Researchers identify immune protein link to calorie restriction’s anti-aging effects
Moderate calorie restriction lowered the immune protein C3, and blocking C3 reduced age-related inflammation in mice, suggesting a drug target to mimic diet benefits without severe dieting.
In a controlled study, volunteers who reduced their intake by roughly a tenth to a quarter over two years experienced a significant reduction in the immune protein complement component 3 (C3), which is linked to chronic inflammation. Analysis of plasma identified white adipose tissue macrophages as the primary producers of age-related C3, overturning the assumption that the liver was the main source. Follow-up experiments in mice showed that a drug blocking C3 activation lowered age-associated inflammatory markers, mirroring one effect of calorie restriction.
The decline in C3 occurred regardless of the participants’ modest weight loss of about 18 pounds, indicating a mechanism separate from fat reduction. Senior author Vishwa Deep Dixit highlighted the possibility of developing therapies that temper excessive C3 activity while preserving essential immune functions. The team is now evaluating existing FDA-approved inhibitors for potential use in humans to extend health span.
Why it matters
Targeting C3 could offer a safer way to gain calorie-restriction’s longevity benefits without strict dieting.
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