Whole Grain

From The Experts

Cancer

Currently available research suggests that there is a protective relationship between the regular consumption of wholegrain cereal foods and some types of cancer. Evidence for the protective role of wholegrain foods is strongest for colon cancer however findings from studies suggest that wholegrain foods may also protect against other types of such as prostate cancer.

The diet, cancer and health study followed over 55,000 people over 10 years. Dietary intakes were assessed and it showed that for each 50g of wholegrain products consumed there was a 15% lower risk of colon cancer in men. Those that consumed more than 160g of wholegrains per day had a 39% lower incidence. There was no association seen in women (Egeberg et al., 2010).2

A large cohort study of almost 490,000 people followed over 5 years showed men who consumed higher levels of wholegrains (compared to those that consumed very few wholegrains) had a lower incidence of both colon and rectal cancer. There was no association in women (Schatzkin et al., 2007).6

Another study which only looked at 60,000 women did show an association with those eating the highest levels of wholegrains (compared to those eating the least) having a 33% lower incidence of colon cancer (Larsson et al., 2005).5 This study was followed over 15 years, which may account for the difference in the findings seen in the Egeberg and Schatzkin study.

A review which spanned 71 countries, including New Zealand, looked at associations between dietary intake and prostate cancer. It showed a strong inverse correlation between cereal intake and prostate cancer, suggesting those that eat more cereals have a lower incidence of prostate cancer mortality. When looking in more detail it showed that rice had the strongest association with reduced prostate cancer mortality, while a weak association was shown with wheat and barley and no association was seen with maize and rye (Colli and Colli, 2006).1

Protective compounds such as vitamin, mineral, phytates and antioxidants present in wholegrains may ‘work together to lower oxidative stress, inflammation and pathogen load to maintain gastrointestinal health’ (Jonnalagadda et al., 2011).4 (Fardet, 2010, Slavin, 2004)3

References

  1. COLLI, J. L. & COLLI, A. 2006. International comparisons of prostate cancer mortality rates with dietary practices and sunlight levels. Urologic Oncology, 24, 184-94.
  2. EGEBERG, R., OLSEN, A., LOFT, S., CHRISTENSEN, J., JOHNSEN, N. F., OVERVAD, K. & TJONNELAND, A. 2010. Intake of wholegrain products and risk of colorectal cancers in the Diet, Cancer and Health cohort study. British Journal of Cancer, 103, 730-4.
  3. FARDET, A. 2010. New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre? Nutrition Research Reviews, 23, 65-134.
  4. JONNALAGADDA, S. S., HARNACK, L., LIU, R. H., MCKEOWN, N., SEAL, C., LIU, S. & FAHEY, G. C. 2011. Putting the whole grain puzzle together: health benefits associated with whole grains--summary of American Society for Nutrition 2010 Satellite Symposium. Journal of Nutrition, 141, 1011S-22S.
  5. LARSSON, S. C., GIOVANNUCCI, E., BERGKVIST, L. & WOLK, A. 2005. Whole grain consumption and risk of colorectal cancer: a population-based cohort of 60,000 women. British Journal of Cancer, 92, 1803-7.
  6. SCHATZKIN, A., MOUW, T., PARK, Y., SUBAR, A. F., KIPNIS, V., HOLLENBECK, A., LEITZMANN, M. F. & THOMPSON, F. E. 2007. Dietary fiber and whole-grain consumption in relation to colorectal cancer in the NIH-AARP Diet and Health Study. American Journal of Clinical Nutrition, 85, 1353-60.
  7. SLAVIN, J. 2004. Whole grains and human health. Nutrition Research Reviews, 17, 99-110.