About 1 in 8 women in the US will develop breast cancer in their lifetime, according to the American Cancer Society. While certain risk factors such as age and family history are beyond our control, changing our diet — to eliminate certain foods and add others — can make a big difference. A healthy diet can help keep weight down, build a body’s immunity, decrease the risk of breast cancer and minimize the side effects that come with treatment.
5 Golden Rules
Recent studies have continued to draw the link between breast cancer reduction and diet. Here are 5 rules to follow:
1. Eat more fresh fruits and vegetables
Kelly Turner, PhD, a researcher in the field of integrative oncology, interviewed more than 100 women from 10 countries and studied more than 1,000 cases of cancer remission for her book Radical Remission: Surviving Cancer Against All Odds (Harper Collins, 2014). The women had prevented recurrences of various forms of cancer as a result of diet and lifestyle changes they made. “If you’re eating fresh, raw or lightly steamed vegetables, you’re helping your body fight all sorts of diseases and keeping your immune system healthy,” Turner says. The connection? Foods rich in phytochemicals (chemical compounds that occur naturally in plants) help to prevent the cellular damage and mutations that cause many different types of cancers, including breast cancer.
Two new studies elaborate:
- An animal study published in the Journal of Nutritional Biochemistry found that the phenolic compounds in peaches may inhibit the growth of breast cancer cells and reduce the risk of metastasis, the spread of cancer cells beyond the original site. (Mice were fed an amount of peach extract that would translate to 2 to 3 peaches a day for a 132-pound woman.)
- A study published in the Journal of Clinical Endocrinology & Metabolism revealed that a tomato-rich diet may help reduce the risk of breast cancer in postmenopausal women. For 10 weeks, the study participants ate tomato products with a total of at least 25 mg of lycopene a day. As a result, their levels of adiponectin (a hormone that regulates blood sugar and fat metabolism in the body) increased by nearly 10%. Higher levels of this hormone have been associated with a reduced risk of breast cancer.
Tomato juice, 1 cup: 25 mg
Tomato soup, 1 cup: 9.7 mg
Tomato sauce, 1/4 cup: 8.9 mg
Ketchup, 1 tbsp: 2.7 mg
Raw tomato, 1 medium: 3.7 mg
Women can reduce their breast cancer risk by 14% by replacing one daily serving of meat with a serving of fish, nuts, legumes or poultry, according to research at the Harvard School of Public Health.
2. Reduce your intake of saturated fat, starting with red meat
Research continues to demonstrate a strong link between saturated fat and breast cancer.
- A recent study published in the Journal of the National Cancer Institute found that a diet high in saturated fat — found in red meat and full-fat dairy products — was associated with an increase in two types of breast cancer. After studying the diets of more than 300,000 women, researchers revealed that women who ate more saturated fats and fewer monounsaturated fats (found in nuts and olive oil) and polyunsaturated fats (found in seafood, fish oil and canola oil) significantly increased their risk of the disease.
- New research from the Harvard School of Public Health and published in the British Medical Journal found a link between high consumption of red meat and breast cancer in young women. Compared with women who had one serving of red meat a week, those who ate 1-1/2 servings a day appeared to have a 22% higher risk of breast cancer. Each additional daily serving of red meat seemed to increase the risk by another 13%. The research also found that women could reduce their breast cancer risk by 14% by replacing one daily serving of meat with a serving of fish, nuts, legumes or poultry. The researchers studied data on the health of 89,000 women, ages 24 to 43, who were followed over a 20-year period.
3. Cut back on alcohol
Women who like to kick back with a daily glass of wine may need to rethink that habit. “Our latest research shows that even a half a drink or 1 drink a day increases a woman’s risk of breast cancer,” says Walter Willett, MD, chair of the department of nutrition and epidemiology at Harvard School of Public Health and the researcher who established the landmark Nurses’ Health Study 2 and Nurses’ Health Study 3, which is currently investigating the role of nutrition in breast cancer in women of all ages.
Alcohol raises the blood level of insulin-like growth factors — or IGFs — which, like estrogen, promote the growth of breast cancer. (The National Cancer Institute offers more information about the connection between alcohol and breast cancer.) However, women who take a daily folate supplement of at least 400 mcg or add folate-rich foods to their diet, such as citrus fruits and dark, leafy greens, may help mitigate this risk, say researchers connected with the Nurses’ Health Study.
Patients with higher levels of vitamin D in their blood at the time of breast cancer diagnosis had about half the fatality rate of those with lower vitamin D levels.
4. Amp up your vitamin D (and multivitamins)
A recent study published in Anticancer Research found that patients with higher levels of vitamin D in their blood at the time of breast cancer diagnosis had about half the fatality rate of those with lower vitamin D levels. The meta-analysis combined data from more than 4,500 breast cancer patients from 5 observational studies over a 9-year period. Experts believe that vitamin D activates a protein that blocks aggressive cell division in breast cancer patients. (See MedShadow’s Vitamin D: Pros and Cons for more on the supplement.)
Sunlight is the best source of vitamin D. But you can also find it in supplements (aim for about 600 IU a day) and in certain foods, such as:
- swordfish (566 IU per 3-ounce serving)
- wild salmon (447 IU per 3-ounce serving)
- vitamin D-fortified orange juice (137 IU per 1 cup serving)
- vitamin D-fortified milk (115-124 IU per 1 cup serving)
Taking a daily multivitamin can also help to protect against breast cancer and to possibly reduce the risk in women who consume alcohol, says Dr. Willett. However, women who are undergoing chemotherapy, radiation or hormone or targeted therapies should avoid herbal or antioxidant supplements, such as vitamins C and E. They can decrease the effectiveness of traditional treatments and interfere with how the body metabolizes them. Experts believe this is because the supplements may also protect tumor cells — not just healthy cells.
5. Maintain a healthy weight
As an overall precaution, women should keep their weight down, particularly in the postmenopausal years. Obesity has been consistently shown to increase the rate of breast cancer in postmenopausal women by 30 to 50%, according to reports from the International Agency for Research on Cancer.
In addition, findings from the American Cancer Society Cancer Prevention Study-II reveal that gaining weight as an adult is an even more important risk factor than current weight for postmenopausal breast cancer. The study found that women who gained 60 or more pounds after age 18 had double the risk of being diagnosed with postmenopausal breast cancer as compared to women who maintained their weight over the same time period. Fat tissue is the largest source of estrogen in postmenopausal women. Therefore, women who gain weight have higher levels of estrogen in their body — a risk factor for breast cancer.
“If you’re overweight after menopause, losing that weight can significantly reduce your risk of breast cancer,” says Dr. Willett.
For More Information
BRCA Breast Cancer Genes and Soy (NutritionFacts.org)
Eating to Reduce Breast Cancer Risk (Susan G. Komen)
Nutrition for Breast Cancer Patients and Survivors (Johns Hopkins Breast Center)
10 Foods to Help Prevent Breast Cancer (Block Center for Integrative Cancer Treatment)
Nurses Health Study 3 (how to join)