Week of February 17 - February 23, 2008

Two new studies make a clear connection between folate levels and Alzheimer's risk.

USA

The first study was anounced by Columbia University investigators in New York. The study is published in the January issue of the Archives of Neurology and was led by Dr. José A. Luchsinger, MD, from The Taub Institute for Research of Alzheimer's Disease and the Aging Brain at Columbia University in New York City.

The team studied 965 Manhattan residents without dementia, aged 65 and older, who receive Medicare. Participants underwent physical and psychological examinations, including neuropsychological testing, from 1992 to 1994. During that period, 192 subjects developed Alzheimer’s disease.

As part of the study, researchers tracked the amount of folate consumed by the participants as part of their diet and through supplements. The conclusion: higher folate intake was associated with lower risk of developing Alzheimer’s disease.

"When we looked at supplements and diet separately, we did not find a statistically significant effect," said Dr. Luchsinger. "But when we looked at them in combination, it appeared that it is a person's total intake [of folate] that is associated with this protective effect."

KOREA

The second study comes from the other side of the world in Korea. There, folate deficiency was associated with a tripling in the risk of developing dementia among elderly people, as suggested by research published in the Journal of Neurology Neurosurgery and Psychiatry.

The researchers tracked the development of dementia in 518 people over two years from 2001 to 2003. All participants were over the age of 65 and lived in one rural and one urban area in the south of the Republic of Korea. The research was conducted by Chonnam National University Medical School, in Kwangju.

Validated tests were carried out at the start and end of the two year period to find out if they had dementia.

Similarly, blood tests were used to assess levels of folate, vitamin B12, and the protein homocysteine, and how these changed over time. (High levels of homocysteine have been associated with cardiovascular disease.) At the start of the two year period, 3.5% were folate deficient.

By the end of the study, 45 people had developed dementia. Of these, 34 had Alzheimer’s disease, seven had vascular dementia, and four had “other” types of dementia. Dementia was more likely in those who were older, relatively poorly educated, inactive, and had deposits of the protein ApoE.

The onset of dementia was significantly more likely in those who initially had low folate levels, and whose folate levels then fell further over the two years. People who were folate deficient to begin with, were almost 3.5 times more likely to develop dementia.

NOT 100% CLEAR

What remains unclear is whether a low level of folate increases the risk of Alzheimer's, or low folate levels are caused by already being in a "pre-stage" of Alzheimer's.

The Korean authors suggest that changes in micronutrients could be linked with the other typical signs that precede dementia, including weight loss and low blood pressure. While weight loss is unlikely to alter micronutrient levels in the blood, it may indicate dietary changes effecting the quality of food intake.

The American author said, "At this point, this is just an observational study. We need randomized controlled trials before we can make any inferences of cause and effect."

In summary, a spokesman for the Alzheimer’s Society said: ‘It is too early to advise people to start popping folate supplements. Until we see results from a rigorous clinical trial it is impossible to say whether low folate levels are a cause or effect of dementia. In the meantime we would recommend sticking to a healthy balanced diet rich in essential B vitamins and antioxidants.’

With that said, one thing is clear: Eat right by including foods rich in folate (also known as vitamin B9), such as dark-green leafy vegetables and folate-enriched breads and cereals. It's a key ingredient to good brain health.

More Information:

Folate Facts from the U.S. Government's National Institutes of Health

Sources:

Archives of Neurology, January 2008

Journal of Neurology Neurosurgery and Psychiatry, of the British Medical Journal Specialist Journals, February 5, 2008

EurekAlert

Folic Acid Foils Dementia, saga.com

By:

By Peter Berger, Alzheimer's Weekly

Reviewed for medical accuracy by
Dr. B. Ancselovits, MD, Geriatrician, Alzheimer's Weekly

Copyright:

Copyright © 2008 Alzheimer's Weekly LLC. All rights reserved.