorized grammar day and night. Lincoln mastered grammar and attained his goal of becoming a best speaker of his time.
Lincoln kept his ambition focused on serving the people and winning their esteem. It is said by Lincoln that “Don’t worry when you are not recognized, but strive to be worthy of recognition. “Always bear in mind that your own resolution to succeed is more important than any other.”
Character as destiny 
 Lincoln possessed a well developed conscience and courage. He was morally superior. It is  said by Lincoln that “Character is like a tree and reputation its shadow. The shadow is what we think it is and the tree is the real thing.” Lincoln was fair, trustworthy, sincere, straight forward with sound moral principle. He even had the nickname “Honest Abe.” It is also told by him that  “I am not bound to win, but I am bound to be true.”
Courage and commitment 
 Lincoln possessed supreme will power: strength of mind. He is remembered for his courage and leadership, his peacefulness and compassion, his patriotism and devotion to his country. It is said by Lincoln that “It requires more courage to dare to do right than to fear to do wrong.” It is also said by Lincoln that  “Live a good life. In the end it is not the years in a life, but the life in the years.”
Firm believer of hard  work 
 He acknowledged the power of hard work to achieve success.  It is said by him that  “You cannot escape the responsibility of tomorrow by evading it today.” Another occasion he quoted that “I am always for the man who wishes to work.”
Habit of persistence 
Lincoln is a great example of persistence. Persistence means never giving up and  to do requires self-discipline. He was defeated for the legislature and lost his job in 1832. He failed in his own business in 1833.In 1836, he had nervous breakdown. He bought for senate in 1854 and defeated miserably. In 1860, he was elected president of the United States. "Some day I shall be president" - Lincoln.
Political skills
Lincoln was a skilled politician. He was admired for his warm storytelling and jokes. He was a man of principle and ideas. Though he lacked a formal education but he was a voracious reader and note worthy biographer. Lincoln was naturally prudent and cautious but he took bigger political risks.It is said by Lincoln that “Be with a leader when he is right, stay with him when he is still right, leave him when he is wrong.”
Delegation of responsibility and authority 
Lincoln delegated responsibility and authority. Lincoln knew the value of making requests and persuaded his subordinates to compromise on political/ administrative issues.  It is said by Lincoln that “I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The great point is to bring them to real facts.” On empowerment, it is said by Lincoln that “You cannot build character and courage by taking away a man’s initiative and independence.”
Power of democracy
Lincoln understood the power of democracy to govern people of any country. Lincoln described government as one of the people (instituted by content), by the people (operate as democracy) and for the people (protecting their natural rights). It is also said by him that “The people will save their government, if the government itself will allow them.” He quoted that  “ Public opinion in this country is everything.”



Quotes of Abraham Lincoln for reflection 

"I have always found that mercy bears richer fruits than strict justice."

"A house divided against itself cannot stand."

"Success is going from failure to failure without losing your enthusiasm."

Saturday, July 5, 2014

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. 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.




Thursday, July 3, 2014

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.


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.



Thursday, May 1, 2014

Health benefits of functional foods

Food is made up of chemical compounds called nutrients. The six basic nutrients include proteins, carbohydrates, fats, vitamins, minerals and water. Different foods contain different amounts of nutrients. Most foods contain all three energy providers (carbohydrates, fats and proteins) as well as vitamins, minerals (body regulators), water and other substances. The amount of energy a food provides depends on how much carbohydrate, fat and protein it contains. Food and nutrition play a great role in maintaining and improving overall health. Healthy and balanced nutrition develop our immune system to prevent illnesses as well as contributes to the health of all parts of our body. The benefits of good nutrition can be found in our physical and mental health because a healthy diet provides adequate energy, promotes good sleep and prevents illness. All food is essentially functional as it provides energy and nutrients (nutritional function).Different foods have different tastes (sensory function). However functional foods (healthy foods) perform specific ‘physiological function.’

What are functional foods?

Functional food is any fresh or processed food claimed to have a health – promoting or disease preventing property beyond the basic function of supplying nutrients. Functional food is defined as “any modified food or food ingredient that may provide a health benefit beyond the traditional nutrient it contains" (American Dietetic Association 1995). Functional foods provide essential nutrients necessary for normal maintenance, growth and development and/or provide other biologically active components that impart health benefits or desirable physiological effects.Fruits and vegetables contain many different phytochemicals which reduce risk for cancer and heart disease. Polyphenolic compounds in purple grape juice support normal, healthy cardiovascular function. Sulforaphane in broccoli reduces cancer risk. Tomato is rich in lycophene, a compound that may reduce prostate cancer risk. Soy protein reduces cholesterol levels. Omega-3 fatty acids in fish or flaxseed reduce risk of heart disease and strengthen bone joints. Garlic has sulfur compounds that reduce risk for cancer and heart disease. Oats and oat-containing foods, with soluble fiber beta glucan, reduce cholesterol level. Yogurt and fermented dairy products contain probiotics which may improve gastrointestinal health. Catechins in black and green tea reduce risk of cancer.


Kinds of functional foods

Functional foods can be whole or fortified foods, enriched, or enhanced foods or dietary components that may reduce the risk of chronic disease and provide a health and physiological benefit beyond the traditional nutrients it contains.
Conventional foods are the most basic of the functional foods because they haven't been modified by enrichment or fortification; they're still in their natural state. Most whole fruits and vegetables fall into this category because they're rich in phytochemicals such as lycophene and lutein as well as other beneficial compounds. E.g., "Diets rich in whole grain foods and other plant foods and low in total fat, saturated fat, and cholesterol may reduce the risk of heart disease and some cancers.”

Modified foods have been enriched, fortified or enhanced with nutrients or other beneficial ingredients. Calcium fortified orange juice, folic acid enriched breads and margarine enhanced with plant sterols are functional foods that have been modified. Energy drinks that have been enhanced with herbs such as ginseng and guarana, as well as other potentially controversial foods, also fall into this category.

Fortified foods are foods that have nutrients added to them to boost the levels that are naturally present or to restore nutrients lost during processing e.g., white bread enriched with vitamins and minerals. Super fortified foods include orange juice with Echinacea or salad dressing with PUFAs. A food that is rich in a particular nutrient or some bioactive substance is called super foods.

Dietary supplements are defined as any product (other than tobacco) that is intended to supplement the diet and contains one or more of the following: a vitamin, mineral, herb or other botanical; an amino acid or metabolite; an extract; or any combination of the previously mentioned items. It is not represented as a conventional food or as sole item of meal/diet; and labeled as a dietary supplement. E.g., Calcium, vitamin D, and osteoporosis: Adequate calcium throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis e.g., sodium and hypertension: Diets low in sodium may reduce the risk of high blood pressure, a disease associated with many factors.

Nutraceuticals

A nutraceutical is a bioactive material isolated or purified from foods that is generally sold in medicinal forms not usually associated with foods. Stephen DeFelice, founder of the Foundation for Innovation in Medicine coined the term “nutraceutical” in 1979. Nutraceuticals are naturally – derived, bioactive (usually phytochemical) compounds that have health promoting, disease preventing or medicinal properties (Lachance and Saba2002).A nutraceutical is claimed to have a physiological benefit or provide protection against chronic disease. Thus, nutraceuticals are more correctly defined as parts of a food or a whole food that have a medical or health benefit, including the prevention and treatment of disease. The difference between a nutraceutical and functional food is that nutraceutical refers to nearly any bioactive component that delivers a health benefit, commonly in supplemental form and functional foods are only in food form e.g., linumlife is a lignan extract of flax which may protects prostate health. Fenulife is another product of fenugreek galactomannon that controls blood sugar. Marinol with mega 3 –fattyacid, DHA and EPA may protect heart health. Nutraceuticals can be prepared by manipulating the diet to get maximum level of active components or by combining food ingredients rich in nutraceuticals or by fortifying food with active ingredients or by fermentation of food products. Concentration, time and duration of supply of nutraceuticals influence human health. By manipulating the foods, the concentration of active ingredients can be increased. Diet rich in nutraceuticals along with regular exercise, stress reduction and maintenance of healthy body weight will maximize health and reduce disease risk.
Medical foods
Generally medical foods and dietary supplements are not considered functional foods. Medical foods refer to a food formulated to be consumed or administered internally while under the supervision of a physician. Medical foods are not regular foods. They’re orally administered dietary products formulated for the management of diseases for which specific nutritional requirements have been established. Medical foods may be used to treat diabetes, obesity or heart disease. Some medical foods were designed for the unique nutritional needs of patients with inherited metabolic disorders. Medical foods are specially formulated and processed for partial or exclusive feeding of a patient orally or by enteral tube. It can be used for patients with limited/impaired capacity to ingest, digest, etc. Medical foods used for managing metabolic syndrome, type 2 diabetes, and cardiovascular disease are designed to improve lipid profiles and blood sugar levels, combat insulin resistance, and support favourable changes in body composition (i.e., increased lean body mass). These products generally have a low glycaemic index and often contain folic acid, vitamin B6, and soy fibre, nutrients that help normalize serum homocysteine levels, a known risk factor for cardiovascular disease. In addition to these nutrients, medical foods promoting cardio-metabolic health may contain formulated blends of plant sterols, dietary fibre, herbal extracts, and soy protein. Axona® (caprylic triglyceride) is marketed as for dietary management of Alzheimer disease. Limbrel® (flavocoxid™) is marketed for osteoarthritis.


  Natural functional foods

Fiber is a functional food because it may reduce the risk of chronic disease and provide a health and physiological benefit beyond the traditional nutrients it contains. There are three physiological effects of dietary fiber that currently have sufficient scientific evidence to be recognized as characteristics of dietary fiber—a positive effect on laxation, attenuation of blood cholesterol levels, and/or attenuation of blood glucose levels; increasing the water-binding capacity of the feces, and softening stools. Dietary Fiber consists of non-digestible carbohydrates and lignin that are intrinsic and intact in plants. The fiber in oat meal can help reduce the risk of heart diseases.

Blueberries are often referred to as a natural functional food/super-food. Blueberries contain anthocyanins (flavonoids), the antioxidant pigments and various phytochemicals possibly having a role in reducing risks of some diseases, including inflammation and certain cancers. Researchers have shown that blueberry anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins inhibit mechanisms of cancer cell development.

Herbal tea extracts is regarded as functional dietary food supplements due to their significant content of total polyphenols. These bioactive substances have significant radical scavenging capacity. Consumption of a diet rich in polyphenols has been linked with a reduced risk for cardiovascular diseases and certain types of cancer. These dietary natural antioxidants strengthen the endogenous antioxidant system by reducing oxidative stress and the risk of toxic diseases.

Soybean is in use for more than 5000 years in China and South East Asia as food. "Soybean is a treasure box of functionality." Dry soybean contain 36% protein, 19% oil, 35% carbohydrate (17% of which dietary fibre), 5% minerals and several other components including vitamins. The U.S. Food and Drug Administration (FDA) approved in 1999 a health claim for use on food labels which stated that daily diet containing 25 g/day of soy protein, which is also low in saturated fat and cholesterol, may reduce the risk of heart disease. Modest reductions in serum LDL cholesterol levels have been achieved with soy intake, especially for subjects with hypercholesterolemia. The major effects of soybean soluble fibres on serum lipoproteins appear to be related with bile acid binding and with a decrease in the reabsorption of bile acid. Soybean contains several components with anticancer activity, such as, isoflavones, protease inhibitors, phytosterols, saponins, phenolic acids, and phytates.

Honey contains about 0.5% proteins, mainly enzymes and amino acids (General Tonic). Fructose is the main sugar in most honeys. Three main honey enzymes are diastase (amylase), decomposing starch or glycogen into smaller sugar units, invertase (sucrase, glucosidase), decomposing sucrose into fructose and glucose, as well as glucose oxidase, producing hydrogen peroxide and gluconic acid from glucose. Honey contains a number of trace elements(chrome, manganese and selenium, sulphur, boron, cobalt, fluorine, iodine, molybdenum and silicon).Long term ingestion of honey (sweet medicine)can improve gut and gastroenterological health, improve the immunological reaction towards infections and cardiovascular health.

Fish oil is one of the most popular functional ingredients containing high omega 3 fatty acid and are used widely for various purposes such as cardiovascular health, vision acuity, anti-inflammation, mother and child health. Fish oils are used for their anti-inflammatory and hypolepidemic (lowers blood triglyceride levels) effects. Essential Fatty acids, particularly DHA and EPA, are 10 to 100 times more concentrated in fats from marine sources such as fish than from terrestrial sources. The US Food and Drug Administration (FDA) currently allow omega-3 fatty acid supplements to bear the following qualified health claim: “Consumption of omega-3 fatty acids may reduce the risk of coronary heart disease." Scientists recommend a daily intake of 2.0-4.0 gram fish oil containing about 25% Omega-3 or 30-60 gram of oily fish per day. Omega-3 fatty acids have shown benefits in rheumatoid arthritis, systemic lupus erythrematosus, Crohn disease, ulcerative colitis and immunoglobulin A nephropathy. There is also increasing evidence that diets high in fish may protect against the development of Alzheimer disease and prostate cancer.



Summary

Functional foods/foods for health are an important part of an overall healthful lifestyle that includes a balanced diet and physical activity. Health claims confirm a relationship between components in the diet and reduced risk of disease or health condition, as approved by FDA and supported by significant scientific agreement. The functional foods are thought to provide benefits beyond basic nutrition and may play a role in reducing or minimizing the risk of certain diseases and other health conditions. Examples of these foods include fruits and vegetables, whole grains, fortified foods and beverages and some dietary supplements.