Vegetables and fruits for health

A long lost friend visited me with his daughter recently and over lunch he lamented that his children dislike vegetables - most probably because he has set a bad example by not liking vegetables and not eating any himself! How important are vegetables and fruits in our diet?

A recent study from the University of Hawaii investigated the association of vegetable, fruit and grain intakes with colorectal cancer risk in the Multiethnic Cohort Study (Am J Clin Nutr 2008; 88: 730 – 737). A total of 85,903 men and 105,108 women, living in Hawaii and Los Angeles County, California, completed a 26-page-long quantitative food-frequency questionnaire, over the period 1993 and 1996. The 5 ethnic groups studied were Afro-American, Japanese American, Latino, Native Hawaiian and Caucasian. They were then followed up for an average of 7.3 years. The median intake of vegetables and fruits combined was higher for Latinos and Native Hawaiians and lower for Afro-Americans, Japanese Americans and Caucasians. The risk of developing colorectal cancer in men who took the highest amount of vegetables and fruits was 26% lower than in those who consumed the least. If you only eat fruits but no vegetables, the risk reduction is only 20%. If you only eat vegetables but no fruits, then the risk reduction is 15%. When the analysis was performed for colon and rectal cancer separately in men, the associated risk reduction was stronger for colon than for rectal cancer. In women, the association between colorectal cancer risk and vegetable and fruit consumption was observed but this trend did not reach statistical significance.

In a separate publication, researchers from the University of Florence performed a meta-analysis of the effect of adherence to a Mediterranean diet on mortality and the incidence of chronic diseases [(BMJ 2008; 337: a1344); a free copy of the publication can be obtained at http://www.bmj.com/cgi/content/full/337/sep11_2/a1344] . The analysis was performed on 12 studies involving a total of 1,574,299 individuals. The analysis showed that greater adherence to a Mediterranean diet is associated with a significant reduction in overall mortality (9%), mortality from cardiovascular diseases (9%), incidence of or mortality from cancer (6%) and incidence of Parkinson’s disease and Alzheimer’s disease (13%).

The key components of the Mediterranean diet include generous amounts of fruits and vegetables, consumption of healthy fats such as olive and canola oils, eating small portion of nuts, consuming little red meat but eating fish on a regular basis and, for some, drinking red wine in moderation. From these two recent studies it can be seen that vegetables and fruits are important for maintaining a healthy body and warding off diseases. If you have a family, start them off young with the habit of eating fruits and vegetables. If eating vegetables wasn’t your cup of tea while growing up, perhaps you should start for yours and your children’s sake.