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Getting the latest healthcare news for you
Calorie restriction is known to slow aging, but the diet is tough to maintain. Yale researchers found that moderate calorie cutting significantly lowers an immune protein called C3, which drives chronic inflammation as we age. Blocking C3 in mice reduced age-related inflammation — suggesting future drugs could replicate these benefits without requiring major dietary changes.
Calorie restriction has long been shown to extend lifespan and improve health in animals, but the downsides — vulnerability to infection, impaired growth, and reproductive issues — make it a tough sell for humans. Now, Yale researchers may have found a workaround. A new study published in Nature Aging identifies complement component 3 (C3), an immune protein, as a key driver of age-related chronic inflammation that drops significantly with moderate calorie restriction.
The team analyzed plasma samples from 42 participants in the NIH-funded CALERIE trial, who cut calorie intake by 11–14% over two years. Among 7,000+ proteins measured, C3 stood out as one of the most significantly reduced. Digging deeper, researchers traced the source of age-related C3 production to age-associated macrophages within visceral white adipose (fat) tissue — a surprising finding, since C3 is typically associated with the liver. Crucially, the drop in C3 was independent of how much weight participants lost, suggesting the benefit is tied to calorie restriction itself, not just fat loss.
Key Takeaways:
Why it matters: Chronic inflammation is a hallmark of aging and underlies many age-related diseases. If C3 can be safely targeted with existing drugs, it could open a new therapeutic avenue to extend healthy lifespan without requiring extreme dietary interventions.
