Excessive alcohol consumption has a wide range of harmful health effects, but some previous research has indicated that a moderate intake of wine can have positive cognitive effects. A new study investigates why that may be the case.
Although the negative effects of alcohol consumption are well-known, some studies have indicated that a moderate intake of red wine may delay age-related cognitive impairment, as well as the onset of neurodegenerative diseases such as Alzheimer's and Parkinson's disease.
Moderate consumption was defined in these studies as under 250 milliliters per day.
A new study - published in the journal Frontiers in Nutrition - set out to investigate the molecular mechanism behind this.
The researchers - led by Dr. Esteban-Fernández, from the Institute of Food Science Research in Madrid, Spain - decided to examine the gut metabolites that the human body produces after wine consumption.
Wine compounds prevent neuronal death, gut microbiome plays key role
Dr. Esteban-Fernández and team selected these metabolites from the urine and feces of people who consume wine regularly and moderately.
The researchers then added these metabolites to human neurons. The researchers induced stress in these human cells to simulate the conditions that usually lead to neuronal death in neurodegenerative diseases.
The study revealed that wine-derived metabolites prevent the neurons from dying under these stress conditions.
Surprisingly, the results also showed that these metabolites are active at different points during the cell signaling process that ultimately leads to neuronal death.
According to the researchers, this means that the exact composition of the wine metabolites is crucial for this protective effect. Furthermore, this composition depends, in turn, on the composition of the gut microbiome - that is, the trillions of microorganisms living inside our intestines.
The gut microbiome is responsible for processing and breaking down wine into various metabolites, including phenolic acid and aroma compounds - wine compounds whose neuroprotective effects were demonstrated in this study.
"In other words, differences in our gut microbiota are leading to the different metabolites. Which underpins the idea that humans benefit from food in different ways," the study's lead author explains.
Healthful diet is crucial for healthy brain function
"This individual difference is a factor not to be neglected to understand the health effects of certain foods. We are now in need to advance our understanding of the effect of diet in the promotion of normal brain function," Dr. Esteban-Fernández adds.
She also comments on the importance of a balanced diet for preventing neurodegeneration:
"It is very important to understand that certain food compounds are responsible for this health benefit in protecting against the onset of neurodegenerative diseases; no medication was involved. I am not advocating to replace medicines by diet, but I want to raise more awareness [on] how your diet is helping to prevent diseases or reduces the risk of getting sick. It is more than feasible to go to the supermarket and buy vegetables and fruit: it depends only on the individuals to maintain a balanced diet."
Although she advocates for a diet rich in fruits, vegetables, and low in saturated fats, Dr. Esteban-Fernández also cautions against an excessive preoccupation with nutrition and urges the public to discern between accurate and false diet information.
"Society is nowadays full of false myths about diet, and it is the role of both science and media to avoid the spread of these rumors, as well as make people aware of the importance of diet for your health," the author adds.