What are Apple Polyphenols?
Micronutrients known as polyphenols are members of the larger class of phytochemicals, or substances that are present in plants. Plant-based diets contain over 8,000 recognized polyphenols. In food and plants, polyphenols have antioxidant properties. They aid in shielding plants from infections and UV radiation harm. Polyphenols function as antioxidants, shield our cells from harm, and offer additional advantages when we consume foods high in them.
The main polyphenols found in apples include:
Flavonoids like quercetin, epicatechin, procyanidins, cyanidin, and rutin. Quercetin is the most abundant flavonoid in apples.
Phenolic acids like chlorogenic acid and caffeic acid.
Dihydrochalcones like phloridzin.
These polyphenols are highest in concentration in the apple peels, but also found throughout the flesh and seeds. The variety of apple impacts the type and amount of polyphenols as well.
Do Apples Have Polyphenols?
Yes, apples contain significant amounts of polyphenols. In fact, apples are one of the top contributors to polyphenol intake in the American diet.
Apples contain on average about:
236mg of polyphenols per 100g of fresh apple
57mg of flavonoids per 100g of fresh apple
The polyphenol content can range quite a bit depending on the apple variety. The highest polyphenol varieties include:
Red delicious
Granny Smith
Gala
Pink Lady
Braeburn
Honeycrisp
Apples have one of the highest antioxidant capacities among commonly consumed fruits. Much of this is due to the rich polyphenol content.
Do Green Apples Have Polyphenols?
Yes, green apples are an excellent source of polyphenols. Granny Smith apples are one of the most popular green varieties.
Granny Smith apples contain high levels of various polyphenols including:
Quercetin
Catechin
Chlorogenic acid
Phloridzin
The total polyphenol content in Granny Smith apples is:
273mg polyphenols per 100g apple
65mg flavonoids per 100g apple
So Granny Smith apples are packed with antioxidant and anti-inflammatory polyphenols. The levels are similar and even slightly higher compared to many red apple varieties.
Which Apples are High in Polyphenols?
All apple varieties contain polyphenols, but some are higher than others. The top polyphenol-rich apple varieties include:
Red delicious - contains the highest levels of polyphenols among commonly consumed apples with 328mg per 100g. Also high in flavonoids and phenolic acids.
Granny Smith - contains 273mg polyphenols per 100g. Excellent source of quercetin and other flavonoids.
Gala - contains 252mg polyphenols per 100g. High in flavonoids like epicatechin and quercetin.
Braeburn - contains 221mg polyphenols per 100g. Good source of quercetin, catechin, phloridzin.
Pink lady - contains 209mg polyphenols per 100g. High in flavonoids and chlorogenic acid.
Honeycrisp - contains 164mg polyphenols per 100g. Packed with procyanidins, catechin, caffeic acid.
So enjoy these high polyphenol apple varieties to maximize the antioxidant benefits.
What Part of the Apple has the Most Antioxidants?
The apple peel contains the highest concentration of antioxidants and polyphenols. Apple peels contain about 5x the amount compared to the apple flesh.
Most of the polyphenols, particularly quercetin, epicatechin, procyanidins, and cyanidin, are located in the peel. Apple peels also contain the highest amount of vitamin C, another potent antioxidant.
Apple seeds are also high in antioxidants. Apple seeds contain amygdalin, a compound that converts to hydrogen cyanide. So while the seeds are antioxidant-rich, they should not be consumed in high amounts. Overall the peel is the most antioxidant packed part of the apple.
What Fruits Are High in Polyphenols?
Many fruits contain polyphenols. Some of the fruits highest in polyphenols include:
Berries - blackberries, strawberries, raspberries, blueberries
Cherries
Prunes
Apples
Pears
Oranges
Grapes
Kiwi
Plums
Dark colored fruits tend to be highest like blackberries and black plums. But even fruits that aren't dark pigmented like apples and pears are high in polyphenols. Enjoy a wide variety to get different protective polyphenols.
How Much Polyphenols Per Day?
There is no official Recommended Daily Intake for polyphenols. But studies show health benefits with a daily intake up to about 1g (1000mg) of polyphenols.
The average intake of polyphenols is estimated around 1,000 to 1,500 mg per day. Intake is higher in those who regularly consume fruits, vegetables, coffee, tea, and wine - foods naturally high in polyphenols.
To increase your daily polyphenol intake, aim for at least 3-4 servings of polyphenol-rich foods. For example:
1 medium apple (200mg polyphenols)
1 cup strawberries (240mg polyphenols)
1 cup coffee (400mg polyphenols)
2 ounces dark chocolate (600mg polyphenols)
1 glass red wine (120mg polyphenols)
Consuming a variety of colorful fruits, vegetables, coffee, tea, dark chocolate, herbs, spices, nuts, olive oil, and red wine can help provide beneficial levels of polyphenols.
Apple Polyphenol Benefits
Eating apples, a rich source of polyphenols, has been linked to many health benefits. Here are some of the top researched polyphenol benefits of apples:
1. Lower cholesterol - Apples contain polyphenols like catechin, phloridzin, and chlorogenic acid that help lower LDL (bad) and increase HDL (good) cholesterol. This helps reduce heart disease risk.
2. Blood sugar regulation - The polyphenols in apples, especially phloridzin, help slow digestion of sugars and improve insulin resistance. Apples have a low glycemic index, which helps control blood sugar.
3. Gut health - Apple polyphenols act as prebiotics, feeding beneficial gut bacteria. They also help inhibit growth of harmful bacteria and balance bacterial populations.
4. Cancer prevention - Apple polyphenols like quercetin, epicatechin, and procyanidins have been shown to fight cancer cell growth. They help induce cancer cell apoptosis and inhibit tumor formation.
5. Brain function - Quercetin and other apple polyphenols help protect the brain from oxidative damage and neurotoxins. This may reduce risk of neurodegenerative diseases like Alzheimer's and Parkinson's.
6. Heart health - The anti-inflammatory effects of apple polyphenols help improve blood vessel function and blood pressure. Apples also protect LDL cholesterol from oxidation, benefiting heart health.
7. Antioxidant protection - The diverse polyphenols in apples have potent antioxidant effects, scavenging free radicals and reducing oxidative damage linked to aging and disease development.
8. Anti-inflammatory - Quercetin and other apple polyphenols help inhibit inflammatory compounds like COX-2. This provides anti-inflammatory benefits throughout the body.
Conclusion
Apples are certainly one of the best dietary sources of polyphenols. With their rich content of flavonoids, phenolic acids, and other antioxidant polyphenols, apples provide a variety of health benefits. Choosing polyphenol-rich apple varieties like Red Delicious, Granny Smith, and Gala and eating both the peel and flesh can increase polyphenol intake and improve your overall health. Apples make the perfect nutritious snack or addition to salads, oatmeal, smoothies, and more.
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