Folic acid/folate (Vitamin B9) to protect against development of cancer

The University of Maryland Medical Center’s website on Complementary Medicine (a clearly written, up-to-date resource, by the way) provides this review of folic acid (also known as folate or Vitamin B9) as a supplement protecting against the development of cancers. The strongest evidence appears to be for folic acid’s ability to protect against colorectal and breast cancers. In our excerpt below, we have highlighted two significant passages.

For recommendations on how to take this supplement (you may be getting it in a multivitamin or a B-complex supplement), see the NYBC entry on Folic Acid.



Cancer
Folic acid appears to protect against the development of some forms of cancer, particularly cancer of the colon, as well as breast, esophagus, and stomach, although the information regarding stomach cancer is more mixed. It is not clear exactly how folate might help prevent cancer. Some researchers speculate that folic acid keeps DNA (the genetic material in cells) healthy and prevents mutations that can lead to cancer.

Population-based studies have found that colorectal cancer is less common among individuals with very high dietary intakes of folic acid. The reverse appears to be true as well: low folic acid intake increases risk of colorectal tumors. To have a significant effect on reducing the risk of colorectal cancer, it appears that at least 400 mcg of folic acid per day over the course of at least 15 years is required. Similarly, many clinicians recommend folic acid supplementation to people who are at high risk for colon cancer (for example, people with a strong family history of colon cancer).

Similarly, one population-based study also found that cancers of the stomach and esophagus are less common among individuals with high intakes of folic acid. Researchers interviewed 1095 patients with cancer of the esophagus or stomach as well as 687 individuals who were free of cancer in three health centers across the United States. They found that patients who consumed high amounts of fiber, beta-carotene, folic acid, and vitamin C (all found primarily in plant-based foods) were significantly less likely to develop cancer of the esophagus or stomach than those who consumed low amounts of these nutrients. Another important, good-sized study, however, did not find any connection between folic acid intake and stomach cancer. The possibility of some protection from folate against stomach cancer in particular needs clarification and, therefore, more research is warranted.

Low dietary intake of folate may increase the risk of developing breast cancer, particularly for women who drink alcohol. Regular use of alcohol (more than 1 ½ to 2 glasses per day) is associated with increased risk of breast cancer. One extremely large study, involving over 50,000 women who were followed over time, suggests that adequate intake of folate may lessen the risk of breast cancer associated with alcohol.

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Vitamin B12 deficiency in older adults; Vitamin B12, Vitamin B6, and folate supplements under study to lower risk of cardiovascular disease

This excerpt from the Office of Dietary Supplements – National Institutes of Health Fact Sheet on Vitamin B12 discusses why older adults (people over 50) may need to take supplements or use fortified foods to prevent Vitamin B12 deficiency:


Hydrochloric acid helps release vitamin B12 from the protein in food. This must occur before vitamin B12 binds with intrinsic factor and is absorbed in your intestines. Atrophic gastritis, which is an inflammation of the stomach, decreases the secretion of gastric juices, including hydrochloric acid. Less hydrochloric acid decreases the amount of vitamin B12 separated from proteins in foods and can result in poor absorption of vitamin B12. Decreased hydrochloric acid secretion also results in growth of normal bacteria in the small intestines. The bacteria may take up vitamin B12 for their own use, further contributing to a vitamin B12 deficiency. Up to 30 percent of adults aged 50 years and older may have atrophic gastritis, an increased growth of intestinal bacteria, and be unable to normally absorb vitamin B12 in food. They are, however, able to absorb the synthetic vitamin B12 added to fortified foods and dietary supplements. Vitamin supplements and fortified foods may be the best sources of vitamin B12 for adults older than age 50 years.

Caution: Folic Acid and vitamin B12 deficiency
Folic acid can correct the anemia that is caused by vitamin B12 deficiency. Unfortunately, folic acid will not correct the nerve damage also caused by vitamin B12 deficiency [1,36]. Permanent nerve damage can occur if vitamin B12 deficiency is not treated. Folic acid intake from food and supplements should not exceed 1,000 μg daily in healthy individuals because large amounts of folic acid can trigger the damaging effects of vitamin B12 deficiency [7]. Adults older than 50 years who take a folic acid supplement should ask their physician or qualified health care provider about their need for additional vitamin B12.


A further excerpt from the ODS Vitamin B12 Info Sheet discusses the relationship between vitamin B12, homocysteine, and cardiovascular disease. As noted, “clinical intervention trials are underway to determine whether folic acid, vitamin B12, and vitamin B6 supplements can lower risk of coronary heart disease.”

Cardiovascular disease involves any disorder of the heart and blood vessels that make up the cardiovascular system. Coronary heart disease occurs when blood vessels which supply the heart become clogged or blocked, increasing the risk of a heart attack. Vascular damage can also occur to blood vessels supplying the brain, and can result in a stroke.

Cardiovascular disease is the most common cause of death in industrialized countries such as the United States, and is on the rise in developing countries. The National Heart, Lung, and Blood Institute of the National Institutes of Health has identified many risk factors for cardiovascular disease, including an elevated LDL-cholesterol level, high blood pressure, a low HDL-cholesterol level, obesity, and diabetes. In recent years, researchers have identified another risk factor for cardiovascular disease: an elevated homocysteine level. Homocysteine is an amino acid normally found in blood, but elevated levels have been linked with coronary heart disease and stroke. Elevated homocysteine levels may impair endothelial vasomotor function, which determines how easily blood flows through blood vessels. High levels of homocysteine also may damage coronary arteries and make it easier for blood clotting cells called platelets to clump together and form a clot, which may lead to a heart attack.

Vitamin B12, folate, and vitamin B6 are involved in homocysteine metabolism. In fact, a deficiency of vitamin B12, folate, or vitamin B6 may increase blood levels of homocysteine. Recent studies found that vitamin B12 and folic acid supplements decreased homocysteine levels in subjects with vascular disease and in young adult women. The most significant drop in homocysteine level was seen when folic acid was taken alone. A significant decrease in homocysteine levels also occurred in older men and women who took a multivitamin/ multimineral supplement for 8 weeks. The supplement taken provided 100% of Daily Values (DVs) for nutrients in the supplement.

Evidence supports a role for folic acid and vitamin B12 supplements for lowering homocysteine levels, however this does not mean that these supplements will decrease the risk of cardiovascular disease. Clinical intervention trials are underway to determine whether folic acid, vitamin B12, and vitamin B6 supplements can lower risk of coronary heart disease. It is premature to recommend vitamin B12 supplements for the prevention of heart disease until results of ongoing randomized clinical trials positively link increased vitamin B12 intake from supplements with decreased homocysteine levels AND decreased risk of cardiovascular disease.

Folate, the feds, and you

Folate, a B vitamin, frequently appears in news about dietary supplement research. (Note: folic acid is the form found in supplements or fortified foods.)

For example, an article earlier this year offered this announcement: “Higher Folate Levels Linked To Reduced Risk For Alzheimer’s Disease. ” (JAMA and Archives Journals: 2007, January 9)

And you wouldn’t have to look too far to discover current research on folate deficiency associated with the potential for cardiovascular problems, or folate deficiency linked to higher rates of breast, pancreatic, or colon cancer.  

Of course, when folate was first identified and studied 70 years ago, the chief draw for researchers was its role in combating anemia and supporting the health of women during pregnancy. But since then, as understanding of the vitamin has grown, it’s come under scrutiny for many other reasons.

Indeed in 1996, the US federal government decided that the health benefits of folic acid were very clear–and yet too many Americans were not getting enough from their diets. The response? The Food and Drug Administration (FDA) published regulations requiring the addition of folic acid to enriched breads, cereals, flours, corn meals, pastas, rice, and other grain products–where you’ll find it today (check nutritional labels).

For more information on whether you’re getting enough folate in your diet, and who should consider supplementing, see the Office of Dietary Supplement fact sheet on FOLATE:

http://www.ods.od.nih.gov/factsheets/folate.asp

Fatigue, sleep disturbances, low energy, depression: dietary supplements may help address special health concerns for people with HIV

As we were mulling over the recent New York Times piece on the billions of dollars Americans spend each year on sleep aids that are only mildly effective (see today’s other post under “Melatonin”), we thought we’d reprint this article from the NYBC newsletter THE SUPPLEMENT, which appeared earlier this year.  It deals with the constellation of health concerns, from fatigue to depression, that often affect people with HIV, and gives an overview of some of the dietary supplements that have been used to address these issues.

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Sleeping poorly? Energy low? Feeling down?

Dietary supplements may have something to offer

Sleep disturbances are the third most common complaint among people with HIV seeking medical attention. Everybody knows what it’s like to sleep poorly, then feel cranky and fatigued the next day. But persistent insomnia, followed by chronic fatigue, can become major medical issues for people with HIV (we’re talking about lower CD4 counts and poor medication adherence), so it’s worth reviewing options for dealing with these problems.

A 2005 research presentation suggested that melatonin supplements can improve sleep patterns in people with HIV. Melatonin, a hormone secreted by the pineal gland, has long been studied as a sleep regulator—levels increase in response to darkness, then fall during daytime. It’s also been investigated as an anti-cancer agent, where it has shown the capacity to combat solid tumors. (But melatonin should not be taken by people with cancers affecting immune cells, such as lymphoma or leukemia.)

Good news: a recent trial indicates that low-dose melatonin (0.5 to 1.0 mg) may be perfectly effective as a sleep promoter, making it a very inexpensive option for this purpose.

Fatigue can stem from other causes besides sleep disturbances. Anemia, a shortage of red blood cells, is another leading cause of fatigue among people with HIV, and is especially common among women. (A recent large study found that about 30% of people on HAART had moderate anemia. Women had an 80% greater risk of being anemic than men, and African-Americans had a risk of anemia 2.6 times higher than whites.) It’s important to learn the source of anemia in people with HIV (taking Retrovir, AZT, is a drug-related factor). Treatment options include increasing intake of iron, vitamin B12 and folic acid. Note that NYBC stocks multivitamins with iron for those concerned about their intake of this mineral. You’ll also find folic acid and B12 in our multis, and may want to consider adding a separate vitamin B supplement as well.

While for some people with HIV treating anemia can be a key to helping them overcome fatigue and its frequent companion depression, there are other cases where low energy is not connected to low red blood cell levels, and where the treatment options are therefore different. Particularly in HIV+ men, steroid hormones (testosterone and DHEA) have proven to be useful in combating the fatigue-depression combination. Recent federally-funded research on DHEA showed it to be an effective anti-depressant, with the added interesting feature that it can enhance sex drive (rather than undermining it, as do certain common prescription anti-depressants).  And a Columbia University study of DHEA for fatigue and depression in people with HIV has found it to be a successful treatment for some, with the added bonus that, unlike some prescription energy boosters, it doesn’t carry the risk of addiction.