Medical Studies


Latest News

Cornell University

Breast Cancer
Colon Cancer
Fat Loss
Hair Growth
Heart Disease
Lung Cancer
Prostate Cancer
Skin Cancer
Frequently Asked Questions  
Q: Are apple polyphenols safe?

A: Yes. A study published in June 2004 in Food and Chemical Toxicology tested oral toxicity of apple polyphenol extracts at levels 200 times the recommended dosage for humans. Researchers reported "no significant hematological, clinical, chemical, histopathological, or urinary effects" even at these extreme dosages.

Apple polyphenol extracts are listed (as "apple essence, natural") in the FDA's approved additive/GRAS (Generally Recognized As Safe) database.

Q: Why can't I just eat apples?
A: It would be great if we could all get plenty of concentrated polyphenols from diet alone, but most research indicates most dietary polyphenols are poorly absorbed. In 1997, researchers is the Netherlands reported that "flavonoids (polyphenolic compounds) present in foods were considered non-absorbable because they are bound to sugars."

A study at the Linus Pauling Institute concluded that "despite the high antioxidant capacity of individual apple polyphenols and apple extracts and the significant antioxidant effects of apple extract added to human plasma in vitro, ingestion of large amounts of apples by humans does not appear to result in equivalent in vivo antioxidant effects of apple polyphenols."

Many of the studies on the health benefits of apples are actually testing potent apple polyphenol extracts, not whole apples. Apple polyphenol extracts are highly bioavailable and water-soluble.

You can increase your intake of apple polyphenols by eating fresh apples (including the skin, where the highest concentrations are found), but unless you have your own apple trees, there is no guarantee that your fruit contains enough apple polyphenols.

Worse, the apples at your grocery store are not fresh, and may have lost most of their polyphenol content before you buy them. All commercial apples in the U.S. are cold-stored in warehouses, most for many months. A study on apples published in 2004 found that "total phenolics and total antioxidant activity" decreased in the first three months of cold storage, and that "cold storage rapidly impoverishes these properties in skin." The same study reported "strong, time-related decreases over 6 mo of cold storage..."

Most commercial apple products contain little or no polyphenols due to processing. Polyphenol content also varies greatly between apple varieties and fruit maturity. Relatively higher concentrations have been found in Granny Smith, Red Delicious, Rome Beauty, and Idared varieties.

Japanese researchers report that immature apples, which are too bitter to eat, contain 10 times more apple polyphenols than mature apples. These immature apples are used to produce the high-concentrate apple polyphenol extracts.

Surely, there is some benefit in increasing dietary intake of apples. There are serious questions, however, as to whether eating whole, cold-stored apples will substantially increase your absorption of these valuable polyphenols.

Many of the studies on the health benefits of apples are actually using potent apple polyphenol extracts, not apples, in those studies.

The use of standardized apple polyphenol extracts makes sense in terms of laboratory testing, but using the apple polyphenol extracts may also make sense for people wanting to realize the reported health benefits, for the following reasons:

  • Apple extracts are the actual compounds showing the results in many of the available medical studies.

  • The polyphenol bioavailability of apple peel powder extracts is far higher than from whole apples, which must be digested to extract the phytochemicals.

  • The concentration of polyphenols in apple peel extracts makes it possible to consume higher doses. (Many studies you will read report dose-dependent effects, with higher dosages providing greater benefits.)


Q: What products are available?
A: Apple polyphenol extracts are currently used commercially in health supplements, chewing gum, breath strips, toothpaste, herbal teas, energy drinks and cosmetics. Most of these products are only available to consumers in Japan.

A Japanese company, Asahi Breweries, has announced plans to market and energy drink in the U.S. in 2005 blended with apple polyphenol extract. A U.S. company now has the product available in capsule form. Please check our suppliers page for updated product information.

Q: Are there side effects?
A: In 80+ medical studies we have reviewed, there are no side effects noted.
Q: How are apple polyphenols different from polyphenols in tea, wine and other foods?
A: There is a large body of research on the health benefits of red wine, and green and black tea, most of which attributes health benefits of the polyphenol content. The major difference is that apple polyphenols are water soluble, where most other polyphenols are not. This enhances the bioavailability of apple polyphenols, when taken as extracts without the presence of binding sugars.
Ask Your Question  
If you have a question that is not addressed here, please contact us via email. We will do our best to find the information you need.
What concentrated products are available? Check the Suppliers page here


Sign up FREE to get the latest news on apple polyphenols:

Your First Name:

Your email:

Be the first to know about new studies, reports and products.