The report by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF) adds evidence to the earlier finding that moderate exercise decreases the risk of post-menopausal breast cancer, which is the most common type of breast cancer.
is the leading cause of cancer death in women both in the developed and developing countries. The incidence of breast cancer is steadily going up, and some of the factors responsible could be urbanization, increased life expectancy, and adoption of an unhealthy lifestyle. Diet, weight and physical activity can affect breast cancer risk. In the United States, more than 252,000 new breast cancer cases have been estimated this year.
‘One in three breast cancer cases could be prevented, if women did not drink alcohol, were physically active and maintained a healthy weight.’
In 2010, a systematic review was conducted by the WCRF. For the report, worldwide scientific research on diet, nutrition, physical activity and breast cancer was collated and evaluated by a research team at Imperial College London. It was then independently assessed by a panel of leading international scientists. The research team analyzed 119 studies, including data on 12 million women and 260,000 cases of breast cancer.
The findings showed strong evidence that drinking a small glass of wine or beer a day (about 10 grams alcohol content) increased the risk of pre-menopausal breast cancer by 5 percent and post-menopausal risk by 9 percent.
is converted to a toxic substance called acetaldehyde, which is known to cause cell damage. Consumption of even one glass of alcohol can cause some build up of toxic acetaldehyde, which can in turn lead to breast cancer.
Regular physical activity can reduce the risk of breast cancer. Vigorous exercises such as fast running and bicycling were found to lower the breast cancer risk. According to the report, pre-menopausal women who were the most active had a 17% lower risk and post-menopausal women had a 10% lower risk of developing breast cancer compared to those who were the least active.
Women who followed moderate physical activity such as walking and gardening had a 13 percent lower risk of developing breast cancer compared to the least active women.
Diet plays a key role in lowering breast cancer risk. The report found that consumption of non-starchy vegetables lowers the risk of estrogen-receptor (ER) negative breast cancer - a common but hard to treat type of tumor. Foods that are high in calcium (dairy) and carotenoids also lower the risk of some breast cancers.
Carotenoids are phytonutrients found in carrots, spinach, kale, and apricots.
"These links are intriguing but more research is needed," said Anne McTiernan, MD, PhD, a lead author of the report and cancer prevention expert at the Fred Hutchinson Cancer Research Center.
"The findings indicate that women may get some benefit from including more non-starchy vegetables with high variety, including foods that contain carotenoids. That can also help avoid the common 1 to 2 pounds women are gaining every year, which is key for lowering cancer risk," added McTiernan.
Overweight and Obesity
A higher body mass index is linked to breast cancer risk. Studies have shown that overweight and obesity increase the risk of post-menopausal breast cancer
The female hormone estrogen contributes to the growth of breast cancer. After menopause, estrogen comes from the fat tissue. Thus, having more fat tissue can increase the risk of breast cancer. Women who are overweight tend to have high levels of insulin, which is also linked to breast cancer. The report also found that gaining weight in adulthood increases the risk of post-menopausal breast cancer.
In mothers, breastfeeding reduces the risk of breast cancer
"It can be confusing with single studies when the findings get swept back and forth.With this comprehensive and up-to-date report, the evidence is clear: Having a physically active lifestyle, maintaining a healthy weight throughout life and limiting alcohol -- these are all steps women can take to lower their risk," said McTiernan.
Some of the other risk factors for breast cancer include older age, early menstrual period, early menopause, and family history of breast cancer. There are many factors that cannot prevent the risk of breast cancer. But there are some factors that can lower the risk. According to the AICR, one in three breast cancer cases in the US could be prevented if women did not drink alcohol, were physically active and stayed a healthy weight.
"Wherever you are with physical activity, try to nudge it up a bit, either a little longer or a little harder. Make simple food shifts to boost protection -- substitute veggies like carrots, bell peppers or green salad for chips and crackers and if you drink alcohol, stick to a single drink or less," said Alice Bender, MS, RDN, AICR's Head of Nutrition Programs.
"There are no guarantees when it comes to cancer, but it's empowering to know you can do something to lower your risk." Follow a few simple tips in your daily routine, such as eating healthily and exercising regularly, to maintain a healthy weight and lower the chances of developing breast cancer. And of course! Try and shun those alcohol cravings.
- How Your Weight Affects Your Risk of Breast Cancer - (https://www.cancer.org/latest-news/how-your-weight-affects-your-risk-of-breast-cancer.html)
- Breast cancer - (http://www.wcrf.org/int/research-we-fund/continuous-update-project-findings-reports/breast-cancer)