RESEARCH - Folate supplements improve cognitive function

[Guest guest]

Folate supplements improve cognitive function

Sat Jan 20, 2007 4:51 AM GMT

NEW YORK (Reuters Health) - Among older adults with elevated levels of blood

homocysteine, 3 years of folic acid supplementation improves cognitive

function to levels generally seen in people several years younger, results

of a Dutch study suggest.

High levels of the amino acid homocysteine are associated with an increase

risk of heart disease, stroke and other vascular disease. Evidence also

suggests that homocysteine affects atherosclerosis by damaging the inner

lining of arteries and promoting blood clots. Furthermore, previous studies

have found that folic acid supplements lower homocysteine levels.

Low folate levels are believed to be one of several modifiable risk factors

for age-related cognitive decline, lead author Dr. Jane Durga, currently

with the Nestle Research Center in Lausanne, Switzerland, and her associates

in the Netherlands note in their paper, published in The Lancet.

The Folic Acid and Carotid Intima-media Thickness (FACIT) trial included 818

subjects 50 to 70 years old who were likely to benefit from folate's

homocysteine-lowering effect. Subjects with low blood levels of homocysteine

and those with homocysteine levels caused by factors other than low folate

were excluded.

The participants were randomly assigned to folic acid at 800 micrograms per

day or placebo. Blood folate levels at the beginning of the study averaged

12 nanomoles per liter, but by 2004, had risen to 76 nanomoles per nanomoles

per liter, while in the placebo group, it remained at 13 nanomoles per

liter. This was a statistically significant difference.

The average total plasma homocysteine level was 13.0 micromole per liter in

the folate supplement group and 12.9 micromoles per liter in the placebo

group. This declined to 10.1 micromoles per liter in the folate group and

rose to 13.4 in the placebo group, also a statistically significant

difference.

The subjects completed a variety of cognitive tests at the beginning and the

end of the study. Compared with the placebo group, the folate group had

significantly less decline in sensorimotor speed, information-processing

speed, and complex speed. The folic acid group also improved significantly

more than their counterparts in memory and word fluency.

The researchers determined that patients who received folic acid supplements

performed the tests as well as people 4.7 years younger for memory, 1.7

years younger for sensorimotor speed, 2.1 years younger for information

processing speed, and 1.5 years younger for global cognitive function. "

Delayed memory -- which the authors point out is the most clinically

relevant measure of cognitive performance -- was improved by folate to match

the performance of a person nearly 7 years younger.

The researchers point out that people with high homocysteine levels are more

likely to benefit than those with low levels. They also point out that the

large study population, the low attrition rate, the prolonged study period,

and exclusion of subjects with dementia, helped generate a greater response.

Nevertheless, they still recommend confirmation of their results by other

investigators in other populations.

In an accompanying commentary, Drs. Martha Clare and C.

Tangney at Rush University, Chicago, agree, advocating " inclusion and

exclusion criteria that target individuals at various stages of nutrient

balance. "

The results would be even more meaningful, they add, if biochemical

concentrations of folate and folate metabolites were monitored along with

cognitive function.

SOURCE: The Lancet, January 20, 2007.

http://today.reuters.co.uk/news/articlenews.aspx?type=healthNews & storyID=2007-01\

-20T045125Z_01_MCC017460_RTRIDST_0_HEALTH-FOLATE-SUPPLEMENTS-DC.XML & WTmodLoc=Sci\

Health-C4-Health-8

Not an MD