SIRT1

In one line: One specific sirtuin enzyme that switches repair and stress-resistance programs on by stripping "off" tags from key proteins.

SIRT1 is a deacetylase — it removes acetyl groups from proteins, and that flips their programs on or off. It is one of seven human sirtuins (SIRT1–7) and is not interchangeable with them: SIRT3 works inside mitochondria, SIRT6 guards DNA and genome stability, while SIRT1 sits mostly in the nucleus flipping master switches.

What SIRT1 actually acts on — the reason it matters: it deacetylates PGC-1α (turning up mitochondrial biogenesis — more, healthier cellular power plants), the FOXO transcription factors (stress resistance and antioxidant defence), p53 (tuning cell-survival decisions), and NF-κB (dialling chronic inflammation down). Those four levers are why one enzyme touches ageing, metabolism and inflammation at once.

The controversy an expert should know: whether resveratrol activates SIRT1 directly is genuinely disputed. Sinclair's 2006 work said yes; a 2009–2010 line of research argued the effect was an assay artifact — a fluorescent tag on the test peptide — rather than real activation in the body. Honest read: SIRT1's importance is solid; resveratrol's claim to switch it on directly is not settled.

What raises it for free: fasting, exercise and caloric restriction all raise SIRT1 activity — no supplement required.

SIRT1 runs on the fuel NAD⁺, which halves with age. That decline story — and how boosters refill it — lives on the NAD⁺ & sirtuins pathway; this page is about the enzyme itself.