Study under review: A 2-Year Randomized Controlled Trial of Human Caloric Restriction: Feasibility and Effects on Predictors of Health Span and Longevity
Short of discovering the fountain of youth, are there ways to live longer?
Some think that caloric restriction is an answer. Caloric restriction is defined as lowering caloric intake without depriving oneself of essential nutrients. There is lots of evidence in animals that suggests caloric restriction increases lifespan in many, but not all, species. Observational evidence in people who voluntarily practice long-term caloric restriction corroborates some of the animal evidence. Humans undergoing caloric restriction seem to mimic some of the physiological changes seen in other animals, and risk factors for several disease markers seem to improve in humans undergoing caloric restriction as well.
However, observational studies can only show correlation, not causation. Long-term, controlled clinical studies are needed to show causation. These are very hard and very expensive to conduct for the time needed to actually observe the effects of caloric restriction on mortality. Not to mention the fact that it would be hard to find people who would be willing and able to enroll in such a trial!
A compromise is possible, though. A randomized, controlled clinical trial on the order of months or years that examines markers for disease and longevity would be able to tell us something about how caloric restriction affected those markers. And if those markers correlated well with mortality, we’d be able to take a better educated guess at how these diets may affect longevity. Such a trial would also give us a better idea of whether calorie-restricted diets could be maintained for the medium term, since the self-selection bias which may exist in observational studies would be mitigated.
That’s the purpose of the study under review.
Evidence from animal models suggests that calorie-restricted diets can increase longevity in many, but not all, species. There is some observational evidence suggesting this effect exists in humans as well. This controlled clinical trial’s purpose was to examine how a calorie-restricted diet affects markers of disease and longevity in humans, as well as to test the feasibility of a calorie-restricted diet.
Other Articles in Issue #12 (October 2015)
Am I less hungry after I eats me spinach?
The gut is a hot weight loss topic, even aside from the microbiome -- some pharmaceutical drugs attempt to manipulate hormones or fat digestion in order to spur weight loss. What if an extract of spinach could also impact these factors?
Sugar Wars, Episode 2: “Fructose Strikes Back”
Few food components have been demonized as much as fructose in the past decade. With fructose being presumed guilty in metabolic syndrome and heart disease, this systematic review sheds light on it’s actual impact on blood lipids.
The case of the misleading yohimbe labels
What’s actually in a supplement bottle can be a mystery. These intrepid researchers investigated the actual contents of yohimbe bottles in order to see if this popular but possibly sometimes quasi-legal supplement is more (or less) than meets the eye.
- Interview: Robert Krikorian Ph.D.
Paying attention to omega-3s for ADHD
With more and more people being diagnosed with ADHD, there’s a continuing hunt for helpful treatments. Researchers tested an omega-3 supplement on young males, and also explored a potential dopamine-related mechanism.
- Interview: Trevor Kashey, Ph.D.
From jelly to muscle: collagen and body composition
Collagen has long been equated to junk protein, at least if you’re looking to gain muscle. Could it be underrated for this purpose? A trial of older men tested collagen protein to see if it could boost muscle gain and fat loss.
Throwdown, round 1: plant vs animal protein for metabolic syndrome
The DASH diet is frequently tested in clinical trials, and often performs well. But the diet’s formulation includes strong limitations on red meat, which may be based on outdated evidence. This study compared animal-protein rich diets with a typical DASH diet.
Can omega-3s modulate the mind-muscle connection?
While strength gains are usually associated with protein and muscle-related ergogenics, the nervous system isn’t targeted as often. This study explored a different type of omega-3 source (seal oil) for neuromuscular exercise effects.