Fisetin is a plant polyphenol and a bioactive flavonoid.
A wide category of compounds that mainly helps plants by providing vibrant hues and supporting health with antioxidant activity. Many trees and plants contain it, including Acacia Greggii, Butea Frondosa, Eudicotyledons, Quebracho Colorado and Rhus Cotinus, as well as in fruits and vegetables, especially:
StrawberriesÂ
From early summer to early autumn, strawberries become abundant in farmers’ markets and grocery stores. This seasonal fruit is the best source of fisetin, as strawberries contain 160 grams of fisetin. Strawberries have over 600 different species and are rich in fisetin, folate, niacin, vitamins A, C, E, and K, potassium, iron and lutein – all of these are essential vitamins and minerals to keep you healthy.
As rich in fisetin, strawberries can be an antioxidant that helps protect the body from oxidative stressors, promotes healthy brain cells and keeps proper levels of glutathione that fights off peroxides and free radicals.
According to mice experiments, strawberry flavonoids reduced stress and inflammation in the blood compared to those without them. The researchers fed the mice fisetin supplements for seven months, and they responded better to mental tests and tasks. However, the results for humans may or may not have similar effects.
Moreover, if you are thinking of adding strawberries to your daily diet, you better buy organic ones to prevent pesticides. When organic is not available, you must wash the strawberries with a solution of vinegar and water to remove any unwanted chemicals and pesticides.
Onions
You may be unknowingly consuming fisetin through onions, which are a regular ingredient in your everyday meals. Onions have around 5 grams of fisetin and are a good source of this beneficial flavonoid.
The flavonoids found in onions are much more concentrated in the outer layers of the flesh. Hence, you must peel off as little of it to maximise the health benefits. You may lose flavonoids when you over-peel the onions. Consequently, you may lose around 20 percent of its quercetin and almost 75 percent of its anthocyanins–these two are beneficial to maintaining good health.
Apples
Another good food source of fisetin is apples, which are also rich in fibre, vitamin C, antioxidants like vitamin E, and polyphenols. Apples have over 27 grams of fisetin and other relevant nutrients and minerals that your body needs; hence, apples a great daily addition to your diet!
Additionally, apples have a special flavonoid in epicatechin that can reduce blood pressure. They can decrease the concentrations of LDL cholesterol and triglycerides in your body. Plus, apples support the pancreas in producing insulin and apple fibres can feed the good bacteria in your gut.
Fisetin in apples can eradicate senescent cells and slow down the aging process. Fisetin can also effectively prolong your lifespan and improve your health.
In choosing apples to add to your diet, you must pick fresh and organically-grown ones and ensure to eat the skin to reap their health benefits, including fisetin.
GrapesÂ
Research found out that a component of the grape seed extract can be potentially effective as a senolytic that can extend your lifespan and healthspan when experimented with mice–and this is fisetin. Grapes have over 4 grams of fisetin that can kill cellular senescence, preventing you from having age-related diseases.
Using procyanidin C1 (PCC1), the research team identified a new senolytic that is derived from grape seed extract.PCC1 showed promise at preventing the effects of senescent cells when administered at low concentrations and selectively eradicating senescent cells at higher concentrations.
PersimmonsÂ
Persimmons are also a good source of fisetin as this fruit has over 11 grams of it. Generally, persimmons need proper timing to ripen and become sweet. It looks like an under-ripe tomato or peach and can be an alternative for snacks.
Moreover, persimmons can provide you with vitamins A and C and dietary fibre. There are phytonutrients, flavonoids, and antioxidants in this fruit that prevent tumour development and improve eye health. Fisetin, which can be found in persimmons, has also been shown to kill breast cancer; however, too much fructose in persimmons may harm you.
Other sources of fisetin
Among the food sources of fisetin, strawberries have a much higher concentration of fisetin than any other fruits and vegetables. It is much higher than the typical dietary supplements you can find, as they usually contain about 100 mg. Of course, there are also supplement brands that offer much higher doses; however, the positive and negative impacts of this are yet to be discovered.
There are also other food sources of fisetin but with low amounts, such as lotus root and kiwi. Lotus root contains vitamins and minerals like vitamins C, copper and B vitamins.
This vegetable is also rich in fibre and low in calories. On the other hand, kiwis contain 2 grams of fisetin and are rich in vitamin C and dietary fibre.
Mangoes and cucumbers also have fisetin in their nutritional components. The fisetin levels in mangoes and cucumbers are low and measured in freeze-dried foods. Furthermore, the levels found in fresh fruits and vegetables basically depend on the conditions of how they are grown.
Flavonoids are natural parts of the genetic makeup of fruits and vegetables. There are subclasses of beneficial flavonoids, such as anthocyanins which are heart-healthy antioxidants that can be found in berries, wines and plums.
While the other two are flavonols which fisetin belongs with and are usually present in onions, Brussels sprouts and broccoli, these can generally help decrease allergic reactions; and isoflavones which can be found in soybeans and legumes and lower the risk of breast and prostate cancers [4].
Benefits of fisetinÂ
Fisetin has a lot of health benefits when consumed, as proven by multiple studies. Although there are still more claims that need clinical trials in humans, fisetin generally shows positive effects in animal studies. The following are some potential benefits of fisetin in humans:
Anti-aging
One of the prominent and exciting benefits of fisetin is its potential to reverse aging in humans. There is a study in mice that showed fisetin as the most effective plant compound in destroying senescent cells without harming the healthy ones. The mice who underwent the experiment increased their lifespan by 40 percent.
Helps with diabetesÂ
Fisetin may also restore the blood sugar levels of diabetics. In a study made on diabetic rats and mice, the researchers concluded that fisetin improved the ability to control blood sugar by increasing insulin levels and enzymes that turn sugar into energy, removing sugar from the blood and decreasing the liver’s ability to make unnecessary sugar from lactate and amino acids.
Furthermore, fisetin shows a positive function in slowing down the progression of cataracts. Plus, it protects the kidneys of diabetic mice by blocking inflammation and oxidative stress.
Bone health
One of the aging-related diseases in bones is osteoporosis, and fisetin has the potential to combat this. Basically, osteoblasts refer to your bone-forming cells, and osteoclasts break down bone cells.
These two types of cells are dependent on each other to function correctly, they are involved in the production and processes of bone health. When you have osteoporosis, your osteoclasts are more active than the osteoblasts, causing you to lose net bones.
Studies in rats have shown that fisetin stimulates osteoblasts while blocking osteoclasts.
Mental health
In another study, fisetin was shown to help enhance the memory and learning improvements of older rats. This is because fisetin can activate the pathways in the brain that are involved in storing memories. Fisetin can also help with depression and anxiety in mice by increasing the levels of serotonin and noradrenaline.
Heart health
As fisetin can protect the heart cells from oxidative stress, it also improves the overall heart function of rats with abnormal thickening of the heart walls in a clinical study. Additionally, It protects the heart tissue and mitochondrial function from damage due to a heart attack in rats.