Learn how to stay healthy during COVID-19 with our free guide — Coronavirus: A guide to staying healthy (and sane) while stuck indoors

The Nutrition Examination Research Digest (NERD) aims to provide rigorous, unbiased analysis of the latest and most important nutrition and supplementation studies. Click here to subscribe or login if already a subscriber .

In this article

Does caloric restriction really make you live longer?

Two major hypothetical mechanisms of aging were put to the test in this human trial, the latest from the CALERIE project.

Study under review: Metabolic Slowing and Reduced Oxidative Damage with Sustained Caloric Restriction Support the Rate of Living and Oxidative Damage Theories of Aging

Introduction

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[1], 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[2] 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)[3], rodents[4], and monkeys[5] (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[6], different environmental exposures and responses[7], different causes of death[8], and some may even display different cellular senescent ‘programs’[9].

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.

Who and what was studied?

Become a subscriber to the Nutrition Examination Research Digest to read the full article.

Becoming a member will keep you updated on the most important nutrition studies every month, and give you access to our back catalog of over 500 other articles. It also includes access to Examine Plus.

I want to learn more about nutrition

Already a member? Please login to read this article.

What were the findings?

Subscribe to the Nutrition Examination Research Digest to unlock this article.

Best of all - only $1 for the first month!

Already a member? Please login to read this article.

What does this study really tell us?

Subscribe to the Nutrition Examination Research Digest to unlock this article.

Already a member? Please login to read this article.

The big picture

Subscribe to the Nutrition Examination Research Digest to unlock this article.

Already a member? Please login to read this article.

Frequently asked questions

Subscribe to the Nutrition Examination Research Digest to unlock this article.

Already a member? Please login to read this article.

What should I know?

Subscribe to the Nutrition Examination Research Digest to unlock this article.

Already a member? Please login to read this article.

Other Articles in Issue #43 (May 2018)