Dietary hormetic phytochemicals and cellular resilience: Molecular insights - a review

• Dietary phytochemicals act as hormetins – show adaptive responses at low doses. • Dietary hormetins directly impact process of ageing and neurodegeneration. • They work via Nfr2-mediated pathways like activating vitagenes and autophagy. • Most work on dietary hormesis done on cell and animal models, human trials lacking. • The paper aims to address gaps in knowledge about dietary hormetins promoting health. Dietary phytochemicals or dietary hormetins are bioactive compounds present in plant-based food, which show biphasic response. The diversity, dose and frequency of dietary hormetins regulate their bioavailability. Their hormetic actions include improvement in immune responses, regulation of oxidative stress, reducing inflammaging, slowing down aging and preventing neurodegeneration, among other effects on human physiology. This paper discusses various documented dietary hormetins, their sources and actions. The paper also discusses molecular mechanisms of signaling pathways used by dietary hormetins such as Nrf2 signaling pathway, heat shock protein response, and endoplasmic reticulum response. Human clinical trial studies on dietary hormetins are scarce, creating a huge knowledge gap between theory and practice. This paper aims to bring discussion on dietary hormesis at forefront in scientific community. Dietary hormesis has potential for being natural and evolutionarily conserved path for sustained well-being. Changes in the dietary regimens viz . nutrition-based strategies, could prove instrumental in improving overall health and disease resistance of the population at large, without much investment in medical expenses. Our current understanding about benefits of dietary hormesis is still evolving, paving way for rigorous future studies.