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February 2010
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Happy New Year. In this issue of apple e news we start with research showing that cold and controlled atmosphere storage protects apple antioxidant capacity. We then take a look at two studies on apple antioxidants and their capacity to benefit athletes after exercise - one in relation to muscle recovery and the other in protecting from colds and flu. And finally we look at the new and emerging research on apple antioxidants and the role they appear to play in reducing inflammation, particularly that associated with inflammatory bowel disease.
We hope this issue builds on your understanding of the health benefits of apples. And until next time, remember an apple a day just might keep the doctor away.
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HIGH LEVELS OF APPLE ANTIOXIDANTS CAN BE SUSTAINED BY OPTIMAL STORAGE
New research from Bonn University reveals that apple phytochemicals can be enhanced by cool storage conditions.
Matthes and Schmitz-Eiberger subjected a variety of different apple cultivars to a variety of storage conditions including long-term cold and controlled atmosphere storage as well as storage at room temperature (20oC) to simulate shelf life at home.
Antioxidant capacity and polyphenol content increased in most cultivars following 4 1/2
months of cold or controlled atmosphere storage. However, most fruit stored for two weeks at room temperature declined in antioxidant capacity despite retaining relatively stable polyphenol levels.
Yet according to Newspoll research conducted last year, around 50% of Australians do not keep their apples in the fridge.
To preserve the goodness that comes from the cold storage of apples prior to market, keep your apples in the fridge and, if you prefer not to eat them cold, top up your fruit bowl each morning.
- Matthes et al. Polyphenol content and antioxidant capacity of apple fruit: effect of cultivar and storage conditions. Journal of Applied Botany and Food Quality-Angewandte Botanik 2009:82(2);152-157.
- Newspoll Telephone Omnibus (March 2009).
Click here for abstract
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APPLE ANTIOXIDANTS COULD BENEFIT ATHLETES
Oxidative stress is thought to be responsible for many undesirable effects in the human body, including aging and the increased DNA damage that results in cancer. Oxidative stress is also involved in muscle injuries that can occur from exercise1.
Researchers from the Nippon Sport Science University2, Tokyo fed apple polyphenols to rats to examine their ability to withstand muscle injury following a series of prescribed muscle actions.
Rats fed apple polyphenols displayed more forceful muscle contractions and quicker muscle recovery over the research period than those fed a control diet. They also had lower levels of a range of chemical markers traditionally used to predict oxidative stress, and had higher levels of mRNA for the antioxidant protein glutathione-S-transferase.
From this research Nakazato and colleagues propose a role for dietary apple polyphenols in protection from muscle injury that not only involves direct antioxidant activity but also the way in which they influence gene expression, improving existing antioxidant pathways in the body and increasing the body's own antioxidant production.
This research builds on the story for apple antioxidants in athletic performance. In research conducted by the University of South Carolina3, quercetin, a polyphenol with antioxidant activity that is particularly rich in apples, was shown to offer significant protection from upper respiratory tract infections in male cyclists.
In the study, male cyclists took either quercetin or placebo over a 5 week period during which they also undertook three days of intense training. In the two weeks following training, nearly half of the placebo group (45%) experienced upper respiratory tract infections, compared to only 5% of the group who had consumed the apple antioxidant.
- Powers et al. Exercise-Induced Oxidative Stress: Cellular Mechanisms and Impact on Muscle Force Production Physiol. Rev. 2008:88; 1243-1276
- Nakazato et al. Dietary apple polyphenols have preventive effects against lengthening contraction-induced muscle injuries. Molecular Nutrition & Food Research. 2009 Oct 28 Epub ahead of print
- Nieman et al.(2007) Quercetin reduces illness but not immune perturbations after extensive exercise. Medicine & Science in Sport & Exercise. 2007 39(9);1561-1569
Click here for abstract
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LABORATORY RESEARCH SHOWS APPLE COMPOUNDS MAY BLOCK GENES RESPONSIBLE FOR INFLAMMATION
The phytochemicals present in apples exert more than just antioxidant activity, and emerging research has shown a role in the inhibition of inflammation.
In latest research1, Jung and colleagues from the University of Kaiserslautern, Germany examined the effectiveness of apple juice extracts on inflammatory gene expression in human cell lines and found they significantly inhibited expression of proinflammatory genes, inflammatory enzymes and transcription factors.
Inflammatory processes underlie many human diseases, and polyphenols from a range of food sources have been shown to modify these processes both in the test tube and out. Of all the chronic inflammatory processes, those most likely to be influenced by dietary factors are the inflammatory bowel diseases (IBD) Crohn's disease and ulcerative colitis.
This research adds support to work from Japan2 presented in Apple Review 2009 in which mice with colitis fed apple procyanidins had an improved outcome. It remains early days but research continues to look promising.
- Jung et al. Influence of apple polyphenols on inflammatory gene expression. Molecular Nutrition & Food Research. 2009:53;1263-1280
- Yoshioka et al. Orally administered apple procyanidins protect against experimental inflammatory bowel disease in mice. Int Immunopharmacolo 2008:8(13-14);1082-1087
Click here for abstract
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