More Research Shows a Plant-Based Diet Reduces Cancer Risk

New research shows a significantly decreased risk of colorectal cancer for men who eat a predominately plant-based diet.

The connection between diet and cancer risk for men is clear, says new research published in the journal BMC Medicine. While researchers did not find a link between colorectal cancer risks and women’s diets, men who ate a plant-based diet reduced their risk by 22 percent.

The study involved nearly 80,000 men in the U.S.; men have a higher risk of developing digestive cancers than women. The study also looked at health data from nearly 94,000 women. Nearly three percent of study participants developed bowel cancer during the study period.

Higher risk for colorectal cancer in men, bigger plant-based benefit

According to the researchers, the link between diet and cancer risk is abundantly clear for men: more plant-based, whole foods are essential in decreasing the risk factor.

“Colorectal cancer is the third most common cancer worldwide and the risk of developing colorectal cancer over a lifetime is one in 23 for men and one in 25 for women,” said the study’s corresponding author, Jihye Kim from Kyung Hee University, South Korea.

“Although previous research has suggested that plant-based diets may play a role in preventing colorectal cancer, the impact of plant foods’ nutritional quality on this association has been unclear. Our findings suggest that eating a healthy plant-based diet is associated with a reduced risk of colorectal cancer.”

The researcher team classified nearly 200 foods into three groups: healthy plant foods, such as whole grains, fruits, vegetables, nuts, beans, tea, and coffee; less healthy plant foods, which included refined grains, potatoes, added sugars, and fruit juice; and animal foods, including dairy, eggs, meat, and seafood. Survey respondents indicated how frequently they consumed items from each food group.

“We speculate that the antioxidants found in foods such as fruits, vegetables, and whole grains could contribute to lowering colorectal cancer risk by suppressing chronic inflammation, which can lead to cancer,” said Kim.

“As men tend to have a higher risk of colorectal cancer than women, we propose that this could help explain why eating greater amounts of healthy plant-based foods was associated with reduced colorectal cancer risk in men but not women.”

The researchers found ethnicity also played a role in the risk; Japanese American men reduced their cancer risk by 20 percent, but white men reduced it 24 percent.

“We suggest that the association between plant-based diets and colorectal cancer risk may have been strongest in Japanese, American and white men due to differences in other colorectal cancer risk factors between racial and ethnic groups,” said Kim. “However, further research is needed to confirm this.”

Meat-cancer connection

While the findings don’t make conclusions about meat’s relationship to cancer, the World Health Organization’s e International Agency for Research on Cancer (IARC), established a link in 2015, naming processed meats including hot dogs and lunch meat, known human carcinogens.

The IARC said each 50-gram portion of meat consumed per day increased the colorectal cancer risk by 18 percent.

“For an individual, the risk of developing colorectal cancer because of their consumption of processed
meat remains small, but this risk increases with the amount of meat consumed,” Dr. Kurt Straif, Head
of the IARC Monographs Programme said in 2015.

“In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.”

A number of studies have pointed to the benefits of a plant-based diet in decreasing the risk for cancer. The American Institute of Cancer Research and American Cancer Society both recommend a diet high in plant-based foods. Earlier this month, plant-based meat brand Beyond Meat and the American Cancer Society partnered to research the benefits of vegan meat in cancer prevention.

Lead image courtesy of Unsplash.