Protect Your Heart: Lower your Homocysteine

Homocysteine
Folic Acid
Vitamin B6
The Perils of Vitamin B12 Deficiency

An elevated levels of homocysteine is associated with increased cardiovascular risk. Homocysteine is a substance that is normally converted into harmless amino acids by your body. The metabolism of homocysteine is facilitated by three B vitamins-folate (probably the most important one), B6 and B12. If the conversion does not take place rapidly enough due to a genetic defect or a vitamin deficiency, then arterial walls are damaged and plaque can build up leading to blockages of key arteries. Elevated levels of homocysteine increase the risk for heart attack or stroke (Bots et al., Arch Intern Med, 1999).

Homocysteine

The lower your homocysteine level the better off you may be; some studies suggest that a homocysteine level below 10 ugmole/ml is preferred. But the test is expensive (up to $170). You can lower your homocysteine levels by ingesting more folic acid and vitamins B6 and B12. Folacin can be found in either folate, which comes from plants, or folic acid which is the supplemental form. Folic acid is about twice as potent as folate so 400 micrograms of folic acid is the equivalent of 800 micrograms of folate. Both folate and B6 are found in leafy greens, whole grains, some fruits, and fortified breakfast cereals. Since January 1998, all white flour, breads, pasta, white rice, grits, and cornmeal are fortified with folic acid. People age 50 and older need to make sure they don't get more than 1,000 mcg per day (the new upper intake level specified by the DRIs) because folic acid can mask a vitamin B12 deficiency.

A number of studies on homocysteine point to the importance of folate vitamins B6 and B12 on preventing heart disease.

In the ongoing Nurses Health Study (JAMA, 2/4/98), researchers asked more than 80,000 women without heart disease about their diet and lifestyle at four times over 14 years. Those who had consumed more than 400 mcg of folate per day had the lowest risk of heart attack or dying of heart disease. Further, the lowest heart disease rates were found among those whose B6 intake was more than 3 mg a day.

Similarly, Omenn and colleagues (Circulation, 1998) measured the blood levels of folate, vitamin B6 and homocysteine in 800 healthy volunteers, and 750 people with vascular disease (e.g., stroke, coronary artery disease). They found that those with vascular disease had high homocysteine levels compared to the healthy volunteers. In men, high homocysteine was also significantly associated with low folate levels. Further, although many people with vascular disease did not have high homocysteine levels they often had low B6 levels. This latter finding suggests that low blood levels of B6 may contribute to heart disease even among those with normal homocysteine levels.

Folic Acid

People diagnosed with heart disease may want to make sure they consume about 400 mcg of folic acid per day. Malinow and colleagues (NEJM, 1998) found that individuals with heart disease who ate an ounce of cereal fortified with 400 mcg of folic acid had an 11 percent decrease in homocysteine. But those who ate an ounce of typical breakfast cereal containing 100 mcg of folic acid experience not significant drop in homocysteine.

Vitamin B6

Most supplemental doses of the B-vitamins are safe at high doses because they are watersoluble. B6 is the exception. Daily doses of B6 that are higher than 100 mg can cause a (reversible) nerve toxicity that leads to difficulty walking, clumsiness, numbness or burning, shooting, or tingling pains. The RDA for B6 is only 2 mg.

The Perils of Vitamin B12 Deficiency

About 15 percent of Americans age 65 and older are deficient in vitamin B12. Older adults should be routinely screened for vitamin B12 deficiency by having their blood checked. Vitamin B12 is an essential nutrient for the development and maintenance of the nervous system and the formation of red blood cells. When left untreated, a vitamin B12 deficiency can lead to irreversible neurological damage, including permanent dementia, disorientation. Anyone with neurologic problems such as confusion, memory loss, hallucinations or muscle weakness should be tested for a vitamin B12 deficiency. Otherwise these symptoms may lead to a false diagnosis of Alzheimer's disease or multiple sclerosis.

Symptoms of B12 Deficiency:

• Fatigue
• Confusion
• Memory Loss
• Dementia
• Numbness or tingling in the extremities
• Weakness in arms or legs
• Loss of muscular coordination
• Sore tongue
• Loss of appetite
• Weight loss
• Forgetfulness

Our bodies cannot make vitamin B12, it is obtained from animal products meat, poultry, fish, and dairy products. Typically, vitamin B12 deficiency occurs because the individual is unable to absorb it from their diet. The elderly are especially vulnerable to vitamin B12 deficiency. As we age, our stomachs make less acid and therefore, it becomes more difficult to absorb sufficient levels of vitamin B12. The stomach acid keeps bacteria in check in the small intestine. When older persons secrete less stomach acid, bacterial overgrowth in the small intestine occurs. These bacteria use vitamin B12 and this decreases absorption.

By the age of 80 years, about 40% of older adults have lost the ability to make stomach acid (i.e. achlorhydria) because of atrophic changes in the stomach (Framingham Study, 1986). Older adults are also more likely to be on medications that can interfere with vitamin B12 absorption. For example, colchicine which is used to treat gout, dilantin which is used to treat seizures, and acid-neutralizing drugs for treating stomach ulcers, can all interfere with absorption of vitamin B12. Alcohol abuse can also cause this deficiency.

Risk Factors for B12 Deficiency

• Age
• Strict vegetarian diet
• Post-intestinal surgery
• Intestinal disorders such as Crohn's disease
• HIV/AIDS

Often those who have been diagnosed with a vitamin B12 deficiency do not realize that it is a serious threat to their health. As noted earlier, an untreated vitamin B12 deficiency can lead to irreversible neurological damage, including permanent dementia