Diet/cancer study not conclusive

Nov 3 2004

The following is a statement by Ritva Butrum, Ph.D., AICR Vice President for Research:

My colleagues and I at the American Institute for Cancer Research (AICR) have read with great interest the cohort study appearing in the November 3 issue of the Journal of the National Cancer Institute (JNCI). The study's authors analyzed data from the Nurses' Health Study and concluded that among its subjects, fruits and vegetables were modestly protective against cardiovascular disease and not protective against cancer.

We at AICR feel it is important to note that the authors' finding in regard to cancer contradicts the preponderance of scientific evidence published to date. The landmark AICR Expert Panel Report, Diet, Nutrition and the Prevention of Cancer: a global perspective, examined over 4,500 studies and concluded that evidence linking diets high in fruits and vegetables with lower risk for cancer was "convincing."

Each specific method used by scientists to study the diet has its own set of well-documented limitations, and cannot by itself offer a comprehensive picture. In an editorial accompanying the new JNCI study, Drs. Arthur Schatzkin and Victor Kipnis meticulously outline the many methodological and statistical issues that arise from cohort studies in general and the Nurses' Health Study in particular.

It is vital to place newly published research in a meaningful context. To that end, we wish to direct the public's attention to the most significant limitations of this study. Go to http://www.aicr.org/ and click on "New JNCI Study Not Conclusive" for this background information.

To the millions of Americans who are deeply concerned about reducing their risk of getting cancer, we want to say this: This is only one study, with all the weaknesses inherent to its kind. It is contradicted by literally hundreds of earlier studies. Do not let this single study discourage you from striving to increase the proportion of vegetables and fruit in your meals and snacks. When all of the results are in, eating a plant-based diet, increasing physical activity and maintaining a healthy weight will remain the three most important things you can do to stop cancer before it starts.

The American Institute for Cancer Research (AICR) is one of the nation's largest cancer charities and focuses exclusively on the link between diet and cancer. The Institute has provided over $70 million in funding for research in diet, nutrition and cancer.