Is red wine healthy?

Uncork the secrets of a timeless elixir as we explore the relationship between wine and health. It contains antioxidants and has been purported to improve heart health, longevity, blood sugar, memory, and even treat the common cold. But is any of this true? Can drinking wine really have health benefits? Join us to hear what science actually says about this intoxicating substance. 

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Transcript

Today we’re uncorking the rich history and nutritional value of one of the world’s oldest beverages… wine. We'll explore the history of wine, its potential health benefits, and the risks that come along with enjoying this nectar of the gods.

M: I’m Professor Megan 

S: and I’m Professor Susan, and we’re

Both: Your Nutrition Profs!

M: We are registered dietitians and college professors who have taught more than 10,000 students about health and nutrition. We have answered a LOT of questions about nutrition over the years – 

S: Some questions we get asked every year and some are rarely asked but very interesting.

M: We’re here to share our answers to these common (and uncommon) nutrition questions with you.

S: So bring your curiosity and let’s get started. 

Both: Welcome to our class!

M: It’s February so we are still celebrating American Heart Month! And another celebratory day is also approaching. 

S: Yes, it’s almost Valentine's day. And perhaps more importantly, a few days later on February 18th, it’s National Drink Wine day. 

M: One of my favorite days on the calendar!

S: MIne too!

M: So that brings us to today's question, “does red wine really have health benefits?”

S: And in honor of this topic, we’ll be doing some taste testing as we discuss all things wine. This might be my favorite episode ever.

M: Yes!

Sound of wine cork popping, followed by glugging sound of wine being poured, and glasses being clinked.

S: Cheers.

M: Alright let’s get into it. Wine is a type of alcohol and we all know that alcohol can have toxic effects on the body, so where did this idea of red wine being healthy come from? 

S: You know what, before we can discuss possible benefits, let’s first give a little bit of background on wine, for those of you who may not know.

M: Well, you can make wine by fermenting almost any fruit, but most wine is made from grapes. Red wine is made from black skinned grapes and white wine is made from green skinned grapes. After harvesting, grapes are crushed and pressed to release their juice and no matter what color the grape is on the outside, the juice is clear.

S: That’s really interesting to me.

M: Yeah.

S: Red wine and white wine are made similarly but with one major difference. Red wine ferments with the grape skins, seeds, and pulp while white wine grapes are pressed before fermentation and that separates the juice from the skins. 

M: So in this episode we’re focusing on red wine because of its association with greater health benefits compared to white wine or other alcoholic beverages. Susan, did you know that as of 2023, the red wine market was estimated at ~106 billion dollars?

S: Oh my gosh! Well I know I’ve done my part to contribute to that 106 billion…

M: Me too! And in surveys of American wine drinkers, several studies report that red wine is preferred to white or rose. 

S: That works for me too, I usually prefer red, but I would not pass up a glass of good white or rosé. 

M: Same.

S: Where do you think the most red wine is produced in the world?

M: Italy for sure.

S: Oh yeah. 

M: Italy produces more than 17% of the world’s red wine, followed by France and Spain and then China! 

S: China? 

M: Surprising, right? They’re number 4. Here in the U.S.  we’re the 7th largest producer of red wine, providing about 6% of the world’s supply. 

S: So let’s talk about how wine is made – the sciencey word for this is vinification and the science of wine and wine making is known as oenology. Those are fun words.

M: I like that! Well there are several steps involved in producing wine, and the process has changed very little over the past several thousand years. Of course it starts with growing and harvesting the grapes. And it takes approximately 200 grapes or 2.5 lb to make one standard bottle of wine. 

S: Really? Only 200 grapes? I would have thought it was more. So after harvesting all of those grapes, the next step is fermentation and this occurs when yeast is added to the grape juice. It’s usually done in a big vat. The yeast starts to convert the sugar from the fruit into alcohol, heat, and carbon dioxide. 

M: During this time, a process called maceration takes place which is a soaking of the skins. This adds color, tannins, and flavors to the wine. And keep that in mind, more on tannins are coming up.

S: So after a period of time, the wine is pressed and then aged in wooden barrels or other large containers for anywhere from a few months to a few years and this helps the wine develop its complexity, flavor, and aroma. A single barrel can hold about 60 gallons of wine.

M: Wow!

S: Sounds like a party.

M: Alright so finally it’s filtered to remove any sediment. Some tannins are actually lost here. But at this point, it can be bottled individually or blended with other wines.

S: And Voila! You have beautiful red wine!

M: But not all red wines are the same. There are over 10,000 different varieties of grapes grown for wine but of the 10 most popular, 6 are reds: cabernet sauvignon, merlot, tempranillo, syrah or sometimes called shiraz, pinot noir, and grenache sometimes called garnacha.

S: Cabernet sauvignon is the most popular red wine in the world. And it is really my favorite! We’re drinking a cabernet right now! Yum!

M: It’s my favorite too! It’s described as bold, powerful, full-bodied, low in acidity, and rich in fruit flavors. This grape is also very high in tannins. 

S: I also like merlot. It’s often described as well-rounded, medium bodied with low acidity. It’s consumed on its own but it’s also used a lot in blends. It’s known for its very deep purple color and it is beautiful. My friend who drinks merlot often describes it as “buttery”. 

M: Sounds good. 

S: Mmm-hmm.

M: Tempranillo is the fourth most widely planted variety in the world and the most grown red grape in Spain. It’s considered a medium to full-bodied wine with moderate acidity and high alcohol levels. 

S: I always put tempranillo and Spain together. And I like it too. I think it’s a little bit peppery, in what I think is a good way! It pairs really well with smoky dishes and things like tomato-based sauces. 

M: Yum. So do you like syrah or shiraz?

S: I don’t think I’ve had a lot of those but I’d probably like it.

M: Well, they’re the same grape, they’re just called slightly different names. Syrah in Old World countries, like countries inEurope, the Mediterranean and Middle East regions or Shiraz as it's known in New World countries like Australia, and North and South America. It is a full body, medium acidity, high tannin wine. Old World wine is considered more earthy while shiraz is more fruit-forward.

S: That really does sound delicious. I do like a good pinot noir grape though. Apparently it’s a finicky grape, so it's difficult to maintain and grow. So it’s a challenge. 

M: But worth it..

S: That’s right. So pinot noir is a medium-bodied, highly acidic, and somewhat fruit-forward wine with low tannins. It’s also lighter in color than many other reds.

M: I do like a good pinot noir too! And a shout out to our friend and listener Stacie who always loves a good pinot noir!

S: Oh hi Stacie! 

M: Hey! 

S: She does love pinot.

S: And finally, the Grenache or Garnacha grape – my friend calls it Garrnacha! – is similar to pinot noir. It’s medium-bodied, acidic, fruity and high in alcohol and it’s also fairly light in color. It’s more commonly grown in Old World wine regions like France and Spain and may not be as well known here in the U.S.

M: Yeah, I don’t think I’ve ever had it. 

S: Well, we’ll have to remedy that! 

M: And many wines are made from blends of different grapes to create new and interesting flavors. 

S: So also….yum!

M: Ok, these are some of the most popular grapes used for wines today, but there’s evidence of wine dating back thousands of years. 

S: The world’s first chemically confirmed evidence of a fermented alcoholic beverage was discovered in the northern part of the Henan province in China. Residue of the drink was found on shards of pottery in tombs and a nearby neolithic settlement. This drink was found to be made from two wild grape varieties, rice, honey, and hawthorn fruit. And isn’t it cool that they can figure that out?

M: I know! Science is amazing! And as we said before, China is the 4th highest red wine producing country in the world – so I guess it’s not super surprising that it may also be one of the oldest!

S: Yeah, right. But it’s not just the Chinese who were consuming wine in ancient times. The oldest evidence of actual winemaking was dated back to 5,400 BCE in northwestern Iran.

M: And in 2007, what’s thought to be the oldest known winery was found. It dates back to 4100 BCE, making it over 6000 years old. It’s located in a cave in Armenia and has a wine press, fermentation vessels, and drinking cups. 

S: You can also see images on ancient Egyptian tomb walls of people harvesting grapes, crushing them, and putting them in amphoras which are just large jars. Red wine was even discovered in King Tut’s tomb as one of the items to take with him in the afterlife.

M: And we can’t forget Dionysus, the Greek god of wine, wine-making, and fertility, or Bacchus the Roman god of wine. 

S: Of course! According to legend, Dionysus was the first to turn grapes into wine and taught others how to as well. He represents a dual nature often depicted as a bringer of joy or ecstasy, but also as a bringer of rage and madness. Usually he’s depicted holding grapes or with a grapevine around his head.

M: Wine has been associated with love, romance, and celebrations dating back to at least to Ancient Rome. According to some sources, wine became associated with St. Valentine's day in the Middle Ages. Because St. Valentine is the patron saint of love, it was believed that drinking wine on this day would bring good luck in love. 

S: And that’s how wine and Valentine’s Day became connected.

M: So interesting!

S: It is. 

M: Alright so now that we have a little bit of background, let’s get back to our question, “does red wine have any health benefits”?

S: The short answer – yes.

M: Nice!

S: Red wine’s been linked to several possible health benefits through both in vitro and in vivo studies. You know what? Let’s define those two terms because they always confuse me!

M: Well in vitro is a sciency term that means at a cellular level. This type of research takes place in a test tube or culture dish outside of a living organism. An example of this type of study is the use of red wine extract on colon cancer cells. The extract caused a decrease in tumor growth in these human cancer cell lines. 

S: In vivo studies, that’s the sciencey word for research done on a living organism. For animal models the organism is mostly rats, and of course research can also be done in humans. For our review today, we’re going to focus just on in vivo human studies. 

M: And here’s what we found… Moderate consumption of red wine has been shown to protect against several different diseases including several types of cancer, coronary artery disease, high blood pressure, and metabolic syndrome. 

S: And some studies suggest it can also improve blood cholesterol levels, including increasing good cholesterol and it may even improve insulin resistance which is the problem in those people with type 2 diabetes. 

M: And that’s not all. There is also evidence that moderate consumption of red wine can increase beneficial bacteria in the gut microbiome. So we’ve definitely talked about the microbiome in several previous episodes –

S: Oh, for sure.

M: Yeah, so this beneficial bacteria can kill off some of the bad bacteria in both the gut microbiome and the mouth. And this can cause a reduced risk of cavities or periodontal disease. 

S: But it can turn your teeth pink or red. 

M: Unfortunately, yes.

S: Yeah, well sign me up anyway. Red wine sounds great and I think it’s tasty too. But is all of this true?

M: Well, we’ll find out. But first, let’s talk about some general nutrition. Red wine can vary in Calories and nutrients but according to the USDA, a 5 fl oz glass of red table wine is  about 125 kcal, and it contains a small amount of glucose and small amounts of the minerals potassium, phosphorus, and calcium. Other trace minerals and B vitamins are also included but in extremely small amounts. 

S: So wine is not really a nutritional powerhouse in terms of nutrients.

M: Unfortunately, no. And wine also contains alcohol. The alcohol content of wine can vary between 9 to 15% ethanol, with most red wines coming in around 13 or 14%. Alcohol, although not a nutrient, is important to note as it is a part of wine, and the source of ⅔ of its calories. 

S: So what exactly in wine may be responsible for these possible health benefits? It doesn’t seem to be the nutrients or the alcohol.

M: Well, back in the 1980s, a phenomenon that became known as the French paradox was identified. 

S: I remember that. I learned it in college and yes, you can do the math and figure out how old I am! There was quite a bit of research in the 1990s and early 2000s about this French paradox.

M: Right. The French Paradox was the observation that the French have relatively low rates of heart disease, despite consuming many rich, fatty foods, like cheese, and drinking wine with most meals.

S: There were several books written about it. I remember one called “French Women Don’t Get Fat”. If I remember right it was a non-diet book and it was about enjoying food and enjoying your life. 

M: Yeah, I haven’t read it but I’ve definitely heard of it. So the theory was that the polyphenols in plants may be responsible for these health benefits. Polyphenols are found only in plant foods, and in higher amounts in bright colored foods, like the red and purple skins of grapes that are used to make red wine. 

S: You know, we’ve mentioned polyphenols on several previous episodes too. These are a type of phytochemical which are substances in plants that are not nutrients but they do provide some additional health benefits. 

M: We have discussed them many times, but let’s talk about the ones found in red wine specifically. Polyphenols are found naturally in grapes and some additional polyphenols are even created during the wine making process.

S: In general, polyphenols have anti-inflammatory and antioxidant properties which we have also mentioned on this podcast several times. They are linked with reduced oxidative stress which is a risk factor for cardiovascular disease, chronic obstructive pulmonary disease, kidney disease, cancer, and neurodegenerative diseases, things like Parkinson’s or Alzheimers.  

M: More than 100 different polyphenol compounds have been identified in red wine including resveratrol, tannins, procyanidins, anthocyanins, flavanols, and catechins.

S: So let's start with resveratrol since it’s one you may have heard about. It’s found in the skin of grapes and not too many other food sources. In fact grapes and wine are actually the most relevant food sources of resveratrol for humans.

M: Resveratrol is considered anti-inflammatory and anticarcinogenic. It’s also been called anti-obesity as it’s been seen to decrease lipogenesis (a sciencey word for the creation of fat), and increase lipolysis (a sciencey word for the breakdown of fat), and the use of fat for energy. So that means that we are going to create less fat, as well as increase the breakdown of fat specifically for the use of energy.

S: Some studies have linked it to increased blood flow in the brain so some people think it might improve memory and cognition. And you’d probably see that as a claim on a dietary supplement label.

M: I’ve also seen it as an ingredient in skin care products. 

S: Me too.

M: Yeah, but it’s important to note that not all of these findings are related to red wine specifically, but rather the resveratrol compound itself. 

S: So the polyphenol does this but not necessarily red wine. 

M: Correct.

S: So just because the polyphenol resveratrol has certain properties, it does not mean that red wine definitely has the same.

M: Right. More research is definitely needed. Currently the findings are limited and inconsistent. Various doses of resveratrol have been used in studies and some may be much higher than what you could or should get from a glass or two of red wine. 

S: You’d also have to take into account how the grapes are processed into wine, right? I mean, any time you process an ingredient it can lead to both nutrient and phytochemical changes. Also the type of grape and where it’s grown could make a difference in resveratrol content.

M: Definitely. Thin skinned grapes and those grown in cooler, more humid climates tend to have higher levels of resveratrol. So wines like pinot noir and cabernet franc may be a good option if you’re looking for more resveratrol. 

S: Here’s another thing, ultraviolet light or radiation increases the resveratrol formation in grapes. So some winemakers have applied ultraviolet light irradiation to grapes after harvest in order to increase the resveratrol. Then they can label their wine as a  “functional food” or “nutraceutical”.

M: Of course they do! Of course…. Anything to get those consumers to buy it.

S: Wine as a health food! But resveratrol isn’t the only polyphenol in grapes. Tannins are also found in grape skins. And while all wines have some tannins, red wines have more because of that to the maceration process that we mentioned earlier. 

M: Yes, because white wines are pressed rather than macerated they don’t have as many tannins. 

S: And while the wine is aging, more tannins can develop and be pulled from the wood barrels, especially if they’re made from oak.

M: Tannins in red wine act as a preservative protecting it from oxidation. And there is evidence that just like resveratrol, they have beneficial antioxidant and antiinflammatory properties when consumed.

S: Tannins in wine are responsible for the bitter or dry sensation that you have in your mouth. If you are looking for more tannins, choose wines like syrah and cabernet. I do like dry wines.

M: Me too. But some people are actually sensitive to tannins in wine and experience headaches or migraines after drinking even just a small amount. Since white wine has fewer tannins this may be a better choice if you experience this. Or you can aerate your wine, or “let it breathe” to let some of the less favorable compounds evaporate before drinking.

S: I know quite a few people who get headaches after drinking red wine so most have switched to white or they just don’t drink wine at all.

M: Yeah, I know a lot of people too. We should also point out that when consumed in large quantities tannins are known to interfere with the absorption of nutrients like iron, making tannins what some people call “anti-nutrients”. 

S: We actually discussed this very briefly in our episode about millets from a few weeks ago. So if you’re iron deficient, you may want to switch to white wine with fewer tannins, or like we said before, just skip wine altogether.  

M: While there are several more polyphenols we could discuss, resveratrol and tannins are probably the two most well known. 

S: And some researchers believe that it’s the complex combination of multiple polyphenols and the enzymatic and chemical reactions that occur during fermentation that are key to any possible health benefits associated with red wine. 

M: So that’s our dive into polyphenols. And we do have to say that if you really want the resveratrol or tannins found in grapes you could just eat the fruit! 

S: Yeah, you don’t have to ferment it to enjoy those polyphenol benefits. And you know we always say more whole fruits and veggies are always recommended!

M: It’s also important to mention that polyphenol content in foods and beverages can vary tremendously. It is influenced by factors such as the grape variety, grape ripeness at time of harvest, growing climate, as well as other various environmental factors, along with considerations related to the processing and storage of the wine. 

S: Right, but here’s another thing to consider. It may not just be the wine itself, but the wine as part of an overall eating and drinking pattern that provides the health benefits. 

M: Right. The popular Mediterranean diet and its benefits on health is another possible point in favor of this theory. The Mediterranean diet is quite diverse and features a plant and fish based diet that typically includes red wine. There is a great deal of evidence for the health benefits of following a Mediterranean style diet just in general.

S: Right and you know it always surprises students that moderate intake of wine is included in a “healthful” diet. 

M: I know! Students ask me about that all the time. But the Mediterranean diet has actually  been voted the #1 most healthful diet in America for prevention of common chronic diseases for the 7th year in a row! 

S: For those people who might be unfamiliar, the Mediterranean diet is not a specific, prescriptive (eat this, eat that, eat that) diet, it’s a food intake pattern and it typically includes a recommendation to consume at least 3 servings of fruit and 4 servings of vegetables every day in addition to consuming a little bit of red wine in moderation. 

M: Perhaps it's the synergistic effect of the numerous polyphenols found not only in the red wine but also in the abundance of fruits and vegetables that are consumed as part of this diet that may be of particular benefit. 

S: That’s a really good point. There’s another aspect that I really find intriguing is the “Mediterranean way of drinking”. This refers to regular, moderate wine intake but it’s specifically consumed during meals. 

M: Yeah, because wine tends to be sipped more slowly when you’re also eating. And as we’ve discussed on previous episodes, food in the stomach slows gastric emptying which can improve alcohol absorption. 

S: You know there's even some evidence that alcohol may improve the bioavailability of polyphenols and if you are consuming other high polyphenol foods like the fruits and veggies then that's even better. 

M: Although we do want to also point out that alcohol can inhibit the absorption of several micronutrients like B vitamins and zinc.

S: Hmm. Definitely.

M: And remember, moderation is key! Excessive alcohol consumption can lead to a host of health issues, including liver problems and alcohol use disorder. 

S: So if you do choose to drink, moderation is so important! And we always say, “everything in moderation”. But what’s the definition of moderation when it comes to wine? 

M: There is not one universal definition but the National Institutes of Health here in the U. S. define moderate drinking as no more than one 5 oz glass of wine for women or two 5 oz glasses of wine for men in one day. But note when referring to beer or liquor, that amount is going to differ… 5 oz is not appropriate for liquor. 

S: Definitely not. And keep this in mind, a standard bottle of wine is 750 mL or 25 fluid oz, so there should be about 5 standard servings in a bottle. 

M: And that sounds about right. When you open a bottle of wine, to get about 5 pours out of it. 

S: Yeah. So according to the World Health Organization, there is no safe level of alcohol consumption. And there is an abundance of evidence that consuming any form of alcohol is associated with increased cancer risk.

M: So  the question is... Do the benefits from polyphenols outweigh potential cancer risk from alcohol consumption? We don’t know. And those polyphenol benefits are not guaranteed.  There are so many factors that contribute to disease risk. 

S: Right, it’s really,really, really complicated! And the amount of alcohol that causes risk is unknown. 

M: In addition to increased risk of several forms of cancer including esophageal and colorectal, excessive alcohol consumption has been linked with increased risk of several types of cardiovascular disease, liver disease, pancreatitis, impaired immune function, and dementia. 

S: Not to mention the psychosocial risks associated with alcohol consumption. Acute alcohol use can impair judgment, coordination, memory, and lead to poor decision making. It’s also linked with increased risk of violence and crime. 

M: More than 140,000 deaths are attributed to alcohol use in the U.S. annually and it’s considered one of the top 5 preventable causes of death after things like smoking and poor diet. 

S: And there are some people who should never consume alcohol at all, red wine or otherwise. This is those who are not of legal age, those who are pregnant, and people planning to drive or who are actively driving. I mean, 30% of all traffic fatalities involve drunk driving.

M: And people taking certain medications or who have certain medical conditions as well as those who struggle with alcohol use disorder should also avoid alcohol. 

S: So what’s the bottom line when it comes to red wine and health?

M: The bottom line is that while there are benefits associated with the consumption of several polyphenols that are found in red wine, it’s not the best method of obtaining more polyphenols. 

S: This is good news for those who abstain from drinking for religious reasons, or health reasons, or really any reason! Because fruits and vegetables provide significantly more polyphenols and other beneficial nutrients. Remember, the Dietary Guidelines for Americans recommend consuming a minimum of 2 fruits and 3 vegetables every day. 

M: And with regard to alcohol, the Guidelines recommend that people who do not drink alcohol should not start drinking and for those that do choose to drink, you should do so in moderation. 

S: Moderation means no more than one 5 oz glass of wine for women or two 5 oz glasses of wine for men in one day. And as we said, there are lots of risks associated with excessive alcohol consumption. 

M: Enjoying red wine responsibly can be part of a well-balanced adult lifestyle. And while red wine may offer some minimal health benefits, it’s important to understand individual limits so as not to compromise your well-being. 

S: So cheers to a healthy and love-filled Valentine's Day! 

M: Join us next time when we answer the question, “Should I add Adaptogens to my diet?”

Both: Class dismissed.

S: We hope you enjoyed this episode. You can find the show notes and a list of sources on our website, yournutritionprofs.com. 

M: Your homework is to follow us at your nutrition profs on Instagram and to listen to our next episode. You can listen on Amazon Prime, Apple Podcasts, Spotify, YouTube, or anywhere podcasts are found. We’d appreciate it if you’d “like” us, write a review, subscribe, and invite your family and friends to join us too. 

S: If you have a nutrition or health question you’d like answered, let us know! We may even do a show about it! Send an email to yournutritionprofs@gmail.com or click on the “Contact Us” page on our website.

M: Thanks to Brian Pittman for creating our artwork. You can find him on instagram @BrianPittman77

Both: See you next time!