Live Well: Diet and Breast Cancer—Sorting Fact from Fiction

Many people enjoy sweets during holidays and celebrations, but some worry that these treats may pose health risks beyond tooth decay. Others believe certain foods can cure cancer. It’s common to reflect on your diet after a breast cancer diagnosis and wonder if different choices could have made a difference.

What Does a Healthy Diet Look Like?

For people with breast cancer, a diet that is lower in fat and high in vegetables, fruit, and whole grains is often recommended. But what about other common claims?

Sugar

A popular myth suggests that sugar “feeds” cancer cells and makes them grow faster. While this isn’t supported by scientific evidence, it’s still wise to limit refined sugars for overall health. Naturally occurring sugars found in fruits and vegetables are not a concern and can be part of a healthy diet.

Soy

Soy has been both praised and criticized in relation to breast cancer. Some worry about phytoestrogens—plant-based compounds in soy that mimic estrogen—while others believe soy may help prevent cancer. The evidence is mixed. One large study suggested that a “higher amount of soy intake might provide reasonable benefits for the prevention of breast cancer,” but “more large scale and well-designed prospective studies are needed to verify findings.” However, minimally processed soy products like edamame—just like other legumes, beans, and lentils—can be a low-fat source of protein, fibre, vitamin B, iron, and phytochemicals which are good for overall health.

Fibre

Fibre may also play a significant role in breast cancer prevention. Research has shown that people who consume the highest amounts of fibre are 8% less likely to develop breast cancer, in comparison to those who eat the least. It’s possible that’s because fibre helps regulate blood sugar, and lower levels of estrogen. Fibre has many other health benefits as well!

“Superfoods” and Trends

Each year brings a new food trend claiming to prevent or cure cancer—alkaline diets, antioxidants, and more. While no single food can prevent cancer, eating a variety of whole, unprocessed foods ensures your body gets the nutrients it needs to stay healthy, whether you're recovering from illness or maintaining wellness.

A Balanced Perspective

It’s natural to want to manage cancer risk through something you can control—like your diet. While there are no guarantees, following general guidelines for healthy eating is always a good idea. Focus on balance, variety, and moderation, and speak with your healthcare provider or a registered dietitian for personalized advice. Registered dietitians are covered under your extended health plan. If you need help finding a registered dietitian in your area, reach out to your Member and Family Assistance Program (MFAP).