Harvard’s David Sinclair and Celebrity Biochemist Rhonda Patrick: Eating Bright-Colored Plants to Extend Lifespan

Highlights

• Aging researcher Dr. David Sinclair explains how plants grown under stressful conditions produce bright-colored fruits that, when consumed by people, may activate cellular defenses and longevity pathways.
• Dr. Rhonda Patrick highlights how polyphenols like curcumin, found in turmeric, turn on anti-inflammatory genes and detoxifying enzymes that may improve brain function and extend the number of healthy, disease-free years we live.

Dr. David Sinclair first coined the term “xenohormesis” in a 2004 paper that he and colleagues from Harvard Medical School published. “Hormesis” is when you expose a biological system (a plant, animal, or collection of cells in a dish) to low levels of stress that results in benefits to the system. An example of hormesis is exercise. Short term stress on the body created through exercise ultimately leads to improved physical fitness. “Xeno-”, stemming from the Greek “xénos,” meaning alien or strange, takes this concept a little further. Xenohormesis refers to the consumption of foreign compounds, not produced in the human body, as a means of providing mild short-term stress and ultimately benefiting the consumer.

In this case, the term means consuming plants grown under organic conditions — not being treated with pesticides and other chemicals. Interestingly, plants produce defense molecules called polyphenols, which include resveratrol, quercetin, and fisetin, as their own hormetic response to stress. When their production is activated, these defense molecules extend the plants’ lifespan. According to Sinclair, when we consume these plants, they also stimulate our cellular defense pathways and may confer pro-longevity benefits, somewhat similar to the benefits they provide for plants.

In a YouTube segment, Sinclair provides a detailed explanation of xenohormesis. Following his discussion of this idea, Dr. Rhonda Patrick, a celebrity biochemist and podcaster, provides an explanation of how xenohormesis benefits humans by triggering anti-inflammatory genes and detoxifying enzymes at the cellular level. The information provided in this video segment may inspire health-conscious individuals to eat more plant-based foods containing polyphenols to potentially extend their healthspan.

David Sinclair Breaks Down Xenohormesis

To explain xenohormesis, Sinclair begins by breaking the word down. He says “hormesis” encompasses the idea that what does not kill you makes you stronger, and “xeno” means coming from other species. In other words, the defense molecules that make plants stronger and live longer — polyphenols — can also make us stronger and potentially live longer.

“Eat foods that are stressed,” says Dr. David Sinclair.

Fruits and vegetables not grown organically are not as stressed, because chemicals like pesticides protect them from danger, such as insects and other plants competing for nutrients. This is why Sinclair says to go with fruits and vegetables grown under organic conditions, because they will have produced more polyphenols due to stress. As such, these polyphenols may activate the same pro-longevity processes in our body as they do in plants. Along the lines of the xenohormesis idea, this may provide us with potential healthspan and pro-longevity benefits, according to Sinclair.

The best way to identify organically-grown fruits and vegetables with high levels of polyphenols is to pick the ones that have a stressed appearance, according to Dr. Sinclair. Along those lines, when at the grocery store, do not pick the most perfect-appearing fruits or vegetables. Instead, he says that ideally, look for the organically-grown plants that appear to have undergone some degree of ultraviolet (UV) radiation damage from the sun, potentially conferring a more stressed look to the plant.

Celebrity Biochemist Dr. Rhonda Patrick Provides an Example of a Polyphenol-Rich Root, Turmeric

In the next portion of the YouTube segment, Dr. Rhonda Patrick adds that when our bodies undergo stress, longevity-related genes become activated, together with cellular defense pathways. Interestingly, similar pathways are activated with high-intensity training, sauna sessions, as well as with cold-shock therapy where people undergo periods of time in colder environments like cold water. The activation of longevity-related pathways from undergoing these stressful or aversive situations all fall under the designation of the hormetic effects.

Aside from inducing hormetic effects with exercise, heat, or cold temperatures, we can consume slightly toxic polyphenols like curcumin from the spice turmeric, according to Patrick. She says that our bodies do not like turmeric, because the turmeric root produces polyphenols to fend off insects, fungus, and things that would otherwise kill the plant. Along those lines, turmeric also activates our bodies’ detoxifying enzymes called phase II detoxifying enzymes. These enzymes work to eliminate polyphenols and may also, in turn, help to rid the body of other cancer-causing agents (carcinogens).

Some of the body’s responses initiated by consuming polyphenols from turmeric may improve healthspan. Along those lines, Patrick says that experiments have been done in mice where a molecule called aromatic-turmerone from turmeric improved memory. Although these findings may not necessarily apply to humans, aromatic-turmerone’s capabilities to potentially improve memory in mice opens the possibility that it could improve this cognitive aspect of healthspan in humans. Thus, there is potential that these preliminary findings in mice will pave the way for human trials to explore whether the aromatic-turmerone polyphenol improves memory during aging.

Stressed Plants Produce Bright-Colored Fruits That Trigger Our Bodies’ Defenses

The concept of xenohormesis may help to explain why polyphenols like resveratrol and fisetin extend lifespan in preclinical models. While these findings are preliminary and may not necessarily apply to humans, future clinical trials are necessary to find whether polyphenols reduce the human risk of mortality, potentially conferring a longer lifespan.

On a similar note, some meta-analyses have shown an association between human polyphenol consumption and improved cognition in older adults, leaving open the possibility that a polyphenol-rich diet enhances this healthspan parameter. Other human studies have suggested polyphenols have antioxidant, anti-inflammatory, and anticancer properties and may prevent cardiovascular complications. Furthermore, studies suggest that polyphenols may have therapeutic effects against obesity. For these reasons, including plants with high levels of polyphenols in one’s diet may be a way to extend healthspan.

Furthermore, if someone prefers to consume polyphenols through supplementation, many polyphenols like resveratrol, fisetin, and quercetin are easy to find and order online. By supplementing with such polyphenols, one may ensure that he/she is getting an adequate polyphenol dosage for potential healthspan-enhancing effects.