Have you ever heard of hormesis? Yes, hormesis, a word that sounds like ‘horrible’ and ‘nemesis’ put together. It’s not something you can see or touch but it’s surely something you can experience or feel the consequences of on your body. 

What is hormesis?

It all began in 1943, when the term hormesis was first used by two scientists studying fungi, but it gained popularity in 2007 when a thorough description of the phenomenon first appeared in a scientific paper. Throughout evolution, cells and organisms used hormesis to acquire an advantage and avoid succumbing to environmental insults. An example of such resilience are microorganisms that adapted to the potentially harmful surplus of iron in oceans and lakes, and started to produce enzymes to protect themselves from death. In fact, hormesis is a bunch of adaptive responses that living beings, humans included, activate following moderate stress coming from their environment in order to avoid damage.  Rather, they exploit the situation to improve their functionality. Basically when a moderate stress or a low dose of a toxic chemical agent hits an organism the normal cells’ balance is altered; to avoid damage, the organism activates molecular mechanisms to cope with that stress: this is hormesis, also known as the adaptive stress response. The organism in question not only manages to face the presence of the toxic agent, but also to reinforce its defense against that toxic agent. As the well-known Swiss chemist Paracelsus had already guessed back in the 16th century:

“All things are poison and nothing is without poison, only the dose permits something not to be poisonous”.

The environmental hazards inducing stress can be of different origins: chemicals or toxic agents, temperature and radiation, but also exercise, dietary energy restriction and exposure to low doses of certain phytochemicals. 

How does hormesis contribute to better health?

There are several examples that support the role of the hormesis mechanism in many health benefits. Let’s dive into some of them to better understand how hormesis works in humans.

-Glutamate is fundamental for our brain to function but if its concentration is too high oxygen could get depleted, or oxidative stress could occur. An experiment showed that exposing neurons to moderate doses of glutamate activates hormetic mechanisms making neurons able to cope with more severe stress. 

-Ischemia is the shortage of blood supply in an organ or tissue. Blood transports oxygen so ischemia results in a dangerous shortage of oxygen to that organ. There are several experiments dealing with brief ischemia that showed how an organ (for example, the heart) subjected to mild ischemia becomes resistant to more severe ischemia, such as a heart attack, thanks to hormetic mechanisms. 

Those were very specific examples of hormesis and how it works at the cellular level, but how can we take advantage of hormesis to protect our body from damage?

Here is  some advice to modify your lifestyle and boost your hormesis mechanisms:

How to activate hormesis in your body


 It has been demonstrated that physical activity reinforces muscles and augments their resistance through hormesis, but how? During mild-to-intense exercise muscles experience a brief lack of oxygen (called hypoxia); thanks to hormesis the body starts to produce more mitochondria (the powerhouse of the cell) to compensate for the oxygen shortage. Heavy lack of oxygen would have massively damaged the muscle cells but thanks to that mild oxygen shortage muscles learned how to compensate for the threat.

Take home message: get-off-the-couch and kick your laziness!

Young strong sexy muscular fit woman in doing high knee skip running in the place as hard outdoor workout training in the autumn cold and sunny weather as preparation for marathon race
During mild-to-intense exercise muscles experience a brief lack of oxygen ; thanks to hormesis the body starts to produce more mitochondria to compensate for the oxygen shortage.

Practice intermittent fasting

 energy restriction is perceived by the body as a stress so reducing the amount of food eaten or augmenting the timespan between one meal and another, aka practicing intermittent fasting, activates hormetic mechanisms including increased production of SIRT1, a protein that reinforces the cell’s ability to fight stress and boost survival. It also increases the levels of heat shock proteins that help cells to preserve DNA integrity and be more resistant to hazards.

Take home message: stop overeating, start practicing intermittent fasting!

Learn more: Is hunger good for me?

Close up view of alarm clock on a plate intermittent fasting diet concept , time to eat healthy lifestyle
A little bit of hunger can make you more alert and boost your memory. it can also increase the ability of your cells to fight stress.

Eat food rich in phytochemicals

These are molecules found in fruits and vegetables and include carotenoids in carrots and apricots, or tocopherol in olives and peanuts. They also include glucosinolates in cruciferous vegetables, resveratrol from berries (and wine!) and flavonoids in bitter fruits. They all induce hormesis resulting in increased production of antioxidant enzymes, growth factors and cell protecting proteins, resulting in cells being ready to resist damage and oxidative stress.

Take home message: Reduce your sugar consumption, eat more fruit and veggies! 

Learn more: Why are fruits and veggies good for me?

Variety of fresh organic vegetables and fruits in the garden. Balanced diet
Colorful fruits and veggies contain toxins called phytochemicals  that they use to fight off insects and fungi. They also help your cells fight stress and reduce inflammation.

Expose yourself to altitude and hot and cold temperatures 

the Fahrenheit degrees influence our health more than we think. During the years, researchers found out that body exposure to short periods of cold or heat are less harmful than periods of sustained cold/heat. Brief but repeated exposure to very high or very low temperature results in the activation of hormesis mechanisms leading to:

  • COLD: a booster in the antioxidant system, adipose tissue burning more fat and glucose, less muscular fatigue after training, improved insulin sensitivity
  • HEAT: decreased appetite while increasing energy expenditure

Speaking about altitude, physicists explained that at high altitudes cosmic radiation is less attenuated and researchers showed that cancer rate is lower in people who live at high-altitudes. These two facts gave rise to “the theory of radiation hormesis” explaining how exposure to low-dose radiation can have beneficial effects because it puts DNA repair mechanisms under constant pressure, making them ready to repair damage triggered by higher-level radiation. Additional mechanisms triggered by radiation are: activation of antioxidant proteins and apoptosis— cells auto-inducing their death in case of irreparable cell damage. 

Take home message: get out of your temperature and altitude comfort zones!