Top-rated diet lowers cancer risk in a surprising way, new study finds

Plant-based diets boost the health of the planet as well as the health of people, experts say. (monticelllo/iStockphoto/Getty Images via CNN Newsource)

Meals from the sunny Mediterranean have been shown to reduce the risk of developing prostate, cervical and colorectal cancer, while also decreasing the risk of women dying from any cancer by 17 per cent.

The Mediterranean diet also wins gold medals for healthy weight loss and lowering obesity. Obesity is a leading risk factor for cancer and many other chronic diseases such as Type 2 diabetes, heart and kidney disease, stroke and more.

Now, a large, observational study sheds light on the ways in which the Mediterranean diet may reduce cancer risk — and it’s not just via weight loss.

“This was somewhat surprising. Adherence to the Mediterranean Diet was associated with lower obesity-related cancer risk regardless of BMI (body mass index) or fat distribution,” said first author Inmaculada Aguilera-Buenosvinos, a postdoctoral scientist in the department of preventive medicine and public health at the University of Navarra’s Institute for Health Research in Pamplona, Spain

“This suggests that other mechanisms — such as reduced inflammation, improved metabolic health, or dietary interactions with the microbiome — may be responsible for the protective effects,” said Aguilera-Buenosvinos, also a postdoctoral scientist at the World Health Organization’s International Agency for Research on Cancer, in an email.

A plant-based diet

The Mediterranean diet features simple, plant-based cooking, with much of each meal focused on fruits and vegetables, whole grains, beans and seeds, with a few nuts and a heavy emphasis on extra-virgin olive oil. Fats other than olive oil, such as butter, are consumed rarely, if at all, and sugar and refined foods should be avoided.

Plant-based meal plans like those in the Mediterranean diet are full of fiber, said Lindsey Wohlford, a wellness dietitian at the University of Texas’ MD Anderson Cancer Center in Houston. She was not involved in the study.

“Fiber contributes to fullness and supports a healthy microbiome,” Wohlford said. “Plants are also packed with antioxidants and phytonutrients, which appear to reduce inflammation in the body. We have to eat a variety of plants to get the different nutrients and antioxidants that may help reduce overall cancer risk.”

In the Mediterranean diet, red meat is used sparingly, often only to flavor a dish. Eating healthy, oily fish, which are packed with omega-3 fatty acids, is encouraged, while eggs, dairy and poultry are eaten in much smaller portions than in the traditional Western diet.

The highly processed foods typical in a Western diet can contain chemicals and additives that cause “oxidative damage which can lead to cancer,” said Dr. Neil Iyengar, associate professor of medicine at Weill Cornell Medical College and breast cancer oncologist at Memorial Sloan Kettering Cancer Center, both in New York City.

“What we put into our bodies every day can impact nearly every function of our body through hormones, fat and muscle tissue, and the delicate balance of bacteria in our gut,” said Iyengar, who was not involved in the new study.

“Consuming a minimally processed, plant forward diet can help to reduce or even reverse the oxidative damage that a poor diet can cause to our body,” he said in an email. “We are also starting to see some limited evidence that this type of diet — minimally processed, high fiber, and plant-forward — may even help some cancer therapies to be more effective.”

Each dietary change helps

The study, published Tuesday in JAMA Network Open, analyzed diet and medical data on more than 450,000 people taking part in the European Prospective Investigation into Cancer and Nutrition, or EPIC study, which enrolled participants between 35 and 70 years from 1992 to 2000 across 23 centers in 10 countries. Three of those countries — Greece, Italy and Spain — are known for their use of the Mediterranean diet; the other seven countries are not (Denmark, France, Germany, the Netherlands, Norway, Sweden and the U.K.).

People who most closely adhered to the Mediterranean diet had about a 6 per cent lower risk of developing obesity-related cancers compared to those with less adherence, the study found. While that number may appear small, the significance grows when applied to larger populations, Aguilera-Buenosvinos said.

“Even a small reduction in risk at the individual level can translate into thousands of preventable cancer cases when applied at the population level,” she said. “Promoting adherence to the Mediterranean Diet as a low-cost, accessible, and sustainable dietary pattern could have a major impact on cancer prevention strategies.”

Having occasional breaks from the diet also helped keep cancer at bay, although not as much as fully embracing the Mediterranean style of eating, the study found.

“In other words, it’s ok to have a ‘cheat’ meal here and there,” Iyengar said. “The diet had an even higher protective effect for smokers, which is likely because smokers are starting at a higher risk compared to non-smokers.”

Oddly, the study did not find the Mediterranean diet lowered the risk of hormone cancers, such as breast cancers, a finding that contradicts prior research.

Tips for getting started on the Mediterranean diet

Americans are used to eating ultraprocessed foods, which populate up to 70 per cent of all grocery store shelves, so moving to a plant-based diet can appear difficult at first,

“It can be very overwhelming if you’re not used to eating the Mediterranean diet or plants in general,” Wohlford said. “Set small goals. A good first step is look at what your diet might be missing rather than focusing on removing forbidden foods.”

Add blueberries to your morning meal, munch on a handful of nuts for a snack, and eating a salad with lunch are good ways to start, she said. Then try to fill more of your dinner plate with vegetables, whole grains and legumes, and consider a piece of fruit for dessert.

“We really want a consistent diet that can be sustained over time,” Wohlford said. “Trying a Mediterranean style diet for three or four months to meet certain metrics is not necessarily going to reduce your risk of cancer. You want to adopt this type of diet consistently throughout the course of the rest of your life.”

Article written by Sandee LaMotte, CNN