Xenohormesis is the hypothesis of how signaling molecules produced one species (xeno), once consumed, can induced a protective response in another species during times of severe environmental stress (hormesis).

This revolutionary aspect of evolutionary biology explains how substances from stressed plants Xeno Factors - can influence the internal physiology of those animals that consume them. Studied extensively at Harvard University labs, this concept resulted from experiments showing small molecules from stressed plants, consumed by animals, could impart significant health preserving benefits.



This concept helps to explain how certain plant produced small molecules, of which the polyphenols resveratrol and quercetin are among the most potent yet identified, can induce a survival response in the animals that consume them. This survival response has been shown to be activated in almost every animal tested including mammals and is also the possible explanation for the "French Paradox". Red wine grapes, especially those grown without herbicides and are under "stress" from fungal infection, tend to concentrate Xeno Factors, like resveratrol, in their skins. Fermentation of red wine naturally concentrates these Factors and the large consumption of red wine in France is now believed to be the possible explanation for the reduced risk of cardiovascular disease they enjoyed despite a high fat diet (the French Paradox).



At this time over 18 Xeno Factors have been found in plants which can impart some degree of health benefits to those animals that consume them. The majority of these molecules are polyphenol compounds which tend to be concentrated in the skins of red wine grapes, blueberries and a plant found in China called polygonum cuspidatum or commonly called the Knot Weed plant.

Reference

Baur,J.A. and Sinclair, D.A. (2006)
Therapeutic potential of resveratrol: the in vivo evidence. Nat. Rev. Drug Discov. 5, 493-506.

Baur, J.A., Pearson, K.J., Price, N.L., Jamieson, H.A., and Lerin C. (2006)
Resveratrol improves health and survival of mice on a high-calorie diet.

Nature 444, 337-342 (16 November 2006)
Lamming DW, Wood JG, Sinclair DA. Small molecules that regulate lifespan: evidence for xenohormesis. Mol Microbiol 2004 Aug; 53(4):1003-9