In one study, Fredrik Jerneren, PhD, of Oxford University, United Kingdom, and his colleagues from several other nations, studied 168 men and women age 70 and older. All of the subjects had been diagnosed with mild cognitive impairment (MCI), a common prelude to Alzheimer’s disease.
About half of the subjects took several B vitamins—800 mcg folate, 20 mg vitamin B6, and 500 mcg vitamin B12—and the others took placebos daily for two years. They also underwent brain magnetic resonance imaging scans at the beginning and end of the study.
Jerneren and his colleagues analyzed the results in terms of the subjects’ blood levels of the omega-3 fats.
In people with high levels of the omega-3s, the B vitamins slowed brain atrophy by 40 percent. However, the B vitamins had no significant effect on brain atrophy among people with low blood levels of the omega-3s. In addition, high blood levels of the omega-3s had no effect on brain atrophy in the placebo group.
Jerneren wrote that he and his colleagues “have shown that the effect of B vitamin supplementation on brain atrophy rates depends on pre-existing plasma omega-3 fatty acid concentrations; this finding could possibly explain why some B vitamin trials on brain function have failed.”
In a second report, Rhonda P. Patrick, PhD, and Bruce N. Ames, PhD, of the Children’s Hospital Oakland Research Center, California, studied why the omega-3 fats—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—and vitamin D improve cognitive and brain function in a range of disorders.
“This synergy of omega-3 and vitamin D can be explained in part by their effects on the serotonin system,” they wrote, adding that “vitamin D regulates serotonin synthesis, EPA influences serotonin release, and DHA improves...serotonin receptor accessibility.”
They noted that the neurotransmitter serotonin affects a broad range of brain activities, including cognition, mood, decision making, and impulsive and aggressive behavior. “This may explain why supplementation with these essential micronutrients has been shown to be effective for treating symptoms associated with attention-deficit hyperactivity disorder, bipolar disorder, schizophrenia, impulsive disorder, depression, and obsessive-compulsive disorder,” they added.
Patrick and Ames added that vitamin D and omega-3 supplements are safer and have fewer side effects than such drugs as Prozac and Zoloft.