How to reduce the risk of cancer in your diet – Harvard Gazette

We all know that we are what we eat. Unfortunately, the rule extends to cancer.

More research shows that diet not only affects the risk of obesity, diabetes, and heart disease, but cancer as well, according to experts who convened a panel Monday at the Harvard TH Chan School of Public Health.

Ultra-processed foods—think chips, sweets, and meals that come from the factory rather than the field—are a large part of the US diet and have been linked to cancer rates. Other problem foods include processed meats such as bacon, hot dogs, and common deli items. And, despite the ongoing debate about whether alcohol is good or bad for heart health, when it comes to cancer, the consequences of the drink are pretty clear. It is a carcinogen, according to Timothy Rebbeck, the Vincent L. Gregory Jr. Professor of Cancer Prevention. of Chan School.

The biological mechanisms behind different cancers vary, but inflammation is a common culprit. When diet-induced low-level inflammation becomes chronic, stressed cells can lead to disease.

“Chronic inflammation happens over years and years and the cells become dysregulated, mutated,” Rebbeck said. “That’s the kind of inflammation that we think diet and nutrition—as well as other things—could have an effect on and would be very important in causing cancer.”

The “other things” include high levels of insulin circulating in the body, as occurs with obesity and early stage Type 2 diabetes, and certain fats.

“With high levels of inflammation and insulin — and some lipids are probably cancer-promoting — that’s the biggest influence that diet has on cancer,” said Edward Giovannucci, professor of nutrition and epidemiology at the Chan School .

Eliza Leone, a registered dietitian, also participated in “Reducing Cancer Risk through Nutrition,” which was done in partnership with the Zhu Family Center for Global Cancer Prevention. Gabrielle Emanuel, senior health and science reporter at WBUR, moderated the panel.

As with people focused on heart health and blood sugar, those trying to reduce cancer risk should maintain a diet heavy in fruits and vegetables, along with whole grains and healthy proteins, the panels said. Cut back on red and processed meat, they added.

“A plant-based diet is generally known to be very helpful for long-term health,” Leone said. “That’s a lot of plants, but not just plants.”

The Harvard Healthy Eating Plate is 50 percent fruits and vegetables, she said. The rest is split between whole grains and healthy proteins.

While panelists urged consumers to be wary of health claims about supplements, they noted that studies have suggested that vitamin D has cancer-fighting properties. Results from the VITAL study, led by investigators at Harvard Medical School and Brigham and the Women, vitamin D supplements taken over six years reduced cancer death rates.

Giovannucci said folate, commonly sold as folic acid, may be beneficial against the disease. He warned against megadosing, however, because some compounds, such as selenium and zinc, can promote the disease in very high doses.

Panels also covered the benefits of exercise, including as a measure against bladder, breast, colon, endometrial, esophageal, stomach and kidney cancers. One key reason is the anti-inflammatory power of physical activity, Giovannucci said.

Intermittent fasting has become very popular in recent years, but there is little evidence that the method lowers cancer risk. (Weight control does.) The problem with the regimen, Leone said, is that people often feel justified in eating whatever they want, including junk, when they’re not fasting. Plus, she said, most diets aren’t sustainable long-term and it’s best to focus on healthy choices and portion control.

That kind of control isn’t always easy, the panels acknowledged. More time in the kitchen is a good first step.

“One of the most important things you can do to increase nutrition in your life is to become more comfortable in the kitchen—all of these nutrition recommendations are about what you eat,” Leone said. “With all the research out there, it’s overwhelming. Just start somewhere. Pick one thing that is possible for you and do that.”