Dr's Casebook: Onions, leeks and garlic are beneficial in so many ways

Dr Keith Souter writes: Several ancient Egyptian medical papyri mention the use of onions and garlic in disorders of the bowel and to give workers energy. The physicians of Ancient Greece and Rome also revered onions, leeks and garlic and also associated them with strength and work capacity.

A high intake of Allium vegetables has been shown to reduce total cholesterol and LDL, or ‘bad’ cholesterol levels, while at the same time raising HDL, or ‘good’ cholesterol levels.

In addition, eating Allium vegetables two or more times a week, is associated with a reduced risk of prostate and colon cancer. Research suggests that several of the compounds found in these foods, such as ‘Quercetin’, are able to protect colon cells from cancer-causing toxins, while also stopping the growth and spread of any cancer cells that do happen to develop.

Another interesting piece of research looked at diet and general health in over 65,000 nurses between 1984 and 2002. It found that women who had the highest intake of a bioflavanoid called ‘kaempferol’, which leeks are rich in, had a 40 per cent reduction in risk of ovarian cancer.

This latest research from China was a retrospective study about diet and bowel cancer. In this study over 800 patients with diagnosed colorectal cancer were matched with the same number of healthy controls by age, sex and residence area. Lots of information was collected about lifestyle and diet using a validated food frequency questionnaire. They found that the odds of having bowel cancer was almost 80 per cent lower in adults who consumed high amounts of allium vegetables compared to those who ate the least. They emphasised that there was a definite trend, the risk lowering as the amount of alliums taken increased.