Diet

Which Diets Help Lower Cancer Risk?

Cancer is the second-leading cause of death in the United States.1 Data from the Centers for Disease Control and Prevention show that nearly 600,000 deaths in the United States were attributable to cancer in 2017.1

Several aspects play a role in reducing cancer risk, including diet, and patients may often ask what foods they can eat or avoid to lower their cancer risk. While there is not one food that can fully accomplish this task, evidence indicates that pursuing healthy dietary patterns favoring plants and whole foods is typically associated with the best outcomes.

“Research supports that, in addition to maintaining a healthy weight, eating a diet rich in plant-based foods may reduce the risk of cancer,” Alicia Romano, MS, RDN, national spokesperson for the Academy of Nutrition and Dietetics, told Nutrition411. “Ideally, two-thirds of the plate should be made up of plant-based foods including vegetables, fruits, whole grains, or beans, and one-third or less from animal proteins. Choosing less red meat and processed meat, with an emphasis on fish, lean poultry, and plant-based protein sources, is also ideal,” she added.

In addition to these, the Academy of Nutrition and Dietetics names several other dietary strategies associated with decreased cancer risk, including limiting calorie-dense, nutrient-deficient foods; focusing more on plant proteins than animal proteins; and curtailing alcohol intake.2

What Diets Does Evidence Suggest are Associated With Reduced Cancer Risk?

A number of diets encourage these healthy eating patterns laid out by the Academy of Nutrition and Dietetics, including some that were featured in 2020’s U.S. News and World Report annual rankings of best diets. This year’s top 3 overall diets are the Mediterranean Diet, Dietary Approaches to Stop Hypertension (DASH) Diet, and Flexitarian Diet.

What remains consistent between all 3 diets, Romano said, is their emphasis on plant-based foods. “These 3 diets are all rich in fruits, vegetables, and, whole grains, and also emphasize reduction of red meat intake and processed food intake,” she explained.

Research indicates that the Mediterranean diet, named the top overall diet several years in a row, has a wealth of health benefits. Best known for its focus on fruits, vegetables, grains, olive oil, and low to moderate consumption of fish and poultry, the Mediterranean diet has been shown to be beneficial in several studies at reducing cancer risk.3 A 2017 systematic review and meta-analysis of 83 studies (N=2,130,753) found that the Mediterranean diet appears to have a protective effect against cancer mortality and risk of several cancer types, including colorectal cancer (CRC), breast cancer, gastric cancer, liver cancer, head and neck cancer, and prostate cancer.4 Notably, researchers found that the diet’s protective effects against cancer were largely attributable to consumption of fruits, vegetables, and whole grains.

Named second-best diet in the 2020 diet rankings, the DASH Diet emphasizes decreased sodium intake and increased consumption of vegetables, fruits, and low-fat dairy foods, as well as moderate amounts of whole grains, fish, poultry, and nuts.5

The DASH diet has been studied especially in relation to reduction in CRC risk, said Romano. A 2019 meta-analysis of 6 studies found that DASH Diet adherence was associated with a decreased risk of CRC.6 Researchers concluded that promoting consumption of a healthy diet rich in whole grains, vegetables, fruits, and low-fat dairy products, while reducing intake of salt, sweets, and saturated fat, could help reduce CRC risk.6

Tying with DASH for second place in this year’s diet rankings is the Flexitarian Diet, which is essentially a plant-based diet that allows low to moderate meat consumption. Although there have not yet been robust studies specifically on Flexitarian diets and cancer, a well-planned Flexitarian Diet that is rich in whole fruits, vegetables, whole grains, beans, nuts, and seeds, and reduced in total animal protein intake, would correlate with general dietary advice for reduced cancer risk, said Romano.

The Take-Home Message

Along with being physically active and maintaining a healthy weight, adopting healthy diets like the Mediterranean Diet, DASH Diet, Flexitarian Diet, and similar dietary patterns can help reduce cancer risk in generally healthy people.

“Eating healthy does not have to be complicated. At the end of the day, access to accurate and evidence-based nutrition education is paramount, and it is the job of the dietitian to help educate patients on healthy dietary patterns and improve access to reliable nutritional resources,” Romano told Nutrition411.

—Christina Vogt

References:

  1. Leading causes of death. National Center for Health Statistics. Centers for Disease Control and Prevention. https://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm. Page last reviewed March 17, 2017. Accessed January 20, 2020.
  2. Gordon B. 7 cancer Prevention tips for your diet. Academy of Nutrition and Dietetics. https://www.eatright.org/health/diseases-and-conditions/cancer/7-cancer-prevention-tips-for-your-diet. Page last reviewed September 2018. Accessed January 20, 2020.
  3. What is the Mediterranean diet? American Heart Association. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/mediterranean-diet. Page last reviewed January 9, 2020. Accessed January 20, 2020.
  4. Schwingshacki L, Schwedheim C, Galbete C, Hoffmann G. Adherence to Mediterranean diet and risk of cancer: an updated systematic review and meta-analysis. Nutrients. 2017;9(10):1063. https://doi.org/10.3390/nu9101063.
  5. DASH diet: healthy eating to lower your blood pressure. Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/dash-diet/art-20048456. Page last updated May 8, 2019. Accessed January 20, 2020.
  6. Mohseni R, Mohseni F, Alizadeh S, Abbasi S. The association of Dietary Approaches to Stop Hypertension (DASH) diet with the risk of colorectal cancer: a meta-analysis of observational studies. Nutr Cancer. 2019:1-13. doi:10.1080/01635581.2019.1651880.