ISLAMABAD: A glass of milk a day reduces the risk of colon cancer, according to a study.
Researchers from the Harvard School of Public Health and Brigham and Women’s Hospital in Boston collected data from 10 studies on the cancer.
The several studies have shown that calcium reduces the recurrence of intestinal polyps, growths that can become cancerous, said Stephanie Smith-Warner, an assistant professor of nutritional epidemiology at the Harvard School of Public Health.
The analysis showed: “people who take more than one eight-ounce glass of milk a day had a 15 percent reduction in risk compared to those who drank less than two glasses of milk a week,” she said.
It is the calcium in milk that is primarily responsible for this “modest” reduction in risk, Smith-Warner said. Calcium prevents the proliferation of cells that line the intestinal tract, stopping potential overgrowth that can make the cells become cancerous.
The people with the highest calcium intake, from food and supplements, had a 22 percent lower risk of colorectal cancer, she said adding that “the question of calcium supplements is still not resolved.” One reason is that the analysis showed a threshold effect, with the beneficial effect leveling off at a daily intake of 900 milligrams of calcium, roughly the amount in three glasses of milk, she said.
Another is that “some studies suggest that high calcium intake may increase the risk of prostate cancer,” Smith-Warner said. “We still need to understand the full range of effects of calcium intake.”
Colorectal cancer is the fourth most common malignancy in the United States. The American Cancer Society estimates there will be 106,370 new cases of colon cancer and 40,570 new cases of rectal cancer this year, with a combined total of 56,370 deaths.
“The results of this study have brought us closer to understanding how to reduce the risk of this disease,” said a study’s co-author Eunyoung Cho, a researcher at Brigham and Women’s Hospital and instructor in medicine at Harvard Medical School.
Calcium is not the only risk factor to be considered, Cho added. Doctors should tell patients that other protective measures are “a healthy lifestyle including exercise, maintenance of body weight and a diet low in red meat and high in fruits, vegetables and whole grain foods.”
The study is unlikely to dissuade those who insist that meat and dairy products can lead to cancer. Vegans and groups like the people for the Ethical Treatment of Animals have contended that these foods can contribute to colon cancer because they contain little to no fiber, which has been shown to be protective against the disease.
Source: Online, 8/7/2008