What is Homocysteine?

Q. Coronary Artery disease (CAD) runs in my family. I was told by a friend of mine to have my homocysteine levels checked to see if I also have CAD. What is homocysteine? What levels would indicate I had CAD? and are there natural ways to lower it so I don't develop CAD?

A. Before I go into a little more detail, let me start by saying that Ischemic Heart Disease (IHD) and Coronary Artery Disease are two terms used interchangeably to describe a very similar process. Truth be told, IHD, which is in basically reduced blood flow to the heart muscle, is most commonly due to CAD, which is atherosclerosis of the coronary blood vessels (plaque causing clogged vessels). Homocysteine levels are not enough to diagnose IHD or CAD alone, but they can tell you if you are at a higher risk of having or developing these problems. Read on...

What is Homocysteine?
Homocysteine is an amino acid similar in structure to cysteine. Homocysteine is bio-synthesized from methionine, which it can be recycled back into (or converted into similar cysteine) with the aid of B-vitamins. It is for this reason, that a deficiency in some B vitamins, specifically, folic acid (B9), pyridoxine (B6) or cobalamin (B12) can lead to high levels of homocysteine. Without them, these recycling and conversion processes cannot continue and homocysteine is left to rise.

Homocysteine levels can be high genetically, as well. In a condition known as homocysteinuria, an enzyme integrally involved in the breakdown pathway of homocysteine is deficient. This condition is normally diagnosed in childhood and causes developmental delay, osteoporosis, visual abnormalities, blood clot and severe atherosclerosis. There are more mild forms of this problem in which homocysteine rises more gradually due to a less than efficient conversion process.

Homocysteine levels are measured via blood. Normal levels range from 5-15 micromoles per litre. 15-30 micromoles/l is considered moderate, anything over 100 is considered severely high (all numbers in the middle of these ranges are termed intermediate.). Research has definitively shown that supplementing with the previously mentioned B-vitamins, along with something called TMG (or glycine betaine, found in high amounts in quinoa, spinach, wheat bran, lamb and beef, or taken as a supplement) can reduce homocysteine concentration in the blood. What has not been proven unequivocally is whether this decrease will repair existing damage to the artery architecture.

Homocysteine and Ischemic Heart Disease (IHD)/Coronary artery Disease (CAD)
Increased levels of homocysteine in the blood (sometimes referred to as Homocysteinemia) are a risk factor for heart disease. Some research has shown there is actually a dose dependent relationship, meaning that for each 5 micromoles that homocysteine is increased, the risk of IHD increases by 33%. This relationship seems to be stronger in younger persons than in older. It is believed that the excess homocysteine causes damage to the lining of the arteries and therefore promotes clots.

Studies conducted on individuals with existing IHD and the use of folic acid to lower homocysteine have shown that although homocysteine is effectively lowered by supplementation, there is no change in mortality outcome. Some studies have shown that there is a decreased risk of stroke, while overall death rate in these studies did not change. Similar studies have found no risk or benefit from using homocysteine in groups with preexisting artery deterioration. This being said, the effects of lowering homocysteine may best be observed in terms of preventative medicine, which few studies to date have focused on. If individuals who are shown to have increasing homocysteine levels intervene and decrease these levels BEFORE heart disease sets in, the outcome (or lack of heart disease development, in this case) may prove beneficial.

How do I lower Homocysteine?
Folic acid, B6 and B12 can be taken together in a B-complex supplement, or taken individually. It is worth noting that the older we get the more difficult it is to absorb B12. Elderly individuals may benefit from higher doses orally, or may want to consider intramuscular injections, done by most Naturopathic doctors. Foods high in folic acid include leafy greens, such as spinach, asparagus and turnip greens, legumes, baker's yeast/nutritional yeast, fortified cereals, sunflowers seeds and liver. B6 and B12 are found in fortified cereals, and most meats (B6 can also be found in spinach and bananas).

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