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• Introduction
• Fiction #1: All Anti-Aging Diets Are the Same
• Fiction #2: Caloric Restriction Always Extends Lifespan
• Fiction #3: Laboratory Results Apply Directly to Humans
• Fiction #4: Caloric Restriction Has No Genetic Risks
• Conclusion

Introduction

In a conversation with Dr. Anton Titov, Dr. Matt Kaeberlein, a leading researcher in aging biology, discusses the major misconceptions—or “fictions”—surrounding anti-aging diets. Drawing from his review in the journal Science, Dr. Kaeberlein emphasizes the need to critically evaluate popular assumptions about dietary interventions like caloric restriction, intermittent fasting, and time-restricted feeding.

Fiction #1: All Anti-Aging Diets Are the Same

One of the most common misconceptions is that all anti-aging diets work the same way or are interchangeable. As Dr. Kaeberlein explains, “The idea that anti-aging diets are all the same... remains to be determined.” Different diets may operate through different biological pathways, and their effectiveness can vary widely depending on the individual and the context.

Fiction #2: Caloric Restriction Always Extends Lifespan

“A very common misperception,” says Dr. Kaeberlein, “is that caloric restriction always works.” While it’s true that caloric restriction has extended lifespan in many laboratory experiments—particularly in genetically identical animals—the picture is more nuanced across genetically diverse populations.

Studies in yeast, fruit flies, and mice have shown that approximately one-third of genetic backgrounds do not benefit from caloric restriction at all—and in some cases, it may even shorten lifespan. This demonstrates that caloric restriction is not universally beneficial.

Fiction #3: Laboratory Results Apply Directly to Humans

Most experiments on caloric restriction are conducted in genetically homogeneous (inbred) animals under tightly controlled lab conditions. “That’s useful for controlling variation,” Dr. Kaeberlein notes, “but you might miss that a different genetic background may not show the same effect.”

Humans, by contrast, are genetically and epigenetically diverse. This variability makes it far more complex to predict how any given individual will respond to an anti-aging diet.

Fiction #4: Caloric Restriction Has No Genetic Risks

According to Dr. Kaeberlein, another fiction is that caloric restriction poses no risks. While it may offer benefits in certain people, it could be neutral—or even harmful—in others. “We really have almost no mechanistic understanding of that interaction between genotype and response to caloric restriction,” he says.

This raises an important point: without knowing the specific genetic or epigenetic background of an individual, it's difficult to predict whether caloric restriction will help or hurt. Personalized medicine has yet to catch up with the complexity of dietary aging interventions.

Conclusion

Anti-aging diets are not one-size-fits-all. While strategies like caloric restriction and time-restricted feeding hold promise, their effects vary widely across different genetic backgrounds. As Dr. Kaeberlein stresses, “They don’t always work.” More research is needed to understand the intricate interplay between genes and diet in aging biology, and to move from hype to evidence-based practice.