The Long-Term Benefits of Short-Term Stress

Why ‘hormesis’ is key to your health and longevity

Andrew Merle


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“That which does not kill us, makes us stronger.” — Friedrich Nietzsche

It turns out Nietzsche was right.

This quote gets at the concept of hormesis — although with hormesis you see benefits well before approaching death!

Hormesis is when something damaging or toxic in excess is actually highly beneficial in smaller doses.

The phenomenon of hormesis dates back to 1884 when German pharmacologist Hugo Schulz observed that the growth of yeast could be stimulated by small doses of poisons. The actual word “hormesis” was first used by Chester Southam and John Ehrlich in 1943 when they noticed that extracts from the red cedar tree improved the metabolism of fungal species at low concentrations.

Scientists now know that short-term acute “stress” has powerful health and longevity benefits, as long as the stress subsides at some point.

For example, it’s long been known that exercise is good for us, but it wasn’t exactly clear why. Hormesis is the likely explanation.

When it comes to exercise, a dose of just 15 vigorous minutes per day can reduce the chance of death from a heart attack by 40% and all-cause mortality by 45%.

If you intensely exercised all day, you would cause undo wear and tear on your body and eventually break down. But short bursts of exercise (such as high-intensity interval training or HIIT) stress the body just enough to activate your survival genes. Once that stress response is engaged, your body will recover and build back even stronger than before.

An obvious example is weight lifting. Lifting weights stresses your muscles, then they get sore and grow back bigger than your baseline. But lifting too much weight too often, or at too high of an intensity, can lead to serious injury. It’s all about finding the right dose.

When it comes to exercise, a dose of just 15 vigorous minutes per day can reduce the chance of death from a heart attack by 40% and all-cause mortality by 45%.

In addition to exercise, here are several other scientifically proven ways to benefit from hormesis:

Heat and cold exposure

Mild heat stress has therapeutic effects. The best example of this is sauna use.

Sauna use has actually been shown to mimic the effects of exercise in the body — causing increased core body temperature, sweating, and increased heart rate.

And while extended exposure to extra-hot temperatures would be toxic, short periods can have big benefits.

In fact, a large study in Finland identified strong links between sauna use and reduced death and disease. Men who used the sauna two to three times per week were 27% less likely to die from cardiovascular-related causes than men who didn’t use the sauna. And men who used the sauna four to seven times per week were 50% less likely to die from cardiovascular-related causes. Additionally, frequent sauna users were found to be 40% less likely to die prematurely from any cause.

Frequent sauna use has also been shown to reduce the risk of dementia and Alzheimer’s Disease by 65% (again, the more days per week the better); lower blood pressure; reduce inflammation in the body; and alleviate symptoms of anxiety and depression.

The duration of each session need not be very long. You want to stick it out for around 20 minutes for maximum benefit (in a dry Finnish-style sauna heated at a temperature of at least 174 degrees F), but much longer than that is not necessary or recommended.

To amplify the benefits, you can do as the Finnish do and immediately plunge into ice cold water following the sauna session. This further stresses the cardiovascular system (but not to the point of posing a risk for healthy people).

Cold immersion on its own has significant benefits. Being uncomfortably cold for short periods of time activates protective brown fat in the body and can lead to weight loss, improved immune function, and reduced feelings of stress and anxiety.

You don’t want to get to the point of frostbite or hypothermia, of course — a daily five-minute cold shower can do the trick. Exercising in the cold is especially beneficial (try running outside in the winter or cold water swimming). Or if you’re feeling especially committed, try the Wim Hof Method which combines cold therapy with breath work and mental conditioning.

Eat stressed plants

We know that eating vegetables is healthy, but hormesis helps explain why.

Longevity and anti-aging expert Dr. David Sinclair says eating stressed plants is one of the most powerful things we can do to extend lifespan.

Stressed plants: What does that even mean?

From drought to fungal attack to simply the threat of being eaten, plants are faced with many external stressors. But unlike humans, plants are rooted to the ground and can’t run away to escape harm.

Therefore, they produce a variety of chemicals to defend themselves. And when humans ingest these compounds, it actually helps protect us from the environmental stressors to which we are exposed on a daily basis, such as air pollution or overexposure to UV radiation.

Plant-based compounds activate cellular-protective mechanisms in humans, a phenomenon known as xenohormesis.

Here is just a small sampling of specific foods and drinks to consume to see these benefits:

  • Cruciferous vegetables such as broccoli, broccoli sprouts, cauliflower, cabbage, kale, and brussels sprouts (which contain the compound sulforaphane)
  • Dark chocolate (which contains catechins)
  • Green and white tea (which contain the polyphenol epigallocatechin gallate or EGCG)
  • Turmeric (which contains the chemical curcumin)
  • Coffee (which contains chlorogenic acid)
  • Red wine (which contains resveratrol — although this one is controversial since the negative effects of alcohol could outweigh the small amount of resveratrol found in a glass of wine)

Intermittent fasting

Consuming nothing at all can also put your body into a temporary state of nutritional adversity. Extended malnourishment is not good, but smaller doses of calorie restriction can help promote longevity.

According to Dr. Valter Longo, director of the Longevity Institute at the University of Southern California (USC), the ideal fasting regimen appears to be a combination of daily time-restricted eating with, if you’re up for a challenge and get approval from your doctor, a periodic prolonged fast (five days appears to be optimal, done one to four times per year).

For the daily time-restricted eating, the idea is to consume all of your calories within a maximum of 12 hours (for example, eating all of your meals between 8 a.m. and 8 p.m. and fasting for the other 12 hours). Some people choose to extend the daily fast to 14 or 16 hours, most commonly by eating an early dinner and then skipping (or eating a late) breakfast the following day.

Time-restricted eating has been shown to produce a number of beneficial health effects, including weight loss, improved heart function, and enhanced aerobic capacity, all without altering diet quality or quantity.

As for the periodic prolonged fast, I am a fan of Dr. Longo’s five-day Fasting Mimicking Diet, which still allows small amounts of food each day. (Again, it is advised to check in with your doctor before doing a multi-day fast.)

Sun and alcohol

Other somewhat controversial triggers of hormesis include sun exposure and alcohol consumption.

In excess, UV rays cause sunburn and skin cancer, but small doses provide beneficial vitamin D and sunbathers have actually been shown to live longer. Overall you still want to play it safe — a little bit of sun might be good for you, but you should wear protective sunscreen for any longer exposure.

A similar principle applies to alcohol. Moderate drinking has been shown to have longevity benefits but excess alcohol consumption is undoubtedly toxic.

Overall you want to put your body through short bursts of mild stress to live longer and better. Hormesis is a good reminder of all the benefits that exist just outside of your comfort zone.



Andrew Merle

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