Why is it recommended to drink a glass a day?
We have often heard that wine is healthy, especially red wine. As far back as antiquity and throughout history, various civilisations have believed in the beneficial, even therapeutic, properties of wine.
Always consumed in moderation, wine has been attributed antioxidant, anti-inflammatory, anticarcinogenic and analgesic properties. It is claimed, among other things, to be able to improve cardiovascular health, combat cholesterol and contribute to good mental health.
This remains largely unchanged to this day. Although science has sometimes disproved some of the properties attributed to wine, it has also been able to confirm many others. In other words, many studies today continue to show that a glass of red wine a day is healthy, slimming and even prolongs life.
What substances are contained in wine?
The main component of wine (between 80% and 85%) is water. Among the rest of the substances we find:
– Alcohol: The alcohol content varies according to the wine and is usually between 10% and 14%. It is mainly ethyl alcohol, although other alcohols can also be found: glycerine (which provides sweetness and volume), methyl alcohol (in negligible and innocuous quantities), erythritol and other poly-alcohols.
– Sugar: The proportion is also variable and depends on the type of wine. In any case, it is always the natural sugars in the grape juice that have not been transformed into alcohol during fermentation, and never added sugars. In red wine, these sugars, such as glucose and fructose, are not very important and represent between two and three grams per litre. White wines tend to contain slightly higher amounts. Wines with a higher sugar content include semi-dry wines and sweet wines.
– Acids: such as tartaric, malic and salicylic acids, which make wine an acidic alcoholic liquid with a pH between 2.5 and 4.
– Secondary plant metabolites such as tannins and polyphenols (flavonoids, resveratrol, lignans, anthocyanins, etc.).
– Proteins: Between one and two grams per litre.
– Vitamins: In small quantities, we find thiamine (B1), riboflavin (B2), nicotinamide (B3), pantothenic acid (B5), pyricloxine (B6), mesoinositol (B7), biotin (B8), cobalamin (B12), folic acid (B9), cyanocobalamin (B12) and ascorbic acid (vitamin C).
– Minerals and trace elements are essential substances for many of the metabolic reactions that occur in our body. Wine contains, among others: potassium, sodium, calcium, chlorine, sulphur, fluorine, silicon, iodine, bromine, boron, iron, copper, zinc and manganese.
In short, wine is a very complete mixture containing macro and micronutrients necessary for the proper functioning of the human organism.
How do the substances in wine benefit human health?
Regular and moderate alcohol consumption has a favourable effect on cholesterol levels: it reduces the level of bad LDL cholesterol in the blood and increases the level of good HDL cholesterol in the blood. This favourable effect on cholesterol levels in turn contributes to an improvement in cardiovascular health, e.g. by reducing the risk of thrombosis.
Among the particularly beneficial substances in wine are polyphenols such as catechins, lignans, flavonoids, anthocyanins and resveratrol (the latter molecule is considered by some scientists to be a key anti-ageing molecule). All these substances have antioxidant properties and are therefore capable of reducing the action of free radicals.
“A glass of wine a day can act as a real “antioxidant cocktail” to protect our health”.
Free radicals are unstable molecules that are generated during normal cell metabolism and can accumulate and damage other molecules. This damage, known as oxidative stress, can in turn increase the risk of developing certain types of diseases including: cancer, cardiovascular diseases, neurodegenerative diseases, chronic diseases… Wine, by containing these antioxidant substances, contributes to reducing the risk of suffering from these types of diseases.
Resveratrol is considered to be one of the most effective “radical scavengers” of all. It is found mainly in the stalk, seeds and skins of grapes, and passes into wine during fermentation, especially in red wine.
It should also be noted that there is still a long way to go and possibly not all the substances contained in wine have yet been identified. Therefore, it is to be assumed that it may contain more components with positive effects on our health.
What diseases does moderate wine consumption protect against?
All these components of wine with its antioxidant and anti-inflammatory properties can help to improve our health.
Prevention of cardiovascular diseases
As mentioned above, moderate wine consumption promotes blood circulation and has a positive effect on the composition of blood lipids (helps to reduce harmful LDL cholesterol). In addition, it can improve the function of the layer of cells lining the blood vessels (endothelium), which plays a crucial role in cardiovascular health. Healthy blood vessels contribute to a reduced risk of heart attacks and thrombosis (1).
Thanks in particular to its antioxidant and anti-inflammatory properties, moderate wine consumption has been associated with a reduced risk of certain types of cancer such as breast, colon, lung and prostate cancer (2).
Recent studies have shown that resveratrol is capable of activating molecules known as sirtuins. These molecules are found in our cells and play a key role in cellular metabolism, during the cellular response to stress (oxidative or genotoxic) and in slowing down ageing. Activation of sirtuins by resveratrol may mimic these life-prolonging effects and alleviate certain types of chronic and metabolic diseases.
“Today, inflammation (initially underlying but persistent) is at the heart of the development of many types of diseases (chronic, metabolic, autoimmune, etc.). Therefore, moderate consumption of wine, thanks to its anti-inflammatory properties, can, in some cases, contribute to its prevention”.
Diabetes: it helps to prevent it and improves the health of those affected
Numerous studies have analysed the effects of wine on diabetes. They have concluded that moderate wine consumption contributes both to the prevention of diabetes (3) and to improving the health of those already affected (4, 5).
Oxidative stress is both a cause and a consequence of diabetes. Patients with diabetes have an increased level of oxidative stress. As mentioned above, oxidative stress is detrimental to health and particularly affects the cardiovascular system: it alters the plasma lipoprotein profile, coagulation parameters, endothelium and cell membranes. The antioxidant substances contained in wine can therefore contribute to preventing the onset of diabetes and diabetic complications.
Prevents mental illness
Numerous studies have shown that wine is capable of reducing the risk of mental illnesses, both those related to mood (depression) (6) and those neurodegenerative diseases that affect the cognitive state (Alzheimer’s) (7).
Improving our gut microbiota
Several recent studies have shown that the gut microbiota of people who consume wine moderately is more diverse and healthier. The gut microbiota is the set of beneficial bacteria that live in our intestine and perform a whole series of functions of vital importance for our organism that our own cells are not capable of carrying out (8, 9).
Is red wine healthier than white wine?
As a general rule, red wine is healthier than white wine. This is because it contains more (or a greater quantity) of the beneficial substances mentioned above. This is because during the fermentation process of red wine, the seeds and skins are included, which are the parts of the grape that contain many of the secondary plant metabolites.
Conclusion: Include wine in a healthy lifestyle
Moderate alcohol consumption can have beneficial health effects. While there is no consensus on the recommended amount, a maximum of 20 g of alcohol per day is generally recommended for a middle-aged woman and a maximum of 30 g of alcohol per day for a middle-aged man. Converted into wine, this is equivalent to a small glass of wine (0.15 l) for women and a quarter of a litre (0.25) for men per day.
However, one thing is clear: red wine is not a medicine. Although it contains many beneficial substances, excessive consumption is harmful and particularly affects the liver, nervous, immune and hormonal systems.
The best recommendation for a healthy life is to combine moderate alcohol consumption with other healthy lifestyle habits such as a balanced diet and physical exercise.