Dietary Interventions for Healthy Aging: From Caloric Restriction to Human Application

Jump To Section

• Diet Impact on Biological Aging
• Caloric Restriction Effects
• Alternative Nutritional Strategies
• Human Aging Evidence
• Dietary Recommendations for Longevity
• Full Transcript

Diet Impact on Biological Aging

Dr. Matt Kaeberlein, MD, PhD, begins the discussion by highlighting the profound connection between diet and the biological aging process. He explains that preclinical studies in laboratory animals, particularly rodents, have firmly established this relationship. Dr. Matt Kaeberlein, MD, notes that nutritional interventions can significantly influence both lifespan and healthspan, which is the period of life spent in good health.

Caloric Restriction Effects

The classic example of dietary impact on aging is caloric restriction. Dr. Matt Kaeberlein, MD, PhD, states this intervention has been known since the 1930s to significantly increase lifespan in rodents. He emphasizes that a whole series of work throughout the 20th century established that caloric restriction not only increases lifespan but also broadly delays functional declines associated with aging. Dr. Anton Titov, MD, engages with Dr. Kaeberlein on the mechanisms underlying these effects.

Alternative Nutritional Strategies

Dr. Matt Kaeberlein, MD, PhD, discusses recent interest in alternative nutritional approaches to aging. These include ketogenic diets, protein restriction, and time-restricted feeding or intermittent fasting. He explains that researchers are trying to understand to what extent these interventions can mimic the effects of caloric restriction in laboratory animals. Dr. Kaeberlein describes the current evidence as a "mixed bag," noting that none of these alternatives show effects comparable to traditional caloric restriction.

Human Aging Evidence

The conversation with Dr. Anton Titov, MD, turns to human applications of these dietary strategies. Dr. Matt Kaeberlein, MD, PhD, acknowledges there is correlative epidemiological evidence that populations who eat less have greater life expectancies. He cites the Okinawans in Japan as a classic example of this phenomenon. However, Dr. Kaeberlein clarifies that the extent to which this is mediated through effects on biological aging remains unclear and is an area of active study.

Dietary Recommendations for Longevity

Dr. Matt Kaeberlein, MD, PhD, provides a realistic assessment of current dietary recommendations for healthy aging. He states that while nutrition clearly impacts aging biology, we are still some distance from making strong specific recommendations. Dr. Kaeberlein does offer general advice, noting that not being overweight or obese is clearly associated with better health outcomes during aging. He concludes that the specific strategy to achieve healthy weight—whether protein restriction, ketogenic diet, or intermittent fasting—remains an open question for future research.

Full Transcript

Dr. Anton Titov, MD: So let's start with two hot words: aging and diet, diet and aging. What is the promise? What are the pitfalls? And what is the reality of aging and diet connections?

Dr. Matt Kaeberlein, MD: Sure. I would say what we've learned from preclinical studies in laboratory animals, particularly rodents like mice and rats, is that diet can have a profound effect on the biological aging process, on lifespan, and on healthspan as animals get older.

The classic example is caloric restriction, which has been known since the 1930s to significantly increase lifespan in rodents. A whole series of work throughout the 20th century firmly established that caloric restriction not only increases lifespan but broadly delays declines in function that accompany the aging process.

Recently, there has been a lot of interest in alternative nutritional strategies like a ketogenic diet, protein restriction, or time-restricted feeding and intermittent fasting. We are trying to understand to what extent these alternative nutritional interventions can mimic some of the effects of caloric restriction in laboratory animals.

I would say it's a mixed bag at this point. None of the alternatives to caloric restriction have effects comparable in magnitude to caloric restriction. However, there is certainly evidence that you can get some beneficial effects on healthy aging from some of these alternative dietary strategies.

So it's an ongoing area of research. We've learned a lot about the mechanisms that underlie caloric restriction and some of these other dietary interventions in laboratory animals.

I'd say we are still a long way from being able to evaluate to what extent caloric restriction or some of these alternative nutritional strategies would impact the aging process in humans.

Certainly, there is correlative epidemiological evidence that populations who eat less have greater life expectancies. The Okinawans in Japan are a classic example of that.

The extent to which that is mediated through effects on biological aging is still unclear. It is an area of active study.

So I would say it's clear that nutrition impacts the biology of aging. We understand those mechanisms to some extent, but we're still a ways away from really being able to make strong recommendations to people about specific dietary strategies to maximize their healthy longevity.

Now, having said that, generalizations certainly are reasonable. Not being overweight or obese clearly is associated with better health outcomes during aging.

But the specific strategy by which you achieve that—whether that's protein restriction, a ketogenic diet, or intermittent fasting—and whether one of those is better than the others is still a really open question.