Remember who said this?

“Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point. The question is: does it progress? Turns out one of the major factors in determining if it does is protein intake.”

“The majority of Americans are eating about twice as much proteins as they should, and it seems that the best change would be to lower the daily intake of all proteins but especially animal-derived proteins.”

Dr. Longo is in the back row, second from the right. This is the photo he includes on his University’s profile page. I love that he surrounds himself with his students and colleagues, that it’s not all about him.

Valter Longo said that. Dr. Longo is a cell biologist, a professor at the University of Southern California Davis School of Gerontology (the oldest and largest school of gerontology in the world), Director of the USC Longevity Institute, a researcher in the fields of cancer and Alzheimer’s Disease, and more.

Longo is a renowned expert in the field of aging. His research shows that eating less animal protein can not only extend life, but improve its quality.

Here’s one of his headline-making studies that I blogged about when it came out:

Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population, Cell Metabolism, March 2014

Those who ate the most protein had a 4-fold increase in cancer death risk. 4-fold is nothing to sneeze at. The high-protein eaters also had a 5-fold increase in diabetes mortality. 5-fold is nothing to sneeze at.

Something is going on and Longo thinks it’s the greater amount of growth hormone in the bodies of people who eat a lot of protein – a lot of animal protein, because plant protein was actually beneficial:

These associations were either abolished or attenuated if the proteins were plant derived.

Longo says that less growth hormone (his work focused on the hormone, insulin-like growth factor 1 or IGF-1) causes the body to switch from “growth mode” to “repair mode” which is better for people in middle age. Growth mode promotes cancer and other chronic diseases.

People over 65, he found, did better with a bit more protein than 50-to-65 year olds. That protein is best sourced from plants. Beans, legumes, peas, peanuts, soy products, nuts, and seeds are excellent sources of plant protein.