Fighting Breast Cancer by the Forkful
If the marketing onslaught of pink everything hadn’t clued you in to the fact that October is breast cancer awareness month, consider yourself officially informed. Sigh. If only using my pink blender while wearing my pink lip gloss and eating a pink York peppermint patty could help lower my risk of breast cancer…I’d have the most benign bosoms on the Eastern seaboard.
Luckily, nutrition science has several pink-ribbon-worthy morsels to offer us as far as things we can actually DO (or eat, or not eat) to lower our individual risks of developing breast cancer.
Best evidence: These things should definitely help lower your risk:
- Lose that gut. Being overweight both increases your risk of developing breast cancer, as well as decreases your risk of survival if you have breast cancer. The risk of developing breast cancer is particularly pronounced if you become obese after menopause, with some studies showing as much as a 50% increase in risk. After menopause, the more weight you gain, the greater the risk increases. It also appears that women whose excess fat is concentrated around the belly have a higher risk of developing breast cancer than women whose excess weight is more evenly distributed among their hips and thighs. There are a million reasons to maintain a healthy body weight, and now you can add breast cancer prevention to that list.
- Lay off the sauce. Even moderate alcohol consumption (average of 1 drink/day for women) is associated with an increased risk in breast cancer compared to not drinking at all. And the more you drink, the greater the risk. It appears that alcohol increases the risk of a type of tumor classified as “estrogen or progesterone receptor positive,” suggesting that alcohol works by influencing circulating hormone levels. If you choose to drink (and I personally do), consider targeting a range closer to a drink or two per week instead of a drink or two per day.
- Exercise most days. 30-60 minutes. Moderate is good, but vigorous is better.
Good evidence: These things will probably help lower your risk:
- If you do drink regularly, make sure to meet your daily folate needs. Folate is a B-vitamin that is required for normal cell replication. Drinking alcohol impairs absorption of dietary folate. Studies seem to show that folic acid supplementation can help mitigate the risk of developing cancer among women who use alcohol regularly, but it does not reduce the risk of breast cancer among non-drinkers. The amount of folic acid in a typical multivitamin (400-600mcg) should suffice for moderate drinkers when taken in addition to a diet that includes some fruits, green vegetables and fortified breads/cereals.
- Eat more (organic), traditionally-prepared soy foods. Several large, well-designed studies out of Asia show significant decreases in breast cancer risk among women who consume higher amounts of whole or traditionally-prepared soy foods, such as tofu, misso, tempeh, natto and/or boiled soybeans (edamame) as compared to women who consume the lowest amounts of these foods. Note that there is no good data to support that you can get this same effect from eating processed Western foods loaded up with soy protein isolate (SPI), and some reasons to be wary of doing so. However, if you have a digestive intolerance to soy or have thyroid abnormailities, steer clear of soy; there are plenty of other things you can do to help reduce your breast cancer risk without aggravating the rest of your body. I understand that the message on soy and breast cancer is a confusing one, with some women concerned that dietary soy may actually *increase* breast cancer risk, but the scientific literature (human studies) does not support this association.
- If you can’t/don’t eat soy, eat flax. There is some evidence that suggests eating foods high in phytoestrogen compounds called lignans may have a similar protective benefit as do the phytoestrogenic compounds called isoflavones found in soy; the best dietary source of lignans, hands down, is flaxseed. Besides, flaxseed is a great source of fiber and omega-3’s, so you can kill 3 birds with one vegetarian stone. You multi-tasker, you.
- Go easy on the fat. Most (but not all) studies show that lower-fat diets are associated with a lower risk of breast cancer, particularly diets that are low in saturated and trans fats. In the typical U.S. diet, saturated fat is mostly found in red meat, milk and cheese , whereas trans fats are found in fast foods, margarine, and commercially-baked goods. The best way to minimize saturated fat in your diet is to eat low-fat dairy instead of full-fat, go for quality over quantity with your cheese intake, and use meat as an accent rather than as the main event. I’d advise avoiding trans fat alltogether if possible. Be aware of deceptive marketing tactics pertaining to trans fats: many restaurants or food packages claim “0g trans fats per serving.” It’s that “per serving” you need to watch out for, as they can legally claim 0g if each serving has <0.5g. Are you really going to just be eating just one serving of that food? If not, then you could be eating several grams of trans fat without realizing it. If the label reads “partially hydrogenated oil” of any kind, the food will have trans fats, regardless of what the marketing claims.
Emerging but as-yet inconclusive evidence: These things may help lower your risk:
- Improve your Vitamin D status. Recent government data shows that a frightening 77% of Americans have a Vitamin D insufficiency, and that an astounding 97% of non-hispanic black Americans are Vitamin D insufficient. And the trends show our collective vitamin D status is worsening– NOT improving– due in large measure to more sedentary, indoor-based lifestyles, sunscreen use, and low intake of fortified dairy products. What’s more, even people who take in the current recommended levels of Vitamin D are still coming up deficient, leading most researchers to conclude that the currently recommendations are too low. While there are not yet any human studies which show an association between Vitamin D supplementation and reduced breast cancer, there is mounting circumstantial evidence that points in that direction. Breast cells actually have vitamin D receptors to supply them with this much-needed vitamin, which is shown to have a role in proper cell division and differentiation. Breast cancer tumor cells have Vitamin D receptors too, and in vitro, Vitamin D has been shown to stop them from replicating. Epidemiological evidence shows lower rates of breast cancer among people with greater exposure to the sun, since our bodies are able to manufacture Vitamin D from UV rays. Since Vitamin D is so important for numerous health outcomes– of which breast cancer prevention is just one possible such outcome–and since Vitamin D is virtually absent from our food supply, it’s not a bad idea for most people to take a supplement–at least during the winter months. Personally, I supplement 1,000 IU of Vitamin D3 per day from October through May, and make sure to get 15 minutes of unprotected sun exposure on my arms from June-September. This level of supplementation is safe for everyone, and it should be sufficient to increase your vitamin D status to sufficient levels when taken in addition to a diet that includes some fortified dairy/dairy substitutes, fatty fish (like sardines, salmon, herring and mackerel) and/or other sneaky Vitamin D-rich foods, like dried shiitake mushrooms.