Benefits of Prebiotics

·         Increase good bacteria & reduce harmful bacteria in the gut.
Gut probiotics inhibits growth of harmful microbes.

·         Modulates & enhance immune system.
The enhanced immune system help maintains a disease-free state

Short-chain fatty acids (SCFAs) protect and strengthen mucosa lining. Without the SCFA (butyrates) for energy, colon cells will die.

·         May reduce intestinal infections

·         Reduced abnormal bacterial leakage through the gut wall when taken in        moderation.

·         Synthesize certain vitamins.

·         Increase mineral absorption, leading to stronger bones and increased bone density.

·         Reduce blood triglyceride level.

·         Better weight & appetite management.

·         Alleviate constipation with improved bowel regularity.

·         Reduced flatulence with lessened or no bad smell.

·         Certain SCFAs can prevent allergy.

·         Epidemiological evidence has shown that dietary fiber is beneficial in the clinical management of obesity, diabetes, cancer, and cardiovascular diseases.

·         Dietary fiber improves short chain fatty acid (SCFAs) production, and reduces glycemic response.

·         Moreover, although glucose may serve as the main metabolic fuel, SCFAs produced by colonic bacterial fermentation of dietary fiber furnish a significant portion of daily energy requirement.

·         Reduce risk of inflammatory diseases such as arthritis, IBS etc. due to anti-inflammatory property.

BOOST IMMUNITY

The gut and immune system form a complex integrated structure that has evolved to provide effective digestion and defence against ingested toxins and pathogens indirectly via a healthy population of symbiotic microbes. [Pathology and Neuroscience, University of Dundee, 2004]

In the gut, prebiotics boost immunity in two ways: through intrinsic properties of its compounds and by favoring growth of beneficial bacteria.

Fermentation by colonic bacteria on the food mass produces gases and short-chain fatty acids. It is these short-chain fatty acids—butyric, lactic, acetic (ethanoic), propionic, and valeric acids that lower the pH of the colon enabling inhibition of pathogens growth.

Microbiota (Bifidobacteria and Lactobacilli) provide a barrier by producing antimicrobial substances and/or stimulating mucosal immunity thus reducing chance of infection (Servin, 2004). 

Lactobacilli not only do not produce carcinogen, it inhibits several bacteria that produce carcinogenic enzymes.

A 2002 study found probiotics also secrete biosurfactants that inhibit infections of surgical implants in rats [Gan et al.]

Prebiotics modify the activities of bacteria that are involved in carcinogenesis through substituting their food source from protein metabolism to carbohydrate metabolism. So when you eat more prebiotic food than protein, you are shifting metabolism of Clostridia and Bacteroides towards more benign end products.

Studies indicated   FOS and Oligosaccharides confer the degree of fermentation selectivity towards Bifidobacteria but could not be utilized efficiently by pathogenic ones such as E-coli, Salmonella, and Helicobacter spp.

Certain types of prebiotics such as β-glucans and oligosaccharides stimulate the immune system by interacting with immune cells and through producing antimicrobial substances in the fermentation process leading to inhibition of pathogenic bacteria.

Researchers have shown that certain types of prebiotics (GOS) can prevent allergy and reduce infectious diseases as well as reduce antibiotic use in infants. Human breast milk naturally contain oligosaccharides and are believed to play an important role in the development of a healthy immune system in infants by increasing the body’s immune cells such as T helper cells, macrophages, and neutrophils.

FOS increases butyrate concentrations in the large intestine; in the liver it plays a role in lipid and glucose homeostasis.  It may destroy colonic cancer by stimulating them to commit suicide (apoptosis).

Researchers found that a class of bacteria called Firmicutes can control candida albicans, a yeast infection. Some people proposed it as a supplement for treating yeast infections.

LOWER DISEASE RISK

Scientists speculated Biomarkers that change with fiber intakes, in particular short chain fatty acids and probiotics may play a role in alleviating digestive and inflammatory conditions such as inflammatory bowel disease, irritable bowel syndrome (IBS), systemic anaphylaxis, arthritis,   rashes, allergic rhinitis and asthma). The lower pH reduces peptide degradation and the resultant formation of toxic compounds such as ammonia and amines which can contribute to aforesaid diseases.

Propionate is a microbial fermentation metabolite that lowers liver production of cholesterol by interfering with its synthesis. This resulted in lower risk for coronary heart disease and lower blood pressure. Water-soluble fibers (beta-glucan, psyllium, pectin) as well as resistant starch (gum Arabic, tara gum, locust bean gum/ carob bean gum) were highly effective for lowering serum LDL cholesterol concentrations, without affecting high density lipoprotein (HDL) concentrations.

Test results on the effect of fiber on diabetes were mixed. A comparison of five week controlled diet using oat beta-glucan (5 g) against barley beta-glucan (5 g or 10 g) showed the oat diet was effective in reduced postprandial glucose and insulin responses whereas the barley diet was not. Large-scale cohort studies indicated insoluble fiber was more effective in reducing risk of developing type II diabetes than soluble fiber.

NUTRITION

Bacteria synthesize B and K Vitamins, which are absorbed through the gut.

Researchers found probiotics Lowers pH in the large intestine, leading to better calcium and magnesium absorption in both animal and human studies.  The higher acidity draws out more minerals from food making them available to move from the gut into the bloodstream. This lead to more efficient absorption of calcium and increased bone density.

Interestingly, your body absorption of calcium only occurs when calcium intake is low or calcium requirement is high. This indicates the prebiotic, inulin, enables your body to absorb the amount of calcium it requires, not more than it needs.

WEIGHT LOSS & OBESITY

Howarth et al estimated that increasing fiber intake by 14 g per day was associated with a 10% decrease in energy intake and a 2 kg weight loss over about a 4-month period. This study was based on analysis of more than 50 other intervention studies. Fiber-rich food gives a sense of fullness (satiety), leading to less food being consumed. A nine week study using wheat dextrin conducted by the Chinese found that a significant decrease in caloric intake was seen from week 2 to the end of the 9 week study for those groups taking dextrin compared to controls.

Studies suggested microbiota in the gut may play a role in controlling obesity. Obese people have more firmicutes than bacteroidetes, while in lean people the bacteroidetes predominate. Tests with germ-free mice found that when these mice had “obese mice microbiota” transplanted into their gut, their total body fat significantly increase than colonization with a 'lean microbiota'. [Turnbaugh et al]

IMPROVE LAXATION

All fibers alleviate constipation. Insoluble fiber give bulk to stools, the water held by the fiber and increased bacterial mass from fermentation contributes to larger and softer stools thus increasing the ease of defecation.

Why Cholesterol is Essential for Health (2)

Function of cholesterol

Cholesterol is an integral component of every cell in your body, providing structural integrity and strength to cell membranes. It is not used as an energy source by your body because it is not biodegradable. (Cells membrane allows for the passage of nutrients and wastes into and out of the cell. Interaction with the cell membrane allows for molecular communication signals to pass from outside to inside of the cell.)

Cholesterol is the precursor of many bodily substances such as bile acids, vitamin D and hormones. Additionally, it contributes to the development and working of the central nervous system, and it has major functions in signal transduction.

All cells in the body synthesize cholesterol; the sites that produce the highest amount are the liver, intestines, adrenal glands, and reproductive organs.

What organs used cholesterol for

The liver produces about 20–25% of total daily requirements, half of which it converted into bile acids for digestion.

This is followed by the intestines. Bile salts aid in the intestinal absorption of fat molecules as well as the fat-soluble vitamins, A, D, E, and K.

Cholesterol esters is a major constituent of the adrenal gland; providing the raw material for the synthesis of the steroidal hormones, cortisol (influences or regulates blood sugar, blood pressure, immune function, the body's anti-inflammatory processes and Central Nervous System [CNS] activation.), glucocorticoids (involved in immune and inflammatory processes), and aldosterone (the principal regulator of the salt and water balance of the body, thus influencing blood pressure).

Mineralocorticoids need cholesterol in its formation. This hormone regulates osmotic balance.

Reproduction

The reproductive organs need cholesterol for sperm development. This structural fat is also used in the formation of estrogens, testosterone, androgens and progesterone.

Embryonic development is affected by cholesterol through its covalent bonding to Hedgehog proteins, resulting in their activation. During embryonic development, Hedgehog proteins regulate cell proliferation and differentiation and where each type of cells should migrate to. Without cholesterol, the signaling activity is disrupted and cell differentiation may be impaired.

It is also involved in prenatal genital development.

The above show cholesterol plays a vital part in human embryogenesis and development.

Nerves

Nerves are like telephone lines that allow messages to be sent to different parts of the body for communication. Cholesterol is a precursor of neurosteroids (involved in neurotransmission and excitation).

The myelin sheath is very rich in cholesterol and form a protective layer around nerve neurons. This insulation provides conduction of impulses more efficiently. Myelination occurs most rapidly during prenatal development.

Others

Interaction of cholesterol with ceramides is essential for the barrier function of the skin.

Sunlight act on cholesterol on the skin for Vitamin D synthesis. A study found increased concentration of blood cholesterol during the winter months in participants. They speculated, “Lack of Sunlight could increase blood cholesterol by allowing squalling metabolism to progress to cholesterol synthesis rather than to vitamin D synthesis”.

Some research indicates cholesterol may act as an antioxidant. (Smith LL (1991).

Your brain comprises roughly a quarter of the total free cholesterol in the human body. That is why people with genetic defects that impair cholesterol formation or usage have impaired mental capacity.

Cholesterol is necessary for the ligand binding activity of the serotonin receptor. (Serotonin is a neurotransmitter that has an enormous influence over many brain functions).

It promotes and stabilizes membrane fluidity over a substantial range of physiological temperatures and sterol concentrations.

Cholesterol   is a sterol produced only by animals and can be found in dairy products, animal meat and egg yolk. This article is meant to dispel public fear of cholesterol. It is not meant to be an excuse to indulge in excessive quantities of food with saturated fats (lots of ice cream, whipped cream, rich cakes and coconut milk curries). You only need 20 percent of fats from your diet. Your body can provide the remainder 80 percent. Consume a mixture of saturated, monounsaturated and polyunsaturated fats as each has its own distinctive role in the diet.  Refer to the food pyramid on amount of fats to include in your diet. Excessive amounts will upset the natural balance needed by your body. Minimize fries because high heat changes the structure of fat, rendering it toxic to the body.

Cholesterol loaded food is fine in moderation for those without metabolic diseases.

CAUSES OF DANDRUFF (5)

Diet & Dandruff

The year is nearing is full cycle. It is the season for feasting whether to bid Old Year goodbye or welcome to a fresh New Year; marking the longest night of the year or celebrating the rebirth of the new Sun, people will offer a spread of mouth-watering rich foods, tempting desserts and sweets accompanied by toasting. Gaily decorated shops enticed shoppers with an enormous variety of gift that included hampers filled with boxes of chocolates, sweets, fruits preserved in honey or sugar, crispy potato chips, buttery baked goods, fine wine or liquor… a sweet end leading to a sweet beginning.

The contents of the hampers that I’d just described actually increases the risk of dandruff. Consume them sparingly and binge on ‘anti-dandruff’ food instead.

Nowadays, some dieticians and dermatologist are advocating diet therapy as an adjunct treatment because they believe   certain food increases the risk of getting dandruff and skin problems such as acne and psoriasis while other food reduces the chances. Dandruff-causing culprits are high glycemic index food (sugar and refined carbohydrates), yeast, saturated fats, fried food and alcohol. Ayurveda added food that can create ama (digestive impurities) such as icy cold food and drink as well as food that is not fresh (leftovers) to the list. TCM believe diet that impairs your liver and kidney function is harmful to hair.

Sugar (High glycemic index food)

The glycemic index (GI) indicates how fast and how high blood sugar rises after eating a food. Food that can increase our blood sugar rapidly has a high GI.

Why is sudden, rapid increase in blood sugar bad? The sudden increase lead to insulin spikes, which in turn lead to stimulation of hormone surges that can trigger the output of fatty acids (sebum). Your body deals with the excess sebum by expelling it through the pores of the skin and scalp. Studies have found that when there is excessive sebum, the oil-loving malassezia grow rapidly, irritates your scalp leading to excessive shedding of skin or dandruff.

Moreover, high sugar level in the blood depletes Vitamin B6 and Zinc which are known to fight dandruff. It also has a negative impact on the antioxidants, vitamins C and E, both of which are necessary for healthy, lustrous hair.

Sugar and saturated fats triggers inflammation. Blood sugar spurs the pancreas to produce high levels of insulin thus causing inflammation. Inflammation triggers the immune system to ramp up and the body produces more free radicals that attack collagen (a type of connective tissue). Collagen binds all tissues together and provides structure and strength to organs, skin, bones, walls of blood vessels etc.

Limit the following foods in your diet:

Chocolates, processed potatoes, soft drinks, candies and food made from refined flour such as white bread, pasta, and cakes etc. processed food may contain high amounts of hidden sugar and refined carbohydrate. The GI also increases in carbohydrate food that had been cooked for a long time and became gelatinized.

Yeast

If you are susceptible to yeast infection, avoid fermented products and products containing yeast during yeast infection episodes. According to a holistic dermatologist, dandruff is due to a reaction to Malassezia. The condition can be aggravated by an overgrowth of yeast in the gastrointestinal tract.

Wine and beer use yeast in its fermentation process. Alcohol in wine and beer is a toxin that puts a strain on your liver and releases hormones that causes acne and worsens your dandruff problem.

Some food scientists found dairy products such as cheese and whole milk can acerbate dandruff problem perhaps due to a combination of fats and other elements. Therefore, some people suggested drinking skim milk to reduce fat intake. However, a Harvard study on the effect of drinking skim milk on the skin and acne found that skim milk caused the worse breakouts with an increased 44% likelihood of developing blemishes. They suggested hormones in skim milk may be higher perhaps due to concentration during processing (and caused hormonal imbalance in the body).

Foods to avoid during yeast attack:

Limit sugar because it fuel yeast growth. I notice whenever I take marmite /vegemite, I get yeast infection. So I avoided it now.

Some experts also suggested minimizing fermented foods and drink such as beer, wine, cheese, mushrooms, soy sauce, vinegar and certain types of bread using yeast as rising agent. Some experts suggested taking probiotics (found in yogurt, miso, and sauerkraut) to crowd out yeast in the intestine; others said such food should be avoided. Diet therapy is still in its infancy in the West. We need more evidence backed by research and long term human studies to validate expert advice on specific food to eat or avoid.

What current studies have established is that diet does have an impact on dandruff although there is disagreement on specific foods.

CAUSES OF DANDRUFF (4)

How climate affects dandruff

The North is gripped in the depths of winter now. For some people, it is also the season for winter dandruff. This type of dandruff has flakes that are smaller and less oily than those from other causes of dandruff and is often accompanied by dry skin on other parts of the body, such as the limbs and face. Since time immemorial, people had tried to deal with the problem with various remedies such as slathering on yogurt, rubbing with salt or mud, dousing with teas and washing the scalp with various herbal concoctions.

The hypothesis is winter dandruff is due to exposure to extremes in temperature such as cold, dry winter air outside and overheated rooms indoors. Researchers noted dandruff worsened for Yeast-sensitive people during winter and improved during the warmer months. Winter dandruff symptoms may appear only during winter or worsened during these months.

There is lack of sunshine in winter and UV rays of the sun is reported to kill Malassezia, the yeast often associated with dandruff. Interestingly, sun exposure is also reported to trigger dandruff. Pityriasis versicolor is a yeast infection that develops in hot humid weather on oily skin. The yeast feeds on skin oils (lipids) as well as dead skin cells. Infections are more common in people who have seborrheic dermatitis, dandruff and hyperhidrosis.

Experts believe Malassezia is responsible for both dandruff and pityriasis versicolor, a condition characterized by patchy rashes with scaling on upper torso, arm and lower leg.

When Malassezia is present, there is a higher chance of getting dandruff than pityriasis versicolor. The chances are fifty percent for dandruff and merely two to eight percent for pityriasis versicolor. This strain variability puzzled experts. Why do Malassezia give the skin on the scalp more problem than skin on other parts of the body? Does local immunity play a role in the disease predisposition? Many questions are yet to be answered.

Experts found a number of contributing factors to seborrheic dermatitis, the severe form of dandruff and scaling of the skin. They are   Genetic, environmental, hormonal, and immune-system factors. The condition may be aggravated by sleep deprivation, psychological stress, fatigue, change of season, illness and reduced general health.

Genetic, climatic and hormonal factors are beyond our control. We can adjust lifestyle factors to reduce the chance of getting dandruff. Since cholesterol-loving Malassezia is often associated with dandruff, we can adjust our diet so our body do not overproduce cholesterol. Is that possible? Let us explore this last contributing factor to dandruff in the next article.

CAUSES OF DANDRUFF (3)

Seborrhoeic dermatitis

You know you have Seborrhoeic dermatitis when there are greasy, red, itchy patches on the skin covered with flaky scales that are white or yellow in color. On the scalp, the condition presents as severe dandruff with some shedding of hair. Other affected areas are the sebaceous-gland-rich areas of your skin such as eyebrows, the sides of the nose, backs of your ears, chest, groin and occasionally the armpits.

Looking at your skin under a microscope, you will see your tormentor, the microscopic yeast, Malassezia. It produces toxic substances that irritate and inflame the skin. Although Malassezia grow on the skin of healthy people as well, scalp swabs from sufferers with seborrheic dermatitis show higher levels of colonization. Under the right conditions, Malassezia will morph from a benign organism into a pathogenic one. Further evidence of this is that the condition improves with antifungal treatment, accompanied by a decrease in numbers of Malassezia on the skin.

Certain illnesses

If you have eczema anywhere on your body, it could also be on your scalp, possibly leading to the development of dandruff.

Shedding of dead skin from the scalp of Psoriasis sufferers may be interpreted as dandruff. Malassezia may play a role in psoriasis on the face and scalp.

People with compromised immune system such as those with HIV-AIDS and neuropsychiatrically impaired individuals have a higher incidence of the condition.

Other diseases that increase your chance of developing dandruff are: Autoimmune and neurological disorders such as Parkinson's disease and systemic lupus erythematosus; Atopic dermatitis, Pityriasis rosea, Tinea capitis, Polycystic ovary syndrome etc.

Genetics

Some of the above diseases have genetic basis. Studies have found that people who are sensitive to yeast have a slightly higher risk of having dandruff. There may be a genetic predisposition for them to be more vulnerable to yeast infection.

Another study found an ABO blood group predisposition. A large number of people screened in the study were carriers of Malassezia species, but only a very small group had dandruff. The researchers concluded this clearly establishes the fact that a benign yeast can transform and become saprophytic to feed on dead skin of some individuals in the population. However, they have not established the triggers for the transformation to occur.

Males are more susceptible to dandruff than females. Researchers have shown that testosterone stimulates the growth of certain dermatophytes (infectious fungi on keratin), while estrogen inhibits the same.

INFECTION

Since Malassezia is frequently associated with dandruff, let us take another look at this organism. It was first identified as yeast found on the skin of patients with dandruff in the 19^th century. Bizarrely, this organism can morphs into a fungal (hyphal) form and/or both. Its hyphal form predominates in skin diseases such as tinea versicolor and Pityrosporum folliculitis.

The hyphae filaments used to be called 'Malassezia' and the yeast forms were called 'Pityrosporum' because scientists thought they were two different organisms.   Then in the 1980s, molecular methods of species identification showed they were two forms of the same organism. Malassezia don’t have the ability to make its own saturated fats. Therefore, it feeds on saturated fats on our skin. In its fungal form, it feeds on our dead skin as well.

Like the chicken and egg question, scientists could not determine whether abundant dandruff on our skin encourages Malassezia to proliferate or increased yeast cells irritates our skin and triggers increased scaling.

However, predisposing factors to Malassezia skin disease include:  

• Warm, humid condition, including sweating. Hence, pityriasis versicolor is common in tropical areas.
• Oily skin hence it is found mainly on oil-gland-rich areas such as the scalp, face and upper trunk.

Frederick Manuel and S Ranganathan postulated “on Two Stages of Dandruff” that “Malassezia colonization is a secondary event in dandruff. And

Suggested that a cascade of events preclude dandruff formation”

The two stages in infection of dandruff sufferers are:-

Stage 1

• At the Primary stage, there are multiple host-specific predisposing factors.
• Multiple nonspecific factors can trigger dandruff. They are of non-microbial origin.

Stage 2

• The secondary stage has multiple microbial causes.
• Response varies according to each individual.

(International Journal of Trichology, 2011)

CAUSES OF DANDRUFF (2)

Hair combing / brushing

Combing or brushing help to remove shed skin on our scalp. It has been suggested that inadequate combing or brushing lead to buildup of shed skin giving rise to slightly increased risk of dandruff. However, other studies indicated frequent combing and over shampooing could result in development of dandruff. (Indian J Dermatol. 2010). The reason given was that frequent combing and over shampooing affected the integrity and barrier function of the outermost layer of the skin. This made it easier for organisms to establish themselves and adhere to the skin.

Stress

A 2007 study found that 82 percent of patients with depression and anxiety have excessive flaky scalp. Stress lowers our immunity and induces the body to produce chemicals called glucocorticoids, a substance that can calm us down. Glucocorticoids can alter the cell makeup on the scalp, possibly leading us vulnerable to the fungus malassezia ... and the dandruff it is often associated with.

Hormones

The sebaceous glands that produce sebum become very active during puberty due to Hormonal changes. Sebum comprises a mixture of saturated and unsaturated fatty acids that give our skin integrity.

In 2005, scientists from USA and Korea discovered the fungus malassezia like to feed on saturated fatty acids in sebum. After eating up the saturated fats, our scalp is left with too much unsaturated fats. It was thought that excess unsaturated fatty acids together with changed structure of skin tissues due to glucocorticoids make our scalp vulnerable to flaking and dandruff.

Is malassezia the culprit triggering dandruff due to increased oil production induced by hormones? Perhaps not, because etiological studies found the prevalence rate of dandruff almost equal in pubertal and in older age groups. At puberty, hormones induced high oil production in sebaceous glands whereas in older people, hormonal production has tapered off and oil glands are not as active. Yet, malassezia is prevalent in both wet and dry dandruff.

Did the conflicting opinions and evidence leave you scratching your head in bewilderment?

In the next installment let us explore the issues of infection, genetic factor and illness.

CAUSES OF DANDRUFF (1)

Experts could not agree on the causes of dandruff. However, most experts do agree that it is not caused by poor hygiene. They noticed dandruff commonly occur when there is an overgrowth of a yeast-like fungus called malassezia. This fungus grows on the scalp of all people and usually do not cause any problem. It feeds on the oils our hair follicles secrete. Dandruff formed when excessive amounts of dead skin tissues build up on the scalp and mix with the natural oils there.

So what conditions trigger this fungus to go wild, irritate our skin and stimulate our body to respond by producing extra skin tissues?

Malassezia is one of a number of possible contributors to dandruff.

Other possible causes are:

• Chemicals   and allergens
• Inadequate hair combing / brushing
• Stress
• Hormones
• Diet
• Climate
• Infection
• Seborrheic dermatitis
• Certain illnesses

Chemicals   and allergens

People react differently to chemicals and ingredients in hair care products. Try switching to another hair care product to see whether your dandruff, inflammation and itchiness persist.  If you intend to consult a doctor or dermatologist, bring along your hair care products to check whether any possible ingredient that may be the culprit. Some ingredients that may give allergic reaction are hydrolyzed wheat protein, hydrolyzed soy protein, SLS (Sodium lauryl sulfate), Propylene glycol, quaternium-15, balsam of Peru etc. Preservatives and fragrances are the two biggest allergens. Preservatives are further sub—divided into antimicrobials, antioxidants and ultraviolet light absorbers.

Repeated exposure to allergens or irritants can lead to the skin to become dry, thicken and scaly. An acute reaction gives rise to rashes and sometimes, small fluid filled blisters.

Visit the Environmental Working Group database for more information on ingredients in hair and skin care products: http://www.cosmeticsdatabase.com/research

Homemade dandruff recipes:

FIGHT DANDRUFF NATURALLY (W1) - Homemade shampoo

An anti-dandruff conditioner:

SOOTHING CONDITIONING HAIR RINSE

(To be continued)