What is Homocysteine?

Homocysteine is an amino acid which is not obtained from the diet.  It is derived from an essential amino acid called methionine.  Homocysteine is important because at higher levels, it is toxic to the lining of your blood vessels, called endothelium.  Do you have any idea how much endothelium you’ve got in your body?  If you were to lay all your blood vessels out flat side by side, they would cover the surface area of more than three tennis courts!  A high level of homocysteine causes inflammation of this important lining which can lead to the development of atherosclerotic plaques and blood clots.  For this reason, many cardiologists nowadays consider homocysteine to be a more powerful predictor of heart disease than your cholesterol level.  Elevated homocysteine levels are also associated with strokes, depression and cognitive deficits, as well as osteoporosis.¹

Homocysteine level can be tested with a simple blood test.  The upper acceptable limit for most labs in BC is 13, but a lower number is better.  I recommend a level under 9 for optimal health, as there appears to be no safe threshold level.

Fortunately, homocysteine can be converted back into methionine.  This requires enzymes, vitamins B6, B12, and folate.  The concentration of homocysteine in the blood declines with the supplementation of these vitamins, as well as supplements of betaine and SAMe.  A current trial called the B-VITAGE Trial is underway right now in Australia to determine whether the systematic use of B-vitamins will improve the response of older adults to standard antidepressant treatment.²  Preliminary results are showing those with high homocysteine levels were almost twice as likely to show cognitive decline on several tests.  It is suggested that nutritional supplements to lower homocysteine may actually improve cognitive performance.

If you’ve never had your level of homocysteine tested, you may want to ask your doctor about it.

1.     Refsum H et al, The Hordaland Homocysteine Study, J Nutr. 2006 Jun;136(6 Suppl):1731S-1740S
2.     Ford AH et al, Homocysteine, Depression, and Cognitive Function in Older Adults, J Affect Disord. 2013 Aug 5 pii: SO165-0327(13)00565-X