High dose folic acid in CAD

From: http://www.lef.org/magazine/mag2005/mar2005_report_folic_02.htm

This raises an obvious question: is supplementing with high-dose folic acid (5000 mcg daily) safe? In an exclusive interview with Life Extension, Malcolm J. Lewis, MD, professor of cardiovascular pharmacology and deputy head of the Department of Pharmacology, Therapeutics and Toxicology at Cardiff University, discussed the results of the most recent folic acid trials. Dr. Lewis leads one of the world’s premier team of scientists in investigating the role of this B vitamin and its relationship to cardiovascular disease.




Dr. Lewis confirmed the safety and effectiveness of high-dose folic acid, saying that findings reported at the May 2004 meeting of the British Cardiac Society “clearly demonstrated that although both 400 mcg and [5000 mcg] of folic acid can lower homocysteine levels to the same extent in patients with coronary disease, only the [5000- mcg daily dose] was effective at improving endothelial function (an excellent surrogate for cardiovascular health). None of the subjects in any of our studies has had adverse effects from taking [5000 mcg] of folic acid. Provided vitamin B12 deficiency has been excluded, this dose would seem safe to use.”18



Dr. Lewis added, “It is obvious, therefore, that ‘high’ doses of folate have pharmacological effects which are different from more conventionally used ‘low’ doses. We are currently investigating why this may be the case.”18



Some new studies speculate that folic acid’s ability to reverse endothelial dysfunction is independent of its ability to lower plasma homocysteine levels. Lewis and his team recently reported that reversing endothelial dysfunction with folic acid shows that this B vitamin has myriad effects on the vasculature besides lowering homocysteine. In-vitro evidence demonstrates that 5-methytetrahydrofolate, the main circulating metabolite of folic acid, can increase nitric oxide production and directly scavenge superoxide radicals. These properties may account for some of its cardioprotective effects.19

WOMEN AND HEART DISEASE


Heart disease was once believed to be a man’s disease. Before the age of 60, men die of heart attack at six times the rate that women do. By the age of 70, however, heart attack rates for men and women are virtually even. Doctors now confirm that heart disease is so deadly for women that they have a 50% chance of dying from it. And the younger a woman is, the less likely she is to have symptoms of heart disease.35



After menopause, which signifies the end of a woman’s reproductive years, many women gain weight. As levels of the hormone estrogen decline, blood pressure increases. Studies show that many postmenopausal women have higher levels of triglycerides, total cholesterol, and low-density lipoprotein (LDL) than premenopausal women.36 Realizing the impact of menopause and declining estrogen on women’s heart health, researchers at the Catholic University of Sacred Heart in Rome, Italy, sought to determine whether folic acid supplementation affected endothelial function in 15 healthy postmenopausal women.



Published in 2004, this groundbreaking study measured the women’s plasma levels of folate, homocysteine, glucose, insulin, and lipids, as well as their blood pressure. After just one month of supplementation with high-dose folic acid (7500 mcg daily), the women’s endothelial function improved 37% compared to pre-supplementation values. Among the other cardiovascular risk factors studied, beneficial high-density lipoprotein (HDL) levels increased 6%, while dangerous low-density lipoprotein (LDL) dropped 9%. These findings further substantiate that high-dose folic acid supplementation may improve endothelial function and lipid profile to reduce cardiovascular disease risk.37

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The question is this dose would increas colon cancer incidence?