Scientists studying a remote community on the slopes of the Andes Mountains for 22 years have found that growth-stunting mutations may stunt both cancer and diabetes.1 The international study was led by cell biologist Valter Longo, PhD, of the University of Southern California in Los Angeles and Ecuadorian endocrinologist Jamie Guevara-Aguirre, MD.

Many people in the community have Laron syndrome, a gene deficiency that prevents the body from using growth hormone. The study followed 100 of these people and 1600 relatives with normal stature.

During the 22 years, none of the Laron members developed diabetes, and 1 subject developed a nonlethal cancer. In the normal-size relative population, 5% were diagnosed with diabetes, whereas 17% were diagnosed with cancer during the same time period. Genetic and environmental risk factors were assumed to be the same for both groups.

Dr. Longo and colleagues concluded that growth hormone activity has many downsides for adults who are past their growing years. They found that the overall life span for both groups was approximately the same—although the Laron subjects died more frequently from substance abuse and accidents than the control group did.

No one is certain how growth hormone deficiency protects from these diseases. In in vitro studies, Dr. Longo and colleagues found that serum from the Laron subjects protected against oxidative damage and mutations and also promoted the death of cells that became highly damaged.

If high growth factor levels are identified as a risk factor for cancer, just as cholesterol is for heart disease, drugs that reduce them could become the new statins—and initially only in families with very high cancer or diabetes rates, Dr. Longo notes. Drugs used to block growth hormone have already been approved by the United States Food and Drug Administration to treat a condition related to gigantism. At the same time, animal studies have shown evidence that blocking growth hormone can extend lifespan.

Dr. Longo and his team plan to launch clinical trials to test such drugs in patients undergoing chemotherapy, because studies have shown that growth hormone deficiency protects mouse and human cells from some chemical damage.


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    Guevara-Aguirre J, Balasubramanian P, Guevara-Aguirre M,et al. Growth hormone receptor deficiency is associated with a major reduction in pro-aging signaling, cancer, and diabetes in humans. Sci Transl Med. 2011;3:70ra13.