Nutrition's Role in Preventing Cancer and Recurrence

Once you’re finished with treatment, a healthy lifestyle is still very important. And while you can’t necessarily prevent a cancer recurrence with good nutrition, more and more research is showing a number of health benefits from eating right and exercising.

The American Cancer Society recommends that cancer survivors follow the same nutrition guidelines that are recommended to help prevent cancer. A study of breast cancer patients has shown that the rate of recurrence was higher in women at an unhealthy weight who didn’t eat an adequate amount of fruits and vegetables. And saturated fat has been linked to a higher rate of prostate cancer coming back.

In addition, poor nutrition may lead to obesity, which has been linked to many cancers, as well as other diseases such as heart disease and diabetes.


Obesity is a condition in which a person has too much body fat in relation to lean body tissue, and consuming too many calories is among its causes. Obesity is defined as having a body mass index (BMI) of 30 or greater (see BMI calculator). While many patients expect to lose large amounts of weight during cancer treatment, many discover that they’re actually adding pounds through the process. In fact, about one in three breast cancer patients experiences more than a 5-percent weight gain in the two years after being diagnosed.

Many new and ongoing studies are attempting to prove the connection between obesity and cancer. One study has made a direct correlation between extra weight – even just being overweight and not obese – and an increased risk of breast cancer recurrence.

Excess body weight can increase the risk for several other types of cancer due to the effects that fat tissues and fat cells have on the body, including:

  • Increasing insulin levels and/or hyperinsulinemia (insulin resistance), which may support tumor development
  • Producing excess estrogen, which has been linked to breast, uterine and other cancers
  • Giving rise to chronic low-level inflammation, which is tied to an increased cancer risk
  • Producing certain hormones, which may stimulate or inhibit cell growth
  • Influencing various proteins, which regulate tumor growth

Losing weight can help regulate some of these issues, which in turn may lower your risk for cancer and recurrence. If you need help maintaining a healthy weight, talk to your dietitian or physician before beginning any dietary changes.

Heart disease

Heart disease broadly refers to coronary heart disease, heart attack, congestive heart failure and congenital heart disease. A diet that’s high in fat, salt and cholesterol can contribute to the development of heart disease, as can obesity.

While heart disease isn’t a risk factor for cancer, various cancer treatments, including chemotherapy, radiation therapy and hormone therapy, can cause or worsen heart disease; especially vulnerable are patients who have heart or vascular conditions prior to the start of their cancer treatment. One study showed that women who had radiation to treat breast cancer increased their risk of heart disease by 3 percent on average.

To combat the increased risk, it’s important for cancer survivors to follow the same nutrition guidelines, including limiting the consumption of red and processed meat. Protein can come from many healthy sources, so try to go meatless several days a week, incorporating other protein sources for your meals, such as a black bean burrito or a hearty lentil soup.

Tip from the dietitian

“A well-balanced diet full of variety can assist in preventing recurrence and cancer cell growth. Colorful fruits and vegetables have compounds that may prevent cancer cells from developing and spreading. Fiber and foods with whole grains can help decrease the amount of time cancer-causing compounds spend in the body, also decreasing the risk for recurrence. And a diet including low-fat or fat-free animal products, such as milk, sour cream, cheese, meats etc., can help you maintain a healthy weight.”

       - Margaret Martin, RD, MS, LDN, registered dietitian, PearlPoint Nutrition Services


Diabetes is a condition in which the body doesn’t make enough insulin, resulting in either high or low levels of blood glucose (sugar). The two types of diabetes include:

  • Type 1: The immune system destroys the body’s ability to produce insulin, which results in an inability to convert glucose into energy. Type 1 diabetes cannot be prevented. It typically arises during childhood and accounts for 5 to 10 percent of all cases of diabetes.
  • Type 2: The body either has too little insulin or cannot use insulin effectively. Among the causes of Type 2 diabetes are obesity, high blood pressure and a high-fat and carbohydrate diet. This type of diabetes occurs most often in adults and accounts for 90 to 95 percent of all cases of diabetes.

People with diabetes are at a significantly higher risk for many types of cancer, including liver, pancreas, uterine and others. A recent study also linked diabetes to a higher risk of recurrence of colon cancer. If diabetes is left untreated and blood sugar levels remain high for an extended period of time, significant damage to the heart, eyes, kidneys and nerves can occur. To prevent this, limit the amount of sugar you consume, partake in regular physical activity and take prescribed insulin and blood sugar medications as recommended by your doctor.