Can garlic and onion reduce risk of colorectal cancer?

Vegetables like onion and garlic are high in sulphur compounds which are beneficial for your health. These compounds also give them their unique flavour and taste.  Belonging to the Allium Genus-group, other such vegetables belonging to the allium family are shallots, leeks and chives. Allium vegetables have been studied extensively for their protective potential against cancer. Researchers from the First Hospital of China Medical University conducted a study aimed to investigate and identify the association between consumption of allium vegetables and colorectal cancer (CRC) in the northeast Chinese population.

The risk of having colorectal cancer was 79 per cent lower in adults who consumed high amounts of allium vegetables compared with those who consumed low amounts.

For this hospital-based matched case-control study, 833 patients with CRC were matched with 833 healthy controls by age, sex and residence area (whether rural or urban). The study was conducted between June 2009 and November 2011 in three hospitals. The researchers collected demographic and dietary information via face-to-face interviews using a validated food frequency questionnaire.

The researchers found that the risk for colorectal cancer was reduced for the consumption of allium vegetables including for several individual vegetables including garlic, garlic stalks, onion and spring onion. The risk of having colorectal cancer was 79 per cent lower in adults who consumed high amounts of allium vegetables compared with those who consumed low amounts. The researchers also found that the risk of colorectal cancer was inversely associated with vegetable consumption. The study shows that the greater the amount of allium vegetables consumed, the lower the risk of developing colorectal cancer. However, the link between garlic intake and cancer risk was not significant in those with distal colon cancer.

The study shows that both men and women have a lower risk of developing colorectal cancer when they eat high amounts of allium vegetables. It sheds a light on the prevention of colorectal cancer through lifestyle and dietary changes which needs further investigation.

Source: Asia-Pacific Journal of Clinical Oncology