Breast cancer affects 1 in 8 women and 1 in 880 men. While there are many non-modifiable cancer risks, lifestyle influences are increasingly recognized as major contributors to the risk and recurrence of breast cancer.
As of 2019, approximately 30% of Americans are considered obese. In addition to the well-established increased risk of cardiovascular disease and type 2 diabetes, obesity and diet-related factors are thought to contribute to 30-40% of cancers today including prostate, colorectal, endometrial, kidney, pancreatic, esophageal, liver, and post-menopausal breast cancers.
Central obesity, or that concentrated around the abdomen and internal organs, has been shown to be especially harmful as it has more pro-inflammatory and cancer promoting activity.
The great news is that studies increasingly point to cancer fighting foods and lifestyle interventions.
Cancer Fighting Foods
Fresh fruits and vegetables: A primarily plant-based diet can decrease breast cancer risk by about 15%. Some of the best are cruciferous veggies (broccoli, cauliflower, Brussels sprouts, kale), tomatoes, carrots, dark berries
Foods high in omega-3 fatty acids: especially raw tree nuts (almonds, cashews, walnuts) and seeds
Avoiding alcohol: 3 drinks per week is associated with a 15% increased breast cancer risk, with an additional increased risk of 10% per drink per day
High fiber diet: Aim for >30 grams/day. Some of the best foods for this are whole grains (whole wheat berries, faro, quinoa, oats, and barley) and legumes (beans/lentils)
Soy: Although there was once controversy around soy intake, recent studies have shown that diets high in soy content are associated with lower breast cancer risk and recurrence.
Low-fat and fermented dairy products: These are high in Vitamin D, which is a cancer fighter. Dairy can also be high in saturated fats, which should be consumed in moderation
Good fats: Nuts, avocado, and olive oils
Avoid
Red and processed meats: These can increase breast and colon cancer risk by 6% and 9%, respectively
Processed foods and sugars: Especially avoid soda and juice. A 2019 NIH study showed that highly processed foods led to an average increased intake of 500 calories/day compared to unprocessed foods
Lifestyle Interventions
Exercise: Moderate daily exercise especially walking at a brisk pace; best effects are seen at levels greater than 4 hours per week
Smoking cessation: Smoking is still a leading cause of many cancers. Fortunately, there are abundant free resources for help (www.project filter.org)
The Take-Away
Eat like you live on a farm, consuming plenty of fresh fruits and vegetables, minimal processed foods, and red meats. Evidence based reviews show that overall, the Mediterranean diet most closely adheres to these foods. A sedentary lifestyle paired with excessive intake of high calorie foods, in conjunction with a low intake of healthy foods, ultimately leads to a risk of obesity and cancer. Rather than any one fad diet, focus should be on daily steps we can all take to improve our health.