Science Interviews

Interview

Tue, 16th Dec 2014

Is wine really the best medicine?

Professor Roger Corder, Queen Mary University of London

Listen Now    Download as mp3 from the show The Science of Christmas

It wouldnít be Christmas if we couldnít enjoy the odd tipple. But there areRed Wine so many contradictory messages now about how much we should drink and whatís good or bad for us. Roger Corder is a professor of pharmocology at Queen Mary University London and he told Chris Smith whatís good for us...

Roger -  Itís very clear that moderate drinking can be beneficial in terms of reducing heart disease.

Chris -  Good.  Thatís a relief.

Roger -  For a man, that means 2 to 3 units of alcohol per day is sufficient to have a protective effect.  As soon as you go over 4 or 5 units per day for a man, you start to have harmful effects.  So, the fact that the stories about benefits of wine and adverse effects of wine, itís all about what level of drinking people are undertaking.  What's also clear from my research is certain types of wine have greater benefits than others.  So, if you're in this window of moderation and you have a wine that's rich in tannins, then they can have an additional protective effect on your heart and therefore, be beneficial to a greater degree than other alcohols including white wine.

Chris -  So, there is some chemical evidence and some chemical rationale for why wine should be good for me.  Itís not just that when you're relaxing with your friends, you're in convivial surroundings and enjoying your drink just happens to be going along with that.  But itís the surroundings and the lifestyle that's better for you than the wine itself.

Roger -  There are enough studies to show that moderate drinking has a beneficial effect.  However, that lifestyle factor is also important.  Alcohol drunk with food is less harmful and therefore more beneficial than alcohol drunk without food.

Chris -  What about then if I had grape juice because wine at the end of the day is fermented grape juice, isnít it?  If I compare grape juice with wine that it turns into, does grape juice have these benefits or is it exclusively the preserve of wine?

Roger -  Grape juice is a very high sugar drink.  So, excessive consumption of grape juice can also be harmful for you in the same way as excessive alcohol consumption can be harmful.  What makes the difference between wine and grape juice is when you make wine, you ferment the juice with the pips and skins and with the red wine, you extract all the colour from the skin and the tannins from the pips.  Itís these tannins that confer these extra beneficial effect over compared to other alcoholic drinks.

Chris -  What are they doing?

Roger -  What we know from a number of experimental studies is they protect the blood vessels in a way that you're less likely to develop the lesions that lead to heart disease.  So, those protective effects of grape pip tannins can only therefore be achieved with a tannic wine.  So, modern style wines, which are often made without that long period of extraction to get all the tannins out of the pips, are actually not very different from a white wine in terms of the likely beneficial effect.

Chris -  So, white wine doesnít really have a beneficial effect.  Red wine might have a beneficial effect and red wine with lots of tannin in it and lots of what's in the skins, that should have the best effect.

Roger -  That's correct, yes.

Chris -  But does that go hand in hand with flavour though because obviously, the one thing people are drinking when they have a new glass of wine, they're not thinking first and foremost about their health.  They're thinking, ďDoes this taste nice?Ē

Roger -  To some extent and that's because weíve developed this habit of drinking wine without food.  As soon as you have a tannic wine and combine it with food then a lot of those tannins disappear in the background because they're masked by the foods you're eating while drinking the wine.

Chris -  Tannins are in tea as well so can I just get the same benefit from having a cup of tea?

Roger -  The tannins in tea are slightly different from the tannins in wine.  The tannins in tea are smaller molecules and actually, more astringent than your grape pip tannins.  And so, there's not really good comparison between tea and wine in terms of the likelihood of beneficial effects.

Chris -  Shall we have a go and just try some because I know you've got some bottles there and I'm getting thirsty frankly.  What are you going to serve up first?

Roger -  What I've got here first is a pinot noir wine.  Now pinot noir wines are actually tentatively made in a very light style because people are looking for the fruit flavours with the pinot noir.  Actually, when you look at this wine, there's not much colour to it either.

Chris -  It looks like Ribena really.  Itís very thin, isnít it?

Roger -  Exactly.  This to me is very much a white wine pretending to be a red wine.

Chris -  But this was not very expensive.  This was about 7 quid in the supermarket.  So, it doesnít smell too bad.  A bit thin.

Roger -  Actually, it feels very light in style.  There's no tannins at all.  There's a sort of fruity after taste, which is a mixture of cherry flavours and black fruit flavours.  But really, itís not much in terms of the wine structure.

Chris -  Right, so that one you're saying would be less good for our health.

Roger -  There's really little advantage of a wine like this compared to the sort of modest health benefits you get with a white wine or indeed drinking small amounts of beer.  So actually, those type of drinks actually equate to exactly the same effect.

Chris -  Okay.  So, this one, this is the big daddy of the tannins.

Roger -  This is the big daddy of the tannin-rich wines.  This is a sagrantino di montefalco wine from Umbria in Italy.  Sagrantino grapes yield the most tannin-rich wines you can find in the world.

Chris -  Well, itís got a very big flavour.  Itís very broad.  Itís actually quite sharp.  Itís not smooth.  Itís a bit sharp, but itís got a lovely flavour.

Roger -  What you notice very strongly is the aftertaste of tannins in these wines.

Chris -  Itís quite bitter afterwards isnít it?

Roger -  That's right but that bitterness would disappear if you had some food with it.  You wouldn't notice it.  But itís these tannin-rich wines that are the most protective when it comes to Ė if you think that red wine is good for you, moderation is important but then have a tannin-rich wine.

Chris -  Weíve talked a lot about how the wine contain these tannins and how they correlate with good health but biochemically, when I drink this and it goes into my bloodstream, what actually is it doing to protect my heart and brain?

Roger -  All of your blood vessels have a lining which is called the endothelium.  Itís a single cell layer and it produces a gas called nitric oxide and a vasodilator called prostacyclin.

Chris -  This opens blood vessels up.

Roger -  This opens up your blood vessels and it stops your platelets being sticky.  So, by preventing your platelets from being sticky, your blood is less likely to clot.

Chris -  But Roger, how much of this would I need to drink in order to get those beneficial effects at a clinically relevant level, in other words, a level that will affect my health outcome?  Would I have to drink so much of this wine that effectively, Iíll have to be an alcoholic with a liver problem before I actually protect my heart?

Roger -  This type of wine will typically have about 5 grams per litre of total polyphenols and these are all the natural chemicals that come out of the skin and the pips that give you the tannins.  Now, the grape tannins would have about 2 grams per litre.  Now, that means that if you drink a third of the bottle,l you'll be consuming somewhere in the order of 700 milligrams of flavanols.  We know from other experimental work the sweet spot that 700 milligrams of flavanols, you're really in the sweet spot of protecting your blood vessel from heart disease.

(choir singing)

Chris -  Well, letís polish off our Christmas dinner with a look at some chocolate because you can't have Christmas without chocolate.  This also has a lot of claims made about the health benefits, doesnít it?  Are they grounded in good scientific fact?

Roger -  There is a health claim for dark chocolate.  The health claim is that if you consume 200 milligrams of coco flavanols per day then that will maintain the health of your blood vessels in exactly the same way weíre talking about grape pip tannins protecting your blood vessels.  Unfortunately, most dark chocolate doesnít contain 200 milligrams per flavanols in a suitable amount to eat without you getting overweight.

Chris -  Why is that?

Roger -  Coco levels or the percent coco solids is incredibly misleading because it has no bearing on flavanol content.

Chris -  What do they put in instead then if itís not coco with flavonoids?  What are they putting in?

Roger -  There's two elements to chocolate.  There's the coco mass and the way the coco mass is manufactured, if you ferment it for a long time and it gets really hot, you destroy the flavanols in the chocolate.  The other thing is, you can take a coco mass and then dilute it with coco butter and you can still call the coco butter percent coco solids.  So, you can look at a bar like the one I have here that's marked 85% organic and you're thinking, ďHey, that's a great buy.  It must be good for me.Ē  But itís got coco mass and then coco butter as the coco solids.

Chris -  Can we actually tell if we taste some?  Can you spot the difference?

Roger -  I think you're going to tell as we move up the scale.  So, I'm going to start you off with this 85% and not very good and itís smooth because of the coco butter and a low flavanol coco mass.

Chris -  What's the last one?

Roger -  Well, the last one, this is an experimental chocolate.  This is truly the healthiest of healthy chocolates.  This is a 3% flavanol chocolate.

Chris -  Is this natural or was this made to have extra?

Roger -  This is made to preserve in the manufacturing process all the flavanols that are there in the coco to start with.

Chris -  Now that's nice.

Roger -  That's nice because now, weíre back at 80%.  So actually, this has got less coco solids than any of the other chocolates.

Chris -  But it has a funny aftertaste.

Roger -  The aftertaste is the coco flavanols.

Chris -  I'm not sure I'm so keen on these coco flavanols.  I think I prefer wine.

Roger -  Itís a bit like the aftertaste of the tannic wine though.  You have to agree with similarity.

Chris -  Answer me this, if I've overdone it with the wine, will any of these things help to offset my hangover or is there anything I can do to prevent a hangover?

Roger -  Obviously, to avoid hangover is not to drink too much.

Chris -  A bit late for that.

Roger -  An old fashion way to try and get over hangover was the hair of the dog.

Chris -  Yeah, so having another drink.  Does that work?

Roger -  It doesnít work well and itís the first step towards alcohol dependency.  It works because actually, most alcoholic drinks, these what are called congeners and other substances which your body has more difficulty in metabolising.  And typically, in many alcoholic drinks, there's a bit of methanol.  Itís produced as part of the fermentation process or the wine making process.  What the hair of the dog does is actually stops the metabolism of methanol because ethanol, which is the alcohol that people are liking to drink, is preventing it being broken down into formic acid and formic acid is a neurotoxin.  So, the hair of the dog works by allowing you to get rid of the methanol in other ways, without it being broken down to this harmful neurotoxin.

Chris -  So, the best bet then is actually just to rehydrate and don't drink too much in the first place.

Roger -  Absolutely.  I mean, that's the safest way to do it.

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