It’s a universal truth that humans tell ourselves little fibs to make life sweeter. Is the idea that a glass or two of red wine before bed will keep us heart healthy one of those sweet little lies? How much red wine is it safe to drink and is it really doing you any good? We looked into the most up-to-date clinical trials and research data to sort the facts from fiction.
‘Moderation is key’ is an oft-repeated phrase when it comes to living a happy and healthy life. This has also been said about alcohol: you might be familiar with posters at your primary care practitioner’s office outlining the ‘acceptable’ limits of alcohol consumption per week. You might similarly see flyers quoting cardiologists who suggest that one glass of red wine per week is not just acceptable, but good for you. Other findings, however, caution that there are no safe amounts. So what’s the truth?
Bad Booze News
The most recent research suggests that no amount of alcohol is ‘good’ for you. A systematic analysis published in The Lancet in 2018 states that ‘the level of alcohol consumption that minimized harm across health outcomes was zero.1 That is, both heavy drinkers and occasional drinkers suffer from disease wherein alcohol is a risk factor. The only time alcohol is not a risk factor for the outcome of death is zero drinks.’
This study did find that alcohol use had some protective effect for ischaemic heart disease and diabetes among women. However, these effects were quickly offset when we consider overall health risks. For example, even though their risk of heart disease was lowered, their chance of developing other diseases such as cancer increased.1
But I thought a glass of red before bed was good for me?
Before The Lancet systematic review performed by Kings College London and University of Southampton Medical School professors, researchers believed that low amounts of red wine may actually have a protective function.
Take for example, the concept of the ‘Blue Zones’ – areas on the map where centenarians, or people aged 100 and above, were concentrated. Academics proposed that the cause of longevity in these populations was their low stress and community-based lifestyle, as well as their diet, and part of this diet was ‘Wine by five’!2
At a closer level, proponents of drinking wine claimed that the antioxidants therewith lent benefits such as slower aging and better cellular respiration. A review that was published in a cell biology journal, the same year as the Lancet article, speaks to the protective effects of wine through polyphenols such as resveratrol, anthocyanins and catechins such as resveratrol.2
This review, however, zooms in on molecular mechanisms at a microscopic level. Had this review been submitted to a medical journal, the expert reviewers might have asked the wine scientists how those proposed molecular benefits offset the damage caused by alcohol.
This is a very good example of how researchers have different priorities to each other and are writing for different audiences. Neither review is wrong, nor necessarily misleading, they just have distinct purposes.
When we, as lay people, grab our information from these sources we have to remember to think about the context – who are the authors? For whom are they writing? What are they trying to achieve? The Lancet is for doctors and researchers to get the latest medical research so that they can develop new treatments, diagnoses and form health policy. Journals like Molecule, exist for cell biologists to tell each other their new findings or to spark ideas and discussion.
Why are people keen to claim red wine is healthful?
Wine is bursting with biologically active by-products of fermentation and nutrients that are also jam-packed into grapes. Resveratrol, an antioxidant concentrated in grapes, plays an active role in preventing cardiovascular disease.
Rats who were administered resveratrol showed an improvement in blood pressure, displaying better function in heart contraction.3 Resveratrol also works as a potent antioxidant; it ‘neutralizes’ free oxygen and nitrogen radicals that form as a result of everyday harm that occurs to the body. It also has the ability to penetrate the blood-brain barrier, meaning that this protective antioxidant function can extend to the health of the brain and nerve cells.3
Here Comes the Science Part
In 2021, researchers at Spain’s University of Valencia Medical School, with no conflicts of interest, concluded that moderate red wine consumption increases the expression of longevity-associated genes. They tested this theory on a controlled human environment, specifically nuns and monks whose lifestyle was repetitive and predictable. They also used model organism Drosophilia melanogaster. In nuns, expression of longevity genes catalase, manganese-superoxide dismutase, Srt1 and p53 increased after 14 days of moderate red wine consumption (some may know p53 is the cancer busting apoptosis gene, and Srt1 is involved in chromatin remodelling). D. Melanogaster lifespans increased by 7%. Longevity in humans has yet to be tested.4
Wine has earned a reputation for being healthy from its association to the Blue Zone as well as the antioxidants. If it has antioxidants and antioxidants help people live longer, then it is no surprise that we might believe glass of wine in the evening is good practice. However, we can’t look at the ‘good side’ of wine in isolation.
Does the alcohol cancel out these protective effects?
Is drinking wine for the antioxidants a good idea if the wine in question is a harmful medium? Wine also contains ethyl alcohol, which comes with a slew of negative effects to the body.
For example, the way that alcohol is metabolized in the body results in the byproduct of reactive oxygen species – the same reactive oxygen species that we need antioxidants for.
When we take a gulp of wine, it ends up in our small intestine. From there it goes into the veins that carry it to our liver where it is metabolized. Its metabolism in the body contains many pathways that result in harmful byproducts. For example, one pathway is where alcohol turns into acetaldehyde in the body. Acetaldehyde is highly reactive and toxic, and might be involved in the additive process.5,6
Because of the harmful aftermath of its metabolism, alcohol consumption results in oxygen deficits in the liver, a condition called hypoxia. It also causes damage to tissues, foetuses, cancer and interrupts medication interactions. This is because alcohol has the ability diffuse across different membranes throughout the body.
How much red wine is too much?
According to the National Institute on Alcohol Abuse and Alcoholism, there were 98,457 liver disease deaths among people ages 12 and older. What’s more, 50% of cirrhosis deaths were alcohol-related. From 2007 to 2017, the number of people who needed a liver transplant due to their alcohol-associated liver disease went up by 63%.6
The 2016 Global Burden of Disease looked at alcohol use and the health burden systematically. They looked at the grams of pure ethyl alcohol they estimated a population consume by using sales data and adjusting for tourist purchases. They used data from sales data, statistics from the World Tourism Organization, and survey results. This data was then extrapolated to arrive at population-level estimates after considering age and sex-specific variables.1
They then compared the amount of alcohol consumed to the burden it lent to the health of the population. That is, whether consumers of alcohol also had risks of other diseases. The results showed that even drinking moderately meant that the individual had a higher risk of having other conditions. The risk to overall health could only be minimized by having zero drinks.1
Even though red wine has been touted to help individuals live longer, opposing research has been published that suggests that no amount of alcohol is still the best option to prevent disease.
What’s the truth?
So is the idea that wine is good for you a sweet little lie, or does it carry some merit?
The good news is that we can enjoy alcohol-free wine without the disease burden of alcohol. Longevity is often attributed to low-stress lifestyles, and a lot of the time this means being social and having fun – things that we associate with a glass or two of alcohol. One thing is for sure: it’s not all good and it’s not all bad, and the factors that determine what comes out on top may not be as simple as once thought.
References
- Burton R, Sheron N. No level of alcohol consumption improves health. The Lancet. 2018;392(10152):987–988. doi:10.1016/S0140-6736(18)31571-X
- Snopek L, Mlcek J, Sochorova L, et al. Contribution of Red Wine Consumption to Human Health Protection. Molecules. 2018;23(7):1684. doi:10.3390/molecules23071684
- Mokni M, Hamlaoui S, Karkouch I, et al. Resveratrol Provides Cardioprotection after Ischemia/reperfusion Injury via Modulation of Antioxidant Enzyme Activities. Iran J Pharm Res. 2013;12(4):867–875.
- Gambini J, Gimeno-Mallench L, Olaso-Gonzalez G, et al. Moderate Red Wine Consumption Increases the Expression of Longevity-Associated Genes in Controlled Human Populations and Extends Lifespan in Drosophila melanogaster. Antioxidants. 2021;10(2):301. doi:10.3390/antiox10020301
- Zakhari S. Overview: How Is Alcohol Metabolized by the Body? Alcohol Res Health. 2006;29(4):245–254.
- Alcohol and the Human Body | National Institute on Alcohol Abuse and Alcoholism (NIAAA). Accessed December 2, 2024. https://www.niaaa.nih.gov/alcohols-effects-health/alcohol-topics/alcohol-facts-and-statistics/alcohol-and-human-body
