Does eating nuts reduce the risk of colorectal cancer?

A Korean study recently published in Nutrition Journal evaluates the association between eating nuts and the risk of colorectal cancer.

Cancer of the colon and rectum is one of the most common malignancies worldwide, with around two-thirds of new cases seen in developed or high-income countries. While genetics does play a major part in the development of cancer, it has also been established that a diet low in fat but high in fibre can help reduce the chances of cancer from occurring.

Nutritionists consider nuts as one of nature’s super foods, owing to their rich nutritional content. The high amounts of unsaturated fatty acids, fibre, vitamins, and minerals, as well as phytochemicals and anti-oxidants, make it one of the healthiest dietary options. With the increasing incidence of colon cancer, researchers wanted to find out if eating nuts can be helpful in preventing colon cancer.

Scientists in Korea followed up over 900 patients diagnosed with colorectal cancer and obtained their dietary history. These patients were given questionnaires on what they ate from among 106 items, including different types of nuts, and how often each was consumed. Their answers were compared to around 1,800 control subjects who didn’t have colon cancer.

From the results, available in a recent edition of the Nutrition Journal, the scientists did find a statistically significant correlation between eating nuts and a lower risk of colon cancer. The presence of cancer had an inverse relationship with the nut intake; low rates of colon cancer were seen among men and women who reported eating three or more servings (around 45g) of nuts a day. And while the actual biochemical processes behind this phenomenon remain unknown, the findings can prompt further, more detailed studies in identifying these beneficial factors.

The research was initiated in Korea, where nut consumption is very high, as they are frequently included in many dishes and nuts are one of the most common snack items. However, if validated, these dietary recommendations go beyond country borders and can be universal. Increasing the amount of natural food (and less of the processed variety) can indeed result in tangible benefits. Eating nuts, in moderation, is already healthier and perhaps cancer-fighting too.

Written by Jay Martin, M.D.

Reference: Lee, J., et al.  “The relationship between nut intake and risk of colorectal cancer:  a case control study”.  Nutritional Journal (2018) 17:37.  https://doi.org/10.1186/s12937-018-0345-y.