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Why the Japanese live longer


A research team at the Institute of Human Nutrition and Food Science at Kiel University has discovered promising links between life expectancy and two phytochemicals - the so-called catechins and isoflavones.  The underlying research by the Kiel-based scientists recently appeared in the two journals Oncotarget and The FASEB Journal.

Across the world, it is the people in Japan who live the longest - on average 84 years. In addition to genetic causes and environmental factors, the eating habits also seem to be responsible for the above-average Japanese life expectancy. A traditional Japanese diet is rich in phytochemicals: catechins can be found in green tea, for example, and there are high concentrations of isoflavones in soy.

"We have known for a while that there is a link between diet and life expectancy in Japan in particular. We especially wanted to investigate the role of plant-based ingredients in this more deeply. With the effects of catechins and isoflavones, we have discovered two mechanisms that also are potentially relevant in health prevention", said Junior Professor Anika Wagner, regarding the research results. This research project also received support from the Cluster of Excellence "Inflammation at Interfaces".

In order to investigate the effects of the two compounds on health and life expectancy, the Kiel-based researchers performed studies using the Drosophila melanogaster fruit fly. These showed that both green tea catechins and soy isoflavones significantly increased the life span and fitness of fruit flies. The research team found out that a particular catechin in green tea inhibits two enzymes that are important for digesting carbohydrates. Inhibiting these enzymes reduces the absorption of glucose in the organism. This has the effect of reducing sugar levels. Soy isoflavones exert their positive effects by influencing the cellular energy budget and activating the longevity gene Sirtuin-1.

Further studies will show whether the results can be transferred to other organisms. The primary aim of the research group is to research bioactive food ingredients, foods and diet patterns which have a beneficial effect on health and life span. This concept forms an important part of the research on health prevention within the research focus "Kiel Life Science" at Kiel University.

Photos are available to download:

Original works:

Wagner AE, Piegholdt S, Rabe D, Baenas N, Schloesser A, Eggersdorfer M, Stocker A, Rimbach G (2015): Epigallocatechin gallate affects glucose metabolism and increases fitness and life span in Drosophila melanogaster. Oncotarget, 6(31):30568-78.

Piegholdt S, Rimbach G, Wagner AE (2015): The phytoestrogen prunetin affects body composition and improves fitness and lifespan in male Drosophila melanogaster. The FASEB Journal,


Jun. Prof. Dr. Anika Wagner
Institute of Human Nutrition and Food Science, Kiel University
Tel.: 0431-880-5313


Christian-Albrechts-Universität zu Kiel
Press, Communication and Marketing, Dr Boris Pawlowski, Text/editing: Christian Urban
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