The reason for this protection is probably due to the homocysteine levels, which normally rise with age, being lowered by the B vitamins.
The levels of B vitamins in the study were higher than you normally find in the average multi-vitamin (B6 50mg, B12 1mg and Folic Acid 2.5mg).
Its not wise to take large amounts of single B's on their own. A 50mg B Complex with any shorfall in B12 and folic acid made up seperately to the required levels is probably the best way to go.
Quote:
Daily supplementation with B vitamins may reduce the risk of breast cancer and other invasive cancers in women over the age of 65. That�s what a study published in the Journal of the American Medical Association has to say.
Over 5,000 women at a high risk of cardiovascular disease took part in the study, which investigated the effects of a daily supplement of folic acid, vitamin B-6 and vitamin B-12 on cancer risk.
�If the finding [that cancer risk in women over 65 is decreased] is real and substantiated, the results may have public health significance because the incidence rates of cancer are high in elderly persons. The finding is biologically plausible because elderly individuals have increased requirements for these B vitamins,� wrote lead author Shumin Zhang from Brigham and Women�s Hospital and Harvard Medical School.
Folate, vitamin B-6 and vitamin B-12 are thought to play an important role in cancer prevention. This is because the vitamins play an important role in maintaining the integrity of DNA and regulating gene expression, both critical processes in healthy cell function.
Another positive to take from the results is that they appear to support the safety of B vitamins, and particularly folic acid. Since 1998 the U.S. has required mandatory fortification of all grain products with folic acid�the synthetic, bioavailable form of folate�in order to reduce the incidence of neural tube defects�most commonly spina bifida and anencephaly.
Zhang and co-workers looked at the risk of cancer and B-vitamin consumption among the 5,442 participants (average age 62.8) of the Women�s Antioxidant and Folic Acid Cardiovascular Study. The women either had cardiovascular disease or three or more coronary risk factors.
Over the course of 7.3 years, half of the women received a daily supplement of folic acid (2.5 mg), vitamin B-6 (50 mg) and vitamin B-12 (1 mg), while the other half of the women received a placebo. The study began in 1998�the same year as mandatory folic acid fortification was introduced in the U.S.
During the study, 379 cases of invasive cancer were diagnosed�187 in the B-vitamin group and 192 in the placebo group. No differences were seen in the risk of developing total invasive cancer or breast cancer, when the participants were viewed in their entirety. However, in women over the age of 65 the supplementation was associated with significant 25% and 38% reductions in the risk of invasive and breast cancer, respectively.
Journal of the American Medical Association 300(17): 2012-2021,2008
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