By now, we all know that Angelina Jolie quietly underwent a preventive double mastectomy after learning she carried a genetic mutation that sharply increased her risk of breast cancer. Women with a faulty BRCA1 gene typically have a 45 to 90 percent risk of getting breast cancer during their life, compared to a 12 percent risk for the average woman. "My chances of developing breast cancer have dropped from 87 percent to under 5 percent," Jolie wrote in a New York Times op-ed on Tuesday. "I can tell my children that they don't need to fear they will lose me to breast cancer."
Jolie's surprise announcement shines a spotlight on breast cancer and women's health, bringing intense public attention to issues like prevention and treatment. While her condition is rare – mutations in BRCA1 and another gene, BRCA2, only cause 5 to 10 percent of breast cancers in the United States – all women can take steps to protect themselves against the disease. While you can't do anything about the genes you were born with, committing to a sound diet can help protect against breast cancer. "Researchers estimate that in the U.S., we can prevent about 38 percent of breast cancers with some basic healthy steps," says registered dietitian Karen Collins, a nutrition advisor for the American Institute for Cancer Research. "We can make a difference without doing anything extreme."
While no food or dietary approach can flat-out prevent breast cancer, the risk of developing the disease could be reduced. Here's a roundup of findings.
A plant-based diet. A recent study suggests that women who eat lots of fruit, veggies and legumes, and little red meat, salt and processed carbohydrates may lower their odds of developing estrogen-receptor negative breast cancer, which accounts for about a quarter of all breast cancers. And a study published in the American Journal of Epidemiology found that the likelihood of the cancer was 20 percent less when women followed such a diet.
Red, yellow and orange fruits and veggies. In December, researchers at Harvard Medical School said that women with higher levels of carotenoids, or nutrients found in fruits and veggies, have a lower risk of breast cancer, especially cancers that are more difficult to treat and have a poorer prognosis. Smart choices include carrots, sweet potatoes, spinach, kale, red peppers and winter squash. The study was published in the Journal of the National Cancer Institute.
[See Plant-Based Diets: A Primer.]
Walnuts. Consuming walnuts slowed the development and growth of breast cancer tumors in mice, according to a study published in 2011 in Nutrition and Cancer. Study author Elaine Hardman, a professor at Marshall University's Joan C. Edwards School of Medicine, looked at the effect of a diet containing the human equivalent of 2 ounces of walnuts a day (25 to 30 walnut halves). After 34 days, mice that ate walnuts had less than half the rate of breast cancer as a control group on the same diet minus the walnuts. The number and size of tumors also were significantly smaller for the walnut group. The study authors speculate that walnuts' anti-inflammatory properties are the reason.
Cutting back on alcohol. Even a moderate amount of alcohol is "clearly linked" to an increased risk of breast cancer, according to the American Cancer Society. Compared with non-drinkers, women who have two to five drinks a day are at least 50 percent likelier to develop the disease. If you have to drink, stick to a glass of wine (5 ounces), a shot of liquor (1.5 ounces) or a bottle of beer (12 ounces) a day.
Cabbage and sauerkraut. Researchers at Michigan State University found that people who ate raw or lightly cooked cabbage and sauerkraut at least three times a week were 72 percent less likely to develop breast cancer than those who had it twice or less. High levels of glucosinolates – compounds found in cabbage – may be responsible.
Vitamin D. Multiple studies, including one published in March in Cancer Causes and Control, have linked higher vitamin D levels with a lower risk of breast cancer. In one study, women with high vitamin D intake were up to 50 percent less likely to develop the disease. In another, Canadian researchers found that women who spent time outdoors or got lots of vitamin D from their diet or a supplement were 25 to 45 percent less likely to develop breast cancer. "Vitamin D is a subject under intense research," Collins says. "And it does appear to play a role." Some of the best vitamin D sources include milk, cereal, cod, tuna, shrimp and salmon.
Peaches and plums. Researchers at Texas A&M University found that peaches and plums contain antioxidants that kill breast cancer cells while leaving normal cells unharmed. The positive effect is likely caused by chlorogenic and neocholorogenic acid, both found in particularly high levels in both fruits. Findings were published in the Journal of Agriculture and Food Chemistry in 2010.
Fiber. Getting more fiber could lower breast cancer risk, according to a study published in July in the American Journal of Clinical Nutrition. Researchers found that for every 10 grams of added fiber daily – about half a cup to one cup of beans, depending on type – breast cancer risk decreased by 7 percent. The findings are based on 10 studies involving more than 710,000 people over 7 to 18 years. Other high-fiber foods include vegetables, whole grains and lentils.
Avoiding high-fat dairy foods. A study of nearly 2,000 breast cancer survivors found that those who averaged as little as one serving a day of high-fat dairy foods had a 49 percent higher risk of dying from breast cancer than those who ate little or no high-fat dairy. The research was published in March in the Journal of the National Cancer Institute. High-fat dairy includes whole milk, cream and anything made with them, such as cheese and ice cream.
Updated on 5/15/2013: This story was originally published on Oct. 12, 2011.