Does sulforaphane from broccoli sprouts work against ageing?

Sulforaphane activates an antioxidant programme in cells through a regulatory switch known as Nrf2. That switch increases the production of protective compounds while simultaneously inhibiting a pro-inflammatory signalling pathway. The result: cells become more resilient against oxidative damage. This has been demonstrated consistently in laboratory and animal research, but large clinical studies in humans are still largely lacking.

In addition to its antioxidant effects, sulforaphane also stimulates the cell's 'waste-disposal' system. It activates the system that breaks down and removes damaged proteins. That may sound technical, but the significance is concrete: the accumulation of damaged cellular material is one of the hallmarks of ageing and neurodegeneration. In animal models, this activation leads to an average lifespan extension of as much as 30 to 60 percent, although that translation to humans has not yet been made.

Sulforaphane also influences which genes are switched on and off, by inhibiting enzymes that manage the 'settings' of DNA. In principle, this can regulate genes involved in ageing and cancer. The cell-level findings are clear, but what this means in practice for humans remains unknown.

The strongest evidence from human research concerns skin protection: a few small studies show that sulforaphane can reduce UV-related damage and redness. For major ageing outcomes such as Alzheimer's disease, Parkinson's disease or lifespan extension, there are only encouraging cell and animal studies, and no clinical evidence. Broccoli sprouts are therefore a rich source of a compound with interesting biological properties, but sulforaphane has not yet been proven as an anti-ageing agent in humans.