Expert: Much of Cancer is Preventable With Lifestyle Changes, Not Diet Alone

Much of cancer incidence is preventable, explained Dawn Mussallem, DO, DipABLM, consultant in the Department of Hematology Oncology and assistant professor of medicine at Mayo Clinic, diagnostic breast specialist at the Robert and Monica Jacoby Center for Breast Health, and medical director for the Mayo Clinic Florida Lyndra P. Daniel Center for Humanities in Medicine, during her keynote presentation at the 2023 NCODA International Spring Forum.

Mussallem noted that the World Health Organization estimates that 35% to 50% of all cancers globally are preventable, whereas the American Cancer Society has found that 42% of all cancers in the United States are preventable.

“I really would love to put all of us out of business,” Mussallem said during the presentation. “Much of cancer doesn't even have to happen.”

Dawn Mussallem, DO, DipABLM, discusses the importance of dietary health in cancer prevention during the keynote presentation at the 2023 NCODA International Spring Forum.

Mussallem explained that unfortunately, there is not a single food or tool that can prevent all individuals from acquiring cancer. Instead, there are 6 pillars of lifestyle that people can adopt to best prevent cancer: a whole-food, plant-predominant eating pattern; physical activity; restorative sleep; stress management; avoidance of risky substances; and positive social connections. Mussallem noted that Anne Ornish and Dean Ornish provide examples of the impact of these 6 pillars on cancer occurrence in their book Undo It!: How Simple Lifestyle Changes Can Reverse Most Chronic Diseases.

“In one study—[Dean Ornish] got 30 men who had early-stage prostate cancer, and he put these men onto an intensive lifestyle change program for 3 months,” Mussallem said. “They were on a low-fat diet that was whole food and plant-based, they did 16 minutes of stress management practices a day—that's probably the hardest part of this whole thing—they did 30 minutes of walking 6 days a week, and they had a social connection opportunity once a week for 60 minutes with other people.”

The results of the study showed that 501 genes were favorably influenced, with down regulation to the genes they wanted to down regulate, and up regulation for the ones they wanted to up regulate. These changes were particularly significant for oncogenes for prostate, breast, and colon cancer.

“And they felt better,” Mussallem said. “Just like what I see with my patients—they felt good during this time.”

Another study from the [European Prospective Investigation into Cancer and Nutrition (EPIC)] trial applied these 6 pillars of healthy living to a population of 23,000, according to Mussallem. The results of this trial showed that incidence of diabetes was prevented by a rate of 93%, heart attacks by 81%, strokes by 50%, and cancers by 36%.

Furthermore, in a study with 906 male patients with early-stage prostate cancer, investigators observed that men who ate a standard American diet were 250% more likely to die from prostate cancer and 67% more likely of dying from any cause, Mussallem explained. However, men who were on a plant-predominant diet had a 36% lower chance of dying then men who weren’t.

“A lot of patients come in to see me like, ‘Dawn I’m vegan. I heard about you, and I want you to talk to me and tell me what else I should do,’” Mussallem said.

She explained that often when she investigates further and looks at their diet logs, she sees that much of the patients’ diets, although vegan, consisted of highly processed food.

“Vegan is not a good word,” Mussallem said.

She noted that a study conducted in France helped demonstrate this point further. Over a period of 20 years, 55,000 women with an average age of 53 were broken up between a highly processed plant-based diet versus a whole food plant-based diet.

The investigators observed that the women on the whole food plant-based diet had a 14% lower risk of breast cancer occurrence. Alternatively, those women on the processed plant-based diet were observed to have a 20% increased risk of breast cancer.

“I’ll never forget this—my daughter was friends with this little boy in high school. He was vegan and he thought he was so healthy. He loved coming to my house, but he only wanted to eat French fries and ketchup. I was like, ‘When you come here, you’re going to eat healthy vegan food,’” Mussallem said. “I think the most important part about a whole food plant-based diet is the first part: the whole food part. The second part is eat more plant foods—but this doesn't have to be perfect. I think perfection is sometimes the worst thing we can do. This should be about taking action and doing better than you're currently doing.”

In 2022, JAMA stated that poor diet quality is the leading cause of death in the United States. Today, 90% of Americans do not get 5 servings of vegetables and fruits, Mussallem explained.

“We all know this by the way,”Mussallem said. “This is not new information. Sometimes I come up here and it’s like, ‘I don’t know—I’m not telling you guys anything you don’t want to do.’ But it matters when you see this applied to the numbers and the suffering that we're currently experiencing.”

Reference

Mussallem D. Running Through Life with Purpose and Grace: a Survivor Helping Patients Thrive. Presented at 2023 NCODA International Spring Forum; March 16, 2023.