Reducing / delaying risk of dementias:
Homocysteine blood levels.
Elevated blood levels of homocysteine — a type of amino acid produced
by your body — may increase your risk of developing Alzheimer's disease
and vascular dementia. When working properly, your body breaks down
homocysteine using vitamins B-6, B-12 and folic acid (B-9). If this isn't
happening properly, it may be because you don't metabolize these
vitamins well, or you don't have enough of them in your diet. Blood
tests can determine whether you have elevated homocysteine levels.
Lower
your homocysteine levels. Early research has shown that high doses of
three B vitamins — B-9 folic acid, B-6 and B-12 — help lower
homocysteine levels and appear to slow the progression of Alzheimer's
disease.
http://www.globalhealingcenter.com/natural-health/folic-acid-foods/
http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/9-foods-rich-in-vitamin-b6.html
http://www.healthaliciousness.com/articles/foods-high-in-vitamin-B12.php
Reduce Homocysteine levels:
http://www.medicinenet.com/script/main/mobileart.asp?articlekey=20052