Researchers from Harvard University analyzed data on over 88,000 premenopausal women aged 26 to 45 who are taking part in the Nurse's Health Study II and completed a questionnaire on their eating habits in 1991.
The Nurse's Health study has been monitoring the health of female registered nurses since 1976.
Red meat included unprocessed beef, pork, lamb and hamburger, and processed red meat included hot dogs, bacon and sausage.
For the questionnaire, the nurses were asked to rate the frequency they ate red meat from among nine categories ranging from "never or less than once per month" to "six or more per day."
Taking into account factors like age, height, weight, family history and race, the researchers were able to identify 2,830 cases of breast cancer cases over 20 years.
Using statistical modeling, the researchers! say they were able to estimate breast cancer risks for women with different diets. They said that for each increase from among the nine options for red meat consumption, there was an increase in developing breast cancer.
Researchers said a higher intake of red meat was associated with a 22 percent increase in risk of breast cancer. Each additional serving per day upped the risk by 13 percent.
Substituting chicken for one serving of red meat per day actually reduced the risk of breast cancer by 17 percent, the study said.
In concluding, the study's authors said that eating a lot of red meat in early adulthood "may be a risk factor for breast cancer, and replacing red meat with a combination of legumes, poultry, nuts and fish may reduce the risk of breast cancer."
They cautioned, however that further study of the relation between diet in early adulthood and cancer is needed.
A diet high in red meat has long b! een linked to colon cancer and pancreatic cancer, but its rela! tionship to breast cancer has been little understood.
Not all were convinced by the study.
"As several researchers who have analyzed this study have already pointed out, the totality of the available evidence indicates that red meat consumption has little or no effect on breast cancer risk," said the American Meat Institute's vice president for scientific affairs, Betsy Booren, PhD in an emailed statement.
"This study with extremely weak associations based on self-reported food intake doesn't add much to our current knowledge on this complex condition. It is well known that the best steps women can take to reduce their breast cancer risk are maintaining a healthy weight, exercising, reducing alcohol consumption and not smoking."
Another expert said the study was not definitive.
"The women who ate less red meat may have a healthier lifestyle, and that reduces their risk of cancer, Dr. Stephanie Bern! ik, chief of surgical oncology at Lenox Hill Hospital in New York City told the website Healthday. "The increased risk tied to red meat might only stand in for other unhealthy behaviors," she said. "A healthy lifestyle can lower your risk of cancer in general."
Mia Gaudet, director of genetic epidemiology at the American Cancer Society, told the Associated Press that eating red meat as an early adult could be connected to increased risk of developing breast cancer.
"Breasts are still developing and are more susceptible to carcinogens before women have their first full-term pregnancy," she said.
The American Cancer Society recommends people eat a "plant-based" diet.
"It's important to have a healthy lifestyle throughout your life and not just as you get older and more worried about cancer," Gaudet told the AP. "People should perhaps consider ordering a salad or a vegetarian option sometime."
Source : http://! www.voanews.com/content/red-meat-linked-to-breast-cancer-in-harvard-stu! dy/1934905.html
