Focus on the beneficial effect of polyphenols and other compounds in wine and beer

An issue of the journal Molecules, published in January 2021, includes a number of open access papers that focus on the potentially beneficial effects of the phenolic compounds found in wine and beer.
The role of bioactive phenolic compounds on the impact of beer on health
In the introduction to this paper, the authors state that ‘The characteristic of beer is the high content in phenolic compounds, which are the focus of this review. The consumption of polyphenol-rich foods, like beer, is a well-accepted factor involved in the prevention of oxidative stress-associated diseases’.
Traditionally, beer is obtained from as little as four basic ingredients: barley, hop, yeast and water. The first two ingredients naturally contain phenolics, however during beer production, these molecules undergo chemical modifications and new molecules are formed, influencing both the yield and final characteristics of a beer. Aroma, flavors, taste, astringency, body and fullness are the result of the metabolic activity of microbes on raw materials, and scientific evidences suggesting that they are all influenced by phenol content are summarized in the review.
The review also focusses more deeply on most recent advances on the role of phenolic compounds on affecting human health status and considers how seriously researchers have tackled the effects of alcohol (also present in beer).
The authors state that ‘Beer, like wine, contains the already mentioned substances with indubitable protective capacities, not merely anti-inflammatory and antioxidant, as demonstrated by huge in vitro work on single substances. However, the ambitious objective in studying the effects of beer consumption on human health is to analyse it in toto and, in order to understand the single contribution of phenols and alcohol, parallel experiments with similar doses of an equivalent non-alcoholic beer and of alcohol alone are essential.
The authors searched the research database Scopus.com in order to identify studies that, in the search of the health effects of beer containing phenols, also considered the effects of the presence of alcohol. Less than of 25% (40 out of 161) of entries retrieved were reports on the in vivo (human or animal) or in vitro effects of phenolic compounds within in toto beer. For the 40 studies identified, the authors summarise experimental models, parameters tested and main findings
The authors conclude that studies applying a parallel administration of non-alcoholic beer or/and alcohol alone, in both animal and human intervention studies, support the existence of somehow interfering effects of phenols and ethanol. However, in order to better highlight additive or synergistic effects, further correctly set-up human interventional crossover or observational, or at least animal, studies are required.
Source: Ambra R, Pastore G, Lucchetti S. The Role of Bioactive Phenolic Compounds on the Impact of Beer on Health. Molecules. 2021; 26(2):486. Melatonin in wine and beer
Melatonin is a hormone secreted in the pineal gland with several functions, especially regulation of circadian sleep cycle and the biological processes related to it.
In the introduction to this paper the authors state that “In order to establish the therapeutic use of melatonin for possible improvements in health, it is crucial to establish its bioavailability in humans. Secondly, considering the dietary sources of melatonin, it is desirable to evaluate precisely its content in food products and the expected intake. Finally, its positive effects must be evaluated, preferably in human randomised clinical trials, which are the best to establish cause–effect relationships. Therefore, with this strategy in mind, their review aims to link these three areas, focusing on wine and beer as food sources of melatonin. The review evaluates the bioavailability of melatonin and resulting metabolites, the presence of melatonin in wine and beer, products that include a high range of bioactive phytochemicals and finally the different benefits related to the treatment with melatonin, studied both in animal models as well as mainly in humans”.
From the results of the review, the authors conclude that “the current literature highlights the good bioavailability of melatonin in humans, leading to two active metabolites that should serve to monitor the efficacy and pharmacokinetic properties of melatonin… Moreover, through the interaction with MT receptors in different body organs, melatonin acts as a central synchroniser regulating a wide range of physiological functions, such as glucose and lipid metabolism. Human clinical trials have shown that melatonin may help to reverse/ameliorate certain cardiovascular events.”
Melatonin in the organism acts as an antioxidant, neutralising a large number of reactive molecules, and it indirectly modulates the activity of the endogenous enzymatic antioxidant system. Due to these properties against oxidative stress, as well as the inhibition of different inflammation and apoptotic pathways, melatonin has shown neuroprotective effects in vitro and in animal models of Alzheimer’s Disease, Parkinson or Amyotrophic Lateral Sclerosis, among others. These findings show the strong therapeutic potential of this promising molecule to combat against these neurodegenerative pathologies. Finally, the high concentration of melatonin in wine and beer, and the frequency of consumption (without aberrant behaviours) of these two food matrices, make them two excellent vehicles for incorporating melatonin into the diet naturally”.
The authors add that clinical trials are needed to ascertain the impact of the intake of melatonin-rich foods for cardio and neurological protection, which can help in the design of new dietary recommendations or functional foods.
Source: Marhuenda J, Villaño D, Arcusa R, Zafrilla P. Melatonin in Wine and Beer: Beneficial Effects. Molecules. 2021 Jan 11;26(2):E343. doi.org/10.3390/molecules26020343. doi.org/10.3390/molecules26020486