Cutting calories lets yeast live longer
Earlier study that showed opposite result was flawed
MOTHER LODE Yeast mother cells on a diet of 2 percent glucose bud an average of about 24 daughters in a lifetime. The more researchers reduce the glucose, and thus the calories, that yeast consume, the longer the fungi live and the more offspring they can produce.
M.C. Jo et al/PNAS 2015, SCIMAT/SCIENCE SOURCE
Cutting calories keeps yeast alive and growing long past the time they’d usually stop reproducing, a large-scale study shows.
The finding, published online the week of July 13 in the Proceedings of the National Academy of Sciences, may come as a relief to researchers who study aging. A 2014 report tracked thousands of Saccharomyces cerevisiae at once and concluded that restricting calories did not lengthen the life span of the baker’s yeast (SN Online: 7/30/14). Longevity researchers contended then that the tracking method was flawed and that restricting calories was still the most tried-and-true way to lengthen life.
A new mass-tracking apparatus, called a microfluidic single-cell analysis chip, confirms that yeast on a low-calorie diet live much longer than yeast that gorge on a standard diet. Yeast life spans are measured by counting how many times a single yeast cell, called a mother, can divide. In regular broth containing 2 percent glucose, yeast divide on average about 24 times, Myeong Chan Jo of the Houston Methodist Research Institute and colleagues report. But when researchers dropped the glucose concentration to 0.05 percent, the average mother divided about 34 times.
The previous study’s machine probably prematurely washed away many of the mother cells, so their late-life divisions weren’t counted, Jo and colleagues surmise.
Editor’s note: This article was updated on July 13, 2015, to correct the graph.
