Work continues on effects of B6 on cancer risk
Until recently, there has been scant evidence suggesting that taking vitamins would prevent any form of cancer. Recently, there have been several medical studies demonstrating that taking a multivitamin or individual vitamins reduced the risk of developing cancer in both men and women. One recent study showed that higher blood levels of vitamin B6, in postmenopausal women, significantly reduced the risk of developing breast cancer.
Vitamin B6 occurs in three naturally occurring forms but all need to be converted into a final form (pyridoxal -5 -- phosphate) before it is really biochemically active.
Vitamin B6 is involved in growth, cognition, immune function, neurotransmitter production and even hormone activity. Vitamin B6 is found in many foods including meat, whole grain products, vegetables and nuts. However, much of the vitamin B6 found in foods is not biologically available.
In addition, food processing and cooking can also reduce the availability of vitamin B6. Alcohol consumption can significantly reduce absorption of vitamin B6. This is important because increased alcohol consumption is a risk factor for breast cancer. This interestingly, the specific vitamin is more bioavailable in meat that is in vegetables. Therefore, in a diet that limits red meat, supplementation may be a realistic option.
In the U.S. in 2008, more than 40,000 women died from breast cancer. The annual medical costs for breast cancer exceed $100 billion per year. Prevention should be the primary goal. Risk factors for breast cancer are female sex and age, lack of breast-feeding, alcohol consumption, poor diet and obesity.
The risk of breast cancer is significantly reduced by a healthy weight, less alcohol, being physically active and breast-feeding. These changes in lifestyle modifications could reduce the incidence of breast cancer by 38 percent.
The recent vitamin B6 and breast cancer study was a combination effort by the University of Hawaii Cancer Center, University of Chicago and the Keck School of Medicine at the University of Southern California. In this study, more than 1,400 postmenopausal women had their pyridoxal -5 -- phosphate levels measured.
These women had been part of a larger study group that had been followed since 1996. Those patients who had higher blood levels of the active form of vitamin B6 had about a 30 percent reduction in the risk of developing breast cancer. This study included Hispanic, black, Asian and white ethnic groups. The benefit of vitamin B6 was strongest in preventing estrogen receptor positive and progesterone receptor positive breast cancers.
The trigger by which vitamin B6 prevents breast cancer in postmenopausal women is yet to be determined. However, vitamin B6 is involved in hundreds of different biochemical reactions, some of them involved in the protection of DNA from damage. Damage to DNA increases risk of developing cancer. In addition, vitamin B6 seems to have some antioxidant qualities, again, protecting DNA from damage.
This was an excellent and well-controlled study which will, undoubtedly, stimulate further important research. Be cautioned -- vitamin supplementation cannot overcome a poor lifestyle.
• Patrick B. Massey, M.D., Ph.D is medical director for complementary and alternative medicine for the Alexian Brothers Health System. His website is www.alt-med.org.