Xenohormesis

Xenohormesis is the hypothesis that animals benefit from stress-response molecules produced by stressed plants and microbes, sensing them as cues of environmental adversity. Polyphenols such as resveratrol, quercetin, and curcumin are typical examples, proposed to activate sirtuins, AMPK, and other stress-defence pathways, although direct sirtuin activation by resveratrol has been disputed, with much of the in-vivo effect now attributed to AMPK and indirect pathways. Direct evidence that dietary xenohormetic compounds extend human healthspan is still limited.