- A significantly better mean change in global cognitive function (0.050, 95% CI 0.004 to 0.096, P=0.033).
- A significant comparative improvement in memory (0.132, 95% confidence interval 0.032 to 0.233, P=0.010).
- A significant difference in information processing speed (0.087, 95% CI 0.016 to 0.158, P= 0.016),
- A significantly better sensorimotor speed for the folic acid(Drug information on folic acid) than the placebo group (0.064, 95% CI -0.001 to 0.129, P=0·055).
- Similar information processing speeds between groups (0.037, 95% CI -0.049 to 0.122, P=0.40).
- No significant difference in word fluency between groups (-0.070, 95% CI -0.188 to 0.048, P=0.245).
On the basis of these findings, the researchers said, folic acid appeared to affect age-related aspects of cognitive function.
"The effect of folic acid might be restricted to basic aspects of speed and information processing, rather than high order information processing," Dr. Durga and colleagues wrote. "Word fluency was not affected by folic acid supplementation, perhaps not surprisingly, because encyclopaedic memory is a component of crystallised intelligence that stays relatively intact as one grows older."
Folic acid conferred the mental performance of a younger person for the older adults, even after adjusting for sex and education. These findings were:
- 4.7 years younger for memory overall (95% CI 1.1 to 8.3).
- 6.9 years younger for delayed-recall memory (95% CI 2.1 to 11.8).
- 1.7 years younger for sensorimotor speed (95% CI -0.04 to 3.4).
- 2.1 years younger for information processing speed (95% CI 0.4-3.7).
- 1.5 years younger for global cognitive function (95% CI 0.1 to 2.8).