Tuesday, November 18, 2014

Health benefits of dietary prebiotics

Prebiotics have been an integral part of normal human diet for many centuaries. Prebiotics are essential specific colonic nutrients that have the potential to considerably influence whole body’s physiology and consequently health and wellbeing. Prebiotics affect specifically and selectively the indigenous beneficial bacteria. Prebiotics are able to alter the colonic microbiota toward a healthier composition by increasing for example, numbers of saccharolytic species while reducing putrefactive microorganisms. Some prebiotics are added to foods to improve food quality characteristics such as mouth feel and other textural aspects. Prebiotics have been used as low calorie fat replacers. Human milk can be considered as the original prebiotic for gut microflora management in breast –fed infants.

Definition

Prebiotic is a non-digestible food ingredient which beneficially affects the host by selectively stimulating the growth of and/ or activating the metabolism of one (or more) health promoting bacteria in the intestinal tract (Gibson and Roberfroid 1995).
A dietary probiotic is a selectively fermented ingredient that allows specific changes, in the composition and/or activity of the gastrointestinal microbiota, thus confers upon host wellbeing and health (Gibson et al 2004).

Prebiotic concept

A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health. In order for s food ingredient to be classified as a prebiotic it must
1)  Be neither hydrolysed nor absorbed in the upper part of the gastrointestinal tract;
2) Be a selective substrate for one or a limited number of beneficial bacteria commensal to the colon, which are stimulated to grow and/or are metabolically activated;
3) Consequently, be able to alter the colonic flora in favour of a healthier composition and
4) Induce luminal or systemic effects that are beneficial to the host health.
Synbiotics –probiotics may be used in conjunction with specific substrates (prebiotics) for growth (e.g. a fructooligosaccharide in conjunction with a Bifidobacterial strain or lactitol in conjunction with a lactobacillus organism). This combination could improve the survival of the probiotic organism in the host because its specific substrate is readily available for its fermentation.

Recognized prebiotics

The common prebiotics in use include fructo-oligosaccharides (FOS), galcto-oligosacchardes (GOS),soy-oligosaccharides (SOS), inulins, lactulose and pyredextrins,. The majority of studies carried out to date have focused on inulin, FOS and GOS (Macfarlane et al 2008).

Emergent prebiotics

Emergent prebiotics include genti-oligosaccharides,gluco-oligosaccharides, isomalto-oligosaccharides(IMO),lactosucrose, levans, pectic-oligosaccharides,resistant starch, sugar alcohols and xylo-oligisaccharides (XOS).

Prebiotic mechanism of action

1. Produce short chain fatty acids during fermentation of probiotic carbohydrates.
2. Increase fecal weight and mildly reduce luminal colon pH.
3. Stimulate the growth of carbohydrate fermenting bacteria.
4. Lower the concentration putrefactive, toxic, mutagenic or genotoxic substances.
5. Decrease the concentration of nitrogenous end-products and reductive enzymes.
6. The Bifidobacteria and lactobacilli exhibit low b-glucuronidase and nitroreductase activity.
7. Enhance immunity and modulate mucin production.

Prebiotic food sources

Fructooligosaccharide (FOS) is a naturally occurring prebiotic compound found in many edible sources such as artichokes, bananas, honey, onion, garlic, barley and others. Another prebiotic compound inulin is naturally found in chicory roots, wheat, onion, garlic, bananas, fruits and vegetables.Examples of food sources rich in prebiotics are whole grain, honey, banana, garlic,onion,tomato, leek, artichoke and chicory.

Prebiotic characteristics

1.       Non-digestible or partially digestible
2.       Non-absorbable in the small intestine
3.       Well fermented by beneficial bacteria in the gut and
4.       Selective stimulation of growth and activity of intestinal bacteria.

Metabolic fate of prebiotics

Inulin and oligofructose are not hydrolysed in the mouth, stomach and small intestine. In the large intestine, they undergo complete anaerobic fermentation by bacteria. They do not contribute any calories. They are completely fermented in the colon, so inulin is not excreted in the stool.

Prebiotics and dietary fibres

Prebiotics and dietary fibres are not digested by human digestive enzymes, but prebiotics are fermented selectively in the colon and exert their health effects via colonic microbiota. Dietary fibre on the other hand may not be fermented at all and exert health effects in other ways for example improved bowel function.

Colonic microbial system

The colonic microbial system consists of wide range of bacterial species, a variety of different metabolic niches, bacterial habitats and interrelationships. In general intestinal bacteria may be divided into species that exert either harmful or beneficial effects on the host. Pathogenic or harmful effects include diarrhea, infections, liver damage, carcinogenesis and intestinal putrefaction; health promoting effects may be caused by the inhibition of growth of harmful bacteria, stimulation of immune functions, lowering of gas distension problems, improved digestion and absorption of essential nutrients and synthesis of vitamins.

Health promoting functions of Bifidobacteria

Bifidobacterium is a major group of saccharolytic bacteria in the colon and constitutes up to 25% of the total population in the gut of adult and 95% in the new borns (Kawerze et al 1981). Bifidobacteria produce strong acids as metabolic end products (acetate, lactate), lower the pH and may exert an antibacterial effect. Bifidobacteria produce vitamins largely of the B – group. Bifidobacteria produce certain immunomodulators, which promote immunological attack on malignant cells. Bifidobacteria have been used to restore the normal intestinal flora during antibiotic therapy (Korshunov et al 1985). 

Health benefits of  dietary prebiotics

1)      Increase the absorption of dietary minerals such as calcium, magnesium and iron.
2)      Reduce the risk of colon cancer.
3)      Reduce cholesterol and blood lipids.
4)      Prevent gastrointestinal tract infections.
5)      Increase growth of Bifidobacteria, which has following beneficial effects:
i)        produces nutrients such as B-group vitamins and folic acid.
ii)       Produces digestive enzymes.
iii)     Reduces food intolerance by utilizing residual nutrients from the upper gut.
iv)     Improves nutrient management.
v)      Reduces liver toxins i.e. blood amines and ammonia, by using them as fuels.
vi)     Competitive elimination of pathogenic microorganisms.

Summary

Prebiotics are non-digestible food ingredients. They are selectively fermented by intestinal bacteria ( e.g. lactobacilli, Bifidobacteria). Potential health benefits of prebiotics include increased bioavailability of dietary minerals and reduced risks of various diseases such as cancer, intestinal infections, cardiovascular disorders, obesity and diabetes. Prebiotics are naturally available in several foods such as whole grains, onion, garlic, bananas, fruits and vegetables.

Thursday, October 30, 2014

Health benefits of dietary probiotics

 Probiotics are live microorganisms that could confer health benefits on the host, when consumed in significant amounts. The term prebiotic literally means ‘for life’ Probiotics have been proven to promote gastrointestinal health and immune function. The normal human  gut flora contains 300-1000 different kinds of bacterial species with about 1014 individual bacteria. The predominant inhabitants of human gut include Lactobacillus and Bifidobacterium.




Definition

The  World Health Organization (WHO) defines probiotics as “live microorganisms which  when administered in adequate amounts confer a health benefit on the host.”(FAO/WHO, 2001). The term probiotics was coined by the researchers Lilly and Stilwell in their studies in 1965. In 1989, Fuller popularized the term ‘probiotics.’ Dr. Elie Metchnikoff came upon the discovery of the ‘prolongation of life’ through probiotics. He was the first scientist who proposed the therapeutic use of lactic acid bacteria.

Normal intestinal micro flora

Normal intestinal micro flora is largest reservoir of microorganisms mutual to humans. This complex micro ecosystem remains relatively stable in normal health at a given age ( in other words it varies significantly as a function of age). This normal flora colonizes shortly after birth. This micro flora includes high numbers and variety of intestinal bacteria, estimated at 1,013 in the colon and around 400-500 bacterial/fungal species. The intestinal flora comprises 10 times more bacteria than the body cells. The highest number and complexity of bacteria is found in the terminal ileum and colon. The intestinal flora play a significant role in the development of the immune system and in the resistance of infection by pathogens. 

Probiotic hypothesis

The concept behind probiotics is to enhance good bacteria and discourage bad bacteria in the human gastrointestinal tract. Probiotics help to keep bad bacteria away and out of one’s body. Probiotics help to ‘balance the intestinal bacteria i.e. ensure that there are more ‘good’ bacteria than ‘bad’. The ‘good’ bacteria simply ‘crowd out’ disease causing microorganisms, thereby preventing attachment of pathogenic bacteria by a process known as “competitive exclusion” (Kailasapathy and Chin 2000). Human gastrointestinal tract is supposed to contain 85% “good” bacteria and 15% “bad” bacteria.

Characteristics of probiotics

1. Probiotics neither are enzymes, vitamins or minerals nor foreign substances or chemical compounds. Natural probiotics are microorganisms that reside in the ileum (small intestine) and in the colon (large intestine) which have a symbiotic relationship with humans.
2. The most popular probiotic genuses are Lactobacilli and Bifidobacteria. Lactobacilli love to live in the small intestine and Bifidobacteria love to live in the colon.
3. Probiotics can resist the effects of digestive enzymes, stomach acid and bile. Probiotics support the intestinal microflora against antagonizing microorganisms. Probiotics promote optimal digestion and absorption of nutrients and promote a healthy digestive tract.
4. Probiotics can assist the gastrointestinal tract to absorb minerals, vitamins and other necessary nutrients and the functions of the immune system. They also exert positive actions at the metabolic level.
5. Probiotics work simultaneously, synergistically and symbiotically with other agents.
6. Probiotics can be used in paediatric medicine for babies and young children. Probiotics are acknowledged by the World Health Organization for the benefits of improving gastrointestinal health.
7. Probiotics never lose their beneficial properties during storage.
8. Probiotics are grown, fermented and cultivated from various media such as dairy, vegetables, beans, beets and others.
9.Manufactured probiotics are controlled bacteria (i.e., friendly, healthy, beneficial bacteria) that are manufactured in controlled laboratory environments.

Probiotic organisms

Members referred to as probiotics are bacteria and fungi, most commonly including species of Lactobacillus and Bifidobacterium and species of the yeast genus Saccharomyces.  Other bacterial genera which feature prebiotic  strains include Streptococcus, Enterococcus and Bacillus.The members of Lactobacillus and Bifidobacterium have long history of use and generally recognized as safe (Generally Regarded As Safe,GRAS status).
Lactobacilli which has the ability to produce lactic acid , is classified as Lactic Acid Bacteria (LAB). Probiotic species in the Lactobacilli family found in the human body include L.reuteri, L. casei, and L.rhamnosus. Lactobacilli acidopilus is commonly found in yogurt products. Bifidobacteria are norman inhabitants of the human colon. Bifidobacteria can produce lactic and acetic acids and also grouped as Lactic Acid Bacteria (LAB). Probiotic species in the Bifidobacteria include B.lactis, B. bifidum and B.longum. Streptococci are also found in dairy products.
  Streptococci thermophilus is commonly used to make yogurt. Enterococcus is a lactic acid – producing bacteria. Two species are commonly found in the intestines of humans: E. faecalis (90-95%) and E.faecium (5-10%). Lactococcus is classified as LAB as the can produce lactic acid.Lactococcus lactis is found in dairy products and is commonly responsible for the souring of milk. The name of the probiotic yeast Saccharomyces is from the Latin meaning ‘sugar fungi.’ Saccharomyces cerevisiae is used in making wine, bread and beer. Saccharomyces cerevisiae is more commonly known as Baker’s yeast.
 Probiotic bacteria used in foods for human consumption are generally of human origin and are non-pathogenic. In addition they retain significant viability during processing and transit through the gut.

Probiotic foods

Yogurt  is a probiotic containing food. Yogurt  has been used in the past to treat diarrhea, prevent urinary tract infections or treat recurrent yeast infections. Probiotic containing foods include aged cheese. Kefir, kimchi, sauerkraut, miso, tempeh,  and some soy beverages. Probiotic commercial products include tomato juice, peanut milk, soymilk, buffalo whey/soy milk  and rice. Probiotics are normally added to foods as a part of the fermentation process. The probiotics involved in food fermentation are mainly Lactobacillus and Bifidobacterium. Probiotic bacteria may also be available in capsules or as powder.

Mechanism of action of probiotics

Probiotics deliver active constituents to targets in the host gastrointestinal tract. These active constituents include mainly enzymes, and immunomodulatory and antimicrobial components. Probiotic bacteria promotes human health in any of the following mechanism(s): adherence to intestinal mucosa and mucus, production of antimicrobial substances, antagonism against pathogens, competition for adhesion sites (competitive exclsion), interaction with Gut-Associated Lymphoid Tissue (GALT), immune regulation, in-activation of harmful components  within the intestinal contents (binding of toxins), regulation of metabolic activity of intestinal microflora and overall normalization of the intestinal microflora ( Salminen et al 1996, Brassart and Sciffrin 1997).


Health benefits of probiotics

Medical literature supports the use of probiotics for treating a variety of different diseases – ranging from food allergies to ezema; from Crohn’s disease to antibiotic-associated diarrhea. The well documented health benefits of probiotics include the improvement of gastrointestinal health. Probiotics have been documented about the balancing effects on the immune system or enhancing body’s overall resistance to infection.  Probiotics are useful in the prevention or treatment of several gastrointestinal disorders such as infectious diarrhea, antibiotic diarrhea and traveller’s diarrhea. Probiotic therapy can be helpful for people with Crohn’s disease and irritable bowel syndrome (IBS) (ref; Nutrition in Clinical Practice).
Probiotics may be beneficial for brain function. Probiotic bacteria may have the potential to change brain neurochemistry and treat anxiety and depression – related disorders (ref: PNAS). Consumption of a formulation of Lactobacillus reuteri NC IMB 30242, is able to reduce blood levels of LDL cholesterol (ref: The American Heart Association Scientific Sessions, 2012). Consumption of Bifidobacterium infantis 35624, may have benefits for patients with psoriasis and chronic fatigue syndrome. Probiotics can be used to re-establish healthy vaginal flora and prevent bacterial vaginosis (BV). Probiotics can be used – along with other natural therapies – to treat urinary tract infection(UTI) and yeast infection.
 Finish researchers reported that large amounts of live Lactobacilli consumed daily may have positive effects on rheumatoid arthritis and ankylosing spondylitis. Benefits have also been shown in skin problems such as eczema and psoriasis. Probiotics may be considered a valid alternative to conventional therapy for alcoholic cirrhosis.  Consumption of Lactobacillus rhamnosus and Bifidobacterium lactis reduced the risk of colon cancer.


Thursday, October 16, 2014

Practical applications of Pareto Principle

A strange economic principle first outlined by an Italian Professor Vilfredo Pareto (1848-1923) discovered an imbalance in the distribution of wealth and income in nineteenth century England. Vilfredo Pareto is widely known for his law of income distribution. In the 1860s, he found that the majority of the wealth and income went to a minority of people. In percentage terms 80 percent of the income and wealth went to 20 percent of the population. The Pareto rule is the observation that if you divide the world into causes and results, relatively few causes (roughly 20 percent) nearly always lead to most of the results (roughly 80 percent). It is the observation that a small number of events give rise to the majority effects. Most consequences come from few causes. The great majority of outputs come from a small minority of inputs. In an industrial world, Pareto’s rule was found to apply in an increasing number of situations. Pareto’s rule is a fact of life in the world of selling and sales force management: 80 percent of sales are made by 20 percent of the sales force. Project managers know that 20 percent of the work (the first 10 percent and last 10 percent) consume 80 percent of one’s time and resources. The value of the Pareto principle for a manager is that it reminds one to focus on the 20 percent that matters.


Pareto’s principle, 80/20 rule should serve as a daily reminder to focus 80 percent of one’s time and energy on the 20 percent of one’s work that is really important. Moreover many researchers have confirmed that the rule applies to many other phenomena, including the distribution of measured defects. For instance, it has been found that 80 percent of the observed defects on a product or in a process can be attributed to 20 percent of the possible causes. The 80/20 principle asserts that 20 percent of products, customers or employees are really responsible for about 80 percent of profits. Living the 80/20 way enables anyone to get extraordinary results without extraordinary efforts. In a way this leads to the idea of achievement islands which means that the small time periods when you are in your most productive or creative.
     A small amounts of our energy – leads to – most great things in our lives.
    A small portion of our time- leads to- most of our happiness and fulfillment

Definition

Pareto’s rule states that a small number of causes are responsible for a large percentage of the effect, in a ratio of about 20:80. This means that for many phenomena, 20 percent invested inputs are responsible for 80 percent of the results obtained. In another words 80 percent consequences originate from 20 percent of the causes. The 80/20 rule means that a few (20 percent) are vital and many (80 percent) are trivial. Dr. Joseph M. Juran called Pareto principle as the ‘vital few and trivial many.’ Joseph Juran popularized the Pareto principle in the 1950s by showing that it can be applied to a variety of situations, especially quality problems. The rule is also called ‘the law of the vital few’ or the principle of factor sparsity.
For example IBM found that, on average, 80 percent of the run time of a software application is due to only 20 percent of the lines of code. This realization helped them streamline the most important lines of code and speed up their applications by working on the lines of code that were 16 times (20 %) as important. According to factor 16, the individuals in the 20- percent group are 16 times as important as those in the 80- percent group.

Pareto analysis

Pareto charts are one tool we can use to help us be more effective in tracking down the sources of problems and focusing our efforts where they will have the biggest effect. This is known as pinpointing or localizing, a problem. Pareto charts break a big problem into its parts and identify which parts are most important. A Pareto chart is a special kind of bar chart where each bar represents a different category or part of a problem. The tallest bars on the chart represent that parts that contribute the most to the problem. By focusing our efforts on the tall bars, we can usually get the most from limited resources and maximize our gains. That is because usually it takes just as much effort to cut the tallest bar in half as it does to cut the smallest bar in half.

Pareto thinking

The 80/20 rule asserts that approximately 80 percent of the effects generated by any large system are caused by 20 percent of the variables in that system. The 80 percent of a product’s usage involves 20 percent of its features. In a city’s traffic control system, 80 percent of a city’s traffic is on 20 percent of its roads. The 80 percent of your website traffic comes 20 percent of your pages. The 80 percent of a company’s revenue comes from 20 percent of its products. In a company or industry, 80 percent of innovation comes from 20 percent of the people. The 80 percent of your success comes from 20 percent of your efforts.   The 80 percent of your problems are a result of the same 20 percent of your issues.  In machinery, 80 percent of errors are caused by 20 percent of the components. In an organization, 80 percent of its progress comes 20 percent of the effort. Out of 100 % of the people, 20 percent are making 80 percent of the difference. The other 80 percent make 20 percent of the difference. Top 20s have a better way of thinking, learning and communicating. The 80 percent of our happiness or success is tied to the 20 percent of the inside world. The 80 percent of the profits in an endeavour will be derived from 20 percent of the segments (or client groups). In general 20 percent of your clients yield 80 percent of your profits. Below   20 percent of your total number of friends contribute the great majority of happiness and meaning to life. In summary, a small number of events give rise to the majority of effects. Most consequences come from few causes.


Practical applications

Personal productivity – The 80 percent of one’s time is spent on the trivial many activities. But in order to improve your productivity, you concentrate on the vital 20 percent. The key is to identify those vial few activities, actions, products or programs.
Costs – to reduce costs, identify which 20 percent are using 80 percent of the resources.
Customer profitability – In most successful companies, some customers can be more profitable than others. Many companies struggle to measure the profitability of customers, distributors or agents. If they use 80-20 strategy, such companies can definitely profit from their customer portfolio. 

Tuesday, October 14, 2014

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.


Saturday, October 11, 2014

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.

Tuesday, October 7, 2014

Health benefits of food enzymes

Enzymes are natural catalytic proteins that speed up biochemical reactions by lowering the activation energy. All plants and animals produce enzymes. All vital processes in human body are dependent on enzymes. Enzymes aid in the digestion of food and are essential for all metabolic activity in the body. Each organ has its own set of enzymes. Enzymes vary in different individuals, depending on genetics and life style. More than 3000 different enzymes have been identified in the body. In humans enzymes can be categorized into 3 classes: metabolic enzymes, digestive enzymes and food enzymes. Metabolic enzymes catalyse many different biochemical reactions that take place in the body’s cell and tissues. Metabolic enzymes are involved in the processes of energy production, synthesis and repair of cell structures and replication of genetic material. Digestive enzymes are secreted along the gastrointestinal tract, help break down macronutrients such as protein, fats and carbohydrates found in our diet and enable absorption of nutrients into the blood stream. Humans secrete about 24 different digestive enzymes depending on the type of foods eaten. Digestive enzymes fit into 3 primary categories: proteases digest proteins, amylases digest carbohydrates and lipases digest fats. Food enzymes are introduced to the body through the raw foods we eat and through consumption of supplemental enzyme products. Food enzymes are vital helpers to predigest food and aid greatly in the absorption of nutrients. Food enzymes include digestive enzymes but also enzymes unique to particular foods. Food enzymes of particular food cannot be stored in the body for later use. The three major food enzymes are: amylase, which breaks down starches into sugars; lipase, which breaks down fats into fatty acids and protease, which breaks down proteins into amino acids. Fresh raw foods are capable of self –digestion by its own self-contained enzymes. The cooking and processing of natural foods destroys all of its enzymes.

Definition of enzyme

Dixon and Webb (1979) defines an enzyme as a “protein with catalytic properties due to its power of specific activation.” Enzymes are protein catalysts that increase the velocity of a chemical reaction and are not consumed during the reaction they catalyse.

The food enzyme concept

When ingested, the enzymes in raw food or supplementary enzymes result in a significant degree of digestion, thus lowering the drain on the organism’s own enzyme potential.

The law of adaptive secretion of digestive enzymes

This law states that the organism values its enzymes highly and will make no more than are needed for the job. If enzymes in the food digest some of the food, the body will make less concentrated enzymes.

The concept of food enzyme stomach

The human stomach consists of two physiologically distinct parts: the upper cardiac region(the fore-enzyme stomach) and the lower pyloric region. The peptic digestion of protein takes place in the lower part of the stomach whereas the upper portion is where food enzymes in raw foods predigest food material. According to the food enzyme concept of Dr. Edward Howell, the duration of life varies inversely with the intensity of metabolism. In other words the length of life is inversely proportional to the rate of exhaustion of the enzyme potential.

Food enzyme hypotheses

1. Raw foods contain enough food enzymes for that particular food.
2. Enzymes in raw foods are destroyed with cooking, radiation and processing of food(critical temperature above, wet heat 47 degree Celsius / 118 degree Farenheit)
3. Food enzymes are reduced by long-term storage, shipping and treatment with organic chemicals and toxins.
4. Eating cooked foods deplete the body’s limited enzyme capacity.
5. Modern processes of pasteurization, canning, baking, drying, freezing and microwaving are particularly harmful to the enzymes in food.
6. The enzyme shortage in processed foods may be the direct cause of shortened lifespan, inferior health of the organs and chronic illnesses.


Enzyme-friendly foods

Enzyme research has revealed the importance of raw foods in the diet. The enzymes in raw foods help start the process of digestion and reduce the body’s need to produce digestive enzymes. Plant based enzymes are the most popular choice of enzymes. The plant based proteases are papain from the papaya, ficin from the fig tree and bromelain from the pineapple. Grains are naturally endowed with amylase, and some protease and lipase. Raw honey has considerable amounts of amylase.  Sprouted foods (seeds, grains and legumes) are one of the best sources of living enzymes. Bovine milk contains 35+ different known enzymes most of which are destroyed by pasteurization. Fermented foods (e.g., miso, kabitofu, Toyu, Natto, Tempeh, masato, malakachisu, tofu, certain soybean products such as soy sauce) are loaded with enzymes. Some fruits that contain lots of enzymes include avocados, papayas, pineapples, bananas, kiwi, figs, grapes and mangos. Grains, nuts, legumes and seeds are rich in enzymes as well as other nutrients, but also contain enzyme inhibitors. Unless deactivated, these enzyme inhibitors  can put an even greater strain on the digestive system than cooked foods.

Enzyme – specific foods

Papayas contain large amounts of proteolytic enzyme (protease) called papain. Papain is known to alleviate the inflammation and pain.When digestion is poor, many people use papaya, which is actually a digestant. Pineapples also contain proteolytic enzyme called bromelain, which helps to dissolve antigens that are responsible for allergies and inflammation. Protease enzymes help with food allergies or intolerances to animal protein. Apples contain a number of enzymes including ascorbates oxidase, beta galactosidase, catechol oxidase, pectase, pectin methyl esterase, peroxidase, polygalactouronase, polyphenol oxidase and superoxide dismutase (SOD). Apricots contain amylase, invertase, polyphenol oxidase, and other enzymes. Avocados contain amylase, cellulose, lipase and other enzymes. Green beans contain amylase, lipoxygenase, peroxidase and SOD. Broccoli contains amylase, casein, kinase and SOD. Cabbage contains allene oxidase, cyclise, amylase and other enzymes. Cherries contain beta glycosidase and polyphenol oxidase.

Advantages of food enzyme intake

1. Improves digestion, elimination and bowel disorders.
2. Reduces bloating, belching, gas, heartburn and food allergies.
3. Enhances physical stamina, energy and vitality.
4. Promotes balanced pH in the body.
5. Protects form degenerative diseases.
6. Strengthens the immune system.
7. Relieves muscle stiffness and inflammation.
8. Promotes the efficiency of cardiovascular system.
9. Slows down aging process and contributes to longevity.
10. Influences overall health and weight management.

Enzyme therapy

Presently enzymes are used in supplement form to improve health, in injectable form to treat heart attacks and in topical form to treat skin problems such as burns. The enzymes used most frequently to treat digestive problems include proteases, amylases and lipases. Enzymes are wonderous aids used to improve health, maintain wellness and fight disease and injuries. Enzyme therapy is a plan of dietary supplements of plant and animal enzymes used to facilitate the digestive process and improve the body’s ability to maintain balanced metabolism. Enzyme supplements are often prescribed for patients suffering from disorders that affect the digestive process such as cystic fibrosis, Gaucher’s disease and celiac disease. Supplementary enzymes have the ability to purify blood, strengthen the immune system, enhance mental capacity, cleanse the colon and maintain proper pH balance in urine. Enzyme supplements are extracted from plants like pineapple and papaya and from the organs of cows and pigs. 

Thursday, September 18, 2014

Systems thinking for problem solving

 A system consists of processes that transform inputs into outputs.  The processing is performed by the subsystems. Super systems are other systems in environment of which the survival of the focal system is dependent.  Boundaries are the part of the system through which inputs and outputs must pass, during which exchanges between systems and with their environment reflect a mutually interactive process. The concept of boundary implies a hierarchy of systems in which there is both separateness and connectedness. All systems operate in an environment of cause and effect. Systems science provides a means of analysing and understanding complex processes based on a few basic principles. According to Ludwig Van Bertalanffy (1968), the founder of the systems theory, a system is ‘a set of elements in interaction’. Some examples of systems include scientific, organizational, personal and public systems. Systems are wholes which cannot be understood through analysis.  Synthesis is a prerequisite for the systems thinking. Systems thinking places high value on understanding contexts and looking for connections between the parts, actors and processes of the system. Ludwig Van Bertalanffy, father of systems thinking said, “In one way or another we are forced to deal with complexities, with ‘wholes’ or ‘systems’ in all fields of knowledge. This implies a basic reorientation in scientific thinking.” Stephen Haines also said, “The systems thinking approach is an absolute necessity to succeed in today’s complex world.”
 The term ‘system’ comes from a Greek word systema meaning ‘whole compounded of several parts or members’ or in the literary sense ‘composition.’ System means ‘something to look at.’  A system is constituted by its elements that is, all the parts that make up the whole; the links between the parts, that is the processes and interrelationships that hold  the parts together in view of the whole; its boundary, that is , the limit that determines what is inside and outside a system.  

Systems defined...

Systems are made up of a set of components that work together for the overall objectives of the whole (outputs).


Systems theory

Systems theory was proposed in the 1940s by the biologist Ludwig von Bertalanfy (General systems theory 1968) furthered by Ross Ashby (Introduction to Cybernatics 1956). Systems theory can be defined as a set of unifying principles about the organization and functioning of systems. Systems theory provides an analytical framework for viewing an organization in general.

Systems concept

Systems are defined as meaningful wholes that are maintained by the interaction of their parts (Laszlo 1972). System can also be defined as “a set of interacting or interdependent system components forming an integrated whole (Lidell and Scott 1940).  A system is a dynamic and complex whole, interacting as a structured functional unit. All systems are composed of inter-connected parts. A change to any part or connection affects the entire system. The structure of a system determines its behaviour. “Structure produces behaviour.” To understand a systems’ gross behaviour, it is essential to understand its structure. The change in the structure of a system effects change in its gross behaviour. System behaviour is an emergent phenomenon – how a system behaves cannot be determined by inspection of its part or structure. Feedback loops control a system’s major dynamic behaviour. Every part of a system is involved in one or more feedback loops. Systems have more feedback loops than parts. Feedback loops are the main reason, a system’s behaviour is emergent.

Systems nature (Fredrich Hegel 1770-1831)

1.       The whole is more than the sum of the parts.
2.       The whole defines the nature of the parts.
3.       The parts cannot be understood by studying the whole.
4.       The parts are dynamically interrelated or interdependent.

System components

A system must consist of 3 kinds of things: elements (things), interconnections (processes) and a function (purpose).  A system is an interconnected set of elements that is coherently organized in such a way that achieves something. A tree is a system and a forest is a larger system that encompasses subsystems of trees and animals. The interconnections in the tree system are the physical flows (e.g., water) and the chemical reactions that govern the tree’s metabolic processes. The interconnections or purposes are critically important in a system. Changing relationships usually changes system behaviour. System behaviour operates through feedback loops.

Systems thinking – ‘thinking about systems’

  Systems thinking is the ability to understand interactions and relationships in complex dynamic systems. Systems  thinking focuses on relationships, connectedness, multiple outcomes, holism and boundaries, the environment, the larger system and feedback. Systems thinking helps to view systems from a broad perspective that includes seeing overall structures, patterns and cycles in systems and context. Systems thinking is a superior approach in trying to understand the world’s complexity.


Systems characteristics

1.       A system is a collection of interacting parts. Every system is a part of some larger system. Behaviour of any part is influenced by interaction with other parts.  Systems can be represented in abstract networks of relations between components.
2.       A system boundary defines the set of parts that comprise a system. A system may interact with things outside of its boundary. External interaction is less influential of the system behaviour than internal interaction. Behaviour is understood by examining the entire system, not individual parts.  
3.       Systems are organized in structural and functional hierarchies.
4.       Systems exhibit several of kinds and levels of complexity.
5.       Systems have dynamic processes on one or more time scales.
6.       Systems emerge from proto-systems (unorganized, not complex) and evolve over time to greater organization and complexity.
7.       Systems can encode knowledge and receive and send information.
8.       Systems evolve internal regulation subsystems to achieve stability.
9.       Systems can contain models of other systems.
10.   Sufficiently complex, adaptive systems can contain models of themselves (brain/ mental models).
11.   Systems can be understood – science as the building of models.
12.   Systems can be improved – Engineering as an evolutionary process.

Systems understanding

Understanding of system is achieved through identification, modelling and analysis of relationships and interactions among the parts of a system. System modelling is performed by representing the parts of a system and interactions among those parts. In reality, a system consists of many feedback loops and many interactions among those loops.  It is that total systems view that helps to achieve depth of understanding and real insight into the behaviours of complex systems.


Systems thinking rules (minimalist concept theory, MCT)

Distinction making – All thinking is distinction making. Distinction making is autonomic – one constantly makes distinctions all of the time. It is the making of differentiation between the identity of  concepts and  between what is internal and what is external to the boundaries of the concept.
Interrelating – It is the process of interlinking one concept to another by identifying reciprocal causes and effects.
Organizing systems – It is the process of splitting / lumping concepts into larger wholes or smaller parts and
Perspective taking – It is the process of reorienting a system of concepts by determining the focal point from which observation occurs by attributing to a point in the system, a view of the other objects in the system (e.g., point of view).

System thinking skills (Assaraf and Orion 2005)

1.       The ability to identify the components of a system and processes within the system.
2.       The ability to identify the relationships among the systems’ components.
3.       The ability to identify dynamic relationships within the system.
4.       The ability to organize the system’s components and processes within a framework of relationships (e.g.,chain, circle, network).
5.       The ability to understand the cyclic nature of systems.
6.       Understanding the hidden dimensions of the system.
7.       The ability to make generalizations.
8.       Thinking temporally: retrospection and prediction.

Systems thinking process

1.       List as many elements as possible. Analytical thinking breaks things apart in stages. Systems thinking groups things together in stages.
2.       Group the elements into sub-themes.
3.       Find the central theme – the common theme across the sub-themes.

Systems thinking benefits

1.       A conceptual framework to think strategically and a way to look at a complex issue in multiple perspectives.
2.       A way to acquire new knowledge more easily because basic rules remain the same from system to system.
3.       A better way to integrate new ideas within the systems context and dynamics.
4.       A clearer way to see, understand and assess what is going on in an organization or in any system. Complex problems become easier to understand as do the interrelationships and the multiple causes and effects.
5.       A new and better way to design solutions, create strategies, take decisions and solve problems.