Let’s be clear from the start: According to countless studies, there is no single food that will either prevent or cause breast cancer.
“Using this language creates a lot of patient blame and shame,” said Dr. Eleonora Teplinsky, a board-certified medical oncologist and the head of breast medical oncology at New Jersey’s Valley-Mount Sinai Comprehensive Cancer Care. “I prefer to discuss the topic in terms of risk reduction.”
As Teplinsky suggests, there is evidence that lifestyle choices can impact cancer risk. In general, exercising, choosing a healthy diet and limiting alcohol consumption have been shown to lower the odds of breast cancer.
What’s a healthy diet for those at risk of breast cancer?
“The evidence has clearly shown that being overweight poses a higher risk for breast cancer,” said Dr. Polly Niravath, a board-certified oncologist with Houston Methodist Neal Cancer Center. “Therefore, I always recommend a diet with lean proteins, fruits and vegetables on the plate.” She also suggests avoiding high-sugar processed foods.
Teplinsky noted that plant-forward and Mediterranean diets may help reduce cancer cell growth through their antioxidant, anti-inflammatory and antiproliferative properties. “They may also reduce DNA damage, leading to reduced cancer risk,” she explained.
Increased production of estrogen and insulin has been associated with the development of breast cancer, according to Dr. Thomas Strack, chief medical officer at Faeth Therapeutics, a cancer treatment company that incorporates nutrition as a therapy. It follows, then, that diets featuring foods that decrease those hormone levels — like the Mediterranean diet — may help prevent the disease from flourishing, Strack said.
“Increasing consumption of high-fiber foods, foods containing polyunsaturated fatty acids, such as olive or fish oil, fruits and vegetables, may have a protective role by reducing hormones such as estrogen and insulin, and factors that cause chronic inflammation,” Strack explained.
The idea that being overweight increases the risk of breast cancer has been confirmed — by a variety of medical studies.
“Weight gain in middle life contributes substantially to breast cancer risk,” says a 2004 study by Michelle Holmes and Walter Willett titled ”Does diet affect breast cancer risk?” “Available evidence is strong that breast cancer risk can be reduced by avoiding weight gain during adult years.”
Are certain cooking methods more dangerous than others?
Although no single food or ingredient has been linked with the development of breast cancer, experts say the way we cook our food may impact its health-related danger.
“Charring food does make it carcinogenic,” Niravath said. According to the American Institute for Cancer Research, charring meat, poultry or fish may lead to the formation of heterocyclic amines, or HCAs, which are carcinogens that have been shown to potentially cause cancer. HCAs are formed when amino acids and creatine react to high cooking temperatures.
Word to the wise: Avoid charring your food. Consider marinating your proteins ahead of time and cooking them on either low or indirect heat for a longer time.
The soy myth
For decades now, reports regarding the negative effects of soy on diet in general — and the food’s potential link to cancer — have been making the rounds. Turns out, though, that soy is actually not putting you at higher risk of breast cancer.
“Some of the misunderstandings come from the fact that studies in people and studies in animals may show different results,” the American Cancer Society explained on its website. “In some animal studies, rodents that were exposed to high doses of compounds found in soy called isoflavones showed an increased risk of breast cancer. This is thought to be because the isoflavones in soy can act like estrogen in the body, and increased estrogen has been linked to certain types of breast cancer.”
Rodents, however, process soy differently than people — which is why similar results have not been seen in studies on humans.
“In human studies, the estrogen effects of soy seem to either have no effect at all, or to reduce breast cancer risk (especially in Asian countries, where lifelong intake is higher than the U.S.),” the American Cancer Society noted. “This may be because the isoflavones can actually block the more potent natural estrogens in the blood.”
Strack made clear that “soy is no longer considered a ‘risky’ food for patients at risk for or with breast cancer.”
“On the contrary, soy has plenty of constituents that reduce inflammation and promote healthy metabolism, offsetting the potential risk from estrogen like plant hormones,” Strack said.
Does alcohol increase the risk of breast cancer?
Overall, studies have found that too much alcohol may, indeed, contribute to an increased risk of breast cancer. Liquor can raise estrogen levels, according to the American Cancer Society, which contributes to the growth and development of breast tissue.
Studies have consistently associated an increased risk of breast cancer with alcohol intake, the National Cancer Institute reported. Data from 118 individual studies show that light drinkers have a slightly increased risk of breast cancer than nondrinkers, NCI said. For moderate drinkers, the risk is 1.23-fold higher, and for heavy drinkers it’s 1.6-fold more.
Niravath recommends limiting yourself to three or fewer alcoholic drinks per week.