Journal of Medical Food Jensen, GS, VL Attridge, KF Benson, JL Beaman, SG Carter, D Ager. Consumption of dried apple peel powder increases joint function and range of motion. 2014 Nov;17(11):1204–13.

Topic
What effect does the consumption of dried apple peel powder (DAPP) have on improving joint function and range of motion (ROM)?

Background
Joint mobility affects normal activities of life, and wear and tear from aging can lead to significant structural, mechanical, and composition changes of the joints. Polyphenol flavonoids are capable of producing antiinflammatory and analgesic effects. Naturally occurring compounds may help protect joints and provide an alternative to nonsteroidal anti-inflammatory drugs used to treat joint inflammation and pain. Chronic inflammation is involved in arthritis and is the result of an incomplete inflammatory response: the inflammatory initiators persist, instead of being controlled by the production of anti-inflammatory cytokines. Apples have been shown to have antioxidant and biologically active compounds. Polyphenolic compounds found in fruits have been documented to display anti-inflammatory and antioxidant activity both in vitro and in vivo. Apple extracts have been observed to inhibit the expression of pro-inflammatory genes, inflammatory enzymes, and transcription factors that help modify the inflammatory process. Processing apples significantly reduces the concentration of phenolics and total antioxidant activity compared with fresh apples. However, apples and their peel dried through a special process maintain a high level of polyphenolic antioxidants. Dietary polyphenol antioxidants have been associated with improved joint function and analgesic effects in both animals and humans.

Study Type
Human clinical intervention trial, open-label pilot study.

Study Design
The effects of consumption of dried apple peel powder on joint function and range of motion was determined in an open-label clinical pilot study involving 12 healthy people with moderate loss of joint ROM and associated chronic pain. The 12-week study involved people of both genders with well-defined reduced joint function in several areas of the body. Additional in vitro and clinical testing was performed to help uncover specific mechanisms of action. Subjects consumed 4.25g of DAPP (AppleActiv DAPP™) daily for 12 weeks with evaluations at base line, 2, 4, 8, and 12 weeks. ROM was evaluated at each visit using dual digital inclinometry. Pain scores were collected using feedback from visual analog scales. Blood testing was done for serum antioxidant protective capacity using the cellular antioxidant protection (CAP-e) bioassay. Additional in vitro testing evaluated inflammatory enzymes including COX-2, lipoxygenase inhibition, cellular antioxidant protection by the CAP-e bioassay, and formation of reactive oxygen species by polymorphonuclear (PMN) cells as determined by flow cytometry.

Subjects
12 healthy people.

Dosage
4.25 g of dried apple peel powder.

Results
Twelve weeks of consumption of AppleActiv DAPP was associated with improved ROM. DAPP antioxidants were able to enter into and protect cells from oxidative damage in vitro, and consumption of DAPP for 12 weeks was associated with a statistically significant improvement in serum antioxidant protective status. The apple peel powder inhibited both COX-2 and lipoxygenase inflammatory enzymes. Treatment of inflammatory PMN cells with DAPP before exposure to inflammation-generating factors resulted in reduced reactive oxygen species formation. DAPP was found to reduce several inflammatory factors.

Consumption
of DAPP resulted in improved joint function; the observed pain reduction may be associated with the improved antioxidant status and linked to the apple polyphenols’ anti-inflammatory effects. Conclusion AppleActiv DAPP improved arthritis symptoms and was found to significantly reduce oxidative stress and inflammatory enzymes.