Many plants, including fruits and vegetables, are known for their medicinal properties. These properties come from active compounds called metabolites that plants produce either through metabolism or to aid in that process. Plant metabolites exhibit different activities; while some are able to fight inflammation or kill microbes, others can effectively halt oxidation and delay cellular aging. According to recent studies, a compound known as quercetin possesses unique anti-aging properties. Quercetin can prevent healthy cells from aging — a process known as senescence — and, at the same time, it exerts the opposite effect on harmful cancer cells, promoting senescence, which leads to rapid cell aging and death.
Quercetin in food
Quercetin belongs to a diverse group of phytonutrients known as flavonoids. Flavonoids are plant pigments that give fruits and vegetables their vibrant colors. Flavonoid compounds are known for being potent antioxidants and anti-inflammatory agents. They also exert modulating effects on the immune system. Some of the most extensively studied and well-known flavonoids are quercetin and kaempferol.
Quercetin is considered the most abundant flavonoid in the human diet. Research estimates that an average person consumes about 10 to 100 milligrams (mg) of quercetin from food sources every day. A diet that consists of high amounts of flavonoids including quercetin is said to be good for the health. As an antioxidant, quercetin can neutralize free radicals, which are harmful, unstable molecules that damage cells at high concentrations. Free radicals play a huge role in the development of chronic diseases such as cardiovascular disease, diabetes, and cancer.
Aside from foods, quercetin can now be sourced from health supplements. Dietary supplements typically contain about 500 to 1,000 mg of quercetin. However, if you wish to boost your intake of this beneficial compound, it is still best to obtain it directly from food sources. (Related: Quercetin Offers Numerous Health Benefits.)
Here are some of the best foods to eat to get your daily dose of quercetin.
- Black tea
- Citrus fruits
- Green tea
- Green peppers
- Red apples
- Red grapes
- Red leaf lettuce
- Red onions
- White onions
- Yellow peppers
The anti-aging and anti-cancer properties of quercetin
The anti-inflammatory and antioxidant properties of quercetin are known to help prevent heart disease, protect against the loss of neurons, and enhance cognitive functions like spatial memory and learning. Today, additional research on its biological activity has uncovered how it can also delay or prevent cellular aging and even induce death in cancer cells.
Cell senescence is the gradual deterioration of cell function. During senescence, cells cease to divide due to a variety of mechanisms, which involve the shortening of telomeres or chromosome caps, extensive DNA damage, and the over-activation of inflammatory signaling molecules.
Some studies suggest that senescent cells, which have lost their ability to function properly, do not always succumb to death. Instead, these aberrant old cells accumulate and begin emitting pro-inflammatory signals that promote rapid aging and the development of age-related diseases, particularly cancer.
Based on the results of experiments, quercetin has shown great potential in not only reducing inflammation caused by abnormal senescent cells, but also preventing healthy cells from entering senescence. Quercetin treatment even encourages normal cell behavior and slows down the cell aging process.
On the other hand, quercetin works on aberrant cells differently. This powerful flavonoid induces cell senescence in cancer cells, inhibiting their rapid proliferation. Quercetin also ensures that the cancer cells go through cell death. Studies show that the combination of quercetin and tocotrienols — antioxidant compounds from the vitamin E family — are extremely effective against cancer cells.
But quercetin’s anti-aging properties are not limited to preventing senescence. A study published in Experimental Gerontology showed that it can also rejuvenate senescent cells. Treatment with quercetin and its derivative, quercetin caprylate, promoted physiological alterations to aging cells that not only extended their lifespan, but also enhanced their survival and viability in culture.
To get the anti-aging benefits of quercetin, add quercetin-rich fruits and vegetables to your diet.