Category Archives: homocysteine

More evidence points toward the importance of vitamin B12 to protect against Alzheimer’s disease

In November  I mentioned a study which found that supplemental B vitamins which lowered homocysteine levels in the body might be useful to help elderly individuals with mild cognitive [mental function] impairment.  A recent study (1) has found that Vitamin B12 may help protect against Alzheimer’s disease.  The results of the research suggests that elderly individuals with more of the active part of the vitamin B12 in their blood have a lower risk of developing the disease.  However, the findings don’t necessarily mean that taking B vitamin supplements will stave off mental decline.

To recap on homocysteine:

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 heart disease and other 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. 

The study (1)was set up in order to examine the relationship between blood serum levels of homocysteine and holotranscobalamin (holoTC), the active part of vitamin B12, and risk of incident Alzheimer disease in a sample of community-dwelling elderly.  The research involved over 250 individuals aged between 65 and 79 years old who were free of dementia.  The participants were followed-up for seven years and any cases of Alzheimer’s disease were recorded.   The study scientists then looked to see if there was any association between the serum homocysteine levels, Vitamin B12 levels and Alzheimer’s disease.  The study found that for each micromolar (1 µmol/L) increase in the concentration of homocysteine, the risk of Alzheimer’s disease increased by 16%, whereas each picomolar (1 pmol/L) increase in concentration of the active form of vitamin B12 reduced risk by 2%. The results stayed the same after taking into account other factors, such as age, gender, education, smoking status, blood pressure, stroke and body mass index. The addition of folate did not appear to raise or lower the risk of Alzheimer’s disease.  From the results the authors conclude “This study suggests that both tHcy [homocysteine] and holoTC [vitamin B12] may be involved in the development of AD [Alzheimer’s disease]. The tHcy–AD link may be partly explained by serum holoTC. The role of holoTC in AD should be further investigated(1)

In a press release Babak Hooshmand, one of the study scientists, said (2) “Our findings show the need for further research on the role of vitamin B12 as a marker for identifying people who are at increased risk of Alzheimer’s disease,” “Low levels of vitamin B12 are surprisingly common in the elderly. However, the few studies that have investigated the usefulness of vitamin B12 supplements to reduce the risk of memory loss have had mixed results.

 

The findings of this trial are very interesting but further large-scale research is needed in order to test whether  vitamin B12 supplements can be recommended as a suitable treatment for the prevention of cognitive decline and dementia.   Dr Hooshmand said in the press release “More research is needed to confirm these findings before vitamin B12 should be used solely as a supplement to help protect memory,”

Vitamin B12 is found mainly in meat, fish and poultry.  Eggs and cheese also contain B12 as does brewer’s yeast.  Many vegetarians and vegans have very low intakes of this vital nutrient and may wish to consider a multi-B vitamin supplement.  Folic acid is found in beans, green vegetables and wholegrains.  Vitamin B6 is found in foods like potatoes, bananas, beans and chickpeas, avocados, fish and poultry.  Supplements should never be seen as an alternative to a healthy diet.  If you wish to investigate the option of taking B vitamins it is best to discuss this with your medical doctor first.   

 

(1) B. Hooshmand B et al.  2010.  Homocysteine and holotranscobalamin and the risk of Alzheimer disease.  A longitudinal study.   NEUROLOGY 2010;75:1408-1414

(2) Press Release.  American Academy of Neurology (2010, October 19). Vitamin B12 may reduce risk of Alzheimer’s disease. ScienceDaily. Retrieved December 6, 2010, from http://www.sciencedaily.com­ /releases/2010/10/101018162922.htm

 

 

Written By Ani Kowal

 

Share

Folate might impact cholesterol levels

Folate (the naturally occurring form of folic acid), a B vitamin, is one that I have written a lot about, it has been linked to heart health, mood, pregnancy outcomes and much more.  In July I wrote about the B vitamins, folate and vitamin B12, being linked to heart disease

There has been a lot of research interest in the links between B vitamins and risk of cardiovascular disease (stroke and heart disease) over the last decade.  The rationale behind this is that there is evidence to suggest that elevated homocysteine levels are a risk factor for heart disease and low levels of the B vitamins B6, folate and B12 are linked to raised homocysteine levels.  For more information on homocysteine please click here

A recently published study(1) has found that folate may also be linked to cholesterol levels (another potential risk factor for heart disease).  The study looked at data for blood vitamin B12 and folate levels in over 1700 individuals.  They found that higher folate levels were associated with lower levels of low density lipoprotein cholesterol (LDL-cholesterol, the so called ‘bad’ cholesterol which has been linked to an increased risk of heart disease).  They also found that higher levels of folate were linked to higher levels of ‘good’ cholesterol, high density lipoprotein cholesterol (HDL-cholesterol).  The study authors also compared the individuals of the highest with those of the lowest levels of folate. They found that individuals with the highest folate  had higher levels of HDL-cholesterol, lower levels of LDL-cholesterol and a lower LDL-C: HDL-C- ratio, this is indicative of a favourable cholesterol profile.  In this study Vitamin B12 was not associated with the cholesterol profile.

The study authors call for more research to further investigate the link between folate and cholesterol levels.  The current study only provides a potential link, it does not prove that low folate levels are linked to raised LDL cholesterol levels.  The study does provide further evidence to suggest that there may also be a link between cholesterol and homocysteine levels, other studies have also suggested such a link.  These are very complex interactions and further research to elucidate links could provide really useful information on how diet can be used to reduce the risks of heart disease.

At the present time there is no conclusive evidence to suggest that B vitamins can reduce the risk of heart disease and supplements cannot be recommended as a preventative measure.  Having a good level of B vitamins in the diet is, however, important for health.  Vitamin B6 is found in foods like potatoes, bananas, beans and chickpeas, avocados, fish and poultry.  Vitamin B12 is found mainly in meat, fish and poultry.  Eggs and cheese also contain B12 as does brewer’s yeast.  Folic acid is found in beans, green vegetables and wholegrains. 

Supplements should never be seen as an alternative to a healthy diet and it is wise to check with you doctor before starting any new supplement regiment.  If you are thinking about taking a vitamin B supplement I would always suggest a broad spectrum supplement that supplies adequate, but not megadose, levels of all of the B vitamins (not single nutrient supplements), these vitamins work best together as a team

(1)Semmler A et al.  2010.  Plasma folate levels are associated with the lipoprotein profile: a retrospective database analysis.  Nutrition Journal.  9:31E-pub prior to print.  doi:10.1186/1475-2891-9-31 Published 28 July 2010

Written by Ani Kowal
Share

Higher folate levels recently linked to reduced risk of hearing loss

I have mentioned folate a lot in my blog posts but mainly in relation to women, especially pregnant women.  However, recent research presented at the at the 2009 American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF) Annual Meeting & OTO EXPO, in San Diego, CA(1) has found that high folate intakes in men may be associated with a 20% decreased risk of hearing loss.



The study(1) involved 3,559 cases of men with hearing loss.  The study authors found that men over the age of 60 who have a high intake of foods and supplement high in folate had a 20% decrease in risk of developing hearing loss.  The authors believe this is the largest study to delve into the relation between dietary intake and hearing loss. They also believe their findings could allow for greater education, prevention, and screening efforts in a bid to prevent hearing loss.  Further studies would certainly be necessary as this study only shows an association and not cause and effect. 



Ten years ago a small study in women (2) found that poor folate levels were associated with age-related decline in hearing.  The study was conducted in 55 healthy women aged 60-71.  The women were tested for hearing function and categorised into two groups – those with normal hearing and those with impaired hearing.  Women with impaired hearing had a 31% lower blood level of folate than women with normal hearing.  In addition to this study a couple of years ago a research team (3) found that folic acid supplementation seemed to slow the decline of low-frequency hearing in folate-deficient, older adults.  The objective of this study was to determine whether folic acid supplementation slows age-related hearing loss.  728 men and women were involved.  Subjects received daily oral folic acid (800 micro-grams) or placebo supplementation for 3 years.  Folic acid supplementation slowed the decline in hearing of the speech frequencies associated with aging in a population (but did not affect the decline in hearing high frequencies).  The authors note that the results need to be replicated in further larger studies but that folic acid supplementation seemed to slow the decline of low-frequency hearing in folate-deficient, older adults.



Folic acid may be playing a role in the prevention of age-related hearing loss by improving blood circulation to the artery that supplies blood to the cochlea of the ear.  In addition, folic acid is also related to lowering elevated homocysteine levels.  Elevated homocysteine could be related to age-related hearing loss.  Most people are aware that high levels of homocysteine in the blood have been linked to an increased risk of heart problems.  Recently high homocysteine levels have also been linked to poor bone health, poor eye health (such as age-related macular degeneration) and other health problems.  To recap from my past blog posts: 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.



Foods particularly rich in folate include leafy vegetables such as spinach, asparagus, turnip greens, lettuces, dried or fresh beans and peas, fortified cereal products, sunflower seeds, yeast extract, liver and liver products.  Vitamin B6 is mainly found in meat, fish and eggs.  Vitamin B12 is found in liver, meats, eggs, milk and yeast extract. 


Vegetarians and vegans and those who feel they are not eating a varied, balanced diet may wish to consider taking a multiple B vitamin supplement to ensure good levels of these important B vitamins


 


(1)American Academy of Otolaryngology — Head and Neck Surgery (2009, October 6). Higher Folates, Not Antioxidants, Can Reduce Hearing Loss Risk In Men. ScienceDaily. Retrieved October 6, 2009, from http://www.sciencedaily.com/releases/2009/10/091005161116.htm
(2)Houston DK et al.  1999.  Age-related hearing loss, vitamin B-12, and folate in elderly women.  American Journal of Clinical Nutrition.  69(3):564-571.
(3) Durga J et al.  2007.  Effects of folic acid supplementation on hearing in older adults: a randomized, controlled trial.  Ann Intern Med.  146(1):1-9.
Written by Ani Kowal

Share

Dietary advice for eyesight preservation

Currently it is Save Your Vision Month in America, a campaign run by the American Optometric Association (1).  The role that diet plays in preserving our eyesight is highly important and certainly worth a loud mention.  In August last year I wrote about cataracts and age related macular degeneration (AMD) and mentioned how diet, particularly omega 3 fatty acids from oily fish and antioxidants from vegetables and fruits, was important in preventing these conditions and preserving good eyesight.   In the UK Age-related Macular Degeneration (AMD) is the leading cause of blindness, with 45% of those registered as blind suffering from the disease.  For more info on AMD please read my previous blog post.



Very recently a paper was published (2) suggesting that B vitamins, particularly folic acid, vitamin B6 (also known as pyridoxine hydrochloride) and vitamin B12 (cyanocobalamin) may be particularly important for good eye health.  The study was conducted since previous research had indicated the links between homocysteine concentrations in the blood and the risk of age related macular degeneration (AMD).



I have previously written about homocysteine.  Most people are aware that high levels of homocysteine in the blood have been linked to an increased risk of heart problems.  Recently high homocystein levels have also been linked to poor bone health and other health problems.  To recap from my past blog posts: 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.



The researchers of the eye health study (2) wanted to examine the incidence of AMD in a trial of combined folic acid, vitamin B6 and vitamin B12 therapy.  The trial was well designed and involved over 5000 women aged 40 or older with no diagnosis of AMD at the start of the trial.  These women received either a daily placebo supplement or a supplement containing 2.5mg folic acid, 50 mg vitamin B6, and 1g vitamin B12.  After around 7 years of treatment and follow-up it was found that the women receiving the supplement had a significantly reduced risk of AMD.   The women taking the multi-B vitamin supplement were around 35% less likely to develop AMD than those taking the placebo.



The research seems to support the idea that taking a multiple B vitamin supplements is useful for sight preservation.  It is not entirely clear whether the B vitamins worked to protect eyesight simply via lowering homocysteine levels.  These vitamins may have also been working via exerting antioxidant effects or by improving blood vessel function.  Further studies would be necessary to evaluate these ideas and strengthen data before strong recommendation for B vitamin supplementation can occur.


In the diet the B vitamins may be found in the following sources (vegetarians and vegans may wish to consider a multiple B vitamin supplement):
Vitamin B6 – Mainly found in meat, fish and eggs
Vitamin B12 – liver, meat, eggs, milk, yeast extract
Folic acid – liver, orange juice, green vegetables, nuts



Continuing with the theme of eye health.  Scientists at the University of Liverpool (3) have recently announced that the degeneration of sight caused by AMD could be reduced by up to 20% through dietary changes alone, specifically through the increase of vegetables, fruits and nuts in the diet.  Professor Ian Grierson, Head of Ophthalmology at the University of Liverpool, has produced a comprehensive cooking guide called ‘Fruit for Vision’, designed to add fruit and vegetables into everyday meals.  The recipes were formulated in order to help AMD sufferers slow down the degeneration process by increasing micronutrient, vitamin and antioxidant intake in the diet. Non-sufferers can also use the book to add fruit, nuts and vegetables into each meal to protect against the disease.


Professor Grierson said (3): “Poor eating habits have a huge impact on health in general and the health of your eyes is no exception. Eye problems such as AMD, cataract and even glaucoma can all be affected by what we eat. But a relatively minor change in diet – adding a little more fruit into our meals – can make a profound difference and can keep eye diseases like AMD at bay for up to 20% longer.  There are of course other risk factors related to AMD such as age, light exposure, smoking and being overweight. But if we can improve the kind of food that we eat, we could dramatically reduce the number of people who may suffer from eye diseases in the future.”


Fruit for Vision is published by Indigo Creative Marketing and the Macular Disease Society. It provides easy recipes that incorporate fruit and nuts in to the diet. The recipes suggest minor additions to what we already eat, rather than major dietary changes.



Over in America, the AOA has also released information (4) in order to highlight the importance that diet and nutrition play in eye health.  The AOA highlights six nutrients important for eyesight:
Lutein, Zeaxanthin, Essential fatty acids, Vitamins C, Vitamin E, Zinc  
 
In their press release the AOA mention the following food sources of these specific nutrients:
Lutein and zeaxanthin: Colorful fruits and vegetables such as broccoli, spinach, kale, corn, green beans, peas, oranges and tangerines
Essential fatty acids: Oily fish like trout, salmon, sardines, or herring, nuts and seeds, whole grain foods, chicken and eggs
Vitamin C: Fruits and vegetables, including oranges, grapefruit, strawberries, papaya, green peppers and tomatoes
Vitamin E: Vegetable oils, such as safflower or corn oil, almonds, pecans, sweet potatoes, and sunflower seeds
Zinc: Lean red meat, poultry, liver, shellfish, milk, baked beans, and whole grains



(1)American Optometric Association (AOA)
(2)William G. Christen, ScD et al.  2009.  Folic Acid, Pyridoxine, and Cyanocobalamin Combination Treatment and Age-Related Macular Degeneration in Women.   The Women’s Antioxidant and Folic Acid Cardiovascular Study.  Arch Intern Med.169(4):335-341.
(3)University of Liverpool – press release

(4) Open Your Eyes To Healthy Eating Habits – press release by the AOA


Written by Ani Kowal

Share

New evidence points toward the importance of B vitamins for bone health

On Monday I wrote generally about bone health.  Today I wanted to highlight the relatively recent research linking various B vitamins to bone health and strength. 



Scientists have been interested in preventing heart disease with the use of B vitamins for a while now.  This stems from the mounting research which suggests that elevated homocysteine levels are a risk factor for heart disease.



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 heart disease and other 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



Just recently research has been published (2,3) which suggests that B vitamins may also be important for the health of our bones and that elevated homocysteine levels may be implicated in bone deterioration.



In one study (2) the researchers wanted to examine the associations of blood plasma concentrations of folate, vitamin B12, vitamin B6, and homocysteine with bone loss and hip fracture risk in elderly men and women.  The study included a total of 1002 men and women with the average age of 75, their blood levels of B vitamins were measured at the start of the study and they were followed for 4 years.  Bone loss was associated with low vitamin B6 levels and low levels of vitamins B12 and B6 were associated with hip fracture risk.  The participants with high homocysteine levels also had a higher risk for hip fracture.



The study suggests that both low vitamin B status and high homocysteine levels may be a risk factor for hip fracture.  The authors of the study conclude that it is not entirely clear why or how B vitamins or homocysteine are related to bone health or fracture risk and that clinical trials with B vitamin supplements may help to provide more information. 



I find the results of the study very interesting as they highlight another area where nutrition is linked to health.  An overall healthy diet rich in a variety of unprocessed foods really does provide nutrients to all cells in the body.  Bones rely on essential nutrients as much as any other part of us!  All the cells in our body require regular, good supplies of the whole spectrum of nutrients.  A healthy diet really is important for so many reasons!



Vitamin B6 is found in foods like potatoes, bananas, beans and chickpeas, avocados, fish and poultry.  Vitamin B12 is found mainly in meat, fish and poultry.  Eggs and cheese also contain B12 as does brewer’s yeast.  Many vegetarians and vegans have very low intakes of this vital nutrient and may wish to consider a multi-B vitamin supplement.  Folic acid is found in beans, green vegetables and wholegrains.  If you decide you would like to take a vitamin B supplement I would always suggest a broad spectrum supplement that supplies adequate, but not megadose, levels of all of the B vitamins (not single nutrient supplements), these vitamins work best together as a team!


 


(1)The National Osteoporosis Society
(2)McLean R et al.  2008.  Plasma B Vitamins, Homocysteine, and Their Relation with Bone Loss and Hip Fracture in Elderly Men and Women.  J Clin Endocrinol Metab.  93: 2206-2212
(3)Cagnacci A et al.  2008.  Relation of folates, vitamin B12 and homocysteine to vertebral bone mineral density change in postmenopausal women. A five-year longitudinal evaluation. Bone.  42(2):314-20.


Written by Ani Kowal

Share