Earlier this year I wrote about some studies which suggest that probiotic supplementation in infants and children can help to prevent recurrent ear infections.  Very recent evidence (1) suggests that probiotic supplements may also be useful in children in order to prevent common colds.

The study (1) looked to evaluate the effects of probiotic consumption on cold and influenza-like symptom incidence and duration in otherwise healthy children.  The study was well designed and included 326 children aged between 3 and 5 years old.  104 children received an inactive placebo (plain milk), 110 received a probiotic supplement containing the bacteria Lactobacillus acidophilus (mixed into milk) and 112 children received a probiotic supplement containing Lactobacillus  acidophilus in combination with another bacteria Bifidobacterium animalis (also mixed into milk). The children received two doses daily for 6 months

• Compared to the placebo group, children who received the single probiotic had a 53% reduced incidence of fever, 41.4% reduced coughing incidence and 28.2% reduction in rhinorrhea (commonly known as a runny nose!).  The children receiving the probiotic supplement containing two species of bacteria had 72.7% reduced incidence of fever, 62.1% reduction in coughing incidence and 58.8% reducion in runny nose compared to the placebo group 

• Duration of symptoms (fever, coughing and rhinorrhea) was decreased significantly in children taking the single (by 32%) and combined (by 48%) probiotic supplements.

• Antibiotic use was reduced in children taking probiotics, relative to placebo, by 68.4% for the single and 84.2% for the combined probiotic supplement groups!  Many parents do not wish their children to undergo multiple antibiotic treatments in early life for fear of antibiotic resistance occurring later.  Antibiotics also destroy good bacteria in the digestive system which are now recognised as being very important for overall health.

• Subjects receiving both of the probiotic products had significant reductions in days absent from group child care, by around 30% compared with subjects receiving placebo treatment.

The authors conclude (1) that “Daily dietary probiotic supplementation for 6 months was a safe effective way to reduce fever, rhinorrhea, and cough incidence and duration and antibiotic prescription incidence, as well as the number of missed school days attributable to illness, for children 3 to 5 years of age”.

There have been studies (e.g. 2) which have shown that feeding supplements containing probiotics and/or prebiotics are safe in newborn infants and children and seem to increase resistance to infections during the first 2 years of life.  It may well be useful to speak to your GP or practice nurse about probiotic supplements if your child has already had frequent colds and/or antibiotic use or if you just want to give a regular probiotic supplement as a preventative measure.  Antibiotics are really effective at clearing infections but do also kill the good bacteria in the digestive system.  There is evidence to suggest that good bacteria in the digestive system are important for overall immune health and may prevent subsequent infection.  Taking a prebiotic and probiotic supplement after antibiotic therapy is probably a very wise way of re-establishing balance in the digestive system. 

Prebiotic and probiotic supplements specifically designed for children and infants are readily available to buy and can be taken daily.

(1) Leyer GJ et al.  2009.  Probiotic Effects on Cold and Influenza-Like Symptom Incidence and Duration in Children.  Pediatrics: 124: e172-e179.
(2) Kukkonen K et al.  2008.  Long-term safety and impact on infection rates of postnatal probiotic and prebiotic (synbiotic) treatment: randomized, double-blind, placebo-controlled trial. Pediatrics. 122(1):8-12.

Written by Ani Kowal

Recently a friend recommended that I try taking some Siberian Ginseng to boost my energy levels during a particularly busy time.  Siberian ginseng was not a herb that I knew very much about.  Korean ginseng, often known as panax ginseng or Asian ginseng is the ginseng that I have read a lot about in the past and seems to have immune and metabolism boosting properties.  So what about Siberian ginseng?

Siberian ginseng (Eleutherococcus senticosus) is also known as Eleuthero, Eleutherococco, Ciwujia, Devil’s Bush, Touch-me-not and ussurian thorny pepper bush.  It is a herb that is native to Siberia, Korea and parts of China.  Since Siberian ginseng does not belong to the Panax family it cannot be considered as a ‘true’ ginseng.  Although the beneficial actions of Siberian ginseng seem to be similar to those of Korean ginseng there is some debate as to whether it may be better to rename the herb Eleuthero so as to dissociate it from Korean ginseng.

Herbalists refer to Siberian ginseng as being an ‘adaptogen’.  The term is used to describe herbs that seem to help the body to adapt during times of stress, trauma, fatigue and anxiety.  Sometimes adaptogens are simply referred to as rejuvenating herbs and their use dates back thousands of years in China and India.  It is not entirely known how these herbs work, many of them have antioxidant properties but this does not explain all of their reported benefits.  It could be that adaptogenic herbs can balance the hormonal and immune systems in the body.  I wanted to have a look to see if there was much research evidence to back up the claims that Siberian ginseng can help during times of stress.

A review paper, released very recently (1), was carried out to assess clinical trials of different adaptogenic herbs in fatigue.  The authors who collated the research say that good scientific evidence has been recorded in trials in which Siberian ginseng increased endurance and mental performance in those with mild fatigue and weakness.  The scientists also propose that the beneficial, stress protective, effect of adaptogenic herbs is related to a variety of complex mechanisms in the body that involve hormones and brain activity.

Many of the studies done with Sibersian ginseng have been animal or laboratory studies and the results have been quite positive for the use of the herb to help during times of stress or fatigue.  However, not many studies have yet been conducted in humans.  The few trials that have taken place have been small, but certainly interesting, and further evidence is warranted before any firm conclusions can be drawn.

Two studies were published in 2004 (2,3) which look specifically at Siberian ginseng and fatigue in human subjects.  The first (2) took place in elderly individuals who were suffering from fatigue and feelings of lack of energy.  The study was small and preliminary involving only 20 individuals aged 65 or over.  The participants were given either 300mg a day of died extract of Siberian ginseng or a placebo for 8 weeks.  A health related quality of life questionnaire was taken at the study and then again at 4 and 8 weeks.  At the start of the study the two groups had similar health related quality of life scores.  The participants did not know if they were receiving the Siberian ginseng or the placebo.  After 4 weeks the individuals receiving the active herb had higher scores in the health related quality of life questionnaire (in the social functioning section) than those receiving placebo.  However after 8 weeks the differences did not seem to persist.  The authors of the study conclude that Siberian ginseng may improve some aspects of mental health and social functioning in the short term.  Further studies are necessary to investigate long term effects.

The other study (3) took place in sufferers of chronic fatigue.  Siberian ginseng seemed to be most helpful for individuals with more severe fatigue.  Overall the authors conclude that the findings for the use of Siberian ginseng in chronic fatigue are not yet strong but that “the findings of possible efficacy for patients with moderate fatigue suggests that further research may be of value”.
 

Siberian ginseng has been used for many years as a tonic for vitality and health and I believe we can learn a lot by looking at ancient herbal treatment regimens.  However, I also feel that it is important to investigate the science behind the claims and test the efficacy and safety of herbs before promoting them.  Laboratory evidence for Siberian ginseng is fairly strong and human trials are beginning to emerge to strengthen the health claims.

If your energy, vitality and stamina seem to be waning, rather than reaching for a coffee (which can further stress the body systems) you might want to investigate whether short term use of Siberian ginseng works for you.  Consulting a herbalist is a good option and always read the manufacturers dosage suggestions before use.  The most commonly recommended therapeutic dosage for Siberian Ginseng (20:1 concentration, containing at least 1% Eleutheroside E) is 300 mg - 600 mg per day.

(1) Panossian A, Wikman G.  2009.  Evidence-Based Efficacy of Adaptogens in Fatigue, and Molecular Mechanisms Related to Their Stress-Protective Activity. Curr Clin Pharmacol. 2009 Sep 1. [Epub ahead of print]
(2) Cicero AF et al.  2004. Effects of Siberian ginseng (Eleutherococcus senticosus maxim.) on elderly quality of life: a randomized clinical trial. Arch Gerontol Geriatr Suppl.  9:69-73.
(3) Hartz AJ et al.  2004.  Randomized controlled trial of Siberian ginseng for chronic fatigue. Psychol Med.  34(1):51-61.

Written by Ani Kowal

Tea has long been considered a tonic for health with both black and green teas being studied for their health-giving properties.  Tea contains many bioactive plant chemicals known as polyphenols (tea polyphenols are sometimes termed catechins) which can act as antioxidants in the body and thus potentially be important for disease prevention.

A recent study has shown (1) that green tea may have an effect on the risk factors for heart disease via improving the function of cells, called epithelial cells, which line the circulatory system.  When these cells are not functioning properly it can lead to the progression of atherosclerosis.  Atherosclerosis is commonly described as ‘hardening of the arteries’ it is a chronic inflammatory response in the walls of arteries

The study was small and preliminary but found that green tea consumption has an acute beneficial effect on endothelial function in a large artery (brachial artery) in healthy individuals (when compared to caffeine or hot water).  Green tea seems to work by improving blood flow and the ability of arteries to relax.  The effects were evident fairly rapidly, almost immediately in fact, within 30 minutes of drinking the tea dilation (relaxing) of the artery could be detected.  Measurement of the arteries was performed by high resolution ultrasound.  The researchers only looked at short-term impact (up to two hours).  It is not yet known what the long-term benefits could be.  Further studies are being carried out

Previous studies have found that black tea has also been associated with improved endothelial performance but adding milk to black tea may well reduce the health benefits associated with tea drinking.  Green tea originated in China but is now a popular drink that is consumed throughout the world.  Both green and black tea come from the same camellia sinesis bush but the different processing technique create the differences between the teas.  Green tea is not fermented whereas black tea is, the fermentation process is the reason for the brown/dark colour and the different flavour of black tea.  The flavonoids in green tea are probably more potent antioxidants than those found in black tea due to the different processing techniques.

A cup of tea isn’t going to cure or prevent illness and disease as a stand alone addition to normal daily life!  A healthy lifestyle is one that includes healthy eating, physical activity and other lifestyle factors.  Including green tea can be seen as a way to boost antioxidant defences in conjunction with a healthy lifestyle.  Green tea supplements which contain high doses of the tea polyphenols (e.g. catechins) are now widely available to buy but as yet it is unknown if the potential benefits extend to the supplemental form of the flavonoids.

(1)Alexopoulos N et al.  2008.  The acute effect of green tea consumption on endothelial function in healthy individuals. Eur J Cardiovasc Prev Rehabil. 15:300-305

Written by Ani Kowal

It has been estimated by The World Cancer Research Fund UK (WCRF UK) that lifestyle factors such as being overweight, eating an unhealthy diet and being inactive are responsible for about a third of all cancers in developed countries (1).  Cancers of the colon and recturm, often classed together as colorectal, are the third most common type of cancer worldwide.  In 2002 there were about 1million cases of colorectal cancer recorded.  This kind of cancer seems to be more common in men than women and is fatal in just under half of all cases, making it the fourth most common cause of death from a cancer (2).

The positive news is that food, nutrition and physical activity, so called lifestyle factors, have an important role to play in the prevention of colorectal cancer.  Recently two papers have been published looking at the links between diet and lifestyle and the risk of developing colorectal cancer (3,4).

One of the papers (3) looked specifically at the UK.  The researchers wanted to look at how lifestyle changes being promoted in the UK now might impact the rates of colorectal cancer in the future.  They found that if we could adopt the government recommended health guidelines and stop getting fatter as a nation we could see a substantial drop in the number of people diagnosed with colorectal cancer over the next few decades.  The lifestyle factors that could help reduce colorectal cancer rates included (These are the results for the UK population as a whole, they are not an indication of individual risk):

Eating less red meat - If men reduced their intake of red meat to 80 grams a day it is estimated that the incidence of colorectal cancer could fall by 13.7% by 2024. This translates to 3,642 fewer cases of the disease. The drop would be less substantial for women because they don't eat as much red meat.

Eating more fruits and vegetables – It is estimated that eating five servings of fruits and vegetables daily would cut colorectal cancer incidence by 6.6% for men and 5.6% for women.

Exercising more – It is estimated that if we increased our average activity levels to 30 minutes five times a week we would cut our risk of developing colorectal cancer by 2.4% for men and 2.7% for women

Maintaining a healthy weight - Keeping the weight profile of UK citizens at its current level would reduce projected colorectal cancer incidence by 3.4% for men and 2.6% for women, while slimming the weight profile down to the levels it was between 1986-1987  could cut colorectal cancer incidence by 8.1% and 6.9%, respectively,

Drinking less alcohol - limiting alcohol intake to two to three drinks a day could reduce men's risk by 5.3% and women's by 1.4%.

Over all the scientists estimate that 31.5% of colorectal cancers in men and 18.4% in women could be prevented if reasonable targets with respect to diet (reduced consumption of red meat, increased fruit and vegetables), exercise (30 min 5 days a week), alcohol consumption (3 U a day for men, 2 U for women) and weight control were achieved(3).

The other study I mentioned (4) was a review published in the International Journal of Cancer and also looked at the impact of dietary and lifestyle risk factors on the risk of colorectal cancer.  The paper looked at over 100 published studies and overall the results were similar to the UK study above, they showed that:  The risk of colorectal cancer was significantly associated with alcohol: individuals consuming the most alcohol had 60% greater risk of colorectal cancer compared with non- or light drinkers.  Smoking, diabetes, obesity and high meat intakes were each associated with a 20% increased risk of colorectal cancer.  Physical activity was protective against colorectal cancer

 
Both of the studies described here (3,4) together with other evidence such as that published by the WCRF UK (1,2) clearly show that our lifestyle can have an impact on the health of our gut and may well reduce our risk of developing colon cancer.  The review paper(4) states “Public-health strategies that promote modest alcohol consumption, smoking cessation, weight loss, increased physical activity and moderate consumption of red and processed meat are likely to have significant benefits at the population level for reducing the incidence of colorectal cancer”.  I would add that following a healthy balanced diet (as described in many previous posts), especially one rich in vegetables, fruits and healthy fats and low in processed/refined foods, is vital to achieve good levels of health and protect against all kinds of illness and disease.  

(1)WCRF/AICR.  2009.  Policy and action for cancer prevention.  Food, nutrition and physical activity: a global perspective.  Washington DC: AICR, 2009.
(2)WCRF/AICR.  2007. Food, nutrition, physical activity, and the prevention of cancer: a global perspective.  Washington DC: AICR, 2007.
(3) Parkin DM et al.  2009.  The potential for prevention of colorectal cancer in the UK.  European Journal of Cancer Prevention.  18:179-190
(4) Huxley RR et al.  2009.  The impact of dietary and lifestyle risk factors on risk of colorectal cancer: A quantitative overview of the epidemiological evidence.  International Journal of Cancer.  125: 171-180
Written by Ani Kowal

In my last post I wrote about cinnamon and how it seems to be useful for blood sugar balance, a factor that is important for overall health.  I also wrote about how the glycaemic index and glycaemic load of food and meals can have an effect on the blood sugar (glucose) levels. 

A very recent study (1) has found a link between the glycaemic index of the foods and the glycaemic load of the meals we eat and the risk of developing breast cancer. As previously mentioned, the links between diet and cancer are widely researched.  The World Cancer Research Fund UK (WCRF UK), a charity dedicated to cancer prevention, estimate that lifestyle factors such as being overweight, eating an unhealthy diet and being inactive are responsible for about a third of all cancers in developed countries (2). 

Gycaemic index and glycaemic load are terms used to characterise foods and diets based on their effects on blood glucose levels.  Foods that release sugar quickly into the bloodstream have what is known as a high Glycaemic Index (GI), meals that favour a spike in blood sugar levels are said to have a high Glycaemic Load (GL).  White bread, potatoes, processed/refined carbohydrates have a high glycemic index i.e. they tend to cause a rapid surge in blood sugar.  Vegetables, whole-grain high-fibre carbohydrates, create a more gradual change in blood sugar levels and are considered to have a low glycemic index.  For the classification of more food examples please visit the website 'The Glycemic Index', there you will find a database where you can search for specific foods and find out more about GI and health. 

This recent study (1) took place in Sweeden and looked at data from 61,433 women who completed special food frequency questionnaires in the late 1980s.  After around 17 years there were 2952 women who had developed breast cancer.  Analysis of the date found that eating a diet with high glycaemic load was significantly associated with an increased risk of developing breast cancer.
 
When the data was further analysed: total carbohydrate intake, glycaemic index and glycaemic load were all positively associated with the risk of developing a certain type of breast tumour known as oestrogen receptor (ER+) positive/progesterone receptor (PR-) negative breast cancer (ER+/PR-).  Women with the highest glycaemic index diet had a 44% increased risk of developing ER+/PR- breast cancer compared to women with the lowest glycaemic index diet.  Women in the highest category of glyceamic load had an 81% increased risk of ER+/PR- tumours, and those with the highest carbohydrate intake had a 34% increased risk, compared to those in the lowest groups.  (No associations were observed for ER+/PR+ or ER-/PR- breast tumours)

The investigators speculate that high-glycemic load diets may boost breast cancer risk by increasing concentrations of insulin and sex hormones in the body, which may contribute to the development and spread of breast cancer cells.  The WCRF UK say that the relevance of GI and GL to cancer “might lie in the fact that the rise in blood glucose after a meal is closely linked to that of insulin, which apart from its crucial role in carbohydrate and lipid metabolism, is also one of a family of important growth factors (2)”.  High blood sugar levels after a meal are also related to an increase in inflammation in the body.

A healthy, nutritious diet which is low in processed/refined foods and rich in vegetables, nuts/seeds, beans, pulses, unprocessed meats and fish (especially oily fish such as salmon, mackerel and trout), healthy fats, unrefined wholegrains will generally keep blood sugar levels stable.  Including a source of protein with every meal is also important for blood sugar balance e.g. beans/pulses, unprocessed meat and fish, eggs, nuts/seeds.  For more information on blood sugar balance please read my post on cinnamon which contains relevant links. 

(1)Larsson SC et al.  2009.  Glycemic load, glycemic index and breast cancer risk in a prospective cohort of Swedish women.  International Journal of Cancer.  125: 153-157
(2)WCRF/AICR.  2009.  Policy and action for cancer prevention.  Food, nutrition and physical activity: a global perspective.  Washington DC: AICR, 2009
Written by Ani Kowal

Cinnamon has been a popular spice for both culinary and medicinal purposes for many hundreds of years (thousands in fact).  Over the last 20 years scientific studies with the spice have been increasing and there has been particular interest in the way that cinnamon appears to be useful in helping blood sugar control (especially in type 2, non insulin dependent, diabetes) via its effects on insulin and other cellular mechanisms.

Laboratory studies have suggested that cinnamon has effects on the way that insulin (a key hormone involved with blood sugar balance) is used by cells and also on the amount of insulin produced by the body after a meal, and animal studies have found that cinnamon seems to lower blood sugar levels, lower triglyceride levels (blood fats linked to heart disease), lower total cholesterol levels while increasing the levels of HDL (‘good’) cholesterol (1)

In 2003 a clinical trial(2) took place in Pakistan which looked at the effect of cinnamon supplementation in individuals with type 2 diabetes.  The results showed that cinnamon powder taken over 40 days lowered blood glucose (sugar) levels, triglyceride levels, LDL cholesterol (a type of cholesterol considered to be a risk for heart disease) and total cholesterol levels.  The dose of cinnamon used ranged from 1-6g per day and all doses seemed effective.

This year a very small published trial (3) found that 3g of cinnamon eaten with rice pudding significantly reduced the insulin response in the body compared to no cinnamon in healthy individuals.  The results indicate a relation between the amount of cinnamon consumed and the decrease in insulin concentration.   Another small trial published this year (4) in healthy individuals found that 3g of cinnamon each day for 14 days reduced blood glucose response to oral glucose tolerance tests as well as improving insulin sensitivity.  However, when cinnamon supplementation was stopped the effects were quickly lost.  The authors conclude that cinnamon may improve blood sugar control and insulin sensitivity, but the effects are quickly reversed.

Why is it important that we are aware of blood sugar (glucose levels)?  You may be thinking “I am not a diabetic so why should I be concerned about my blood sugar?”

In September last year I explained how sugar and carbohydrates (which the body breaks down into sugars that are absorbed into the blood) can have a significant effect on raising the risk of heart disease in non-diabetic individuals.  I have also previously written about the effect that balancing blood sugar levels in the body can have including fatigue and craving prevention and keeping energy levels stable during the day (see posts dated 8th and 10th September 27th April)

Unfortunately over the years ultra low fat diets and increased consumption of processed and refined foods has led many people to eat diets that are high in sugar and/or high in (non-vegetable and fruit) carbohydrates.  Foods that release sugar quickly into the bloodstream have what is known as a high Glycaemic Index (GI), meals that favour a spike in blood sugar levels are said to have a high Glycaemic Load (GL).  To identify foods with a high glycaemic index that will contribute to increasing the GL of a meal please view the website: The Glycemic Index, there you will find a database where you can search for specific foods and find out more about GI and health.  

Unbalanced blood sugar levels following a meal (post-prandial dysmetabolism) can cause havoc in the body.  A high post-meal blood sugar level can lead to damaging free radicals (reactive oxygen molecules) being released which are a risk for atherosclerosis (damage to blood vessels) and metabolic syndrome (a big risk factor for heart disease) as well as many other conditions ranging from cancer to arthritis.  The high blood sugar can lead to internal inflammation, dysfunction in the lining of the blood vessels and may also lead to an increase in triglycerides (blood fats) - all risk factors for heart disease.  On a more immediate unbalanced blood sugar levels can sometimes lead to feelings of fatigue, lack of energy and cravings. 

Cinnamon appears to work by helping the body with the way it deals with sugar in the blood via various mechanisms– the effects of cinnamon appear to be important in type 2 diabetics but also healthy individuals.  Cinnamon supplements are available and you can use cinnamon as a sweetener on morning oats/porridge and in baking and cooking.  However, the best way to balance blood sugar levels is to eat a healthy, nutritious diet with a low glycaemic load (see the posts mentioned previously).  Eating a healthy, balanced diet will help to prevent blood glucose imbalance in the body.  A diet that is high in minimally process foods, vegetables, fruits, unrefined whole grains, beans/pulses, nuts/seeds, lean protein, oily fish (such as salmon, mackerel, sardines and trout) will go far in reducing the post-meal increases in glucose, triglycerides (blood fats) and other markers of disease compared to a typical western diet that is processed and full of high GI carbohydrates.

(1)Kim SH, Hyun SH, Choung SY: Anti-diabetic effect of cinnamon extract on blood glucose in db/db mice. J Ethnopharmacol 104:119–123, 2006
(2)Khan A, Safdar M, Khan MMA, Khattak KN, Anderson RA: Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care 26:3215–3218, 2003
(3)Hlebowicz J et al.  2009.  Effects of 1 and 3 g cinnamon on gastric emptying, satiety, and postprandial blood glucose, insulin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and ghrelin concentrations in healthy subjects.  Am J Clin Nutr.  89:815-821
(4) Solomon TP & Blannin AK.  2009.  Changes in glucose tolerance and insulin sensitivity following 2 weeks of daily cinnamon ingestion in healthy humans. Eur J Appl Physiol. 2009 Apr;105(6):969-76.
Written by Ani Kowal

"Trichotillomania is an impulse control disorder or form of self-injury characterized by the repeated urge to pull out scalp hair, eyelashes, facial hair, nose hair, pubic hair, eyebrows or other body hair, sometimes resulting in noticeable bald patches. Trichotillomania is classified in the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders) as an impulse control disorder. It may seem, at times, to resemble a habit, an addiction, a tic disorder or an obsessive-compulsive disorder. Trichotillomania often begins during the individual's teenage years. Depression or stress can trigger the condition. Due to social implications the disorder is often unreported and it is difficult to predict accurately prevalence (1)" but it is estimated to affect 2-4% of the population and seems to be more common in women than men.

Usually trichotillomania is treated with SSRI (Selective Serotonin Reuptake Inhibitor) anti-depressant drugs which many people prefer not to take due to the potential side-effects.  Researchers at the University of Minnesota Medical School have just published a study (2) which suggests that NAC (N-Acetylcysteine) a commonly available health food supplement may help to stop the urges of those suffering with trichotillomania.  NAC is an amino acid that acts as an antioxidant in the body.

The study(2) was small but well designed involving 50 trichotillomania sufferers, with an average age of around 34, for 12 weeks.  Half were given 1,200mg of NAC each day for 6 weeks.  For the following 6 weeks they were given 2,400mg NAC per day.  The other half were given placebo (inactive) supplements.  After 9 weeks, those taking NAC had a significant reduction in the incidence of hair-pulling.  After 12 weeks 56% of those on the NAC supplement reported feeling much, or very much improved (compared to only 16% of those on the placebo).  No side-effects were found when taking the NAC supplement.
 

The study offers significant hope to sufferers of this distressing self-harming condition and is also an important study as it is one of the first studies of compulsive behaviours to look at lowering levels of glutamate, a chemical that triggers excitement, in the brain to curb harmful behaviours.  NAC seems to affect levels of glutamate in a very specific area of the brain which may be why it seems to help patients curb their self-harmful behaviour.

Dysfunction of glutamate-mediated brain nerve functions has also been implicated in obsessive-compulsive disorder (OCD).  The study authors believe that NAC and other glutamate modulators may be applicable to other disorders, addictions and compulsive behaviours.  Prior to this study a case was documented (3) where NAC was shown to be clinically helpful for a sufferer of OCD (obsessive compulsive disorder).  Further studies are certainly warranted in this area, especially since many individuals are looking for natural alternatives to psychiatric drugs.  It may be that NAC will be useful in conjunction with other known nutritional mood influencing aids, I certainly look forward to further studies being published in this area.

If you are suffering with trichotillomania (or other compulsive behaviours) you may wish to contact the following online support networks and may wish to speak to your doctor or health professional about trying NAC to see if it is useful for you:
UK and Ireland Trichotillomania Support Group  and the Trichotillomania Support Online

(1)http://wapedia.mobi/en/Trichotillomania
(2) Grant JE et al.  2009.  N-Acetylcysteine, a Glutamate Modulator, in the Treatment of Trichotillomania: A Double-blind, Placebo-Controlled Study. Arch Gen Psychiatry. 66(7):756-763
(3) Lafleur DL et al.  2006.  N-acetylcysteine augmentation in serotonin reuptake inhibitor refractory obsessive-compulsive disorder.  Psychopharmacology.  184(2):254-256.

(Written by Ani Kowal)

On Thursday I went to the Nutrition Society Summer meeting at the University of Surrey.  The five day conference had concentrated on various aspects of over- and undernutrition.  The symposia that I attended were exceptionally interesting and thought provoking.  One of the presentations(1) was given by Dr Paul Kelly of Barts and London School of Medicine and Dentistry.  He was speaking about the microorganisms in the digestive system and links to diarrhoea in individuals in developing countries.  However, he briefly mentioned an animal study that linked the makeup of the bacteria in the digestive system and a propensity to obesity.  This got me thinking about whether that link was present in humans.  Upon returning home I had a search through the medical databases to see if there was any literature to support these thoughts.

Can bacteria in the gut have anything to do with developing excess body weight or obesity?

There seems to be a fair amount of recently published interest in the topic of digestive bacterial balance and the links to obesity and overweight (e.g. 2,3,4,5,6).  For many years the large intestine was thought only to be important for water absorption and storage of waste.  However, the adult human gut contains up to 100 trillion microbial organisms (including bacteria and yeasts) collectively known as the microbiota or microbiome.  These gut bacteria seem to have an effect on the entire body and not just the health of the digestive system.

Obesity is a complex disease involving many factors with no miracle cure and no easy solutions - I am not about to disillusion anyone by inferring that bacterial balance is a major factor and probiotics (supplemental good gut bacteria) are the cure.  However, gut bacteria may well be having some kind of impact on the development of excess body weight in some people.  What we eat does affect the composition of the microorganisms that are present in our digestive systems and in turn these microorganisms can have an effect on the health of our body.  A review published in French this year (2) looked at the evidence which suggests that the gut microorganisms are linked with metabolism and inflammation, and could be involved in type 2 diabetes, metabolic syndrome and obesity.

An extensive review published in America last year (3) looked at a wide range of evidence in order to investigate the potential role of the gut bacteria in the development of obesity. The authors of the paper found that interactions among the microorganisms in the gut appear to have complex effects in the human body and that the gut organisms may have an important role in regulating weight and may also be partly responsible for the development of obesity in some people.  Evidence suggests that our gut microorganism environment is established within the first year of life and then remains fairly constant through adulthood.  However dietary factors, infections and antibiotic use may lead to long-term changes.

The gut bacteria may be acting on weight via effects on: calorie utilisation from food, metabolism, inflammatory responses, hormone regulation or other means and evidence does suggest that obese and lean individuals seem to have different composition of gut bacteria (3).  A study published last year (4) followed children from birth to age 7 years.  Children of normal weight and those who were overweight had significant differences in their gut bacterial composition suggesting that an important link between bacterial balance and obesity development possibly via inflammatory pathways.  The authors conclude that their findings may offer “new possibilities for preventive and therapeutic applications in weight management”.

Can modifying the gut bacteria through diet and/or probiotic or prebiotic (such as FOS, fructooligoosaccharides) supplements have an impact on body weight?

The review paper (3) emphasises that the best, nonsurgical, strategy for reversing obesity in the population seems to be to promote small but long-term changes in diet and physical activity.  The authors go on to say that further evidence with regards bacterial gut balance is needed but that microorganisms may well be influencing obesity.  They suggest that probiotic and prebiotic supplements may be useful in order to positively change the gut bacterial balance and help prevent and treat overweight but that these manipulations should clearly not be viewed as a substitute for a healthy diet and exercise.

Prebiotics act as food for the good ‘friendly’ bacteria in the digestive system and studies (3) suggest that prebiotics in the diet may reduce our energy and food intake, increase satiety, reduce hunger and appetite and reduce total daily calorie intakes.  FOS may also have effects on blood sugar balance in the body.

Probiotics, live ‘friendly’ bacterial supplements, may also change the bacterial balance of the digestive system and have an effect on overall health in the body, but studies in humans and the links to weight control are lacking.  An interesting study presented at a conference this year (6,7) found that probiotics during and after pregnancy may help prevent the development of obesity after birth.  The study found that at 1 year after giving birth, 25% of women given probiotics along with dietary counseling had central obesity based on that definition, compared with 43% of women given diet advice alone. In a press release the author stated that "This is the first study showing that probiotics-supplemented diet during pregnancy and breastfeeding influences the adiposity [fat mass]of women over the 12-month postpartum period," Further evidence is needed but the author said that modification of bacterial balance in the intestines with probiotic supplements "together with a balanced diet may offer a reasonably economic, practical, safe and potentially successful method to be used with other lifestyle-related factors in controlling obesity" (7).

Further conclusive evidence needed, however prebiotics (such as FOS) and probiotics do seem to positively change the composition of bacteria in our digestive systems and affect overall health.  Supplements are readily available but should not be seem as a quick-weight loss fix.  A healthy diet and lifestyle is of paramount importance for weight control and overweight prevention and treatment.

(1)Dr Paul Kelly.  2009.  Symposium 4: Gut function: effects on over and under-nutrition.  Nutrition, intestinal defence and the microbiome.  The Nutrition Society Summer Meeting.  University of Surrey.  Thursday 2nd July 2009.
(2) Pataky Z et al.  2009.  Gut microbiota, responsible for our body weight?  Rev Med Suisse.  5:662-664 [Article in French]
(3) DoBaise JK et al.  2008.  Gut microbiota and its possible relationship with obesity.  Mayo Clinical Processings.  83:460-469
(4) Kalliomaki M et al.  2008.  Early differences in fecal microbiota composition in children may predict overweight.  Am J Clin Nutr.  87:534-538
(5) Tennyson CA &Friedman G.  2008.  Microecology, obesity and probiotics.  Curr Opin Endocrinol Diabetes Obes.  15:442-447
(6) Kirsi Laitinen, nutritionist and senior lecturer at the University of Turku in Finland.  Study findings presented at 17th European Congress on Obesity http://www.easo.org/eco2009/index.htm 6-9 May 2009 held in Amsterdam
(7)  Anthony J. Brown, MD.  2009.  Probiotics may help ward off postpartum obesity.  2009-05-08 15:24:34 -0400 (Reuters Health).  http://www.reuters.com/article/healthNews/idUSTRE5475QP20090508

Written by Ani Kowal

The links between diet and cancer are widely researched.  The World Cancer Research Fund UK (WCRF UK) estimate that lifestyle factors such as being overweight, eating an unhealthy diet and being inactive are responsible for about a third of all cancers in developed countries (1).  The WCRF UK are a charity committed to cancer prevention.

A recently published study (2) has found a significant link between eating a diet high in carotenoid rich fruits and vegetables and a reduction in the risk of breast cancer in premenopausal women.

Carotenoids such as alpha and beta carotene, lutein and zeaxanthin are a family of over 700 naturally occurring yellow, red, orange and dark green pigments found in vegetables and fruits.  Good sources include carrots, sweet potatoes, tomatoes, squash, peppers, cantaloupe melons, nectarines, papaya, mango and dark green vegetables such as spinach, kale, watercress and asparagus.  Introducing a good mix of these fruits and vegetables on a regular basis in the diet will help keep carotenoid levels in the body high.

The study (2) involved 5,707 women with invasive breast cancer (2,363 premenopausal women and 3,516 postmenopausal women) and 6,389 individuals with no breast cancer, control subjects (2,594 premenopausal women and 3,516 postmenopausal women).  In an interview, these women were asked about their intake of carotenoid rich fruits and vegetables.  The researchers found that pre-menopausal women eating high intakes of vitamin A, beta-carotene, alpha-carotene, lutein and zeaxanthin appeared to have a reduced risk of breast cancer.  Eating at least two servings of carotenoid-rich vegetables each day was associated with around a 17% reduced risk of breast cancer.  As an association study the results are positive but further studies would be necessary before any firm conclusions could be drawn about the effect of dietary carotenoids on cancer risk. 

Carotenoids may be acting to prevent cancer via different means.  Carotenoids have been shown to interfere with oestrogen (hormone) signalling which may explain why their cancer-preventing effects would be limited to premenopausal women.  In addition to this, carotenoids act as antioxidants in the body and antioxidants have been linked to cancer prevention.  Antioxidants prevent damage to the body cells by naturally occurring unstable oxygen molecules, known as free radicals.  Antioxidants may help to ‘quench’ or mop-up the destructive free radical molecules and therefore protect against cell-damage (which could lead to cancer formation).

Absorption of carotenoids from foods into the body is greatly affected by fat.  Without a fat source carotenoids are not easily absorbed.  Fat acts as a carrier for these nutrients to allow them passage from the gut into our blood and bodily cells.  This is not a suggestion to drown your vegetables or salads in gallons of oil, however, I am a firm believer in using small amounts of olive oil in dressings and cooking.  Including some nuts, seeds or olives in salads may also be helpful in order to gain maximum absorption of these important nutrients. 

(1)WCRF/AICR.  2009.  Policy and action for cancer prevention.  Food, nutrition and physical activity: a global perspective.  Washington DC: AICR, 2009.
(2) Mignone LI et al.  2009.  Dietary carotenoids and the risk of invasive breast cancer.  International Journal of Cancer.  124:2929-2937
Written by Ani Kowal