Hanover, NH--Imagine taking a vitamin for longevity! Not yet, but a Dartmouth discovery that a cousin of niacin prolongs lifespan in yeast brings the tantalizing possibility a step closer.

The research, reported in the May 4 issue of Cell, shows how a new vitamin extends lifespan in yeast cells, much like calorie restriction does in animals. It could pave the way for developing supplements to benefit humans.

Radical calorie reduction can extend life. Dieting or fasting mice live longer and lowering the glucose that yeast grow on extends their lifespan, according to Dr. Charles Brenner, associate professor of genetics and of biochemistry, who led the research.

If we could do this in humans -- give people a drug or vitamin that would mimic effects of calorie restriction without having to skip lunch -- we would be able to provide some of the benefits of calorie restriction, which are pretty striking in model organisms, said Brenner, also a member of the Norris Cotton Cancer Center at Dartmouth-Hitchcock Medical Center.

Many benefits, explains Brenner, depend on a family of proteins called sirtuinsdubbed anti-aging gene products for the important roles they play in longevity and energy expenditure, although the precise mechanisms are still being figured out.

His team found that providing a newly discovered vitamin activates the yeast anti-aging gene product Sir2, which resembles sirtuins found in humans. The new work builds on Brenners prior discovery of the vitamin, termed NR (nicotinamide riboside), a natural product found in milk. Like the B3 vitamin, niacin, NR is a precursor to a versatile cellular factor that is vital for all life.

The factor, called NAD, short for nicotinamide adenine dinucleotide, is elevated by calorie restriction. So the researchers set out to develop an intervention to elevate NAD, using yeast cells, whose genes are easy to manipulate. Its surprising that no one was be
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Contact: Hali Wickner
hali.wickner@dartmouth.edu
Dartmouth Medical School
3-May-2007