On 15th October I wrote about the connection between B vitamins and healthy bones and I also mentioned how elevated homocysteine levels may be implicated in bone deterioration and heart disease.  Today I want to look at the link between elevated homocysteine levels, low vitamin B12 levels and cognitive (mental) decline.

To recap: Homocysteine is produced when the amino acid (the building blocks of protein) methionine is broken down in the body.  Normal levels of homocysteine are important to help build and maintain body tissues, however elevated concentrations in the blood can be harmful and have been associated with an increased risk of many disorders.  At normal levels homocystein can be converted in the body into a harmless substance called cystanthionine.  The conversion of homocysteine into this harmless substance depends upon various B vitamins  (B6, B12 and folic acid).  Having good levels of these B vitamins appears to be a very good way of preventing high homocysteine levels and low levels of B vitamins have been associated with raised homocysteine levels.

A new study (1) was recently published which showed that older adults who have vitamin B12 levels that are low, but still within the normal range, may exhibit a quicker rate of brain shrinkage (brain volume loss) as they age compared to those who have good levels.  The authors wanted to investigate the association between vitamin B12 status and brain volume loss in a population of adults aged 61-87 over a 5 year period.  The participants were free of cognitive impairment (they were free of dementia) at the start of the study.  Those with lower vitamin B12 levels at the start of the study experienced the greatest decrease in brain volume over the 5 year period.  This was only a small preliminary study involving 107 individuals, the authors suggest that low vitamin B12 status should be further investigated and that trials with vitamin B supplements would be useful.

A loss in brain volume has been linked to a faster rate of mental decline and progression to diseases such as Alzheimer’s disease and dementia.  Vitamin B12 is extremely important in order to keep nerve cells healthy.  The study mentioned above (1) suggests, but does not prove, that modifying vitamin B12 status could be important in protecting the brain and preventing cognitive decline.  The results of the study do suggest that it is important to keep our vitamin B12 levels higher than just the minimum.

A study last year (2) looked at the association between cognitive decline and vitamin B12.  The study included 1684 individuals who were followed for 10 years.  Mental state (cognition) was examined a minimum of 3 times over the 10 years as were serum vitamin B12 concentrations.  Analysis of the results found that reduced vitamin B12 status was associated to cognitive decline.  The investigators also found that a high homocysteine level was associated with a greater rate of cognitive decline.  Again the authors indicate the need for further studies and supplementation trials for the prevention of dementia.

A review (3) paper published this year discussed the importance of vitamin B12 for brain health throughout life from infancy to adulthood.  In childhood low vitamin B12 levels may be related to behavioural problems and in adults it seems to be related to social development, depression and cognitive problems.  It seems as though this nutrient really is vital throughout our lifespan. 

Many older adults in the UK have lowered vitamin B12 levels.  In the diet, B12 comes from meat, fish, dairy, other animal products, and fortified breakfast cereals. Strict vegetarians, who avoid meat, and vegans, who avoid all animal products, are also at risk of B12 deficiency.  Studies seem to suggest that anything in the stomach that affects the normal acidity and digestive processes, ranging from infections to acid reflux medications to aging, may also interfere with the absorption of vitamin B12. 

The vitamin B group work very well as a team and interact in many processess, if you decide to take a supplement it may well be worth considering a multi-B vitamin supplement rather than single B vitamin supplement, or a broad spectrum multi-nutrient supplement (I prefer food state supplements which appear to be more easily absorbed by the body).

(1) Vogiatzoglou A et al.  2008.  Vitamin B12 status and rate of brain volume loss in community-dwelling elderly.  Neurology.  71:826-832
(2)Clarke R et al.  2007.  Low vitamin B-12 status and risk of cognitive decline in older adults.  Am J Clin Nutr.  86:1384-1391
(3)Black MM.  2008.  Effects of vitamin B12 and folate deficiency on brain development in children.  Food Nutr Bull.  29:S126-131

Written by Ani Kowal

On the 22 October I mentioned the potential use of Vitamin D supplements for helping individuals suffering from the mood disorder SAD (seasonal affective disorder).  This year a number of papers have been published (1,2,3,4) which suggest that vitamin D could potentially be useful for the treatment of other mood disturbances and depressive episodes.

In 2007 a review paper was published (5) which suggested that vitamin D deficiency may play a role in depression and other mood and mental health disturbances, especially in the elderly where low vitamin D levels are commonly found.  The paper highlighted a number of trials that which showed that vitamin D supplementation appeared to be useful in the treatment of depression but expressed a need for further studies.

Vitamin D seems to be a hot topic this year and I have written about it a number of times in my blog posts.  Low vitamin D levels seem to be linked to cancer, heart disease, SAD, chronic fatigue syndrome, migraine headaches and various other diseases, not only bone conditions such as osteoporosis and osteoarthritis.  It is becoming glaringly obvious that this ‘sunshine vitamin’ is more important than we once thought. 

Two studies this year have linked low vitamin D status, as measured by low circulating blood levels of vitamin D, with depressive symptoms.  One study (1) was carried out in overweight and obese individuals and the other (3) in older adults (aged 65 – 95 years).  Both studies found that there was an association between depression status and severity with decreased serum (blood) vitamin D levels.  In the study with overweight/obese participants high-dose vitamin D supplementation led to significant improvements in depressive symptoms, compared to placebo, during the study.  The studies so not prove a causal relationship between low vitamin D and depression but they do add to the mounting evidence which suggests a very real link.  Further, larger studies will be needed to verify the information and investigate this exciting association further.

It is not currently known why vitamin D may be useful in treating mood disorders or why low levels may have a part to play in causing mood problems.  It may be that vitamin D has an effect on hormones linked to mood.  Studies are bound to unravel the mystery over the next few years!

A recent analysis(6) 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 (7,8,9,10).  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. 

Walking and exercise have also been linked to improved mood, so a lunchtime walk, in daylight, may bring added mood lifting benefits.  Only small amounts of vitamin D are found in food sources such as oily fish (mackerel, salmon and sardines) and eggs.  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.

You may also want to think about getting a daylight lamp for your work desk to help improve mood.  Some of these lamps produce light that the body can use for vitamin D production (check with the manufacturer of the lamp).

For more interesting information about the benefits of vitamin D and sunlight for health please visit the Sunlight Nutrition And Health Research Centre, the information there is well presented and backed up by significant amounts of good evidence.

(1)Jorde R et al.  2008.  Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial.  J Intern Med. Sep 10. [Epub ahead of print]
(2)Murphy PK & Wagner CL.  2008.  Vitamin D and mood disorders among women: an integrative review.  J Midwifery Womens Health.  53:440-446
(3)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.
(4)Johnson MA et al.  2008.  Vitamin D deficiency and insufficiency in the Georgia Older Americans Nutrition Program.  J Nutr Elder.  27:29-46
(5)Berk M et al.  2007.  Vitamin D deficiency may play a role in depression.  Med Hypotheses.  69:1316-1319
(6)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]
(7) Finch S et at.  1998.  National Diet and Nutrition Survey of People aged 65 Years and Over.  London: H. M. Sationery Office.
(8) 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
(9) 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
(10) 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

Last week I wrote about light box therapy, and other ideas, for improving mood in SAD (seasonal affective disorder).  A more conventional approach to SAD is pharmaceutical antidepressant therapy with, for example, SSRI (selective serotonin reuptake inhibitors) type antidepressants which include fluoxetine (Prozac) and paroxetine (Paxil, Seroxat).  However, these drugs come with certain side effects (including an increased risk of suicide attempts) and their effectiveness has also been questioned.  For these reasons, many individuals seek alternative ways of dealing with low mood.  One well recognised natural agent is the herb St John’s wort (Hypericum perforatum).  Historically this plant has been used as a remedy for the treatment of depression and there is now quite a bank of medical and scientific evidence(1) confirming the effectiveness of this herb for aiding various mood disturbances.

St John’s wort is a shrubby perennial plant with bright yellow flowers, named after St John the Baptist.  Ancient Greeks and Romans believed that the herb could deter evil spirits but today it is mainly used as a natural, alternative to antidepressants.  The herbal supplements are made from the dried flowers of the plant.  The herb has been routinely used in Germany for many years where doctors and health practitioners frequently prescribe supplements for depression.

Very recently a paper was published (1) reviewing the available evidence for the use of St John’s wort in the treatment of depression.  The review included 29 high quality studies (randomised and double-blind) from a variety of countries, the studies included a total of 5489 patients and ranged from 4 weeks to 12 weeks in length.  The researchers found that, for people suffering from mild to moderate depression, St John’s wort can provide effective relief, similar to that of standard antidepressants but with fewer side effects. 

The authors note, and it is important to state, that people suffering from depressive symptoms (including a low mood, loss of interest or pleasure in life and activities) who wish to use a St John’s wort product should ALWAYS consult a doctor.  The quality of products available on the market varies widely and the herb can interact with other medications so it is always best to check with a medical practitioner before embarking on a treatment plan.

The antidepressant properties of St John’s wort are thought to be ascribed to the compounds hypericin and hyperforin that are contained within the herb.  It is not entirely known how the herb works to lift the mood but it seems to act on certain ‘feel-good’ brain chemicals (known as neurotransmitters) such as dopamine, serotonin and noradrenaline.

The typical recommended dose is 300mg of St John’s wort extract three times a day for supplements standardised to contain 0.3% hypericin.  One a day supplements containing 900mcg hypericin are also available.  ALWAYS check with a doctor before taking the herb.  It may take 4 weeks before you see any benefit.  Side effects are uncommon, however in people with fair skin it is advisable to avoid prolonged exposure to sunlight whilst taking the herb.

The herbal supplement also seems useful for the treatment of other mood disturbances such as anxiety, apathy, insomnia, stress and SAD, if you think you could benefit from taking St Johns wort I would suggest chatting with a health professional prior to undertaking a supplementation regimen.
 

(1)Linde K et al.  2008.  St John’s wort for major depression.  Cochrane Database of Systematic Reviews Issue 3. Art. No.: CD000448. DOI: 10.1002/14651858.CD000448.pub3

Written by Ani Kowal

Iron deficiency anaemia is the most common nutritional deficiency worldwide, affecting around 2 billion people.  Here in the UK the National Diet and Nutrition Surveys have revealed that most children under the age of 18 have dietary iron intakes below the RNI (reference nutrient intakes).  This is very worrying as iron is important for normal neurodevelopment (development of the brain and nervous system) and deficiency, with or without anaemia, in infants and children appears to adversely affect social and emotional development, intellectual performance and concentration span and has been linked to ADHD (Attention Deficit Hyperactivity Disorder), hyperactivity, aggressiveness, poor mood and fatigue.

The most recent study was published in an American journal in May(1).  The study leader, Dr Betsy Lozoff, is a leading researcher in the field of iron deficiency in childhood.  The researchers looked at the social and emotional behaviour in a group of infants who were 9 months old at the start of the study.  Tests confirmed that around a third of the children had iron deficiency anaemia, a third had iron deficiency without anaemia and a third had sufficient iron levels.  All infants then received a 3 months course of liquid iron supplement.  The supplement was given to all infants, even those with sufficient iron levels in order to prevent deficiency during their transition to being fed cows milk (which is very low in iron). 

At 12 months the infants were assessed.  Those with poorer iron status were more shy, harder to sooth, less likely to be engaged in their surroundings and less likely to orientate themselves in their surroundings.  The associations were present in iron deficient infants regardless of anaemia status.  Dr Lozoff concludes that the results need to be confirmed in larger trials but her findings do add to the ever growing body of evidence that links iron deficiency in children and developmental problems.

Iron is essential in the diet as it is used by the body in the manufacture of the blood protein haemoglobin, which is responsible for the transport of oxygen from the lungs to all cells in the body so that they can generate energy.  If iron levels are very low it can cause a condition in the body called iron deficiency anaemia.  This can be checked via tests which screen for haemoglobin in the blood.  However, individuals can become deficient in iron without becoming anaemic.  Iron deficiency without anaemia is widespread and not detected by the most commonly used screening procedures.  Both deficiencies are related to low mood, fatigue and mental ‘slowness’ in adults(2,3) and a host of behavioural and mental developmental issues in children(4).  It is not entirely understood why iron deficiency is linked to childhood behavioural issues, such as ADHD, but it may be related to the fact that iron is essential for the normal development of the brain and the functioning of dopamine, a brain chemical.  The most accurate way to check for overall iron status is to screen for ‘serum ferritin’ levels, this will pick up on iron deficiency (with or without anaemia).

In infants breast feeding for less than 6 months duration, the use of non iron-fortified infant formula and the introduction of cow’s milk before 1 year of age are risk factors for iron deficiency and in children dietary deficiency is common.  There are two forms of dietary iron: Haem iron (found in meat sources) and non-haem (found in non-meat, vegetarian sources) iron; and the extent to which iron from food is absorbed depends upon the form it is in.  Haem iron is the most easily absorbed form.  However, absorption is greatly affected by other factors. Most importantly vitamin C, found abundantly in fruits and vegetables, is important in promoting the absorption of non-haem iron.  Adding fruits and vegetables high in vitamin C to a meal may triple iron absorption from foods such as wholegrain cereals and pulses.  On the contrary tea and coffee reduce the amount of iron that is absorbed from all foods.  Try avoiding tea and coffee with meals as they can reduce iron absorption by 50%.  Calcium also reduces iron absorption, drinking a glass of milk with a meal can also half iron absorption.  Phytic acid (also known as inositol hexaphosphate) found in peanuts, wholegrains and seeds can greatly reduce the absorption of iron. 

For individuals who are vegetarian or rarely consume meat, wholegrain cereals, eggs, nuts, dried fruit and pulses (beans and peas) will provide adequate iron if consumed as part of a high vitamin C containing meal.  If you are relying on non meat sources of iron you may wish to consider taking a 100-200mg vitamin C supplement with your main meal to ensure good absorption.

Iron is a nutrient that can accumulate in the body and an excess can be damaging so ALWAYS get iron levels checked prior to embarking on a supplementation programme.  When asking the doctor for a test for yourself or your child, be sure to ask for a ‘serum ferritin’ test (rather than a test for anaemia) as this will provide a better indication of bodily iron status. 

Unfortunately, in the UK there is no consensus among doctors as to what a ‘normal’ blood ferritin level should be.  Many doctors who regularly employ complementary medicine would suggest that in children a ferritin level of less than 30ng/ml (30ng ferritin per 1ml blood) or 50mcg/l in adults would indicate a deficiency.  If you have any concerns do talk them through with your GP.

(1)Lozoff B et al.  2008.  Dose-response relationships between iron deficiency with or without anemia and infant social-emotional behaviour.  J Pediatr.  152:696-702
(2)Khedr E et al.  2008.  Iron states and cognitive abilities in young adults: neuropsychological and neurophysiological assessment.  Eur Arch Psychiatry Clin Neurosci. Jun 20. [Epub ahead of print]
(3)Patterson AJ et al.  Dietary and supplement treatment of iron deficiency results in improvements in general health and fatigue in Australian women of childbearing age.  J Am Coll Nutr. 2001 Aug;20(4):337-42
(4)Lozoff B et al.  2006.  Long-lasting neural and behavioral effects of iron deficiency in infancy.  Nutr Rev.  64(5 Pt 2):S34-43; discussion S72-91

Written by Ani Kowal

New research(1) has just emerged from Baycrest which shows that adults with type 2 diabetes who eat unhealthy, high-fat, meals may experience memory declines immediately afterward, but this may be offset by taking antioxidant vitamin supplements together with the meal.

Baycrest is an academic health sciences centre, affiliated with the University of Toronto, which is internationally-renowned for its research on aging and the conditions associated with ageing such as memory loss, depression and stroke.

The study authors make reference to the fact that there is already a growing body of evidence that links diabetes to cognitive (mental) complications in humans.  Adults with type 2 diabetes seem especially vulnerable to acute memory deficits after eating unhealthy foods.  This latest study suggests that taking high doses of antioxidant vitamins C and E with such meals may help minimize those memory slumps.

One of the study authors, Michael Herman Chui, said “Our bottom line is that consuming unhealthy meals for those with diabetes can temporarily further worsen already underlying memory problems associated with the disease”.

The study was a very small preliminary trial that involved only 16 adults (with an average age of 63) with type 2 diabetes who were not regularly taking antioxidant supplements.  They attended three weekly sessions that involved consuming a different test meal on each visit. One meal consisted of high fat foods (a Danish pastry, cheddar cheese and yogurt with added whipped cream); the second meal consisted of only water; and the third test meal was the same high-fat meal plus vitamin C (1000 mg) and E (800 IU) supplements.

After eating the meal, participants completed a series of tests that measured their recall abilities for words they had heard and paragraph information they had read.  It was found that vitamin supplementation consistently improved recall scores.  Compared to those who consumed only water or the meal with antioxidant vitamins, participants who ate the high fat meal showed significantly more forgetfulness (of words and paragraph information) in immediate and time delay recall tests. 

The study authors emphasize that their findings obviously require further replication in much larger trials. Future studies will also need to look at how the antioxidant vitamins may be working.  Personally, I would also like to see further trials using antioxidant foods, such as fruits and vegetables, in conjunction with meals to test if the same benefits are seen as with supplementation (I have a feeling results would be very positive)!

Type 2 diabetes is associated with persistent, long term oxidative stress, a known major contributor to cognitive (mental) decline and Alzheimer disease. Consuming unhealthy foods can induce this type of stress which is triggered by elevations of free radicals: unstable molecules that can damage body tissue, including brain tissue. These destructive reactions tend to occur over a 1-3 hour period after the ingestion of food.  Fruits and vegetables contain numerous antioxidant nutrients and can minimise oxidative stress, it is important to include such foods as an integral part of all meals.  This study showed that antioxidants could reduce immediate memory deficits caused by unhealthy eating.

Dr. Carol Greenwood, senior author of the study, cautioned that relying on antioxidant vitamins at meal time is not a quick fix. “While our study looked at the pill form of antioxidants, we would ultimately want individuals to consume healthier foods high in antioxidants, like fruits and vegetables” (well said!).

An overall healthy lifestyle is important in maintaining optimal mental health at all ages.  This includes regular exercise, staying mentally active, being socially engaged in a variety of activities as well as adopting a healthy diet rich in fruits, vegetables and healthy fats found in oily fish, nuts and seeds.

(1) Chui MH & Greenwood CE.  2008.  Antioxidant vitamins reduce acute meal-induced memory deficits in adults with type 2 diabetes.  Nutrition Research.  28 (7): 423-494
(2) Baycrest press release

Written by Ani Kowal

Last weekend (18/05/08) The Sunday Times ran a story entitled “Superfood celery combats brain diseases”.  Quite timely I thought, as I was in the middle of preparing a post on the important role that dietary flavonoids , also known as bioflavonoids  (a group of over 4000 types of polyphenol plant compounds), play in maintaining mental health e.g. memory, learning and general mental performance.  The newspaper article focussed on the flavonoids, luteolin and diosmin, found in celery and how they may be important in slowing the progress of brain diseases such as Alzheimer’s disease.

A recently published medical review paper(1) brought together evidence for the role of dietary derived flavonoids and mental health.  In this paper Dr Jeremy Spencer, a researcher and lecturer at my old University, highlights a number of studies in both humans and animals which have found that flavonoids, from a variety of dietary sources such as grapes, tea, blueberries, cocoa, onions, broccoli and tomatoes (to name but a few), have beneficial effects on cognitive (mental) performance.  He postulates that the benefits come from the ability of the flavonoids to protect brain neurones, reduce neuronal inflammation, enhance neuronal function and even stimulate neuronal regeneration (regrowth). 

The paper is extensive, however I would just like to mention one study that is reviewed(2).  In this study 1640 individuals, all over the age of 65, were followed for ten years and their dietary habits assessed over that time.  All of them were free of dementia at the start of the study.  Cognitive (mental) performance was examined four times over the ten year period.  Flavonoid intake was associated with a significantly better cognitive performance at the start of the study and throughout the study period.  The individuals with the highest flavonoid intakes were found to have better preservation of mental performance with ageing than subjects with the lowest intakes of flavonoids.  After 10 years the individuals with the lowest intakes were found to have lost an average of 2.1 points on a test of mental performance (the Mini-Mental State Examination) compared to those with the highest intakes who had lost on average only 1.2 points.  Such data provides a strong indication that regular dietary flavonoid consumption may have a positive effect on preserving mental performance with ageing.

As Dr Susanne Sorensen of the Alzheimers Society is quoted as saying in the newspaper “we know a healthy balanced diet can reduce dementia risk.  This work reinforces the need to eat a diet rich in fruits and vegetables”.  There are many dietary factors which can contribute to a healthy brain and positive mood and I am sure that I will address these factors in my future writings!

It is clear that a diet rich in a variety of different vegetables and fruits is really very important for all aspects of health.  There is NO substitute for a diet plentiful in a variety of vegetables and fruits.  Choosing produce with a mixture of colours will provide an array of different flavonoids.  Flavonoid supplements do exist and these may be helpful to take in addition to a healthy diet as a means of boosting intakes.  If you do choose to take a supplement look out for one that provides an assortment of many different flavonoids (they may be labelled as bioflavonoids).

(1) Spencer JPE.  2008.  Food for thought: the role of dietary flavonoids in enhancing human memory, learning and neuro-cognitive performance.  Proceedings of the Nutrition Society.  67:238-252
(2) Letenneur L et al.  2007.  Flavonoid intake and cognitive decline over a 10 year period.  Am J Epidemiol.  165:1364-1371

Written by Ani Kowal