Homocysteine is an amino acid that can be measured with a simple blood test. The study, which appeared in the Journal of Affective Disorders in August 2013, studied 358 people aged 50 and up who had symptoms of depression.
They gave the subjects cognitive tests that looked at immediate and delayed memory, as well as global cognitive performance. They measured total plasma homocysteine, red blood cell folate levels and serum vitamin B12. Seventy-one participants had homocysteine levels exceeding 13 micromoles per liter (high). This group got lower scores on the cognitive tests than the rest of the subjects. Their level of depression (such as major depression vs. depressive symptoms) did not matter. They were also found to have lower median levels of vitamin B12 and folate.
Homocysteine can be lowered by supplementing with folic acid and vitamin B12. This may mean that older adults can head off cognitive impairment by getting adequate amounts of these nutrients.
Editor’s Note: Consult with your doctor before supplementing with these nutrients. Vitamin B12 is found naturally in red meats, nutritional yeast, and dairy products. It can be stored by the body, and it is possible to over-dose. Supplementation may be needed for vegetarians. Folic acid, also known as folate, is added to most breakfast cereals and found in a wide variety of foods. Liver, yeast, spinach, Brussels sprouts and asparagus have high levels of folic acid.
Study: Homocysteine, depression and cognitive function in older adults by Fordemail et. al. Journal of Affective Disorders Volume 151, Issue 2 , Pages 646-651, November 2013.