A pesticide extends lifespan in C. elegans
In a recent study, researchers screened for a number of chemicals that might extend lifespan in C. elegans, the tiny worm that is often used in aging research. They found one, a pesticide: Extension of Lifespan in C. elegans by Naphthoquinones That Act through Stress Hormesis Mechanisms
Hormesis occurs when a low level stress elicits adaptive beneficial responses that protect against subsequent exposure to severe stress. Recent findings suggest that mild oxidative and thermal stress can extend lifespan by hormetic mechanisms. Here we show that the botanical pesticide plumbagin, while toxic to C. elegans nematodes at high doses, extends lifespan at low doses. Because plumbagin is a naphthoquinone that can generate free radicals in vivo, we investigated whether it extends lifespan by activating an adaptive cellular stress response pathway. … Our findings reveal the potential for low doses of naturally occurring naphthoquinones to extend lifespan by engaging a specific adaptive cellular stress response pathway.
It’s important to note that low doses were used; at higher doses, the pesticide was still toxic. More isn’t better in this case.
Stress response mechanisms are the key to health and long life
The stress response mechanism in this case, and many others, is known as hormesis, which is characterized by a U-shaped curve: beneficial effects starting at low doses, but the effects becoming harmful at higher doses. In other words, low doses of some substance that we normally think of as toxic can be actually beneficial. This has even been shown with such classic poisons as mercury (Hormesis associated with a low dose of methylmercury injected into mallard eggs).
Hormetic effects have been found in a wide range of substances and practices, but the key point is that they all activate cellular stress response mechanisms. One of the main mechanisms at work is Nrf2, which activates over 200 genes. These genes in turn are anti-inflammatory, antioxidant, and stimulate of mitochondrial biogenesis.
It’s thought that the level of activation of Nrf2 plays perhaps the key role in differences in longevity between species.
Longevity promoting effects are due to activation of stress response
Many substances and actions have been found to activate the stress response. Calorie restriction and intermittent fasting, exercise, broccoli and curcumin, other fruits and vegetables, chocolate, and many other phytochemicals. Restricting glucose extends lifespan (in C. elegans) as well.
Furthermore, type 2 diabetes may come about due to a lack of hormesis. Since diabetes is a kind of archetype of aging and the ill health associated with obesity and modern life, it’s not too far-fetched to say that the stress response due to hormesis is necessary for health and long life.
Daily doses of good stress for health
One must stress the body to remain in good health. Being a couch potato and eating to excess will send one’s health on a downward spiral. In contrast, exercise, intermittent fasting, eating a variety of fruits and vegetables, an occasional glass of red wine, some supplements such as resveratrol and curcumin, restricting sugar and refined carbs in the diet, will all cause an increase in the cellular stress response and lead to better health and, hopefully, longer life.