More news on calorie restriction, from Dr. Stephen D. Hursting, a researcher at the University of Texas at Austin. If restricting calories delays and/or prevents tumor formation – as a wide body of research shows – the question is how. And why does obesity increase the risk of cancer? (It does: If you haven’t already read about it – take a look at AICR’s new analysis on the obesity-cancer link.)
Dr. Hursting’s lab is trying to figure out what’s going on in the link between energy intake and cancer. He talks about the animal research involving a key factor in metabolizing energy: IGF-1, which is linked to increased risk of cancer. His research has shown that calorie restriction and obesity both appear to share a common signaling pathway.
He also spoke about some intriguing, relatively new research looking at how exercise plays a role in cancer prevention and energy. Although it looks like exercise does add to the calorie restriction effect, he said, obesity prevention by exercise is not the same as by weight. Two animals can be the same weight – one by diet and the other by exercise – yet there appear to be different signaling effects and gene expressions happening.
The morning research conference session starts out with the tantalizing question of how can delay aging, asked by Rafael de Cabo, PhD. Dr. Cabo, who works at NIH’s National Institute on Aging, said how in the lab, the only way that we can restrict aging so far is by calorie restriction. Caloric restriction also delays tumor formation. (In lab research, caloric restriction diets are usually extreme.)
Caloric restriction seems counter-intuitive, he explains. You would think that lowering one’s calories – energy – would lead to fatigue and the organisms’ functions would shut down. But that is not the case; it somehow uses the energy it has in a different way.
Somehow, Dr. Cabo said, the organism or cell has a way to sense the nutrients. Dr. Cabo presented his lab’s research on the link between a specific gene — Nrf2 – and caloric restriction. He is looking at if Nrf2 activates the effect of calorie restriction, and if so, how it works. As usual, his research is turning up more questions and is ongoing.