OIV scientific sessions, 38th OIV Conference, Mainz, Germany

During the OIV scientific session of the “Health and Safety” Commission, several interesting topics were presented.

Dr. Imke Reeseexplained that adverse reactions after drinking wine are commonly reported. However, in most reports reproducibility of these reactions is not addressed, which leaves it unclear whether these reactions are in fact adverse reactions in an allergological sense. Often an objective convincing history as well as a thorough diagnostic workup to identify the underlying mechanism is lacking, resulting in purely subjective reports.

Sulfites and biogenic amines are suggested to play a major role in eliciting wine-induced adverse reactions. However, there are only a few clinical studies with double-blind, placebo-controlled oral provocation tests and these studies revealed conflicting results. Apart from sulfites and biogenic amines, there is a whole range of other possible triggers and mechanisms of adverse reactions. Even severe anaphylactic reactions against grape allergens and ethanol itself have been reported. Since it is obligatory to label common and potential allergens within the EU, fining agents made of milk (casein), egg and fish have been suspected to elicit allergic reactions as well, although a clinical relevance is not very likely.

Wine-induced symptoms are diverse in aetiology, but not all of them can be reproduced. A thorough diagnostic workup including evaluation of food protocols is mandatory for evaluating wine-induced adverse reactions. Once the underlying mechanism has been elucidated and the eliciting agent has been objectively determined, the patient can be informed about the food substances that should be eliminated and how to cope with it while maintaining a high quality of life.

Prof. Nicolai Worm reviewed the epidemiological data and investigated possible mechanisms whether moderate wine consumption can protect from non-alcoholic fatty liver disease (NAFLD) and explained that NAFLD has become an endemic disorder. An estimated 30 to 40 % of adults are affected. In adults who are overweight, this figure reaches already around 70 %. Of particular concern is the fact that one third of overweight schoolchildren already have a fatty liver. When we look at patients with type 2 diabetes, 80 % have this lipid disorder.

NAFLD is of concern not only because it can develop into chronic inflammation of the liver, liver cirrhosis and liver cancer, but also because it leads directly to type 2 diabetes. In addition, a growing number of studies is showing that NAFLD is associated with an increased risk of heart disease, independently of all known risk factors for heart disease.

NAFLD is the consequence of our modern Western lifestyle. A too high caloric intake together with little physical activity are considered to be the major risk factors. Whereas many studies have identified a high intake of alcoholic beverages as a risk factor for alcoholic liver disease, recent cross-sectional studies have demonstrated that moderate alcohol consumption, and especially wine consumption, is associated with a decreased risk for NAFLD. A recent prospective cohort study has even found a decreased incidence of NAFLD with moderate alcohol and wine consumption.

Whether and to what extent this seemingly paradoxical relation is causally related has not been clearly established so far. Possible mechanisms include an increase in insulin sensitivity and the anti-inflammatory effects of alcohol per se as well as the effects of the many polyphenolic substances in wine and other alcoholic beverages. Resveratrol for example, is capable to inhibit the transcription factor SREBP-1c which is responsible for the de novo lipogenesis from carbohydrates in the liver.

Prof. Kristian Rett presented the dark side of bariatric surgery (*). He explained that obesity is a major public health problem in the Western world that has reached epidemic dimensions. Gastric bypass (GB) is a surgical procedure that reduces nutrient and calorie uptake by reducing stomach capacity and re-routing of nutrients (bypassing the lower part of the stomach, the duodenum and the upper jejunum) is said to be the most effective and sustainable treatment. GB was shown to reduce body weight and mortality in the very obese, and to improve diabetes, hypertension and other obesity related conditions. On the other hand, a variety of intestinal adaptions to the altered anatomy profoundly affect multiple different aspects of the digestive tract. An unknown number of GB patients develop post-bypass carbohydrate – and alcohol intolerance. Both conditions cause either no symptoms or unspecific “dumping-like” symptoms. Recent data suggest, that post-bypass hypoglycemia affects more than 30% of the patients, a condition, that is not only inconvenient, but potentially life threatening. He tried to identify patients at risk by continuous glucose monitoring (CGM) combined with nutrition and symptom diaries. His hypothesis is that “extra-moderate” wine consumption may slow down accelerated glucose appearance in subjects with post-bypass hypoglycemia syndrome and might therefore add a potentially causal treatment option.

(*) Bariatric surgical proceduresBariatric surgical procedures cause weight loss by restricting the amount of food the stomach can ho... cause weight loss by restricting the amount of food the stomach can hold, causing malabsorption of nutrients, or by a combination of both gastric restriction and malabsorption.