For the implementation of the project, scientific expertise from different research institutes has been put together. The clinical part of the study will be carried out at the University Hospital of Clermont-Ferrand in France while the French National Institute for Agronomic Research (INRAE) in Clermont-Ferrand and Hochschule Geisenheim University will provide state-of-the-art analytical methods to learn more about the health benefits of a plant-based diet.
The French-German research team draws on previous studies which put the plant compound hesperidin, contained in oranges and orange juice, in the center of attention of nutritional scientist. Recent findings suggest, for instance, that hesperidin may have beneficial effects on blood vessels and therefore help to maintain a normal blood pressure. In addition, orange juice is rich in potassium for which the EU has already authorized a “Health Claim” with regard to its positive effect on blood pressure. This means that for foods containing a certain potassium content, the health benefit may also be claimed on the packaging.
Hypertension is a risk factor for different cardiovascular diseases, such as heart attacks and strokes. A study recently published in the British Journal of Nutrition with more than 34,000 Dutch adults indicated that the consumption of one glass of fruit juice (0.33 l) may reduce the risk of strokes by 24 percent and the risk of coronary heart diseases by 20 percent. In addition, two other clinical studies by British and Spanish universities, published in summer 2020, showed that the daily consumption of orange juice is associated with improved blood parameters in one marker for the functioning of vasodilation (FMD).
For the new HESPER-HEALTH study, healthy adults with pre-existing cardiovascular risk factors are recruited for the first time. Over a period of six weeks, they are either given a small glass of orange juice on a daily basis or one of two placebo drinks which were developed in Geisenheim. Due to the so-called cross-over design of the study, each participant will consume all three drinks in subsequent, randomized phases – a method that corresponds to the highest clinical quality standards. In addition to a sugar content that is equal to orange juice, one of the placebo drinks will also contain added purified hesperidin from oranges. This approach is meant to establish whether the observed health effects can be causally attributed to the plant compound.
Apart from researching short and mid-term effects on the cardiovascular system, the study will also examine probable changes in the composition of natural intestinal bacteria (microbiota) of the participants. Previous studies reported that even a short-term consumption of orange juice has a positive impact on microbiota. If HESPER-HEALTH can validate this effect over a period of 6 weeks, other beneficial health effects of orange and orange juice consumption can be explained scientifically, especially since intestinal microbiota is considered an important barrier of the human body to ward off pathogenic bacteria and viruses.
The HESPER-HEALTH study uses innovative analytical technologies. Researchers of the INRAE Institute in Clermont-Ferrand chose an approach called “nutrigenomics”. It allows to identify genes and metabolic pathways which are activated when consuming orange juice or hesperidin, and thus providing unique and profound insights into the underlying mechanisms. By using this technology, the French researchers were already able to demonstrate in earlier projects that hesperidin positively affects different metabolic processes in white blood cells.
Dr. Christine Morand (INRAE), one of the lead authors of the HESPER-HEALTH study, is excited about the upcoming start: “I am very much looking forward to this two-year clinical trial which is supposed to provide more information on how the consumption of orange juice may beneficially affect blood vessel function. Many people know about the positive health effects of polyphenols, including hesperidin, from products such as dark chocolate, olive oil or green tea. So far, however, little is known about polyphenols in fruit juices. I hope that our new study will help to change that.”
Prof. Dr. Ralf Schweiggert, Head of Institute and Professor for Analysis & Technology of Plant-based Foods at Hochschule Geisenheim University, will accompany the study together with the Geisenheim expert on polyphenols Dr. Christof Steingaß, and explained: “We are only just starting to understand the importance of hesperidin and other polyphenols from citrus fruits and the juices made thereof. HESPER-HEALTH will provide new information about these plant compounds – hoping that we can better explain why a well-balanced diet, which is rich in fruit and vegetables, is good for your health. For many people, drinking a glass of orange juice is part of their healthy diet, for example at breakfast. At the same time, however, its high sugar content is often criticized. Although it goes without saying that orange juice is much more than just “sugared water”, we need to learn more about the health effects of this complex mixture of vitamins, minerals and polyphenols. This is exactly what we wish to achieve with HESPER-HEALTH.”
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