One potential piece of the puzzle if you’re of a mind to tweak your lifestyle: diet. Concrete conclusions with regard to diet and disease are tough to come by because smoking-gun studies that prove a correlation between a food and risk are difficult to do. Lots of studies, for example, are based on people’s recall of what they ate. (If you can’t remember what you had for breakfast yesterday you see the problem.) That said, the evidence does, over time, tend to accumulate and lead to a consensus. When it comes to breast cancer, the strongest scientific evidence on the relationship between cancer and diet thus far supports a largely plant-based, anti-inflammatory, fish-oriented diet that avoids red meat, says Joe Feuerstein, MD, an integrative physician in Stamford, Connecticut, who counsels patients with a wide variety of ailments on how to harness their diet for better health. Why is controlling inflammation key? “Inflammation is part of the body’s normal healing response to damage,” says Dr. Feuerstein. “However, as part of this response there is a release of substances in the body that promote cell division, which is not something that is optimal in patients with cancer.” As for red meat, it contains hormones (which can fuel breast cancer growth), endocrine disrupting chemicals, and contains heme (iron), a potentially gene-damaging oxidant, says Feuerstein. Put the meat on the grill and you’ve added heterocyclic amines, compounds associated with cancer risk in lab studies, to the mix. How much of a difference will changing your diet make? “You won’t eliminate your risk” by eating mostly plant-based and anti-inflammatory, says Feuerstein. “But you can try to make the grass of your garden as inhospitable to weeds as possible,” he says. Here are Feuerstein’s top six supermarket picks he recommends to women hoping to avoid breast cancer or to keep it at bay.
Cruciferous Vegetables
This family of vegetables derives its name from cross-like leaves and stems (cruciferous comes from the word crucifix), and includes Brussels sprouts, bok choy, arugula, collard greens, kale, broccoli, and cauliflower. This family of vegetables is high in calcium and two types of compounds in particular — indoles and isothiocyanate — that have been widely studied for their cancer-fighting properties. Studies in animals have been more conclusive than those in humans, but Feuerstein recommends them because “they contain compounds called indole-3-carbinols, which contribute to the detoxification of excess estrogen,” he says. (Estrogen, a hormone, fuels breast cancer growth.) “Consider them your friends,” says Feuerstein.
Eggs
The evidence for eggs as a preventive ingredient is all over the place, says Feuerstein. He recommends a couple a week because, in addition to being a non-meat source of protein, they’re rich in choline, lutein, and zeaxanthin, all micronutrients believed to have disease-fighting properties. (If you’re looking to fill out your breakfast repertoire beyond a couple of eggs a week, Feuerstein is a fan of a yogurt parfait made from a fermented nut yogurt, like a cultured cashew yogurt, with flaxseed and berries.)
Fish
Epidemiological research has long since picked up on the fact that breast cancer is less common in countries where people eat a lot of fish (versus the meat-heavy Western diet). That could be because fish, in addition to being a good non-red-meat source of protein, has anti-inflammatory properties in the form of polyunsaturated fatty acids (PUFAs). Recent research in mice bred for an aggressive form of breast cancer, in fact, found that exposure to PUFAs mitigated the animals’ risk of developing the disease over the course of their lifetimes. “Go with cold-water fatty fish such as tuna — light ‘skipjack’ tuna, not albacore, since the bigger the fish, the more possibility it will have mercury — and sockeye salmon, sardines, herring, and mackerel,” says Feuerstein.
Green Tea
Green tea has been identified as a potential super-ingredient because it is consumed heavily in Asian cultures, where breast cancer risk is lower. Research is ongoing. “We’re finding more and more that there are major antioxidant effects in green tea,” says Feuerstein. Antioxidants help prevent damage to cells from free radicals that are generated as part of normal metabolism and which can cause genetic damage in cells leading to cancer growth. “The polyphenol compounds in the leaves work as antioxidants and detoxify cell-damaging free radicals,” says Feuerstein. Some research suggests that the polyphenols in green tea may also reduce the activity level of estrogen, which fuels breast cancer growth. One major study of post-menopausal Asian women who drank green tea found a 25 percent reduction in breast cancer recurrence, says Feuerstein.
Soy
There was once a lot of concern about women with breast cancer eating soy because the chemical structure of soy is similar to estrogen. But this theory has largely been debunked in many long-range studies, says Feuerstein. “Soy is a nutrient-rich plant protein that contains all nine essential amino acids, which is relatively rare in the plant world,” he says. “It’s an ideal protein source.” When considering which soy product to eat, seek out soy in whole food form, such as tempeh, edamame, miso, and tofu, not soy shakes, supplements or soy protein, he advises. “There is some concern that the concentration of phytoestrogens in processed soy foods is much higher than those in the natural health food product.”
Yogurt
As little as a quarter or ⅓ cup of dairy milk was shown to increase the risk of breast cancer by 30 percent, according to a study published in the International Journal of Epidemiology in 2020. One reason may be the sex hormone content of dairy milk, since cows are lactating (and many are pregnant). But the risk seems to be ameliorated, says Feuerstein, if the dairy is fermented, as it is in yogurt — which is also a good source of calcium and protein. “Yogurt also contains beneficial bacteria, such as probiotics, that may lessen inflammation and lower breast cancer risk,” he says.
