How Does Protein Affect Cancer?

Research Finds Amount, Quality of Protein May Impact Tumor Growth
Thursday, April 17, 2014 - 1:57pm
Chief, Genitourinary Section; Leader, Genitourinary Program, Department of Medicine; RPCI

Many dietary studies have been done showing the connection between nutrition and cancer. However, there is a lack of research focusing solely on the effect that protein has on tumor growth inhibition, specifically for prostate and breast cancers. Dr. Luigi Fontana at Washington University of St. Louis and I recently decided to study this hypothesis — can a lower intake of protein slow cancer growth?

What Remi Adelaiye, a PhD student in my lab, discovered was striking. Not only do lowered amounts of protein in a diet delay cancer growth in preclinical research, changing the quality of protein also affects the tumor. In other words, the source of the protein has the same role in slowing prostate and breast tumor growth as does reducing the total amount. For example, proteins that come from vegetables are more effective at slowing tumor growth than are proteins that come from animals. Why is this? Let’s start at the beginning.

Amino acids are the basic elements that build protein. We know of some amino acids that are key when it comes to stimulating tumor cell growth. So, simply put, we believe that the animal proteins may contain these specific amino acids that promote tumor growth while vegetables do not. Therefore, by eliminating proteins, specifically animal proteins, we reduce much of the fuel for the tumor cells found in prostate and breast cancers.

Please keep in mind that, as of right now, this is a hypothesis and expanded research is still needed. That said, it’s important work and the early results are encouraging. This is the first time that researchers have displayed a significant effect on tumor growth by changing the protein content of a diet. It’s already an established fact that vegetables are better for you than red meat or dairy products and our results tend to back that up.

Our goal for the future is to have this research reach the point of a clinical trial. We believe dietary intervention would be worthwhile for cancer patients, including those faced with relapse or those already undergoing treatment. We are looking for funding for this exciting project, and hope that one day our research will benefit our patients.