Following my last post I was interested to read a well researched review paper (1) that looks into the link between vitamin D deficiency and the development of dementia.  The report is published in the May issue of the Journal of Alzheimer’s disease and is written my William B Grant PhD of the Sunlight, Nutrition and Health Research Centre (SUNARC).  SUNARC is an organization devoted to research and education relating to the prevention of chronic disease through changes in diet and lifestyle.  I have previously mentioned SUNARC when reporting on the importance of Vitamin D for health.

Previously I highlighted the link between vitamin D and the brain when I wrote about the potential use of the sunlight vitamin for helping sufferers of SAD (seasonal affective disorder) and also possible link between low vitamin D levels in those suffering from depression and mood disorders.

William Grant, the author of the paper, begins by highlighting the rise in individuals who are suffering with dementia in the Western world.  The condition deserves attention since the number of people living into old age is increasing and it is a worthwhile aim to help individuals achieve lasting health as they age so they may live life to the full.  There are several risk factors for the development of Alzheimer's disease and vascular dementia. Based on an increasing number of studies linking these risk factors with Vitamin D deficiency, the article(1) suggests that further investigation of possible direct or indirect linkages between Vitamin D and these dementias is certainly needed.  Diet and lifestyle are being increasingly researched in relation to their links with dementia prevention and vitamin D is gaining attention for its role in many condition from heart disease, diabetes, bone health, cancer, infections, chronic fatigue and more.

Low blood serum levels of vitamin D have been associated(1) with increased risk for several diseases which are also considered risk factors for the development of dementia  or are often reported to precede the incidence of dementia e.g. cardiovascular diseases, diabetes mellitus, depression, dental caries, osteoporosis, and periodontal disease.  These studies are only observational studies,nproviding medical researchers with links between vitamin D and dementia.  As yet there no randomised controlled trials to draw evidence from.

The way that vitamin D may be working to protect the brain is via several mechanisms.  It seems to be able to act by protecting the neurones in the brain (brain nerve cells), it may also be protecting the blood vessels in the brain and having an effect by protecting against excess calcium entry into the brain.  Vitamin D also seems to act as an anti-inflammatory – an important factor since dementia is often linked to inflammation in the brain and body (1).  There is also plenty of evidence to suggest an important role for vitamin D in brain development and function.

Writing in the article, Dr. Grant states, "To date, the evidence includes observational studies supporting a beneficial role of vitamin D in reducing the risk of diseases linked to dementia such as vascular and metabolic diseases, as well as an understanding of the role of vitamin D in reducing the risk of several mechanisms that lead to dementia." “However, until RCTs are performed, the hypothesis cannot be considered a fact”

A recent analysis(2) found that there is a global widespread insufficiency of vitamin D and there is evidence from the National Diet and Nutrition Surveys (NDNS) which suggests that in the UK deficiency of this vital nutrient is a real problem (3,4,5,6).  The problem is made worse in the older generations, as we age our bodies find it increasingly difficult to manufacture vitamin D.  In the UK many of us do not get enough sunlight exposure to generate decent levels of vitamin D in our bodies, especially in the autumn and winter months when we cover our bodies up and don’t get out during the daylight hours very often. 

Only small amounts of vitamin D are found in food sources such as oily fish (mackerel, salmon and sardines) and egg yolks.  As many of us in the UK are falling short of recommended vitamin D levels, if you rarely get out into the sun, you may wish to consider a vitamin D supplement which provides around 12mcg/day (around 500iu a day).  Such a supplement may be particularly useful during the autumn and winter months.

For more interesting information about the benefits of vitamin D and sunlight for health please visit the SUNARC website, the information there is well presented and backed up by significant amounts of good evidence.

(1)Grant, WB.  2009. Does Vitamin D Reduce the Risk of Dementia?  Journal of Alzheimer's Disease 17:151-159.
(2)Hagenau T et al.  2008.  Global vitamin D levels in relation to age, gender, skin pigmentation and latitude: an ecologic meta-regression analysis.  Osteoporosis International May [E publication ahead of print]
(3) Finch S et at.  1998.  National Diet and Nutrition Survey of People aged 65 Years and Over.  London: H. M. Sationery Office.
(4) Gregory L et al.  2000.  National Diet and Nutrition Survey of People aged 4-18 years. Vol 1.  Report of the Diet and Nutrition Survey.  London:  The Stationery Office
(5) Henderson L et al.  2002.  National Diet and Nutrition Survey: Adults Aged 19-64 years.  Vol 1: Types and Quantities of Foods Consumed.  London: The Stationery Office
(6) Hypponen E & Power C.  2007.  Hypovitaminosis D in British adults age 45y: nationwide cohort study of dietary and lifestyle predictors.  Am J Clin Nutr.  85:860-888.

Written by Ani Kowal

What we eat can certainly have an impact on the way our brains function.  Previously I have written about the importance of a healthy diet for brain function and also the links between the Mediterranean style diet and the brain. 

In both of these posts I write about how important oily fish seem to be for the efficient functioning of the brain (mental function is often referred to as cognition).  Previously I have concentrated on the fact that oily fish provide omega 3 fatty acids which are vital for the structure and function of the brain.  However, oily fish also provides a dietary source of Vitamin D.  This is important, since food sources of vitamin D are limited.  Oily fish such as mackerel, salmon, sardines and trout are the primary food source.  Egg yolks contain some vitamin D and some foods are fortified with this ‘sunshine’ vitamin.  Our main source of vitamin D is the manufacture in the body via the exposure of our skin to sunlight.  Recently, however, there has been a lot of concern that UV exposure in the UK may be insufficient to keep vitamin D levels high enough for optimal for health with many individuals in the UK are falling short of recommended levels.  More can be read on the importance of vitamin D in previous blog posts.

A very recently published study (1) has found a link between vitamin D levels in the body and brain function (cognitive performance).  Previous studies have found that an inadequacy in vitamin D could be linked to problems with brain function but so far results have been inconsistent.  This study (1), which was conducted by University of Manchester scientists, was set up in order to examine the association between blood serum vitamin D levels and cognitive performance in middle-aged and older men.  3,133 Eurpoean men aged 40-79 years were included in the research.  Cognitive (brain) function was tested via a number of different validated tests.  Blood serum vitamin D levels were measured as was physical activity, functional performance and mood/depression.

Higher levels of vitamin D were significantly associated with better cognitive function as measured by one of the tests, the Digit Symbol Substitution test (DSST).  This test is an internationally-recognised test that assesses an individual's memory, recognition capabilities and speed of information processing.  Reduced cognitive function was most pronounced in individuals with the lowest vitamin D levels.  This research provides valuable information, however further research is warranted to determine whether health vitamin D levels, or vitamin D supplementation, can play a role in preserving cognitive function in older adults (1).

Although the study is only an association study it has some key strengths: it was based on a large population sample and took into account potential confounding influences, such as depression and levels of physical activity.   Interestingly the association between increased vitamin D and faster information processing was more significant in men aged over 60 years, although the biological reasons for this remain unclear and requires further investigation.

The positive effects vitamin D appears to have on the brain need to be explored further but certainly raise questions about its potential benefit for those with or susceptible to dementia.  Dr Susanna Sorensen, Head of Research at The Alzheimer’s Society made a comment (2) on the research via the charity website:

“One in three people over 65 will die with dementia making research into this area vital. This study, including over 3,000 men from a number of European locations, shows that maintaining vitamin D levels could play a role in reducing the decline of brain function. 

However, further research is needed to determine whether or not vitamin D can help preserve brain function in older people or reduce risk of dementia. As vitamin D is readily available to most people, through exposure to sunshine or eating oily fish, it will be interesting to see the results of future studies.

In the meantime, current evidence tells us that a healthy lifestyle, including a balanced diet and exercise, is the best way of reducing your risk of dementia.”

Alzheimer's Society is the UK's leading care and research charity for people with dementia and those who care for them.  There are 700,000 people with dementia in the UK with numbers set to rise to one million by 2025.  Alzheimer's Society is a membership organisation, which works to improve the quality of life of people affected by dementia in England, Wales and Northern Ireland.  Please visit their website for more information.  You may also like to read the two posts I mentioned at the start of this piece which are about brain function.

If you rarely get out into the sunlight you may wish to consider taking a vitamin D supplement which provides around 12mcg of the nutrient per day (around 500iu).  Vitamin D supplements may be particularly useful during the autumn and winter months and for individuals who have darker skins or who don’t go outside regularly.

(1) Lee DM et al.  2009.  Association between 25-hydroxyvitamin D levels and cognitive performance in middle-aged and older European men.  J Neurol Neurosurg Psychiatry. Published Online First: 21 May 2009. doi:10.1136/jnnp.2008.165720
(2)Alzheimer's Society comment on research into impact of vitamin D on brain performance
Published Wednesday 20th May 2009 in Research news http://www.alzheimers.org.uk/site/scripts/news_article.php?newsID=469

Written by Ani Kowal

Last week I wrote about folic acid and how it may be associated with a reduced risk of premature birth.  A recently published study (1) has found that folic acid may also reduce the risk of a baby being born with severe congenital heart defects (heart defects present from birth).

The study took place in Quebec, Canada(1).  The researchers wanted to see whether the fortification of food programme, that has been in place since 1998 and has already proved to be effective in preventing neural tube defects, had impacted the incidence of severe congenital heart defects.  The 1998 government policy requires the mandatory fortification of flour in Canada with folate.

The study(1) looked at infants who were born between 1990 – 2005 who had severe congenital heart defects.  The scientists then analysed the data to compare rates of heart defects before and after the food policy was in place.  Among the 1 324 440 births in Quebec between 1990-2005 there were 2083 infants born with severe congenital heart defects.  Analysis of the results showed no change in the birth prevalence of severe birth defects in the nine years before fortification, while in the seven years after fortification there was a significant 6% decrease per year.  The authors of the study conclude that the public health measures to increase folic acid intake in Canada were followed by a decrease in the birth prevalence of severe congenital heart defects. The findings support the hypothesis that folic acid has a preventive effect on heart defects.

According to Raluca Ionescu-Ittu, a PhD candidate on the team, "this decrease is very significant and probably underestimated. During the study period, there was an increase in other factors associated with a higher prevalence of congenital heart defects, so without the fortification we would probably have seen an increase in these defects." (2)

Despite the positive findings the authors of the study stress the need for women of childbearing age, especially those planning a pregnancy, to take folic acid supplements and not rely on food as a source.  The fortification programme was aimed at the general population, women planning a pregnancy need extra folic acid, it is a good idea for pregnant women to take a folate supplement at least three months before becoming pregnant.  Data that I mentioned last week indicates that there are benefits to taking a folate supplement a year prior to conception.  Folic acid seems to have effects on various aspects of embryonic and infant development.  Natural sources of the vitamin, such as green vegetables, might not provide sufficient doses for pregnant women.  Most medical doctors therefore recommend supplements in addition to a healthy diet rich in folic acid. 

As I have previously stressed: it is important for any woman who is planning a pregnancy to aim to eat a consistently healthy diet rich in vegetables, fruits, healthy fats and unprocessed meats, fish and wholegrain unrefined carbohydrates.  A healthy diet really does affect the unborn child, probably in more ways than we currently know through scientific investigation.  It may also be worth to consider taking a broad spectrum multivitamin and mineral food-state supplement specifically designed for pregnancy in order to maintain good levels of all essential nutrients.  An omega 3 fatty acid supplement could also be considered, especially if oily fish and nuts/seeds are not regularly eaten.  Before deciding to take any supplement during pregnancy please discuss your thoughts with a GP, nurse or midwife.

(1)Ionescu-Ittu R et al.  2009.  Prevalence of severe congenital heart disease after folic acid fortification of grain products: time trend analysis in Quebec, Canada. BMJ 2009;338:b1673
(2) McGill University Health Centre (2009, May 14). Folic Acid Effecive In Preventing Congenital Heart Defects, Canadian Research Shows. ScienceDaily. Retrieved May 19, 2009, from http://www.sciencedaily.com¬ /releases/2009/05/090514111404.htm
Written by Ani Kowal

In April this year I discussed the evidence that probiotics may be helpful in the treatment and prevention of bacterial vaginosis.  Vaginosis usually involves a disruption in the normal bacterial and yeast balance in the vagina and is characterized by increased vaginal discharge (which is often odorous) without inflammation, sometimes there will also be itching present.

Normally a healthy vagina contains ‘friendly’ or beneficial bacteria, which protect it from invading pathogens (detrimental bacteria) such as those which cause urinary tract infections, thrush and vaginosis.  A healthy digestive system will also be dominated by a variety of different friendly bacteria.  If the vagina and digestive system are mainly colonised with 'good' bacteria these provide a barrier to the entry of pathogenic/harmful bacteria into the vagina.  Having a strong and healthy immune system protects the body from many bacterial infections and personal hygiene is also important to protect against vaginal infections (bacteria from the anal area may enter the vagina during sex or when wiping after a bowel movement).

Bacterial vaginosis is common in pregnant women and can put a woman at increased risk for a variety of complications, such as premature delivery.  There is great interest in understanding how vaginosis can be prevented.  Prebiotic and probiotic oral supplements or probiotic vaginal creams and suppositories may be helpful and are generally safe during pregnancy (but always check with your doctor, heath professional or midwife before deciding to try any treatment during pregnancy).  Recently (1) a study has found that vitamin D may also be playing a role.

Readers of my blog will know that Vitamin D has been very widely researched over the last few years and the importance of this sunshine vitamin for various aspects of health is vast. Many people in the UK often do not achieve good levels of vitamin D and this may be putting them at increased risk of various health problems.  A lack of this crucial nutrient has now been linked to heart problems, cancer, brain disorders, sleep problems, headaches, weight problems and immune problems to name but a few.  Vitamin D may play a protective role against vaginosis since it has quite an influence on the immune system.

The current study(1) looked to assess whether poor vitamin D status played a role in predisposing pregnant women to bacterial vaginosis.  469 pregnant women were included in the research.  The study investigated the relationship between vitamin D status and bacterial vaginosis in 209 white and 260 black women at less than 16 weeks of pregnancy with singleton gestations. Blood samples were taken, and blood serum was analysed to ascertain the levels of vitamin D.   Pelvic examinations were performed, and vaginal smears were used to assessed and diagnose rates of bacterial vaginosis.  The reason why skin colour may be an issue is that individuals with darker skin tones find it more difficult to manufacture vitamin D since less UV light can pass (3-36% in darker skins).  Pale skins allow more UV light to pass (53-72%) and make vitamin D manufacture easier.

The data indicate that overall, women with bacterial vaginosis had lower serum vitamin D levels than those without bacterial vaginosis. The prevalence of bacterial vaginosis decreased as vitamin D concentration in the blood increased.  The findings suggest that vitamin D insufficiency is associated with bacterial vaginosis in the first 4 months of pregnancy. Further, poor vitamin D status also seemed to contribute to the strong racial disparity in the prevalence of bacterial vaginosis.  This study only provides an idea, or hypothesis, for a link between vitamin D levels and rates of bacterial vaginosis.  Further controlled intervention trials will be needed to provide confirmation.

Foods rich in vitamin D are limited, with oily fish such as mackerel, salmon and sardines being the primary natural source.  Egg yolks also contain limited amounts of the vitamin and some breakfast cereals are fortified with the vitamin.  The exposure of our skin to sunlight is definitely the main source of vitamin D.  Recently, however, there has been mass debate about whether UV exposure in the UK is sufficient to keep vitamin D levels optimal for health.  Most individuals in the UK are falling short of recommended levels. 

If you rarely get out into the sunlight you may wish to consider a vitamin D supplement which provides around 12mcg of the nutrient per day (around 500iu).  Pregnant women are advised to check with their doctor, health professional or midwife before starting any supplement regimen.  Vitamin D supplements may be particularly useful during the autumn and winter months and for individuals who have darker skins or who don’t go outside regularly.

(1)Bodnar L et al.  2009.  Maternal vitamin D deficiency is associated with bacterial vaginosis in the first trimester of pregnancy.  J Nutr.  (April 8, 2009). doi:10.3945/jn.108.103168
Written by Ani Kowal

It is well known that women of childbearing age are recommended to take a supplement that contains folic acid, this is due to the fact that folate (folate is the naturally occurring form of folic acid) in very early pregnancy, before most women even know they are pregnant, can reduce the risk of birth defects especially spina bifida.  Unfortunately many women in the UK do not achieve good levels of folate in their daily diets or through supplements.  A concern in the UK is the rising levels of teenage pregnancy, these young women are often not taking nutrient supplements when they get pregnant and their diets may also be lacking in the vitamins, minerals and essential fatty acids that are vital for the developing foetus.

There may be additional benefits to taking folic acid supplements before conceiving a child.  A new study(1) has found that folic acid supplements prior to conception (and in early pregnancy) may help prevent premature births. The study links early and pre-pregnancy folic acid intakes to a reduced risk of premature births.  Prevention of premature birth is very important, infants born early, before 37 weeks of pregnancy rather than the normal 40 weeks, have an increased risk of many health and developmental problems.

It has previously been shown that women who deliver premature babies tend to have lower levels of folate in their blood but this study(1) wanted to look at the effect of folate supplementation on rates of premature birth.  The researchers assessed 34,480 pregnant women, about 20% of these had been taking folate supplements for a year or more before getting pregnant, 36% had been taking them for less than a year and 44% were not taking any supplements at all.  160 of the women delivered their babies before 32 weeks of pregnancy while 1,658 women delivered their babies before 37 weeks.

The data showed that using folate supplements for a year or more was associated with a 70% reduced risk of delivering a baby at 20-28 weeks.  Taking the supplements for less than a year was linked to 50% reduced risk of premature births compared to women who did not take supplements.  For deliveries between 28-32 weeks the risk was 50% lower for women on supplements for a year or longer and 30% lower for those taking supplements for less than a year compared to those women not taking supplements.  There was no relationship between folate supplement use and risk of delivering a baby between 32 and 37 weeks' gestation.  The preventive effects of supplementation were most powerful for preventing the earliest, and hence riskiest, preterm births.

In brief: These findings show that folate supplementation for a year or more before conception is associated with a 50%–70% decrease in early, but not late, spontaneous preterm births and that the longer a woman takes folate supplements before becoming pregnant, the lower her risk of a preterm birth.  The study only shows a possible association between folate supplementation and reduction in the risk of premature birth.  Further randomised trials are necessary to provide confirmation of the link.  It could be that taking supplements is a general marker for healthy behaviour.  However, there is a body of evidence that suggests there could be biological reasons why folate may protect against premature birth.  Low folate levels are associated with increased intrauterine infection which is linked to early premature births.  Folate also seems to reduce inflammation within the body during pregnancy.  Since folate is necessary preconceptionally and in the early weeks of pregnancy in order to prevent birth defects it is definitely worth considering long term supplementation prior to conception.

It is important for any woman who is planning a pregnancy to aim to eat a consistently healthy diet rich in vegetables, fruits, healthy fats and unprocessed meats, fish and wholegrain unrefined carbohydrates.  It may also be worth considering a broad-spectrum food-state supplement specifically designed for pre-pregnancy in order to main good levels of all nutrients.  An omega 3 fatty acid supplement could also be considered, especially if oily fish and nuts/seeds are not regularly eaten.  Before deciding to take any supplement during pregnancy please discuss your thoughts with a GP, nurse or midwife.

(1) Bukowski et al.  2009.  Preconceptional Folate Supplementation and the Risk of Spontaneous Preterm Birth: A Cohort Study. PLoS Medicine. 6 (5): e1000061 DOI: 10.1371/journal.pmed.1000061

Written by Ani Kowal

Age related macular degeneration (AMD) is the most common cause of blindness in people over the age of 50 in the UK.  In March this year I wrote about the links between B vitamins, homocysteine and AMD and in August last year I discussed the links between diet in general and eyesight preservation.

The macular is the light sensitive area in the centre of the retina that controls visual field and the ability to see colours.  AMD is caused by the deterioration of the macular.  As this happens the peripheral, outer, vision remains intact as the centre field of vision becomes slowly blurry, grey or filled with a large black spot.  Two forms of AMD exists: the dry form which develops slowly, accounting for 90% of all cases; and the wet form which causes rapid deterioration of central vision.

The exact causes of AMD are unknown although free radical damage, where unstable oxygen molecules damage the eye cells, is strongly implicated.  Tobacco smoke and sun exposure can increase the level of free radicals in the body and both are a risk for AMD.  High blood pressure and diabetes are also risk factors as these conditions can limit blood flow to the eyes.

For more information please visit Macular Disease Society website.  The Macular Disease Society aims to build confidence and independence for those with central vision impairment.  They are the only UK charity dedicated to helping people with macular degeneration and offer information, a helpline, counselling and emotional support among other resources.

Evidence for diet and nutrition in the prevention, and to a certain extent treatment, of the condition is growing yearly.  Since free radicals are implicated in the causation and progression of AMD it may be that antioxidant nutrients such as vitamins A, C and E, carotenoids like lutein and zeaxanthin and various phytonutrients and flavonoids, bioactive plant chamicals, are protective.  Omega 3 fatty acids may also play a protective role via their anti-inflammatory effects.

This month three studies (1,2,3) have been published linking diet to AMD.

The first study (1) involved 4003 participants in the Age-Related Eye Disease Study (AREDS), there were 7,934 eyes included in the study.  Dietary intakes of vitamins C and E, zinc, lutein and zeaxanthin, the long chain omega 3 fatty acids DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), and low-dietary glycaemic index foods were analysed and the association between AMD was evaluated.  The results showed that consuming diets that had a low glycaemic index and high intakes of the nutrients listed was associated with a reduced risk of AMD.
 

A healthy diet rich in a variety of vegetables, fruits, beans/pulses, nuts/seeds, unprocessed meats and fish, especially oily fish, and unprocessed, unrefined wholegrain carbohydrates will provide these nutrients.  Lutein and zeaxanthin are plant pigments that are found in broccoli, spinach, green leafy vegetables and egg yolks.

The study(1) also found that diets containing foods with a low glycaemic index, also appeared protective against AMD.  Glycaemic index is a measure of how rapidly a food causes blood sugar levels to rise. High-GI foods, like white bread, many processed foods (especially high carbohydrate foods) and potatoes, tend to spur a quick elevation in blood sugar, while low-GI foods, such as lentils, nuts, beans and many high-fibre unrefined grains, create a more gradual increase in blood sugar.  The blood-sugar surges associated with high-GI diets may eventually damage the macula.  This is probably because consistently high blood sugar levels can damage fats and proteins and may put the body into oxidative stress, which over time damages cells and may lead to various diseases, including AMD.

The other two studies (2,3) looked at the links between dietary fat intake and AMD.  In the blog post that I wrote in August last year I discussed many studies that linked a high intake of long chain omega 3 fatty acids, found in oily fish, to a reduced risk of AMD.  The first of these two studies (2) found that regularly eating foods rich in healthy fats such as fish, nuts and olive oil is associated with a reduced risk of AMD and the second study (3) has found that avoiding trans fats (often found in baked and processed foods) is also associated with a reduced risk of the condition.

The first report (2) involved 2,454 participants in the Blue Mountains Eye Study, which began in 1992. The individuals involved completed food frequency questionnaires that were used to analyse and determine their intake of various fatty acids. Digital photographs of the retina were used to assess the development of AMD five and ten years later.

Eating one serving of fish per week was associated with a 31% lower risk of developing early AMD. Eating one to two servings of nuts per week was associated with a 35% lower risk of early AMD.  It is not known for definite why the fatty acids are protective against AMD but the fats may be protecting the eyes by reducing inflammation, blood vessel formation or oxidative damage in the retina.  Omega 3 fatty acids are known to be helpful in reducing inflammatory chemicals in the body (I have previously written a lot about this in various blog posts).

The other report (3) analysed data from 6,734 individuals aged 58-69.  During the follow-up period, 2,872 cases of early AMD and 88 cases of late AMD developed.  Individuals who consumed higher levels of trans-unsaturated fats-often found in baked goods and processed foods-were more likely to have late AMD.  This study also found that individuals  who consumed the most omega-three fatty acids were less likely to have early AMD.

Trans-unsaturated fatty acids may be causing damage through their effect on cholesterol levels as well as through their inflammation increasing effects.  Trans fats are also linked to an increased risk of heart disease as well as other conditions.

Available ‘eye health’ supplements often contain vitamins C, E, beta carotene and the mineral zinc in addition to lutein and zeaxanthin.  The rationale behind this comes from dietary association studies and some research evidence.  If you are considering supplements remember that they are not a substitute for nutritious daily meals!  A healthy diet, rich in a variety of vegetables and fruits, will provide an array of antioxidant nutrients to keep the whole body healthy, including the eyes.  Healthy omega 3 fats from oily fish and nuts/seeds (especially flaxseeds and walnuts) are also a vital part of a balanced diet.  Individuals who do not regularly eat oily fish such as salmon, mackerel, sardines or trout (at least twice per week) may consider taking a fish oil supplement to provide 250mg-350mg EPA and 250-350mg DHA per day, vegetarians may consider a flaxseed oil supplement to provide 500-1000mg alpha-linolenic acid per day.

(1) Chung-Jung C et al.  2009.  Dietary compound score and risk of age-related macular degeneration in the age-related eye disease study.  Ophthalmology.  116:939-946
(2) Tan JSL et al.  2009.  Dietary Fatty Acids and the 10-Year Incidence of Age-Related Macular Degeneration.  The Blue Mountains Eye Study.  Arch Ophthalmol. 127(5):656-665.
(3) Chong EWT et al.  2009.  Fat Consumption and Its Association With Age-Related Macular Degeneration.  Arch Ophthalmol.  127(5):674-680.

Written by Ani Kowal

Previously I have written about folic acid and the prevention of birth defects and also the necessity of this vitamin for heart health.  A newly published study (1) has found that this essential B vitamin may also suppress allergic reactions and reduce the severity of allergy symptoms and asthma symptoms. The research was conducted by the Johns Hopkins Children’s Centre.

The Johns Hopkins Children’s Centre is Maryland’s largest paediatric hospital (USA).  Hopkins Children’s offers the best care available in modern paediatric medicine and U.S. News & World Report ranks Hopkins Children’s among the top four children’s hospitals in the USA.

The scientists believe that this is the first human study to look at the link between the levels of folate in the blood and allergy.  Folate is the naturally occurring form of folic acid.  Previous evidence exists to show that folate can help regulate inflammation which is a big factor in allergy.  For more information on eating to help prevent and reduce allergy symptoms please read my previous posts on asthma and hay fever these are full of general tips, advice and supplement ideas.

In this current study(1) the researchers from the Johns Hopkins Children’s Centre reviewed the medical records of over 8,000 people aged 2-85.  The researchers looked at the effect of folate levels on allergic symptoms and on the levels of specific immune system markers, IgE antibodies, which tend to rise in response to an allergen (allergic trigger).

It was found that individuals with the highest levels of folate had the lowest levels of IgE antibodies in their blood.  These people also reported fewer allergies and allergic symptoms, less wheezing and had a lower likelihood of having asthma.  In a press release (2) the scientists said: "Our findings are a clear indication that folic acid may indeed help regulate immune response to allergens, and may reduce allergy and asthma symptoms," They also say "But we still need to figure out the exact mechanism behind it, and to do so we need studies that follow people receiving treatment with folic acid, before we even consider supplementation with folic acid to treat or prevent allergies and asthma."

Specific findings of the study (2):
*People with the lowest folate levels (below 8 nanograms per milliliter) had 40% higher risk of wheezing than people with the highest folate levels (above 18 ng/ml).
*People with the lowest folate levels had a 30% higher risk than those with the highest folate levels of having elevated IgE antibodies, markers of allergy predisposition.
*Those with the lowest folate levels had 31% higher risk of atopy (allergic symptoms) than people with the highest folate levels.
*Those with lowest folate levels had 16% higher risk of having asthma than people with the highest folate levels.
*The Hopkins team is planning a study comparing the effects of folic acid and placebo in people with allergies and asthma.

Many cereals and grain products are already fortified with folate, and folate is found naturally in green, leafy vegetables, beans and nuts.  As mentioned in the posts on asthma and hay fever an overall healthy diet rich in vegetables, fruits, omega 3 fats from oily fish and nuts/seeds (especially walnuts and flaxseeds), unprocessed wholegrains and unprocessed meats will go far in nourishing the body, keeping inflammation low, and helping it to deal effectively with potential allergic triggers.  Please do read the previous posts for more information on specific important nutrients to help prevent and treat allergyies. 

(1)Matsui EC and Matsui W.  2009.  Higher serum folate levels are associated with a lower risk of atopy and wheeze.  published online 01 May 2009.  The Journal of Allergy and Clinical Immunology.  DOI: 10.1016/j.jaci.2009.03.007.
(2) Press release, Folic Acid May Help Treat Allergies, Asthma 

Written by Ani Kowal

Gout is a condition that we don’t tend to hear too much about but it is actually the most common cause of inflammatory joint disease in men over 40 years old in the UK.  Gout is an arthritic, inflammatory joint, condition that causes swelling and intense pain in one joint in the body, commonly the big toe although it can affect any joint.

Gout affects over five times more men than women.  In men, it can occur any time after puberty, whereas in women it is uncommon before the menopause. People who are overweight, have high blood pressure, eat diets rich in protein and drink large quantities of alcohol have an increased risk of developing gout.  It is estimated, by the UK Gout Society, that there are around 70,000 sufferers of gout in the UK (1).  I would suggest visiting the UK Gout Society website for fantastic information about the condition.

The following information comes from the UK Gout Society(1)

Gout occurs as a result of excess uric acid (urate) in the blood and tissues. After prolonged exposure to uric acid, crystals of urate can form in and around the joints and kidneys. If uric acid crystals enter the joint, they may trigger the development of inflammation. The affected joint becomes red, swollen and extremely painful and tender. Infrequently, stones (calculi) may form in the kidneys. Most patients with gout have high levels of urate in their blood because they do not pass enough in their urine. In most cases this is caused by an inherited peculiarity of the kidneys, which is in other respects harmless. It can also be caused by high levels of uric acid in the diet or by some drugs eg. diuretics. Much less commonly, patients produce too much uric acid in the first place, owing to an inherited metabolic abnormality or disorders associated with greatly increased production of cells in the body (1).

Uric acid is the end product of purine metabolism in the body. The levels normally found in the blood and tissues are derived from both the breakdown of old cells and from the degradation of purine containing foods in normal diets.  Foods containing high levels of purines include:
Meat and game – particularly red meat and offal, such as liver and kidney
seafood – especially mussels, herrings, sardines
alcoholic beverages – including beer, lager, port and some red wines

For detailed ways of treating and preventing gout please visit the UK Gout Society where a leaflet “All About Gout” can be downloaded free of charge.

The reason I wanted to write about gout was that a recent study (2) has found that individuals who have a high vitamin C intakes tend to have a significantly reduced risk of suffering from gout and that vitamin C supplements may well be useful in the prevention of this painful inflammatory condition.

The study ran from 1986-2006 and looked at the relationship between vitamin C intake and incidence of gout in almost 47000 men.  None of the men had a history of gout at the start of the study.  Vitamin C intake was assessed every 4 years through validated questionnaires.  1317 cases of gout were confirmed during the study.  Men who consumed the least vitamin C had a significantly higher incidence of gout than those consuming the most. 

Men who consumed 500-999mg Vitamin C per day had a 17% lower risk of developing gout than men who consumed less than 205mg per day.  Those consuming 1000-1499 mg vitamin C per day had a 34% lower risk of gout than those consuming less than 250mg per day and those with an intake of 1500mg per day or higher had a 45% lower risk of developing gout (2). 

Vitamin C seems to be having an effect by reducing the levels of uric acid in the blood thus preventing a build up in joints which may eventually lead to gout.  The vitamin C may be affecting the absorption of uric acid by the kidneys and/or by increasing the speed at which the kidneys work to protect against inflammation.  Taking a high dose of supplemental vitamin C is quite safe, with most medics agreeing that up to 2,000mg per day is tolerable.  

A study last year (3) found that a higher vitamin C intake in men was associated with significantly lower uric acid concentrations in the blood serum.  A vitamin C intake of up to 500mg/d  was associated with lower uric acid concentrations, further increases in vitamin C was not significantly associated with further lowering of uric acid concentrations.  A double-blind placebo controlled study (4) in 184 individuals looked at the affect of taking a 500mg day of vitamin C supplements for 2 months on serum uric acid concentrations in the blood.  At the end of the study period, serum uric acid levels were significantly reduced in the vitamin C group but not in the placebo group.  The vitamin C seemed to be affecting the way the kidneys worked to reduce uric acid levels.

These studies seem to suggest that vitamin C might be beneficial in the prevention and management of gout and other urate-related diseases.  Eating plentiful amounts of fruits and vegetables will help keep vitamin C intakes high.  Taking a ‘food state’ vitamin C supplement (these supplements are made from food sources rather than chemicals and are easy for the body to absorb and tolerate) of 500-1000mg per day could be considered if you have previously suffered with gout and want to try and prevent subsequent attacks.

(1) UK Gout Society website
(2)Choi et al.  2009.   Vitamin C Intake and the Risk of Gout in Men: A Prospective Study. Archives of Internal Medicine.  169 (5): 502-507
(3) Gao X et al.  2008.  Vitamin C intake and serum uric acid concentration in men.  Journal of Rheumatology.  35(9):1853-8
(4) Huang HY et al.  2005. The effects of vitamin C supplementation on serum concentrations of uric acid: Results of a randomized controlled trial.  Arthritis Rheum.  52(6):1843-1847

Written by Ani Kowal