By Cara Murez
Health Day Reporter
TUESDAY, November 29, 2022 (HealthDay News) — Are you an older man concerned about your risk of colon cancer? Eating whole grains, vegetables, fruits and legumes may improve your chances of dodging the disease, new research shows.
“Although previous research has suggested that plant-based diets may play a role in preventing colorectal cancer, the impact of the nutritional quality of plant-based foods on this association has been unclear,” said study co-author Jihye Kim of Kyung Hee University in South Korea : “Our results suggest that a healthy plant-based diet is associated with a reduced risk of colorectal cancer.”
Kim noted that colon cancer is the third most common type of cancer worldwide and that a man has a one in 23 lifetime chance of developing it. A woman has a lifetime risk of one in 25.
The new report was published online on November 29 BMC medicine.
The researchers looked at a population of nearly 80,000 American men and found that those who ate the highest average daily amounts of healthy plant-based foods had a 22% lower risk of colon cancer than those who ate the lowest amounts of those foods .
Studying more than 93,000 American women, researchers didn’t find the same association.
“We speculate that the antioxidants found in foods like fruits, vegetables, and whole grains might help reduce colon cancer risk by suppressing chronic inflammation that can lead to cancer,” Kim said in a journal press release.
“Since men tend to have a higher risk of colon cancer than women, we suggest that this may explain why eating larger amounts of healthy plant-based foods was associated with a reduced risk of colon cancer in men but not in women,” Kim added.
The risk also varied by race. While the risk of colon cancer was 20% lower in Japanese-American men who ate the most plant-based foods than those who ate the least plant-based foods, it was in white men who ate the highest amounts of these healthy foods ate, 24% lower than the men with the most plant-based foods of the same race who ate the least.
No significant associations were found between plant-based diets and colon cancer in Black, Hispanic, or Native Hawaiian men. This could be due to other cancer risk factors that exist in these groups, the study authors suggested.
The data are from a multiracial survey of adults recruited from Hawaii and Los Angeles between 1993 and 1996. About 30% of the male participants were Japanese American, 26% White, 24% Hispanic, 13% Black, and 7% Hawaiian Native.
Study participants reported their usual food and drink intake over the past year. The researchers assessed this intake across healthy and unhealthy plant-based foods, and then calculated the incidence of new colorectal cancer cases through 2017 using data from cancer registries.
Investigators considered other factors such as age, family history of colon cancer, body mass index (based on height and weight), smoking history, physical activity, alcohol consumption, multivitamin use, daily energy intake and, for women, use of hormone replacement therapy. Almost 5,000 participants (2.9%) developed colon cancer during the study period.
The study was observational and failed to establish a cause-and-effect relationship. Nor did it take into account the beneficial effects of fish and dairy products on colon cancer. It is also not known how long the participants stuck to their recorded diets.
Future research is needed to examine genetic and environmental factors that may influence the link between plant-based diets and racial and ethnic colon cancer, the authors said.
The American Cancer Society has more on colon cancer.
SOURCE: BMC medicinePress release, November 29, 2022