Why do B vitamins seem to be so crucial to our cognitive and overall health? Lower levels of the Bs correlate with high levels in the blood of a substance known as homocysteine. Scientists have for decades been looking into whether high homocysteine increases the risk for heart disease becuase of evidence that it can contribute to clogged arteries.
Now Tufts researchers have also found that elevated homocysteine might predispose people to impaired cognitive ability, possibly by clogging arteries that lead to the brain as well as to the heart.
(Source: Tufts University Health & Nutrition Letter)