If you allow yourself to drink 1 - 2 glasses of red wine a day, you will probably lengthen your life and have somewhat prevented atherosclerosis - this is a known fact. At the same time, however, your risk of breast cancer and colon cancer will be increased - this is also a known fact. It is not so widely known, however, that this disadvantage can apparently be eliminated with the B-vitamins folic acid and B6. When alcohol poses a cancer risk it might be because alcohol interferes with the exact processes performed by these two vitamins.
About two years ago it was discovered that alcohol apparently does not increase the risk of breast cancer in women if they get enough folic acid. In 2004, a similar discovery was made with regard to colon cancer in a follow-up of 500,000 men and women in different countries. In this study, the risk was increased by 30% if the daily alcohol intake was of more than two units a day, but there was no increased risk in the ones who had the largest intake of folic acid. The same result was obtained in a Swedish study of ovarian cancer.
Now, a new Swedish study shows that the same goes for vitamin B6 (aka pyridoxine). The diet of 61,433 women were examined during the years 1987 - 1990 and again in 1997 and the women were followed for an average of 14.8 years. During this period, 805 women were diagnosed with colon cancer. The 20% of the women with the highest intake of vitamin B6 had a reduced risk of 33% of developing colon cancer.
The protective effect of this vitamin, however, was particularly great if the women had a regular consumption of alcohol. Drinking at least 2 units of alcohol a week and at the same time being in the top 20% with regard to vitamin B6 intake would result in a risk of colon cancer that was only one fourth (28%) compared to the ones who got the least vitamin B6.
Just like folic acid and vitamin B12, vitamin B6 plays a role in the so-called 1-carbon metabolism. This means that one of its tasks is to form chemical groups (methyl groups) consisting of only one carbon atom; they are used in the construction of enzymes and the cells' DNA (hereditary material), etc.
So, these vitamins deliver particles to the various construction tasks of the organism. Alcohol disturbs this delivery which might explain - or at least partly explain - why alcohol seems to increase the risk of cancer. On the other hand, it appears that strengthening the 1-carbon metabolism with folic acid and vitamin B6 can repair the damage.
Good sources of vitamin B6 are meat, liver, kidney, yeast, whole grain, nuts, and greens. Previously, whole grain was a decisive source of vitamin B6 but the decortication of grains have resulted in us generally having significantly smaller amounts of vitamin B6 in our blood than domestic animals, for example. It can be difficult to achieve the recommended dose of 1.7 mg. of dietary fibres a day.
Folic acid is particularly abundant in liver, greens, and yeast. In practice, the most important source is greens, but, unfortunately, the majority of us do not get enough of this.
The authors of the current study carried out at the Karolinska Hospital in Stockholm naturally conclude that their findings may be essential in the prevention of colon cancer on account of so many people consuming alcohol and the fact that the vitamin B6 status of the population can so relatively easily be improved with dietary changes and vitamin supplements.
References:
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
Eunyoung Cho et al. Alcohol intake and colorectal cancer: A pooled analysis of 8 cohort studies. Annals of Internal Medicine 2004;140:603-13.
