Plant-based diet could lower risk of colorectal cancer by nearly a quarter

By Alice Clifford via SWNS

A plant-based diet could lower the risk of colorectal cancer by nearly a quarter - but only in men, a new study reveals.

Amongst men, the effect of the diet depends on your ethnicity with white men benefiting more than some other races.

Out of almost 80,000 men studied, those who ate high amounts of healthy plant-based foods had a 22 percent lower risk of colorectal cancer.

However, researchers did not identify any significant links between the nutritional quality of plant-based diets and colorectal cancer risk among almost 94,000 women in the study.

Dr. Jihye Kim, a professor in the department of medical nutrition at Kyung Hee University, South Korea, an author of the study, said: “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.

“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.”

She added: “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.

"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 team also found that this link varied depending on race and ethnicity.

Among Japanese American men, colorectal cancer risk was 20 percent lower for those who ate the highest amount of healthy plant-based foods.

This type of food also had a positive impact on white men. Those who ate high amounts of healthy plant-based foods were 24 percent less likely to suffer from colorectal cancer.

However, there was no significant difference between men who did and did not eat a healthy plant-based diet among African American, Latino or Native Hawaiian men.

Dr. Kim said: “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.

“However, further research is needed to confirm this.”

A healthy plant-based diet includes eating whole grains, vegetables, and legumes.

Contrastingly, unhealthy plant-based foods could be refined grains, fruit juices, and added sugars.

The team analyzed the data from 79,952 men and 93,475 women from Hawaii and Los Angeles.

On average, male participants were aged 60 and female participants were aged 59 at the beginning of the study.

Of all the people involved, 30.2 percent of men were Japanese American, 25.8 percent were white, 24 percent were Latino, 13 percent were African American and seven percent were Native Hawaiian.

Each participant reported their usual food and drink intake during the previous year.

The researchers then assessed whether their diets were high in plant-based foods.

Finally, they calculated the incidence of new colorectal cancer cases until 2017 using data from cancer registries.

The team accounted for participants’ age, family history of colorectal cancer, BMI, smoking history, physical activity levels, alcohol consumption, multivitamin use and treatment, and daily energy intake.

They also considered the use of hormone replacement therapy among women.

Of all the participants, 2.9 percent developed colorectal cancer during the study period.

Yet due to the observational nature of their study, the researchers urge caution as their results cannot be fully conclusive.

This could be because they didn’t take into account the positive effects of other foods such as fish and dairy.

Similarly, as their diets were recorded at the beginning of the study, they may not be representative of their diet throughout their lifetime.

The study was published in the journal BMC Medicine.