Many individuals are aware of the link between excess salt intake and high blood pressure.  Numerous studies exist to back up this link and further studies have shown that it is possible to achieve significant reductions in blood pressure, in individuals with high and normal blood pressure levels, by reducing salt intake.

A research paper just published in the British Journal of Medicine (1) has now found that higher salt intake is associated with significantly greater incidence of strokes and heart attacks.  The association seems stronger with increasing intakes of salt (it is a dose-dependent association).  A difference of 5 g a day in a person’s usual salt intake was found to be associated with a 23% difference in the rate of stroke and 17% difference in the rate of total cardiovascular disease (heart disease, stroke and other diseases involving the heart and blood vessels such as atherosclerosis).  Worldwide, raised blood pressure accounts for around 62% of strokes and 49% of coronary heart disease events.  The authors of the study note that (1) “each year a 5 g reduction in daily salt intake at the population level could avert some one and a quarter million deaths from stroke and almost three million deaths from cardiovascular disease worldwide”.  A significant finding, furthermore, because of probable imprecision in measurement of salt intake, the authors say that these effect sizes are likely to be underestimated!

The research paper (1) mentions that most adult populations around the world have average daily salt intakes far higher than 6 g, and for many in eastern Europe and Asia have intakes higher than 12 g.  The World Health Organization recommended that salt consumption should ideally not exceed more than 5 g per day.

Most of the salt we eat comes from that added to food in the manufacturing process by industry, caterers and food producers.  The authors of the paper (1) discuss the fact that In the UK there is a voluntary scheme for the food industry – where there is encouragement for the reformulation of many food items towards a lower salt content and proposals of improved labelling. These efforts have led to a reduction of 0.9 g a day (or about 10%) in population salt intake in four years (from 9.5 to 8.6 g a day), which is still far from the recommended 6 g a day initial targets that were set in the UK. While the voluntary approach is the preferred choice for many governments it may well be time for a more formal ‘regulatory’ approach in order for recommended targets to be reached and for health to be positively influenced.

Practical tips:
*Minimise the amount of processed/refined foods you eat – ready prepared meals are often very high in salt content and other common household staples, such as bread, can also be packed with added salt. 
*Always check the label to view the salt content of foods, salt is often 'hidden' in various foods that you wouldn't expect to contain it e.g. biscuits and condiments to name but a few.
*Instead of adding salt to food at the table or during cooking try using herbs and spices to add flavour
*Visit the Food Standards Agency website for loads more information on salt and health and ways to reduce daily consumption

(1)Strazzullo P et al.  2009.  Salt intake, stroke, and cardiovascular disease: meta-analysis of prospective studies.  BMJ.  339:b4567,
Written by Ani Kowal

Vitamin D has been a major topic of research over the last 2 years.  It seems as though this vitamin is essential to many aspects for health from bone to brain.  Low blood serum levels of vitamin D have been associated with increased risk for several diseases e.g. cardiovascular diseases, diabetes, depression, dental caries, osteoporosis, and periodontal disease.  Today I wanted to look further into the role that vitamin D may play in helping individuals who suffer from low mood or depression.  Previously I mentioned that vitamin D may be helpful to individuals suffering with Seasonal Affective Disorder (SAD) and have also written about vitamin D for healthy brain function and possible prevention of dementia/Alzheimer’s Disease.

There are ‘receptors’ for vitamin D within the brain and this may be the reason why recent research is discovering a link between vitamin D and mood.  In 2006(1) a study found that low levels of vitamin D (serum 25-hydroxyvitamin D) was significantly associated with a high depression score.  Other studies (e.g. 2,3,4) have found similar associations between low vitamin D levels and poor mood.

Vitamin D, acts as a multipurpose steroid hormone within the body and is vital to health.  A lack of vitamin D, or low vitamin D levels, particularly among older adults, have been linked to cognitive (brain) function, depression, bipolar disorder, and schizophrenia.  As mentioned above vitamin D activates receptors on neurons in regions of the brain which are implicated in the regulation of behaviour.  Vitamin D also acts to protect the brain by balancing antioxidant and anti-inflammatory defences (5).

The association studies mentioned above are interesting but don’t prove that vitamin D can help treat depression.  Interestingly, a study took place last year (6) which looked at vitamin D supplementation and depression in overweight and obese individuals.  The study involved over 400 individuals who were given high dose vitamin D supplementation: 20,000iu per week, 40,000iu per week or a placebo for one year.  Depression was rated using a special scale called the Beck Depression Inventory (BDI).  The first observation that was made by the research scientists was that individuals with the lowest vitamin D levels scored significantly higher in the depression scale than those with better vitamin D levels.  After one year of supplementation the two groups given vitamin D had significant improvements in BDI scores, this did not occur in the placebo group.  Vitamin D supplementation seemed to be positively affecting mood.  The authors conclude that “It appears to be a relation between serum levels of [vitamin D] 25(OH)D and symptoms of depression. Supplementation with high doses of vitamin D seems to ameliorate these symptoms indicating a possible causal relationship”. The research was carried out in overweight and obese individuals and further trials are necessary in normal-weight individuals. 

These results suggest that vitamin D deficiency could have the ability to cause depression and that ensuring good vitamin D levels in the body could help to prevent/treat depression.  Here in the UK that would seem particularly vital in the autumn and winter months when there is less sunlight and vitamin D levels tend to drop to their lowest.

Evidence for the use of vitamin D in depression and mood disorders is preliminary and not yet conclusive.  Further evidence is needed to see whether vitamin D is as useful in cases of moderate-to severe depression as it is in mild cases.  However, as I have previously written many of us in the UK have very low vitamin D levels.  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).  Only small amounts of vitamin D are found in food sources such as oily fish (mackerel, salmon and sardines) and egg yolks.  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.  If you think you want to supplement much higher levels (more than 1000iu daily) then please visit your doctor since vitamin D is a fat soluble vitamin and it is possible to take too much.  When looking for vitamin D supplements two forms are generally available.  Cholecalciferol, known as vitamin D3, and ergocalciferol or vitamin D2. Cholecalciferol is generally taken to be the more potent, easily absorbed and preferred form of vitamin D

(1)Jorde R et al.  2006.  Neuropsychological function in relation to serum parathyroid hormone and serum 25-hydroxyvitamin D levels:  The Tromso study.  Journal of Neurology.  253(4):464-70
(2)Wilkins CH et al.  2006.   Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults. Am J Geriatr Psychiatry. 14(12):1032-40.
(3)Murphy PK et al.  2008.  Vitamin D and mood disorders among women: an integrative review. J Midwifery Womens Health.  53(5):440-6.
(4) Hoogendijk WJ et al.  2008.  Depression is associated with decreased 25-hydroxyvitamin D and increased parathyroid hormone levels in older adults. Arch Gen Psychiatry.  65(5):508-12.
(5)Cherniack EP et al.  2009.  Some new food for thought: the role of vitamin D in the mental health of older adults.  Curr Psychiatry Rep. 11(1):12-9.
(6)Jorde R et al.  2008.  Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomised double blind trial.  J Intern Med.  264:599-609
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.  I have previously written about this condition but to re-cap:  

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.

Previously I have gone into detail as to why long chain omega 3 fatty acids may be important for eye health and written about various published studies.  A new paper (1) has just been published in the American Journal of Clinical Nutrition which adds further weight to the evidence.  The researchers of this study(1) wanted to investigate whether long chain omega 3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are found in oily fish such as mackerel, trout, sardines and salmon, are associated with a reduced likelihood of developing AMD.  The study involved over 1800 people who were are risk of developing AMD,.  The individuals were followed from 1992 to 2005 and their diets were assessed vial a special validated questionnaire.  The results show that participants who reported the highest long chain omega 3 intakes were 30% less likely than their peers to develop AMD.  This study showed a strong association between omega 3 fatty acids and protection against AMD but further trials would be needed to prove cause and effect.  The authors conclude that “If these results are generalizable, they may guide the development of low-cost and easily implemented preventive interventions for progression to advanced AMD”

Long chain omega 3 fats certainly seems to be part of the story.  Antioxidants and other nutrients have also been implicated in the protection against eye disease.  Please read my previous posts on AMD and cataract for more information on how certain nutrients may be important for good eye health.  It is not yet recommended that omega 3 supplements be taken specifically for protection against AMD, however these fats are vital for health for a number of reasons, if you do not regularly (at least twice a week) eat oily fish you may wish to consider a fish oil supplement.  Vegetarians and vegans can take a flaxseed oil supplement (which provides short chain omega 3 fatty acids) or look into buying EPA/DHA supplements produced from algae, these supplements are becoming increasingly available.

(1)SanGiovanni JP et al.  2009.  omega–3 Long-chain polyunsaturated fatty acid intake and 12-y incidence of neovascular age-related macular degeneration and central geographic atrophy: AREDS report 30, a prospective cohort study from the Age-Related Eye Disease Study.  Am J Clin Nutr 2009;90 1601-1607
Written by Ani Kowal

Research scientists from the University of Newcastle (1) have found that up to about 50% of women in the UK might be suffering from a lack of vitamin A.  This huge lack of this vital vitamin appears to be due to a genetic issue.  It seems that about half of the women in the UK may suffer from a genetic variation which reduces their ability to produce enough vitamin A from beta-carotene.  In the past it has been assumed that the body can convert beta-carotene into plentiful amounts of vitamin A, but this study indicates that this conventional wisdom may be misplaced.

Vitamin A is sometimes called retinol.  It is an essential nutrient, a vital vitamin that is important for a strong and healthy immune system - important to help protect against common infections, colds and flu.  Vitamin A is also crucial for healthy skin and mucous lined membranes in the nose, lungs and eyes.

In the past women were told to be careful not to consume too much vitamin A because in pregnancy too much of this vitamin seems to be associated with some birth defects.  To prevent the problem of intoxication with vitamin A pregnant women were told to avoid vitamin A rich foods and to consume beta-carotene instead.  Beta carotene is found in dark green vegetables such as Brussels sprouts, asparagus, watercress and spinach as well as orange vegetables, especially carrots, sweet potatoes and squash and orange fruits such as papaya, mangoes, cantaloupe melons, peaches, apricots.  The thinking behind this was that the body would convert as much beta-carotene as it needed into vitamin A.  This recent research (1) suggests, however, that for many women beta-carotene is not an effective substitute for vitamin A.

In a press release one of the research scientists commented (2) “Vitamin A is incredibly important -particularly at this time of year when we are all trying to fight off the winter colds and flu”. "It boosts our immune system and reduces the risk of inflammation such as that associated with chest infections”."What our research shows is that many women are simply not getting enough of this vital nutrient because their bodies are not able to convert the beta-carotene."

Further research is certainly needed as this was only a small and preliminary study.  What the research showed (1) was that 47% of women in a volunteer group carried a genetic variation which prevented them from being able to effectively convert beta-carotene into vitamin A.  The study scientists also found that all the volunteers only consumed about one third of the recommended intake of (preformed) vitamin A.  Vitamin A is found ‘preformed’ in foods such as eggs, milk, liver, cheddar cheese, cod liver oil, salmon and mackerel.

This is a worrying statistic since many women may well be lacking enough vitamin A in their diet to reach optimal levels for body function, especially immune function.  The authors explain (2): "Worryingly, younger women are at particular risk," "The older generations tend to eat more eggs, milk and liver which are naturally rich in vitamin A whereas the health-conscious youngsters on low-fat diets are relying heavily on the beta-carotene form of the nutrient."

The authors comment that they need to carry out larger studies that involve both men and women.  In order to keep the immune system healthy this winter you may want to try and make sure you eat enough sources of preformed vitamin A, as well as including plenty of beta-carotene in the diet.  Taking a low dose, food-state, multi-vitamin and mineral supplement could also help by preventing any shortfalls in the diet (but a supplement should never be seen as an alternative to a healthy diet).  Until there is further evidence I don't think it is necessary to supplement specifically with vitamin A.  Vitamin A is a fat-soluble vitamin and it is possible to take too much, so taking a low-dose multi-nutrient supplement is more advisable.  If you are pregnant always check with your doctor before taking any kind of supplement.

(1)Leung WC et al.  2009.  Two common single nucleotide polymorphisms in the gene encoding β-carotene 15,15'-monoxygenase alter β-carotene metabolism in female volunteers.   The FASEB Journal. 23:1041-1053
(2)Press release.  Newcastle University (2009, November 18). UK women at risk from vitamin A deficiency. ScienceDaily. Retrieved November 19, 2009, from http://www.sciencedaily.com/releases/2009/11/091118072051.htm
Written by Ani Kowal

This Autumn I wrote about Seasonal Affective Disorder (SAD) and light therapy.  Many people, myself included, find that waking up in the dark is difficult since the body doesn’t seem to have time to adjust to the start of the day.  In the spring and summer it seems easier to get up and start the day energetically since the light steadily increases from early morning – this allows for a gradual wake up.  This dawn awakening seems to be important in controlling our internal body clocks, or circadian rhythm.  This internal 'body clock' is associated with hormonal release and other physiological responses.  It may well be that disruption in morning waking during the dark autumn/winter months plays a part in SAD for some sufferers.

For years I used a timer switch on my bedside lamp, it was set so that the light went on 15minutes before my alarm clock so that my body started to be ready to wake.  The problem here was that the light was bright straight away and there was no ‘dawn effect’.  There are now some fabulous dawn simulators available such as the Lumie Bodyclock, these sunrise alarm clocks usually consist of a unit with a light that gradually increases in intensity over a 30 minute period until it is at it’s brightest when an alarm usually sounds. 

SAD is often associated with hypersomnia, excessive amounts of daytime feelings of sleepiness.  People with hypersomnia often have difficulty waking up in the mornings and can feel disorientated for the first few hours in the morning.  Other symptoms which are related to SAD include anxiety, irritation, reduced energy, restlessness, slow thinking, slow speech and memory difficulty.

The thinking behind the Lumie Bodyclock is that if we wake up with gradual, dawn light our circadian rhythm / natural body clock, is less disrupted.  Increasing numbers of studies (e.g.1,2,3,4)  have now been carried out with dawn simulators for SAD, the studies have proved very positive with some indication that the dawn simulation sunrise alarm clocks, are as good as light boxes at helping mood in SAD sufferers.  One study (1) concluded that: Naturalistic dawn simulation was an active antidepressant that does not require the effort of post-awakening bright light therapy. The authors say that dawn simulation can be considered as an alternative to bright light therapy or medication.

Another study (2) took place in 50 medication-free patients with SAD that was associated with hypersomnia (excessive amounts of daytime feelings of sleepiness).  The individuals received either 1 week of dawn simulation or a dim placebo signal.  The participants assessed their level of drowsiness upon awakening using a scale called the Stanford sleepiness scale (SSS),a psychiatrist then rated difficulty awakening after the treatment week.  Dawn simulation lowered both the difficulty awakening score and the 'sleepiness scale' score compared to the placebo dawn signal.

If you have been diagnosed with SAD or feel that you suffer from some of the symptoms of SAD, which you can read about in my previous blog post, you may want to consider purchasing a sunrise alarmclock such as the Lumie Bodyclock to see if it brings relief, especially if you suffer from difficulty waking and getting up in the mornings.  This is a convenient form of light therapy which, as mentioned above, may be as effective as light box therapy. 

(1)Terman M & Terman JS.  2006.  Controlled trial of naturalistic dawn simulation and negative air ionization for seasonal affective disorder.  Am J Psychiatry.  163:2126-2133
(2) Avery DH et al.  2001.  Dawn simulation and bright light in the treatment of SAD: a controlled study.  Biol Psychiatry.  50:205-216
(3)Avery DH et al.  1993.  Dawn simulation treatment of winter depression: a controlled studyAm J Psychiatry.  150:113-117
(4)Avery DH et al.  2002.  Is dawn simulation effective in ameliorating the difficulty awakening in seasonal affective disorder associated with hypersomnia? J Affect Disord. 69(1-3):231-6.
Written By Ani Kowal

Following a healthy eating regimen during pregnancy is highly important for the health of both mother and unborn child.  A recent study (1) has emphasised that it is important for pregnant women to include plenty of vegetables as part of their diet.  The study found that daily vegetable consumption by pregnant women was associated with a reduced risk of type I diabetes (insulin dependent diabetes) in their children.

The study (1) assessed and followed 5724 infants and looked at the diet their mothers consumed during pregnancy.  The children were given assessments at age 1, 2.5 and 5 years of age for diagnosis of type 1 diabetes (insulin dependent diabetes).  Low daily consumption of vegetables by the pregnant mother (vegetables were eaten 3-5times per week) was associated to an increased risk of type 1 diabetes in the child when compared to a higher vegetable consumption during pregnancy.

In essence the study found that pregnant women who eat vegetables (at least once) every day seem to have children who are less likely to develop type 1 diabetes.  This is only an association study and does not prove that vegetables protect against diabetes but it is informative and further supports the importance of eating well during pregnancy.  In a press release (2) one of the study researchers commented "This is the first study to show a link between vegetable intake during pregnancy and the risk of the child subsequently developing type 1 diabetes, but more studies of various kinds will be needed before we can say anything definitive,"  "We cannot say with certainty on the basis of this study that it's the vegetables themselves that have this protective effect, but other factors related to vegetable intake, such as the mother's standard of education, do not seem to explain the link," "Nor can this protection be explained by other measured dietary factors or other known risk factors."  It therefore seems plausible that the myriad of nutrients and flavonoids in vegetables are having some kind of action within the growing foetus.

My interest in nutrition prior to, and during, pregnancy started when I was studying for my first degree.  We learned about the work of David Barker who was a researcher at Southampton University.  His hypothesis, which was known as ‘Barker’s hypothesis’ at the time, suggests that maternal diet affects foetal growth and is associated with chronic conditions in the child later in life.  It is suggested that what a pregnant mother consumes during pregnancy might affect the risk of her child developing conditions such as heart disease, stroke and diabetes (3).  This idea is now more widely known as the ‘Developmental Origins of Adult Health and Disease’ hypothesis.  Both over- and under- nutrition and eating during pregnancy can affect the growth and later health, and perhaps weight, of the child (4).  It is important to remember that what you eat during pregnancy not only affects you, the mother, it may also affect the health of the next generation and may directly contribute to cycles of obesity as well as other conditions (4)

As I have mentioned in previous posts relating to pregnancy, if you are pregnant you may wish to consider taking a multi-nutrient supplement specifically designed for pregnant women together with a fish oil (or flaxseed oil) supplement to provide omega 3 fatty acids.  Taking these sorts of supplements may help to make-up for any shortfalls in the diet but cannot be viewed as an alternative to a healthy diet.  Always check with your doctor of health professional before taking any supplements during pregnancy.

(1)Brekke et al.  2009.  Daily vegetable intake during pregnancy negatively associated to islet autoimmunity in the offspring-The ABIS study. Pediatric Diabetes, 2009; DOI: 10.1111/j.1399-5448.2009.00563.x Published Online: 16 Sep 2009
(2) University of Gothenburg (2009, October 27). Vegetables Can Protect Unborn Child Against Diabetes. ScienceDaily. Retrieved October 28, 2009, from http://www.sciencedaily.com/releases/2009/10/091027132422.htm
(3) Barker, D.J.P. (1997). "Maternal Nutrition, Fetal Nutrition, and Disease in Later Life". Nutrition, '13', pg. 807
(4)McMillen C et al.  2009.  Developmental Origins of Adult Health and Disease: The Role of Periconceptional and Foetal Nutrition.  Basic & Clinical Pharmacology & Toxicology.
102 (2): 82 – 89
Written by Ani Kowal

On Monday I wrote about omega 3 fats and how they are important for brain function and in protecting against and treating depression.  Today I wanted to look at a UK study which has just been published in the British Journal of Psychiatry (1).

The study authors (1) wanted to examine the association between overall dietary patterns and depression.  Data from over 3000 participants aged around 55 years was analysed.  Two main dietary patterns were found in the participants.  A ‘whole food’ pattern which was high in vegetables, fruit and fish and a ‘processed food’ pattern which was high in sweetened desserts, friend foods, processed meats, refined grains and high-fat dairy products.  Self reported depression was assessed in the study participants 5 years after the initial dietary analysis.  A special reputable scale, called the Center for Epidemiologic Studies – Depression (CES–D) scale, was used to make the assessment.  The study showed that participants who adhered most strongly to the ‘whole food’ pattern of eating had a significantly lower risk of depression.  Those individuals with the highest consumption of processed foods had the highest risk of depression.  The authors conclude “In middle-aged participants, a processed food dietary pattern is a risk factor for CES–D depression 5 years later, whereas a whole food pattern is protective”.(1)

The study is interesting as it looks at diet as a whole rather than individual nutrients or components.  The study shows that eating healthily and including a high proportion of vegetables, fruits and fish is associated with protection against depression in middle-age.  Processed and refined foods can not only damage our health they also seem to impact our mood.   Specifically, the researchers in the study found that (1) participants whose diet was high in processed foods had a 58% higher risk of receiving a CES-D depression rating five years later.  The study does not prove that a processed food diet causes depression, it simply shows an association or a link, it could be, for example, that people who become depressed become inclined to eat more processed foods or that there is a yet undiscovered factor behind the association.

However, the results of this study show a strong association and are interesting, when added to results from several other studies there is certainly a suggestion that a healthy diet does protect against mental illness.  Eating a high quality, healthy and nutritious diet is important for overall health an wellbeing.  Vegetables, fruits, beans/pulses, unprocessed meats and oily fish are important components to consider.  If you are concerned that your diet consistently falls short then you may wish to consider taking an omega 3 fatty acid supplement together with a good quality food-state multivitamin and mineral supplement.  It is important to be clear that supplements can never be viewed as a replacement for a healthy diet.

(1)Akbaraly TN et al.  2009.  Dietary pattern and depressive symptoms in middle age.  The British Journal of Psychiatry.  195:408-413
Written by Ani Kowal

If you were to search this blog you would notice that I have written extensively about mood, depression, mental health and the brain.  This area of nutrition excites and intrigues me greatly and I have specifically researched it and kept up to date with it, for over eight years now.  A key factor for mental health appears to be omega 3 fatty acids, specifically the long chain forms EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid) found in oily fish.

A professor that lectured me during my MSc (Nutritional Medicine) course back in 2001, Professor Basant Puri wrote a fabulous book that was published in 2005 entitled “The natural way to beat depression: the groundbreaking discovery of EPA to successfully conquer depression”  it details how the long chain omega 3 fatty acid, EPA can be used, in conjunction with other therapeutic techniques, to successfully treat depression.  At the time of publication Professor Puri had a 100% success rate of treating individuals with depression who had been unresponsive to other treatment.  An amazing statistic.  He has also written about the usefulness of omega 3 fats in the treatment of ADHD and chronic fatigue syndrome and was the first recorded person to use omega 3 fats to treat a depressive patient.

Today I wanted to look briefly at a few recent studies that have shown how useful long chain omega 3 fatty acids can be in the treatment of mood disorders.

Firstly (1) a study this year found that dietary intakes of fish and long-chain omega-3 fatty acids may be associated with a reduced risk of chronic depressive symptoms, especially in women.  The authors assessed the associations between fish consumption and dietary intakes of EPA and DHA with depressive symptoms in a population-based sample of 3317 men and women.  As a whole (in men and women together), the highest intakes of EPA, DHA, and EPA + DHA were associated with a lower risk of depressive symptoms after 10 years, with the observed associations being more pronounced in women.  This is an interesting association (but does not prove cause and effect) which adds to the building evidence base.

A review of 3 studies (2) found that omega-3 fatty acids were shown to be more effective than placebo for depression in both adults and children and in a study of bipolar depression. No significant side effects were reported in any of the studies.

Another study (3) looked specifically at psychological distress and depressive symptoms, which commonly occur in women during menopausal transition.  The authors of the study wanted to see whether treatment with EPA, compared to inactive placebo, was helpful to women with moderate to severe psychological distress.  This was the first study to look at omega 3 supplementation in the treatment of psychological distress in middle-aged women and it found that EPA was significantly more helpful than placebo to women with psychological distress symptoms (without major depressive episodes) after just 8 weeks of supplementation.

The evidence that depression is associated with abnormalities in fatty acid metabolism and deficiencies in omega 3 dietary fatty acid intake is accumulating and cannot be ignored.  The key important fatty acids are EPA and DHA, found in oily fish (e.g. salmon and mackerel).  If you do not regularly eat oily fish, such as salmon, trout, mackerel and sardines you may wish to seriously consider taking a daily fish oil supplement.  For vegetarians and vegans a flaxseed oil supplement could be considered. Also, there are now a couple of companies who make vegetarian and vegan EPA and DHA from algal sources, a very exciting development and well worth investigating if you wish to take an omega 3 supplement.

Some very interesting links concentrating on nutrition and mental health:

Mental health foundation, food and mental health campaign

Food and behaviour research

Food for the brain

(1)Colangelo LA et al.  2009.  Higher dietary intake of long-chain omega-3 polyunsaturated fatty acids is inversely associated with depressive symptoms in women. Nutrition. 25(10):1011-9.
(2)Osher Y, Belmaker RH.  2009.  Omega-3 fatty acids in depression: a review of three studies. CNS Neurosci Ther. Summer;15(2):128-33.
(3) Lucas M et al.  2009.  Ethyl-eicosapentaenoic acid for the treatment of psychological distress and depressive symptoms in middle-aged women: a double-blind, placebo-controlled, randomized clinical trial. Am J Clin Nutr. 89(2):641-51.
Written by Ani Kowal