Pure maple syrup linked to liver health

New research conducted at the University of Tokyo suggests that pure maple syrup may promote a healthy liver. The pilot study, conducted by Dr Keiko Abe of the University of Tokyo's Graduate School of Agricultural and Life Sciences, showed that healthy laboratory rats fed a diet in which some of the carbohydrate was replaced with pure maple syrup from Canada yielded significantly better results in liver function tests than the control groups fed a diet with a syrup mix containing a similar sugar content as maple syrup.

The results will be published in the November issue of Bioscience, Biotechnology, and Biochemistry.

Although most healthy individuals take liver function for granted, liver health is of great importance because of the hundreds of vital functions it performs that are essential to human life, which include storing energy (glycogen) and regulating blood glucose, the production of certain amino acids (building blocks of protein), filtering harmful substances from the blood. Liver disease not related to alcohol consumption is estimated to affect 25% of people in the United States, according to the American Liver Foundation. It shows up most often in middle aged people who are overweight, have abnormal blood lipids and diabetes or insulin resistance conditions when grouped together, known as metabolic syndrome.

"It is important to understand the factors leading to impaired liver function – our lifestyle choices including poor diet, stress and lack of exercise, as well as exposure to environmental pollutants that produce tissue-damaging free radicals," says Dr Melissa Palmer, clinical professor and medical director of hepatology at New York University Plainview. "The preliminary results of this research are encouraging and emphasize the importance of choosing a healthy diet to help counteract the lifestyle and environmental factors that may impact liver function, even our choice of a sweetener. In addition to Dr Abe's recent findings, published research suggests that pure maple syrup may prove to be a better choice of sweetener because it was found to be rich in polyphenolic antioxidants and contains vitamins and minerals," notes Palmer.

The animals were evaluated using the latest analytical methods including gene expression profiling called nutrigenomics. In the study, rats were fed diets consisting of 20% pure maple syrup, or 20% syrup mixture with similar sugar content as maple syrup. After 11 days, the rats on the maple syrup diet showed significantly decreased levels of liver enzymes AST, ALT and LDH in the blood, standard biomarkers for evaluating liver function. The gene expression profiling observations also suggest a mechanism whereby the maple syrup diet caused genes involved in the production of harmful ammonia in the liver to down-regulate, that is, to be less active.

"This research contributes to our growing understanding of the incredible health potential of maple syrup," remarked Serge Beaulieu, President of the Federation of Quebec Maple Syrup Producers. "We learned previously that maple syrup contains antioxidant compounds that may actually help regulate glucose metabolism and increase insulin release, possibly aiding in the management of type 2 diabetes. And now Dr. Abe is exploring the relationship between maple syrup consumption and liver health. Her current findings give us even more reason to enjoy our maple syrup."

This study was funded by the Conseil pour le developpement de l'agriculture du Quebec (CDAQ) and Agriculture and Agri-Food Canada (AAFC) on behalf of the Canadian Maple Syrup Industry and the Federation of Quebec Maple Syrup Producers.

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