Researchers and other inquisitive minds have for years — OK, centuries — struggled to identify and control the cellular levers that govern aging. Untold numbers of laboratory animals have given their lives in this pursuit. So, whenever some tiny shred of evidence emerges that promises some clarity in this area, people tend to get a bit excited. That’s what happened last week, when the journal Cell Metabolism published the results of a study suggesting that cutting calories may slow the aging process.
“Maybe there’s no need for a fountain of youth after all,” CNN reporter Susan Scutti crowed.
The study found that reducing caloric intake by as little as 15 percent for two years streamlined the metabolic process, which leads to fewer of the damaging byproducts that cause chronic disease and generally hasten the journey to the grave. Earlier research had delivered similar conclusions, but this was the first randomized controlled trial involving “non-obese” humans. The results were “pretty remarkable,” lead study author Leanne Redman, PhD, tells Scutti. “Reducing calorie intake provides health benefits to all people regardless of their current health status.”
Redman, an associate professor of clinical sciences at Pennington Biomedical Research Center in Baton Rouge, La., admits that the study’s original goal of cutting calories by 25 percent was not realistic but notes that even the more moderate reduction led to significant improvements in the basic biomarkers of aging among the participants. Metabolic rates slowed and levels of oxidative stress dropped — the body essentially became more efficient at burning fuel. “It’s important,” she says, “because every time we generate energy in the body, we generate byproducts.”
All this talk of the life-extending benefits of calorie counting will no doubt raise the spirits — if not the share prices — of portion-control preachers like Weight Watchers and Jenny Craig, but there’s little to suggest in the research that it’s a practical longevity strategy. That’s especially true for the estimated 15 percent of elderly Americans who live independently and already suffer from poor appetites and low nutrient intake. If there’s a slice of irony in the recent research, it’s the fact that so many geezers skip meals already, a habit that tends to shorten rather than lengthen their lives.
And even if you’re a big eater willing to submit to regular fasting, it’s not entirely clear you’d benefit from the exercise. Biologist John Speakman of the University of Aberdeen in Scotland calls Redman’s study a “big breakthrough,” but cautions that it’s far from conclusive. “We can’t infer that these changes are causally linked to reduced aging,” he tells Scutti. “Nevertheless, it is a step forward to indicate that these two ideas are not rejected by the current research.”
What the current research does seem to be rejecting, however, is the whole idea that the quantity of calories is less important than its quality. I suppose you could chalk that up to consumer reality: It’s much easier to count calories than evaluate nutrients. Besides, we are a nation brimming with eager consumers of life-extending gimmicks, and each new caloric-reduction “breakthrough” encourages visionary researchers and entrepreneurs to trot out some new dietary regimen guaranteed to adjust your metabolic process and add years to your life.
University of Southern California gerontologist Valter Longo’s ProLon program may be the most notable example of this trend. As I noted in a piece last year, ProLon clients pay $299 for five days’ worth of low-calorie (700 to 1,100) meals, or about a nickel per calorie — a small price to pay, I guess, to recalibrate your metabolism. The purported health benefits — improved levels of glucose, triglycerides, cholesterol, and such — last for up to three months. With nearly 4,000 meal kits delivered, Longo’s profit margin (he reportedly donates his shares in the company to a nonprofit that supports further research) may be healthier than his customers.
Still, Redman and her ilk argue that all their work on caloric reduction isn’t so much intended to encourage folks to eat less as it is to gain some insights into the body’s mysterious aging process. As Rozalyn Anderson, PhD, who last year led a similar study at the University of Wisconsin, Madison, put it in Scientific American, “We really study this as a paradigm to understand aging. We’re not recommending people do it.”
In other words, it’s nothing to get excited about.