An apple a day keeps the doctor away, right? Some medical research published last fall may make you confused about this wisdom. In these two studies, scientists looked at whether a diet high in fruits and vegetables would reduce the risk of getting colorectal and lung cancer. Much to their surprise, scientists did not find a strong link. The participants in this study were a large group of female nurses and male doctors who filled out diet history surveys a few times in the last 10-15 years.
While these are important studies, they are only two from many other studies conducted over many years showing a strong benefit from fruits and vegetables. The weight of evidence over the past 30 years still favors eating a diet rich in fruits and vegetables. Further, neither of these two new studies showed fruits and vegetables to be harmful. Studying diet is a complex field. The recent studies do mean that scientists have more research to do to determine the links between diet and health -- and some of the data collection in PLCO is contributing to this effort.
PLCO is, indeed, studying how people's diet might affect their risk for cancer. The diet history surveys we asked you to fill out in the past year are a very important part of this knowledge. But, unlike many other studies, PLCO has an extra powerful tool. The saliva samples you are donating (see article, Because You Asked) will allow PLCO researchers to link diet with biologic makeup. This will be an invaluable tool in helping to unravel how diet fits into the cancer puzzle.
Regardless of these most recent publications, there is also strong evidence that a diet high in fruits and vegetables protects against heart disease and stroke. So keep striving for five or more servings of fruits and vegetables everyday!
For further information, please see:
The Journal of the National Cancer Institute
Volume 92, Issue 21, pages 1740-51
Volume 92, Issue 22, pages 1812-23