Researchers compared test scores after three years of folic acid supplements to results after a placebo supplement in 818 older adults. Test scores showed memory improvements in the folic acid group. This group also had a slower decline in scores of other mental skills and muscle speed skills.
Folic acid -- also called folate -- is a B vitamin. It's found in leafy green vegetables such as spinach. In the U.S., folic acid is also added to enriched grain products such as flour, breads, cereals, and pasta.
Better Memory, Slower Mental Decline
How big were the differences in test scores? Here's a look at the folic acid group's test results after three years:
- Memory scores were that of someone five-and-one-half years younger.
- Scores on muscle skills were that of someone two years younger.
- Scores on an information-processing test were that of someone two years younger.
Folic acid didn't make a difference on word-fluency tests, say the researchers. They included Jane Durga of Wageningen University in the Netherlands.
About the Study
Participants were 50-70 years old. They took the supplement or a placebo for three years.
The folic acid dose was 800 international units per day. That's double the amount recommended for women of childbearing age to help avoid birth defects in newborns.
While none of the participants had low folate levels, they did have high homocysteine levels, an inflammatory marker linked to heart disease. Previous research suggests that high levels are linked with mental declines associated with Alzheimer's disease in elderly people.
High homocysteine levels have been associated with poor mental function and stroke risk. Another study found that high levels of homocysteine in the blood were a strong indicator of stroke risk.
'Low' Health Risks for Most People
The risk of health problems from folic acid supplements is "low," says a folic acid fact sheet from the Office of Dietary Supplements (ODS). Excess folic acid usually leaves the body in urine, says the ODS, which is part of the National Institutes of Health.
Anyone taking such medications should consult a medical doctor before taking a folic acid supplement, says the ODS.