Vitamin B and Folate to Fight Off Alzheimer's?

Summarized by Robert W. Griffith, MD
October 26, 2005

This is a slightly-edited version of one of the Patient Pages published by the medical journal 'Neurology'. The original was written by Elizabeth Roaf, MD and Janet Jankowiak, MD. Robert Griffith, HealthandAge.com Editor.

Introduction

Researchers are always looking for risk factors for developing Alzheimer's disease, and a group working in Bologna, Italy, has studied the relevance of homocysteine. So, too, have workers at Tufts University, Boston, USA. Both groups obtained similar results, so that we can attach considerable importance to their findings.

The Italian Study

Over 800 healthy older men and women were studied. Their average age was 74. At the start of the study they had their plasma homocysteine levels measured, along with vitamin B12 and folate levels. Information was obtained on social and health history - education level, smoking, high blood pressure, cardiovascular disease, and diabetes. The subjects were followed for an average of 4 years, during which time dementia developed in 112 of them - 70 of these had Alzheimer's, and the others had vascular or some other dementia. Analysis showed that those participants who had a raised homocysteine level at baseline (above 15 micromol/L) were over twice as likely to develop dementia (Alzheimer's or vascular dementia) than those with a normal homocysteine level. Low serum folate concentrations were also associated with increased risks of dementia and Alzheimer's disease, though to a lower degree. Both these factors - increased homocysteine and decreased folate - were independent of each other, and of possible bias from social and medical circumstances.

The Tufts Study

This study involved 321 men of average age 67 at baseline. They were free of heart disease, and had no major health problems. Dietary intake was assessed using a 126-item questionnaire, and blood was taken for vitamin B vitamins and homocysteine levels. At baseline, four tests of mental ability were done - working memory, recall, verbal fluency, and spatial copying (copying a 3-dimensional drawing). The tests were repeated 3 years later, with analysis of the differences between the first and second sets. A decline in spatial copying scores was associated with high levels of homocysteine and low levels of folate, vitamin B6, and vitamin B12, as well as with a low dietary intake of these vitamins. High levels of plasma folate and high dietary folate intake were protective against this decline in spatial copying, as well as against a decline in verbal fluency. Finally, a high homocysteine level was linked to a decline in recall memory. In this study, all the associations observed were independent of each other and existing social or medical conditions.

What These Two Studies Tell Us

These studies provide evidence of an association between elevated homocysteine blood levels and a decrease in cognitive function, which can lead to dementia. However, it's still uncertain whether the increase in homocysteine is merely a 'marker' for folate and/or other B vitamin deficiencies. The Tufts scientists claim that homocysteine itself may be toxic to nerve cells or interfere with their functioning, but the findings don't necessarily prove this. The relationships between the different B vitamins and homocysteine will be clarified in future studies. In the meantime, to help avoid mental decline and dementia, people should make sure their intake of folate, B12, and B6 is adequate. Most cereals sold today are fortified with these vitamins, and offer an easy way to meet this goal.

So what works, and what doesn't?

Most of the treatments listed above don't have any evidence supporting their use, and are unlikely to be better than taking a 'wait-and-see' attitude. Steroid injections, manipulation, and exercise may have short-term benefits. And for long-term improvement, look to physical therapy combined with ultrasound, deep-friction massage, and exercise.

But a wait-and-see approach (with occasional analgesics, as necessary) is likely to be quite satisfactory in the majority of cases. For people who have to carry on working, braces or splints may provide relief from pain, but steroid injections are not advisable.

We hope that the unsatisfactory options available for treating tennis elbow will lead to the development of more effective treatments, which will be shown to work well in carefully designed clinical trials.

Sources

• Homocysteine and folate as risk factors for dementia and Alzheimer disease. RG. Ravaglia , FP. Forti , MF. Maiola ,  et al., Amer J Clin Nutr, 2005, vol. 82, pp. 636--643



• High homocysteine and low vitamin B vitamins predict cognitive decline in aging men: the Veterans Affairs Normative Aging study. TKL. Tucker , ON. Oaio , ST. Scott ,  et al., Amer J Clin Nutr, 2005, vol. 82, pp. 627--635

Related Links
Vitamin E and Alzheimer's
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