Men who eat a diet rich in vegetables, whole grains, beans and lentils can reduce their risk of colon cancer by more than a fifth, a study found.
Women were also included in the study, but no link was found between eating a lot of plant foods and a lower risk of cancer, which the scientists attributed to men having an overall higher risk of the disease.
The study, published in the journal BMC Medicine, involved 79,952 men and 93,475 women around the age of 60 in the US.
Researcher Jihye Kim, from Kyung Hee University in South Korea, said: “We speculate that the antioxidants in vegetables and whole grains could contribute to lowering [bowel] risk of cancer by suppressing chronic inflammation, which can lead to cancer.’
For the study, people were asked how often they ate certain foods and drinks from a list of more than 180 items.
Portion size was also asked.
Men who eat a diet rich in vegetables, whole grains, beans and lentils can cut their risk of colon cancer by more than a fifth, a study finds (file image)
People could tick that they consumed each food from ‘never or almost never’ to ‘two or more times a day’.
For drinks, answers ranged from “never or almost never” to “four or more times a day.”
The food groups were classified 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 products, eggs, fish or seafood, meat).
The researchers then divided the daily consumption per 1,000 kcal into quintiles, from the largest consumption to the least.
On average, men were 60 years old at the start of the study, while women were 59 years old.
Researcher Jihye Kim, from Kyung Hee University, South Korea, said: ‘Colon cancer is the third most common cancer worldwide and the risk of developing colorectal cancer is one in 23 for men and one in 25 for women.
“We speculate that the antioxidants found in foods such as fruits, vegetables and whole grains may help lower the risk of colorectal cancer by suppressing chronic inflammation, which can lead to cancer.”
“Since men have a higher risk of colorectal cancer than women, we suggest that this could help explain why eating higher amounts of healthy plant foods was associated with a reduced risk of colorectal cancer in men, but not in women.”
The authors found that the link between men also varied by race and ethnicity.
The study, published in the journal BMC Medicine, involved 79,952 men and 93,475 women around the age of 60 in the US (file image)
For example, among Japanese-American men, the reduced cancer risk was 20%, but it was 24% for white men.
The team said more research was needed on the differences between ethnicities.
During the study, 4,976 people (2.9%) developed colorectal cancer, and factors that were likely to influence the results, such as whether people were overweight, were taken into account.
Dr. Helen Croker, head of research interpretation at the World Cancer Research Fund, said: ‘We welcome this research adding to our own evidence that eating vegetables, whole grains and beans reduces the risk of developing colon cancer.
“We also recommend that people limit the amount of red meat they eat and avoid processed meat altogether.
‘Interesting in this paper was that plant-based diets were only associated with a lower risk of colorectal cancer in men. It is speculated that one of the reasons for this may be that men generally had lower intakes of plant foods and higher intakes of animal foods than women – so there may have been a ceiling effect for the benefits women may experience.”
Beth Vincent, health information manager at Cancer Research UK, said: ‘This US study adds to much of the existing evidence on the benefits of eating a balanced diet high in fruit, vegetables and fiber for both men and women.
‘The study tried to compare ‘healthy plant foods’ and ‘unhealthy plant foods’ and found an association with colon cancer in men. But because of the design of the study, the authors themselves acknowledge that we can’t read too much into their results.
‘The study assumed that people could remember what they had eaten a year ago. It also assumed that the participants’ diets remained the same for years and that all meat and animal products were unhealthy – which is not the case.
“Eating a balanced diet can help maintain a healthy weight, which reduces the risk of cancer.”
“Not smoking, cutting back on alcohol, and staying safe in the sun are other important ways to reduce your cancer risk.”