Short Ecuadorians Hold Secret to Anti-Aging
Scientists have been surprised by a group of short-statured Ecuadorians with their immunity to cancer and diabetes. It seems that now, scientists have figured out what their secret is.
The secret is Laron syndrome, a rare disease which stunts growth and gives sufferers a short stature. Across the world, Laron syndrome affects 250 people. It has been known that the cause of the disease is a genetic mutation which does not permit normal cell growth and replication but apparently, that same cause renders Laron sufferers immune to cancer and diabetes.
The syndrome results from a gene mutation which codes the growth hormone receptor (GHR), a protein which binds with the human growth hormone leading to the production of insulin-like growth factor 1 (IGF1) which causes cells to grow and then divide. Having two of these mutated genes, that person can develop the disease.
In high levels, IGF1 has been linked to cancer and diabetes in previous studies while low levels were linked to longer lives in all organisms from yeast and worms to mice.
Felipe Sierra, director of the Division of Aging Biology at the National Institute on Aging said that cancer is inexistent in worms, and once that potential had been established they moved on to mice. In the study of humans, the findings validate what they had done until now.
Of course, in the short-statured Ecuadorians, the low levels of IGF1 meant an increased resistance to diseases.
Valter Longo of the University of Southern California, who led the study, said that blocking the same growth hormone receptors in other people would reduce the incidence of disease. He also said that such drugs are already available.
In some humans, the growth hormone is unusually active, making them grow continuously in a condition known as acromegaly or giantism. People that suffer from this disease will typically grow to over 7 feet tall. Treatment for acromegaly involves medication that blocks the human growth hormone receptors, imitating what happens naturally in Laron sufferers.
Studying the Larome syndrome sufferers, researchers looked at how the defective receptor caused short stature and at the same time immunity to diseases in humans.
Dr. Longo stated that in other studies, researchers had managed to extend the life of mice by 40 percent through manipulation of the growth hormone receptor.
The analysis was led by Jamie Guevara-Aguirre, a doctor in Ecuador who is experienced in treating Laron patients. He gave the Ecuadorian Laron sufferers and their families questionnaires about their health. He then followed a group of these people for 22 years, testing their IGF1 levels.
The Laron sufferers had lower levels of IGF1, none suffered from diabetes and only one of them had a (non-life threatening) type of cancer. Meanwhile, their family members, who didn’t suffer from Laron’s, had normal death rates for cancer and diabetes.
Even though none of them suffered from these diseases, the Laron sufferers didn’t outlive their unaffected family members. Instead, it seemed they died of acute conditions, alcohol related causes and mostly, males died of causes linked to their behavior.
Interestingly, the Laron sufferers had increased rates of obesity but no diabetes. Their obesity rates increased in time with the widespread obesity epidemic.
Dr. Longo said that what was more interesting was the fact that just like mice, humans with low IGF1 were protected from insulin resistance and diabetes and all were a little obese – mice and humans reacted remarkably similar to these genetic changes.
Researchers are also testing their families to see whether with only one mutated hormone receptor gene, they still benefit from the same immunities.
Longo plans to use IGF1 lowering drugs in cancer sufferers, to see whether by lowering their levels, they are able to retard the advance of the disease.11