Folic Acid: Don't Be Without It
by Hans R. Larsen, MSc ChE
Health starts with the individual cells of our body. If our cells are healthy so are we. Healthy cells, in turn, depend on the continued, faultless replication of our DNA. DNA can be seriously damaged through attacks by free radicals so an adequate antioxidant status is essential to cell health. It is now becoming clear though that antioxidants alone are not enough to protect our DNA; more and more research points to the B vitamin folic acid as being equally or perhaps even more important in ensuring proper DNA replication. It is not surprising that a folic acid deficiency has been implicated in a wide variety of disorders from Alzheimer's disease to atherosclerosis, heart attack, stroke, osteoporosis, cervical and colon cancer, depression, dementia, cleft lip and palate, hearing loss, and of course, neural tube defects. The list of conditions involving a folic acid deficiency is growing day-by-day, as is clinical evidence that most of these conditions can be reversed by supplementation.
Folic acid (folinic acid, folacin, pteroylglutamic acid) was first isolated from spinach leaves (its name derives from the Latin folium meaning "leaf") in 1964 and early on was found to be essential in the prevention of anemia in animals. Later it was discovered that ensuring that mothers had adequate folic acid levels could prevent neural tube defects in human babies.
Folic acid is essential for the synthesis of adenine and thymine, two of the four nucleic acids that make up our genes, DNA and chromosomes. It is now also clear that folic acid is required for the proper metabolism of the essential amino acid methionine that is found primarily in animal proteins. Methionine is converted to homocysteine in the body. Homocysteine, in turn, may be converted back to methionine in a process requiring folic acid (tetrahydrofolate) and vitamin-B12 (cobalamin) as a catalyst or it may be metabolized into cysteine in a process catalyzed by vitamin-B6 (pyridoxine). Cysteine is a vital link in the synthesis of glutathione, one of our most important antioxidants. A high blood level of homocysteine has been found to be highly detrimental to health and is invariably accompanied by a low level of folic acid(1,2).
Homocysteine and heart disease
There is rare, unanimous consent within the medical community that homocysteine levels in North America are too high. One study estimates that 56,000 lives could be saved every year if average levels could be lowered by just 5 micromol/L(10,11). Fortunately, lowering your homocysteine level is simple by supplementing with folic acid and vitamins B12 and B6(2,4,5,9-13). Although most research into the harmful effects of homocysteine has centered on heart disease there is growing evidence that high homocysteine levels (or low folate levels) are involved in many other disorders.
Folic acid protects the brain
Research has also shown that many drugs such as methotrexate, levopoda, niacin, phenytoin (Dilantin), carbamazepine, and theophylline can markedly reduce folate levels(2,10,11). Researchers at Oxford University recently reported that Alzheimer's patients have substantially lower levels of folic acid and vitamin B12 than do normal people of the same age. They also found that a high homocysteine level is a potent risk factor for AD; study participants with a level above 14 micromol/L had an almost five times higher risk than participants with levels below 11 micromol/L. Participants with low folate and vitamin B12 levels had a three to four times higher risk of AD than did people with normal levels(16).
Folic acid is especially important for women
Low folate levels are also heavily implicated in the development of cervical cancer. Cervical dysplasia is the precursor of cervical cancer and is usually first detected through a routine Pap smear. Fortunately, folate supplementation (0.8-3.0 mg/day) is very effective in reversing cervical dysplasia and preventing the cancer(22-24). Researchers at the Harvard Medical School recently reported that women who supplemented with folic acid (0.4 mg/day or more for at least 15 years) had a four times lower risk of developing colon cancer than did women with a daily intake of 0.2 mg/day or less (the daily contribution of a typical North American diet)(25-27). Many postmenopausal women have increased homocysteine levels that are believed to contribute to the risk of osteoporosis; folate supplementation can reverse these high levels(28).
And the list goes on
There is no question that folic acid is extremely important to health and wellbeing. Not only is it important for heart health, mental health and women's health, but it is now also clear that it affects many other facets of health and disease. Researchers at the Cleveland Clinic Foundation have found that patients with end-stage renal disease have extremely high homocysteine levels and can be protected from cardiovascular events by supplementing with folic acid, vitamins B6 and B12(29). Diabetes patients tend to have high homocysteine levels and folate is especially important for them(30). Recent research has also shown that low folate levels (high homocysteine levels) are implicated in age-related hearing loss, psoriasis, and restless leg syndrome(31-33).
It is indeed astounding that one single vitamin, folic acid, can have such a profound effect on our health and yet perhaps it is not so surprising when one considers its vital role in DNA synthesis and homocysteine metabolism.
So how much is enough
Supplementation with folic acid and vitamins B6 and B12 costs only pennies a day and yet it is indeed hard to imagine a better investment in protecting your health.