For nearly 60 years, research has shown that eating less can lead to a longer life – if you’re a worm, fly or mouse.
But if two USC professors are on the mark, greater longevity may be a fact of life for humans as well.
Valter Longo and Caleb Finch say today’s trove of gerontology research proving the benefits of calorie reduction in simple organisms may translate into human medications capable of preventing and delaying age-related diseases.
The researchers’ thoughts appear in the Feb. 28 issue of the journal Science.
“We treat diseases when patients already have them,” said Longo, lead author of the article and holder of the Paul F. Glenn Chair in Cellular and Molecular Gerontology in USC’s Leonard Davis School of Gerontology.
“Our ideas here focus more on using existing research proven to extend the lives of lab animals to develop preventative drugs for aging humans,” said Longo. “The hope is to reach the point where we can have healthy 100-year-olds.”
Since the 1940s, research has shown that reduced calorie intake extends longevity in organisms from yeast to mice and postpones or prevents an array of diseases, without causing irreversible developmental defects.
In 1947, pioneering work by scientist C.M. McKay demonstrated that calorie restriction (CR) increased life span in rodents by 35 percent and resulted in a lower incidence of tumors, kidney disease and chronic pneumonia.
Finch, the article’s co-author and holder of the ARCO/William F. Kieschnick Chair in the Neurobiology of Aging at USC, has shown that low-calorie diets also can slow brain aging in rodents.
Other studies of laboratory mice have shown that calorie restriction enhances immune responses to influenza during aging, strongly inhibits inflammatory responses in aging – which may lead to Alzheimer’s disease, vascular disease and many cancers – and reduces mortality.
Furthermore, “in a small group of healthy non-obese humans, CR also causes physiological, hormonal and biochemical changes resembling those caused by CR in rodents and monkeys,” wrote Longo and Finch.
“There has been strong evidence demonstrating the influence of metabolism on disease,” Finch said. “A new type of drug that could fool the body into thinking it’s in restrictive calorie mode could be a key to addressing many age-related diseases.”
Genetic mutations of specific growth-hormone pathways in yeast, worms, flies and mice also have shown promise in extending life span, but with adverse effects, including dwarfism and reduced fertility.
“The chance of similar pathways in humans automatically increases with results like these,” said Longo. “You wouldn’t go from yeast to worms to flies to mice and just stop there. There have been hundreds of millions of years of evolutionary separation, yet these genes were conserved in all of the tested organisms.”
The researchers say it is important to examine the positive and negative effects of CR and genetic mutations.
“The key is to learn from CR because of its few adverse effects, and then find ways to simulate longevity-extending mutations by way of drugs,” said Finch.
“The development of the drugs is straightforward,” added Longo. “Whether they’ll work is another question. Much more research and funding are still needed in this area.”
The USC researchers hope to contact physicians who treat human dwarfism cases since these doctors may be able to provide insight into unique medical and genetic conditions, which then can be compared to existing data for people of normal stature.
“It’s obvious that people aren’t going to starve themselves until they’re 100,” said Longo. “So it’s important that we use as much available information as possible to develop medicines that may help fight diseases associated with aging.”
Contact Gia Scafidi at (213) 740-9335.