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By Bonnie Jenkins, Advanced Natural Medicine
If you or a friend or relative have survived a heart attack or stroke, you know that life afterwards is forever changed. A victim of cardiovascular disease (CVD) lives in fear of when the next attack might strike. And if you haven't been stricken yet, count your blessings – because in the United States alone, someone suffers a heart attack every 20 seconds, and a stroke every 53 seconds.
The pharmaceutical industry offers plenty of temporary fixes, including statin drugs for reducing cholesterol, aspirin for thinning the blood and anti-hypertension medications for reducing blood pressure. Essentially, they all help prolong the life of a patient with CVD. But none of these drugs is without risk or side effects. And none of them fight the very cause of atherosclerosis – homocysteine.
Although I’ve talked about homocysteine in past bulletins, several readers have asked for a more detailed explanation they can take to their doctors. It seems that, even though high homocysteine levels are an even greater risk factor for CVD than high cholesterol, most doctors don’t test for it. But they should – especially in their older patients, since homocysteine levels naturally rise as we age.
What’s Inside Your Vessels?
First, let’s tackle the basics. Homocysteine is a by-product of the amino acid methionine, which is naturally found in food and your body. If the right cofactors are present, it will eventually convert to cysteine and other beneficial compounds. If the cofactors are lacking, it will build up to toxic levels, generate free radicals that increase injury to the arterial walls, and accelerate oxidation and the buildup of cholesterol in blood vessels, setting the stage for heart attack and stroke.
Here’s what happens: Homocysteine sets off a dangerous chain of events by irritating the inner lining of arteries and veins. Eventually, the inside of the arteries and veins become rough instead of smooth. As they become diseased, the inner arterial wall thickens and results in arteriosclerosis. Cells lining the artery proliferate and combine with protein and lipids in a mass called an atherosclerotic plaque. Plaques are typically the first sign of cardiovascular disease. With time, plaques gather cholesterol and fat, finally becoming atheromas. Atheromas distort the artery wall, allowing for calcification. When an atheroma blocks blood to the heart, it is referred to as a heart attack. When it blocks blood to the brain, it is a stroke.
If that weren’t enough, it was recently reported that homocysteine interferes with the production of nitric oxide, a substance that impairs the blood vessels' ability to dilate — which also contributes to the risk of heart attack and stroke.
The Aging-Alzheimer’s Link
A recent study at the National Institute on Aging found that homocysteine does more than just damage the arterial wall. As a major consequence of folic acid deficiency — a particular problem with the elderly — elevated homocysteine impairs DNA repair.
People with elevated levels of homocysteine also have nearly double the risk of developing Alzheimer's disease, according to a new report from scientists at Boston University. The findings, in a group of people participating in the long-running Framingham Study, are the first to tie homocysteine levels measured several years before with later diagnosis of Alzheimer's and other dementias. The report, which appeared in the New England Journal of Medicine, provides some of the most compelling evidence yet of an association between high plasma homocysteine and eventual significant memory loss.
Another report published last year reiterates the finding that a high level homocysteine in blood serum and spinal fluid have consistently been found in individuals who suffer from Alzheimer's disease.
B Wise
Luckily, there’s a simple (and natural) fix. Since most people with a high homocysteine level don't get enough folic acid, vitamin B6 or B12 in their diet, supplementing with these vitamins helps return homocysteine to normal levels.
In 1969, Kilmer S. McCully, M.D. of Harvard Medical School found that heart patients had nearly 80 percent less vitamin B6 than healthy individuals. As a result of his work, he postulated that B6 might help protect the arteries from the damage that precedes heart disease. In addition, a deficiency of vitamin B12 is associated with elevated homocysteine levels and folic acid is essential for its proper metabolism.
It’s estimated that by supplementing with just 400 mcg. of folic acid daily the number of heart attacks suffered by Americans each year would be reduced by 10 percent. It’s also estimated that individuals with low vitamin B6 levels have a five times greater risk of having a heart attack than individuals with higher B6 levels!
More than 20 case-control and cross-sectional studies on more than 2,000 subjects have provided what Harvard epidemiologist Meir J. Stampfer, MD, calls "remarkably consistent" findings regarding the relationship between homocysteine levels and cardiovascular diseases. Specifically, patients with stroke and other cardiovascular diseases tend to have higher blood levels of homocysteine than subjects without disease. Dr. Stampfer points out that homocysteine levels do not have to be elevated by very much to increase risk, since most of the patients in these studies had levels that were within what is generally regarded to be the normal range.
Decades after Dr. McCully's breakthrough study, the data continues to pour in. One of the largest studies was reported in the 1992 report from the Physician's Health Study. The study, which included 14,916 male physicians, found that men whose homocysteine levels were in the highest five percent were three times more likely to have a heart attack over a five-year period than men with lower homocysteine levels.
One Last Thing . . .
So here’s the bottom line – have your doctor order a blood test to check your homocysteine levels. While most labs claim that anything under 15 micromoles per liter (mmol/L) is in the normal range, new evidence is emerging that homocysteine levels above seven cause a progressive risk of heart attack.
What do the numbers mean? In one study of 248 patients, Dutch researchers found that each 3-mmol/L increase in homocysteine caused a 35 percent increase in heart attack risk. And since homocysteine levels increase substantially as we get older, it’s important to know where you stand.
Unfortunately, even though the test is FDA-approved, Medicare won’t cover it because it doesn’t believe that the test is “medically reasonable and necessary.” But some private insurers will, so you might want to check with your insurance company. If you do have to pay out-of-pocket to have your level tested, the average cost is $185. But it just may be the best money you ever spent.
This Just In . . .
If you think that soy protein is just for vegetarians and athletes, think again. According to a small trial, soy protein could help diabetics protect their hearts and kidneys from damage caused by the disease.
The crossover randomized clinical trial was conducted on 14 Type II diabetes patients with nephropathy (diabetes-related kidney damage). The patients were asked to follow a diet typically recommended to control nephropathy, including protein based on 70 percent animal and 30 percent vegetable protein for seven weeks.
After a washout period of four weeks consuming the pre-study diet, the subjects were readmitted to repeat the same cycle with a similar diet containing 35 percent soy protein and 30 percent vegetable protein.
The patients saw a significant reduction in total cholesterol, triglyceride and LDL-cholesterol after following the soy diet. And while there were no significant changes in HDL-cholesterol, and LDL-HDL ratio, the researchers reported a favorable effect on renal function.
If you or someone you know suffers from Type II diabetes, you know that the disease can dramatically increase your risk of heart and kidney damage. But, by making a few small changes in your diet (like opting for a soy-based burger instead of a Whopper), you just might boost the odds in your favor.
References:
Klerk M, et al. “Effect of homocysteine reduction by B-vitamin supplementation on markers of clotting activation.” Thrombosis and Haemostasis. 2002;88:230-235.
Mattson MP, et al. “Folic acid and homocysteine in age-related disease.” Ageing Research Reviews. 2002 Feb;1(1):95-111.
“Soy protein has protective effect for diabetes patients.” NutraIngredients. 22 October 2003.
Teunissen CE, et al. “Biochemical markers related to Alzheimer's dementia in serum and cerebrospinal fluid.” Neurobiological Aging. 2002; Jul-Aug;23.
Verhoef P, et al. “Homocysteine metabolism and risk of myocardial infarction: relation with vitamins B6, B12, and folate.” American Journal of Epidemiology. 1996;143:845-859.
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