Quercetin and fisetin are flavonols, which are a type of flavonoid naturally found in plants.
With strong antioxidant properties, flavonols have been linked with several health benefits, including anti-inflammatory, anti-obesity, anti-diabetic, and cardioprotective effects. Both quercetin and fisetin show promise in extending lifespan, but more research is needed to confirm this link.
Read on to learn about the best natural sources of quercetin, the best fisetin supplement you can find, and how to incorporate these two flavonoids into your diet safely.
The Benefits of Quercetin
Quercetin can reduce oxidative stress and markers of inflammation, which is important for cell damage prevention.
A groundbreaking study found that supplementation of quercetin and dasatinib (a drug used in the treatment of leukemia) can help the body eliminate senescent cells. These old and diseased cells are linked with inflammation and aging, so removing them more efficiently could extend our lifespan.
Regular consumption of quercetin can affect blood lipid levels, as some studies demonstrated that it could slightly increase HDL cholesterol and decrease LDL cholesterol. In addition, a 2016 meta-analysis found that quercetin supplementation could reduce blood pressure, but the effects are possibly limited to dosages over 500 mg per day.
However, it seems that high-doses of quercetin (over 2000 mg/day) have some negative effects like slightly increased gut permeability, which intensifies translocation of microbes, leading to inflammation and increasing the risk of several diseases. Additionally, since the quercetin inhibits heat shock protein synthesis, our heat acclimation processes slow down, which delays the exercise-induced stress response.
The Best Source and Form Of Quercetin
If you are looking for the best sources of quercetin, you can find this powerful flavonol in many foods, including capers, dill, arugula, asparagus, radish, coriander, sorrel, fennel leaves, cherries, and berries.
Fisetin is found in more popular foods, with strawberries being the best source by far. Other sources include apples, onions, tomatoes, grapes, cucumbers, persimmons, etc. Since we use many of these foods every day, consuming enough fisetin shouldn’t be a problem. On the other hand, not many people eat quercetin-rich foods, which is why quercetin supplementation can be beneficial.
Studies show that 500-1000 mg/day of quercetin is sufficient to reap the benefits of quercetin supplementation, while going over 2000 mg/day can increase gut permeability. So, staying within the 1000 mg/day limit seems to be the safe option.
Our quercetin reviews below should help you find the best quercetin brand and safely incorporate this compound into your life.
Quercetin And Fisetin For Longevity
Both quercetin and fisetin play an important role in healthy aging, as they activate SIRT1, which is an enzyme that plays a vital role in longevity in lower organisms. The effects mimic caloric restriction, which is a proven way to increase lifespan. This can potentially lead to weight loss, but the quercetin weight loss reviews and studies haven’t found substantial evidence yet.
Research has discovered that fisetin has senolytic effects in mice and human tissues in vitro. Quercetin has shown such promise in human trials, and since both flavonols seem to have similar mechanisms of action, we can expect the same benefits with fisetin.
Of course, more studies are needed to estimate this potential for increasing lifespan in humans. If you want to learn more about why we age and how to increase longevity, you can read our review of senolytics supplements.
Quercetin Reviews: The Best Quercetin And Fisetin Supplements
Quercetin supplement reviews show that there are a lot of good quercetin products out there. On the other hand, fisetin is a little more scarce, and since there are no in vivo human studies, there is no known optimal dosage.
So, what is the best quercetin supplement?
Best High-Dose Quercetin
Best Naturals Quercetin contains 1000 mg of quercetin per serving, with 120 capsules (60 servings) per bottle. This is also the best quercetin for allergies, as reviews highlight its effectiveness at easing symptoms during allergy season.
Some people have also been taking it to shed weight, but quercetin reviews for weight loss are mixed, and there is no substantial evidence to support this claim.
Best Low-Dose Quercetin
A bottle of Jarrow Formulas Quercetin contains 100 500-mg veggie capsules. You could take two a day, but people who worry about gut permeability sometimes take just one per day.
While some people have tried this quercetin for weight loss, reviews are contradictory. Anti-inflammatory properties are better attested to, as people regularly report how this supplement helps in high pollen seasons.
Best High-Dose Fisetin
If you want more fisetin than what you can get from your diet, you can try this fisetin supplement by HumanX. Each capsule contains 500 mg of fisetin, which should be enough, but we won’t know until we see some human studies.
The company claims several benefits such as brain protection and anti-aging support, and users seem to agree. There is a 30-day satisfaction guarantee, so you can always get your money back if you are not happy with the results.
Best Low-Dose Fisetin
If you want to add a little fisetin on top of your quercetin, but you are not a big fan of strawberries, Rejuvenation Therapeutics has a supplement that can help. Their fisetin capsules have 100 mg, which isn’t much but can easily stack with fisetin you get from your diet.
More studies are needed to establish the effects of low-doses of fisetin inflammation, brain function, and other aspects of overall health.
Editor’s note: we are regularly updating this review. If you see any problems, weird interpretations of the data, or just want to say hi, please reach out to firstname.lastname@example.org.