Washington: You might curse your genes for being really short but not anymore, thanks to a study, which suggests that lack of growth hormone activity may protect abnormally short people from cancer and diabetes.
Valter Longo of the University of Southern California and Ecuadorian endocrinologist Jaime Guevara-Aguirre followed a remote community on the slopes of the Andes mountains.
The community includes many members with Laron syndrome, a deficiency in a gene that prevents the body from using growth hormone.
In a study that extended over 22 years, the team documented no cases of diabetes and one non-lethal case of cancer in Laron``s subjects.
And relatives living in the same towns during the same time period, 5 percent were diagnosed with diabetes and 17 percent with cancer.
"The growth hormone receptor-deficient people don``t get two of the major diseases of aging. They also have a very low incidence of stroke, but the number of deaths from stroke is too small to determine whether it``s significant," Longo said.
If high growth factor levels "become a risk factor for cancer as cholesterol is a risk factor for cardiovascular diseases," drugs that reduce the growth factor could become the new statins, Longo said.
Later, the researchers linked growth factor deficiency to reduced tumour risk.
Although the team has not understood exactly how growth hormone deficiency might protect a person, they found that serum from Laron``s subjects had a double protective effect: it protected DNA against oxidative damage and mutations but it promoted the suicide of cells that became highly damaged.
Laron``s subjects tend to have very low insulin levels and low insulin resistance, which may explain the absence of diabetes.
Another way to block these hormones is restriction of calories or of specific components of the diet such as proteins.
The study appears in Science Translational Medicine.