Study under review: Metabolic Slowing and Reduced Oxidative Damage with Sustained Caloric Restriction Support the Rate of Living and Oxidative Damage Theories of Aging
The cause of aging has been a central human question for millennia. While many of the early attempts to answer it were based on pseudoscientific concepts, a robust field of scientific literature has been built over the last several decades. As it is currently understood, biological aging is related primarily to cellular senescence, which is the process through which cells lose their ability to divide and function properly. As far as we know, cellular senescence seems to be caused by a variety of factors, which are summarized in Figure 1. Many of the approaches aimed at promoting longevity focus on reducing cellular senescence by influencing some of its underlying causes.
One of the main interventions that has been examined for increasing longevity has been caloric restriction. Caloric restriction has been used as an anti-aging therapy for two primary reasons: it reduces both overall metabolism and free radical production. Reductions in metabolism as well as reductions in free radical production have been shown to reduce cellular senescence in mice and worms, giving an underlying rationale for utilizing caloric restriction as a therapeutic intervention to slow aging and increase longevity.
Currently, most of the experimental data on caloric restriction and the hard outcomes of longevity and aging (e.g. death) have been in model organisms such as nematodes (roundworms), rodents, and monkeys (albeit to a far lesser extent compared to the first two). The problem is that these investigations may not extrapolate well to humans for several reasons, since humans differ from these species in several ways, including: drastically different metabolic rates and profiles, different environmental exposures and responses, different causes of death, and some may even display different cellular senescent ‘programs’.
Recently, large collaborative projects have emerged to begin examining the potential for caloric restriction as a tool to defend against aging and increase longevity in humans. The present study is part of one of these projects. It examined the effect of two years of caloric restriction on overall metabolism, hormonal function, and measures of oxidative stress.
Caloric restriction has been investigated as a tool to increase longevity for decades, primarily due to the idea that reducing overall metabolism and/or oxidative damage slows the processes of aging. To date, most of the data is in model organisms and very little evidence exists in humans. The present study was the first to examine the effect of long-term (two years) caloric restriction on metabolic rate and oxidative damage in humans.
Other Articles in Issue #43 (May 2018)
Eggcellent eggs part II: can people with diabetes safely eat two eggs per day?
This long-term follow-up to a study we covered way back in NERD #7 examined the effects of eggs on people with diabetes and prediabetes.
Whose performance benefits from nitrate supplementation?
The literature examining nitrates’ effects on performance is mixed. Part of the reason for the discrepancy may come down to training status
The misunderstood noodle
Does pasta pack on the pounds? This meta-analysis aimed to find out.
Interview: Andrew Vigotsky
In this interview with biomedical engineering PhD candidate Andrew Vigotsky, we talk biomechanics and the state of sports science research.
Interview: Lara Hyde, PhD
We chat with the creator and host of Nourishable about nutritional epigenomics and epigenetics, as well as the nuances of communicating science to the public.
Do vegetarians lack CCC insurance? A look into creatine, carnitine, and carnosine in vegetarian diets
These three molecules play an important role in sports performance. This trial is the longest interventional study to date looking at how switching to a lacto-ovo-vegetarian diet impacts them.
Does whey supplementation help muscle function recover after lifting?
In this review, we cover the first meta-analysis examining whey protein’s impact on muscle function recovery after resistance training.