What is Xenohormesis?

Area of Science:

• Biochemistry
• Evolutionary Biology
• Nutrition Science

Background:

• Polyphenols (e.g., resveratrol, quercetin) from stressed plants activate sirtuin enzymes.
• This activation extends lifespan in fungi and animals, mimicking caloric restriction.
• The origin of this response to non-nutritive foreign molecules is unclear.

Purpose of the Study:

• To review evidence for the Xenohormesis Hypothesis.
• To explore the role of plant stress molecules in modulating animal physiology.
• To consider alternative explanations for the health benefits of plant-based foods.

Main Methods:

• Review of existing scientific literature on xenohormesis.
• Analysis of the broader context of phytochemical exposure in animals.
• Consideration of alternative hypotheses.

Main Results:

• The Xenohormesis Hypothesis proposes sirtuin enzymes evolved to detect plant stress signals as environmental indicators.
• Xenohormesis is defined as an adaptive physiological response to non-nutritive molecular cues.
• Evidence suggests xenohormesis likely occurs to some extent.

Conclusions:

• The Xenohormesis Hypothesis offers a potential explanation for how plant compounds benefit organisms.
• The extent to which xenohormesis accounts for phytochemical benefits requires further investigation.
• There is a need to re-evaluate the relationship between complex organisms and their food sources.