Research shows that eating whole-grain foods may promote healthier weight and lower diabetes risk, and now scientists are studying whether these foods also protect against cancers of the colon and rectum.
A new study, just published in the British Journal of Cancer, found that consumption of whole-grain products may protect against these cancers – but maybe not for everyone.
The researchers used data from the Danish Diet, Cancer and Health cohort study (part of the EPIC* study) that followed over 26,000 men and 29,000 women for about 10 years. They looked at people’s total whole grain consumption as well as specific products: whole-grain rye products, whole-grain bread (mostly wheat) and oatmeal.
Their findings: Higher intake of total whole-grain products was associated with a 15% lower risk of colon cancer among men. They also saw a tendency towards lower risk of rectal cancer among men.
Researchers did not find any associations of risk of colon or rectal cancer with consumption of whole-grain products among women.
Some possible reasons why they found an association for men but not women include:
1. Not enough variation in intake of whole grain products amount the women – to show effect there has to be a large difference between the highest and lowest intakes.
2. There were fewer colon and rectal cancer in women than in men, so there may not have been large enough numbers to be statistically significant.
3. The protective effect of whole-grain products may be stronger for men than it is for women.
Other studies have shown mixed results of protection from whole-grain foods against colorectal cancer, so this study adds more valuable data to this question. But there are plenty of reasons to choose whole-grain foods over more processed grains – including fiber, vitamins B and E, selenium, magnesium, antioxidants and other phytochemicals, all which contribute to overall health.
And, AICR’s expert report found that foods containing dietary fiber probably protect against colorectal cancer. As part of a healthy diet, along with plenty of other fiber containing foods such as vegetables and fruits, whole grains do play an important role in cancer protection for men and women.
*EPIC (European Prospective Investigation into Cancer and Nutrition) was designed to investigate the relationships between diet, nutritional status, lifestyle and environmental factors and the incidence of cancer and other chronic diseases. EPIC is a large study of diet and health having recruited over half a million (520,000) people in ten European countries: Denmark, France, Germany, Greece, Italy, The Netherlands, Norway, Spain, Sweden and the United Kingdom.