Quercetin: What We Can Learn From the Romans - Part 2

Written by Anil Bajnath, MD
Posted November 18, 2021

Dear Longevity Insider,

The Romans used quercetin to treat diarrhea. But it doesn't stop there... Bye bye allergies? Quercetin significantly increased the production of IFN-γ and decreased IL-4 in normal blood cells in a recent study. Quercetin was also shown to increase the number of cells that produce IFN-γ and decrease the number of cells that produce IL-4 when looked at with a microscope.

These results suggest that quercetin may help in preventing allergies by helping to balance your immune system.

Quercetin is able to stop matrerial metalloproteinases from being inhibited by plasminogen activator inhibitor 1. Quercetin does this in human dermal fibroblasts and also blocks IL-1-induced IL-6 production from human mast cells.

Quercetin may also decrease inflammation by blocking nuclear factor kappa B. NFκB is a protein found in cells that helps regulate the inflammatory response to illness and injury. Quercetin was shown to inhibit intestinal pro-inflammatory cytokines such as tumor necrosis factor (TNF) and IL-1β, as well as NFκB DNA binding activity in human intestinal epithelial cells. In a different study, quercetin was shown to decrease the number of receptors on the surface of cancer cells that help cancer spread throughout the body. While more research is needed, this suggests that quercetin may be able to prevent metastasis and reduce the size of tumors.

The Big Picture

Longevity is a measure of a person's life span compared to the average life span of people of the same age and sex in a certain population. Healthspan is a measure of the number of years you are relatively healthy compared to the average person. We focus on healthspan as opposed to lifespan in longevity because what good is having a long life if you are unhealthy for most of it?

On a study that looked at the effects of quercetin on Alzheimer’s disease, researchers found quercetin's ability to increase lifespan by injecting young fruit flies with quercetin dissolved in water every day for 10 days. The study found that both male and female fruit flies lived longer with less age-dependent decline in courtship behavior compared to fruit flies that did not receive the quercetin injections.This research suggests that quercetin could restore signaling pathways interrupted by Aβ expression. Aβ refers to beta amyloid peptides that are part of normal cellular activities that build up into plaques in (AD). While the effect of quercetin is still not fully understood, quercetin was found to decrease Aβ production in cells with the mutation.

Researchers also used human cells to see how effective quercetin is at preventing cell death, or apoptosis. The researchers found that when treated with quercetin, it was able to significantly induce the apoptosis of tested cells.

Quercetin has also been shown to increase the activity of sirtuin 1 (SIRT1), a protein that helps control metabolism and cell death. SIRT1 is believed to be involved in the production of nitric oxide, which may help prevent heart disease by increasing blood flow. Cell death is critical to longevity as it keeps the body from growing old and worn down by senescent cells.

If we recall, senescent cells are cells in which the genetic material has deteriorated. A cell becomes senescent because it can no longer replicate itself. This is also known as the Hayflick limit, which discusses the number of times a cell can divide before it becomes senescent. The cell will eventually grow old and dysfunctional because the genetic material has deteriorated beyond repair. These senescent cells are hazardous to our bodies, as they release cytokines that cause inflammation, an immune system response to infection, or injury that leads to unnecessary damage to healthy cells.

But quercetin (among other power nutrients) have been used by folks to flush these senescent cells away.

To your longevity,

Anil Bajnath MD
CEO/Founder, Institute for Human Optimization
Chief Medical Officer, Longevity Insider HQ