Highlights

  • mTOR modulates biochemical pathways to influence cell growth and production and skews toward overactivation with age, which may increase cancer risk.
  • mTOR suppression strategies that may help slow aging include taking compounds like rapamycin, quercetin, and curcumin and practicing dietary fasting.

mTOR—an acronym for mechanistic target of rapamycin—is a set of proteins that modulate biochemical pathways to influence cell growth, maintenance and production of cells, and cell turnover. Interestingly, people attempt to slow aging by inhibiting mTOR with interventions such as dietary fasting; quercetin and curcumin supplements; and the anti-fungal, antibiotic drug rapamycin. A better understanding of the rationale behind inhibiting mTOR’s function may help people decide whether to tailor their routines for longevity with mTOR inhibition.

Dr. Paul Anderson, an educator and clinician specializing in naturopathic medicine, which blends modern with traditional practices, broke down mTOR and its inhibitors in a YouTube segment. More specifically, he gave details on how mTOR received its name, which contains the drug name rapamycin. Also, he provided a rundown of how mTOR works at the molecular level in promoting cell growth and how mTOR inhibiting strategies suppress this function and may promote longevity. In his YouTube segment, Dr. Anderson gave insight elucidating key details regarding mTOR and targeting its suppression for longevity.

mTOR’s Discovery and Its Inhibition with Rapamycin

To start his YouTube segment, Dr. Anderson relayed the history of mTOR’s discovery, centering his explanation on the drug rapamycin, from which mTOR’s name is derived. In that sense, rapamycin was discovered in 1964 in the soil of Easter Island and was shown to have anti-fungal and anti-bacterial effects. Yet, the pathway through which rapamycin works was not unveiled until the 1990s. The lag between rapamycin’s discovery and uncovering the cellular pathway through which it works happened due to research technology development in the 1990s that allowed the identification of mTOR and the discovery that rapamycin inhibits it.

The new technology facilitating mTOR’s identification allowed cell biologists to manipulate cellular pathways without degrading cellular proteins like those in mTOR. With these newly developed techniques, they discovered that mTOR activity greatly affects cell maintenance and growth. Furthermore, biologists uncovered that rapamycin inhibits mTOR. In other words, rapamycin incompletely blocks mTOR at the molecular level.

By inhibiting mTOR, rapamycin has been shown to suppress immunity. Furthermore, given its immune-suppression properties, rapamycin’s FDA-approved usage is for patients receiving organ transplants. Along those lines, clinicians prescribe rapamycin to organ transplant recipients to help them avoid organ tissue rejection, which an immune reaction can trigger.

mTOR Inhibition in an Attempt to Slow Aging

As for why some choose to use mTOR suppression with inhibitory compounds, Dr. Anderson says we lose regulation of pathways related to mTOR as we age. In this way, mTOR’s function can skew toward excessive cell growth, which may lead to physiological processes like precancer and cancer. In such circumstances, mTOR inhibition can lower mTOR activity and potentially reduce the risk for age-related diseases like cancer.

Natural modulators of mTOR, aside from rapamycin, include high amounts of protein and elevated insulin, which can increase mTOR activity. On the other hand, physiological states induced by dietary fasting can lower mTOR activity. Also, the naturally occurring molecules quercetin and curcumin can lower mTOR activation.

Ways to Suppress mTOR

Various strategies exist to initiate a fasting state to inhibit mTOR. For example, one technique involves going at least 16 hours without eating during every 24-hour daytime period—a form of intermittent fasting. Other ways to initiate fasting include going 24 or 36 hours without eating whenever possible.

Another strategy entails taking supplements like quercetin, a plant pigment shown to inhibit mTOR. If inhibiting mTOR does indeed slow aging, then quercetin may also help to slow aging.

Another supplemental compound, curcumin, a yellow substance found in the spice turmeric, has been shown to have mTOR-inhibiting properties. Accordingly, supplementing with curcumin may also promote longevity if the notion of mTOR suppression slowing aging is correct.

How Elevated Insulin and Protein Levels Trigger mTOR

As for how insulin and elevated protein trigger mTOR activity, mTOR gets upregulated when it senses lots of cell-feeding processes, according to Dr. Anderson. In that sense, insulin activates receptors on cells that turn on a cell-feeding mechanism. Likewise, when protein building blocks (amino acids) are abundant, cell-feeding mechanisms become activated. Because mTOR can amplify cell growth and proliferation, a cell-feeding state can put the body into a mode with higher mTOR activity that promotes growth.

Deciding Whether to Target mTOR Inhibition to Slow Aging

Like all cellular pathways within our cells, mTOR’s function is necessary for survival. Yet, its overactivation may drive age-related processes like precancer and cancer, leading some aging researchers to believe that the mTOR pathway plays a crucial role in aging. With that in mind, Dr. Anderson’s insights on this pathway may help anyone seeking to slow aging decide whether to do so with mTOR suppression.