Plant-based diet could cut bowel cancer risk in men by 22 per cent

Published in the journal BMC Medicine, the study involving 79,952 US-based men found that those who ate the largest amounts of healthy plant-based foods had a 22 per cent lower risk of bowel cancer compared with those who ate the least.

However, the researchers found no such link for women, of whom 93,475 were included in the research. The team suggested that the link is clearer for men, who have an overall higher risk of bowel cancer.

All participants in the study were asked how often they ate certain foods and drink from a list of more than 180 items. They were also asked about portion size.

They would then tick that they consumed each food item ‘never or hardly ever’ up to ‘two or more times a day.’ For drinks, the responses ranged from ‘never or hardly ever’ to ‘four or more times a day.’

The food groups were classed as healthy plant foods (whole grains, fruits, vegetables, vegetable oils, nuts, legumes such as lentils and chickpeas, tea and coffee), less healthy plant foods (refined grains, fruit juices, potatoes, added sugars), and animal foods (animal fat, dairy, eggs, fish or seafood, meat).

The researchers divided the daily consumption per 1,000 kcal into quintiles, from the biggest consumption to the least. On average, men were aged 60 at the start of the study, while women were aged 59.

Most people diagnosed with bowel cancer are over the age of 60.

The authors found that the link among men also varied by race and ethnicity. For example, among Japanese American men, the reduced risk of cancer was 20 per cent, but it was 24 per cent for white men. The team said more research was needed on the differences between ethnicities.

During the study, 4,976 people (2.9 per cent) developed bowel cancer. Factors aside from diet that were likely to influence the results, such as whether people were overweight, were taken into account.

The researchers have cautioned that the observational nature of the study meant no definitive conclusions could yet be made about a causal relationship between plant-based food intake and colorectal cancer risk. However, the additional health benefits of such a diet should not be overlooked or ignored.

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