Posted on 05/05/2005 6:41:47 AM PDT by truthandlife
High daily levels of vitamin B6 may reduce the risk of getting colon cancer by 58 percent, claims a new study from Harvard Medical School.
The research, published in the May 4 issue of the Journal of the National Cancer Institute, builds on other studies that have already indicated a strong preventive effect from the vitamin.
"There are several smaller studies that have found a protective effect from dietary intakes of B6," said lead researcher Esther K. Wei, an instructor in medicine at Harvard Medical School and Brigham and Women's Hospital. However, "this is the first large study of women to look at blood levels of B6" and find a protective effect, she added.
Wei and her colleagues evaluated nearly 33,000 women who were participants in the Nurses' Health study, a long-running study that began in 1976. Since then, researchers have focused on subsets of the original 121,700 participants, all nurses between 30 and 55 years of age when they enrolled, to study various health issues.
Among this subset, Wei and her team analyzed blood samples collected in 1989, looking for levels of a substance called PLP (pyridoxal 5'-phosphate) -- the main active form of vitamin B6 in the blood. Then they looked at medical records to determine who contracted cancer of the colon or cancer of the colon and rectum (colorectal).
They found a total of 194 colorectal cancer cases and 410 cases of colon polyps, which often precede colorectal cancer. After dividing the women into four groups, from lowest to highest blood levels of PLP, the researchers found that the highest quartile group had a 44 percent lower risk of colorectal cancer and a 58 percent lower risk of colon cancer. The same associations held for the development of polyps.
The associations between high blood levels and lower risk held even after Wei's group controlled for other colon cancer risk factors, such as family history of the disease.
Women in the group with the highest blood levels of B6 had about six times the blood levels of the nutrient as those in the lowest group, Wei said.
Dietary intake of Vitamin B6 was also associated with reduced risk. Women in the lowest intake group got a median of 1.6 milligrams a day compared to 8.6 milligrams in the highest intake group. The recommended daily intake of B6 for most adults varies from 1.3 to 1.7 milligrams a day, depending on age and gender. Those in the lowest group were getting close to the recommended amount of daily B6, Wei said, while those in the highest group, which got the most protective effect from colon cancer, were getting about five times the recommended daily intake, but still at a safe level, she said.
According to the Institute of Medicine, 100 milligrams per day of B6 is the upper threshold of a safe intake level.
It's possible, said Wei, to take in 8.6 milligrams of Vitamin B6 a day by taking a multivitamin and eating vitamin B6-rich food. But she stressed that "you don't have to take in 8.6 milligrams a day to get a reduced risk," since reductions in cancer risk started showing up at levels of just 3.3 milligrams a day.
Vitamin B6 is involved in around 100 physiologic reactions and functions in the body, according to Wei, including protein metabolism, red blood cell function and proper functioning of the nervous and immune systems.
The vitamin can be sourced from multivitamins, fortified cereals, beans, meat, poultry, fish and some vegetables and fruits.
Scientists aren't sure why high blood levels of vitamin B6 protect against colon and colorectal cancer, Wei said, but she noted that "individuals who have high levels of B6 have less chance of having damaged DNA, which can lead to cancer."
Dr. Durado Brooks, director of colorectal cancer for the American Cancer Society, called the new study "interesting work." If the finding about blood levels of the vitamin and reduced cancer risk is replicated, he said, "it will be a useful bit of information to give people about lowering their risk of colon cancer."
Meanwhile, there are a number of measures people can take to lower risk, he said. "Multiple vitamins with folate have been previously shown to reduce risk." Keeping a healthy body weight and maintaining an exercise program can reduce risk, too, he said. For those at average risk of colon cancer, the Cancer Society recommends formal screening beginning at age 50.
The screening tests include a fecal occult blood test, barium enema or examinations of the colon via a test called a sigmoidoscopy or a colonoscopy.
Colorectal cancer is the third most common cancer in the United States, according to the American Cancer Society. The Society estimates that 104,950 new cases of colon cancer and 40,340 new cases of rectal cancer will be diagnosed in 2005, with about 56,290 deaths linked to the disease. The death rate from colorectal cancer has been declining, however, probably because of early detection and improved treatments.
Intesting. Thanks.
Gee, the article should have included what foods are high in B6.
Sounds interesting BUT how long with it take before they have another study out saying: PEOPLE ARE AT RISK FOR HEART ATTACKS FOR TAKING TOO MUCH B6. Just like the did with Vitamin E and Vitamin A.
The vitamin can be sourced from multivitamins, fortified cereals, beans, meat, poultry, fish and some vegetables and fruits.
Calves liver burger smothered in spinach with a large bell pepper juice, and a side of salmon croquettes.
Pyridoxine(B6) is also useful to many of us to act as an insect repellant. DEET causes a neurological reaction in me and makes my brain swell(I was hospitalized as a result). I discovered that if you take a mega dose of B6 a few hours before exposing yourself to mosquitoes and other nasty bugs like ticks, they pass you up. B vitamins tend to sweat out and even mask the carbon dioxide in your breath, which is what most insects that bite home in on. It's how they find you.
Thanks for pointing that out. Everytime I see some claim that high amounts of some vitamin can prevent something, it seems that the other side of that coin crops up later, and it's a BAD thing.
The thing that people don't realize is that the vitamins we take everyday are really just man-made chemicals. How can chemicals be good for you? We really need to just get our vitamins from food and not from man-made chemicals. At least that is what I believe.
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Mmmmm.... meat and veggies.
All B vitamins and there's a bunch, are not those which accumulate in your system. They are passed right thru by your lungs, kidneys, and sweat. The fat solubles can build up in your system to toxic proportions. For example, one bite of a polar bear's liver contains enough vitamin A to kill a human. Most toxic minerals and vitamins accumulate in your liver. It's why chelation therapies work well in some people. Pass thru minerals like molybdenum will bind with copper or selenium etc....and take them out of your system because molybdenum gets a free pass right thru. If it's grabbed a few copper molecules on it's way, it detoxifies you.
My mother was one of the first test cases to reattach the small intestine to the large intestine after the colon was removed. I'll be trying this also.
Jeeze remind me to skip the "Polar Bear" section of my meat department in my supermarket tomorrow! ;-)
Based on all the latest "fads," we will all be taking 20-30 pills a day consisting of some supplement or the other. Gee, what is it now, extra calcium, magnesium, folic acid, multi-vitamin, omegas, Vitamin E, Vitamin D and the list goes on. To sum it all up, I'm beginning to get confused as to how much of what we're supposed to have and is it good or is it bad based on today's study.
Vitamins in bottles are truly just supplements.
I don't take vitamins and hardly ever did. Everytime I started taking more of a certain kind of vitamin because they said it prevented some kind of cancer or heart attack, within the next year I would see another study saying its not good for you and we should stop those levels. I got sick of it so I stopped taking vitamins and decided that food can give me just as much as I need and No more so I don't create toxins in my body.
True. Besides I love to eat so eating more of certain veggies or certain foods makes me happier! ;-)
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Done!
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