Vitamin B6 Acts Against Colon Cancer

June 14, 2005

Alcohol increases the risk of several types of cancer. This may be because alcohol disturbs certain essential metabolic processes. But vitamin B6 and folic acid appear to repair the damage caused by alcohol, thereby restoring those processes.

If you allow yourself 1-2 glasses of red wine a day, you probably prolong life and help yourself against arteriosclerosis. It is a known matter. At the same time, however, it increases the risk of breast cancer and colon cancer. It is also a known matter. Less well-known is that this disadvantage apparently can be eliminated with the B vitamins folic acid and vitamin B6. When alcohol is a cancer risk, it may be because alcohol interferes with the processes that the two vitamins are involved in.

About two years ago, it was discovered that alcohol does not appear to increase the risk of breast cancer in women who get enough folic acid. In 2004, something similar was found for colon cancer in a follow-up of about 500,000 men and women in several countries. In this study, the risk was increased by 30% if more than two alcoholic beverages were consumed daily, but it was not increased in those who got the most folic acid. The same result was found in a Swedish study of ovarian cancer.

Now a new Swedish study shows that the same applies to vitamin B6, also called pyridoxine. 61,433 women whose diets were examined in the years 1987-90 and again in 1997 were followed for an average of 14.8 years. During that period, 805 of the women developed colon cancer. The fifth of participants who got the most vitamin B6 had a one-third lower risk of colon cancer.

However, the protective effect of the vitamin was particularly strong in women who regularly consumed alcohol. If you had at least two alcoholic beverages a week and belonged in the fifth with the highest intake of B6 in your diet, you could enjoy a risk of colon cancer that was only a little over a quarter (28%) as high as if you had been in the fifth of participants with the lowest intake.

Vitamin B6, like folic acid and vitamin B12, plays a role in the so-called 1-carbon metabolism. This means that, among other things, it has the task of forming chemical groups (methyl groups) that contain only one carbon atom and are used in the construction of enzymes, the cells’ genetic material (DNA), etc.

These vitamins supply small parts for the organism’s various construction tasks. Alcohol disrupts this supply, which may be the explanation for why alcohol increases the risk of cancer – or part of the explanation. On the other hand, it seems that enhancing the 1-carbon metabolism with folic acid and vitamin B6 repairs the damage.

Good sources of vitamin B6 are meat, liver, kidney, yeast, whole grains (i.e. not wholemeal bread), nuts and green vegetables. Whole grains used to be a crucial source of vitamin B6, but the dehulling of all grains has meant that humans generally have significantly less vitamin B6 in their blood than, for example, livestock. It is difficult to get the recommended daily 1.7 mg in the diet.

Folic acid is found mainly in liver, green vegetables and yeast. In practice, the most important source is green vegetables. Few people get enough of them. Six a day is the rule.

The authors of the current study, conducted at Karolinska Hospital in Stockholm, understandably conclude that their findings may be significant for the prevention of colon cancer, both because many people use alcohol and because the population’s B6 status can be easily improved by, among other things, dietary changes and vitamin supplements.

By: Vitality Council

References:
1. Larsson SC, Giovannucci E, Wolk A. Vitamin B6 intake, alcohol consumption, and colorectal cancer: a longitudinal population-based cohort of women. Gastroenterology. 2005 Jun;128(7):1830-7.
2. Eunyoung Cho et al. Alcohol intake and colorectal cancer: A pooled analysis of 8 cohort studies. Annals of Internal Medicine 2004;140:603-13.

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