More Reasons For Red Wine Being Good For Us

Here on the Naked Scientists we've often talked about how scientists are uncovering more ways in which enjoying an occasional glass of red wine might be good for us - and in particular a compound found in grape skins and red wine called resveratrol. It has already been shown to increase the life span of mice by 15% and clinical trials are currently underway involving people with diabetes. Now we have news this week from scientists who have discovered yet another possible health-giving benefit of the red stuff - it could boost athletic performance and even help keep us thin. That's according to a new study, led by scientists from the Institute of Genetics and Molecular and Cell Biology in Illkirch in France, who have shown that high doses of resveratrol given to mice improves their muscle endurance and also stops them getting overweight. The researchers fed a group of mice on a very high fat diet, and then gave half of them a very high dose of resveratrol - the equivalent to a hundred glasses of wine each day for a human being. After 3 weeks, the mice that were taking the red-wine like supplements, only weighed 20% more than mice on normal diets. While the high fat diet mice that weren't taking the supplements weighed 60% more than the normal mice. To test their fitness endurance, the mice were put on treadmills, and it turned out that the ones taking the resveratrol supplements could run twice as far as mice on normal diets that hadn't taken any of the compound and there didn't seem to any nasty side affects of taking such large amounts of it. The researchers think this muscle boosting affect is likely to be linked to the affect resveratrol has on those tiny energy producing units inside living cells called Mitochondria - essentially what they do is burn the food we eat and convert it into energy that we use to move and grow. Now, it's thought that resveratrol might trigger the process that gives each cell more mitochondria - and with more mitochondria, more energy can be produced - a little bit like building more wind turbines to harness more wind energy. The amount of red wine you would have to drink to have these affects are unfortunately, rather huge, so taking resveratrol in wine form may be little use to us. But it may be possible to take supplements of the compound in the future - athletes may even start taking it to boost their performance - could red wine become a banned substance in the Olympic Games?

19th Nov 2006

Moody Teenagers

That is SO unfair - Researchers have stumbled on the cause of teenage angst. Sheryl Smith, from SUNY Downstate Medical Centre in New York, has found that a hormone called THP or allopregnanolone, which normally provokes mental calm in adults has the opposite effect in the teenage brain. At around the time of puberty there are significant increases in the levels of a cellular receptor (docking station) for the nerve chemical GABA. This is especially marked in a part of the brain known as the limbic system, which controls emotion. THP usually increases the activity of this GABA signalling system, which in turn helps to reduce anxiety and act as a natural stress buster. But during puberty it has the opposite effect and instead makes the brain's emotional centre more excitable, triggering anxiety and mood swings. Thankfully, parents can breathe a collective sigh of relief, because the effect is only temporary (except amongst men in whom it seems to get progressively worse with age)!

18th Mar 2007

Solar Powered Bikinis

You've heard of solar powered boats, solar powered cars, and even solar powered handbags have had their share of the limelight, but now it's the turn of the solar bikini and solar bathing shorts. New York University's Andrew Schneider unveiled his beach-friendly solution to a flat iPod and warm beer at the Interactive Telecommunications Program show. It consists of a standard bikini retrofitted with photovoltaic cells stitched together with conductive thread. It pumps out 6.5 volts and terminates in a USB socket for connecting to an iPod. The male version, which is dubbed the iDrink, apparently has a much greater surface area of solar cells and can produce up to 1.5A of current, enough to power a miniature can-cosy peltier cooling device, which is capable of keeping your beer cold. Cool as it sounds, at the moment it's not clear whether wearers will actually be able to take a dip in their new beachwear, or whether the combination of electricity and sensitive parts of the anatomy could prove painful...

21st Jan 2007

iLightning

A paper in this week's New England Journal describes a man admitted to hospital with a rather strange pattern of skin injuries including ruptured eardrums, a broken jaw and burns to his chest, neck and the insides both ears!

Doctors discovered that the 37 year old had been out jogging in a thunderstorm, whilst listening to his iPod. Lightning had hit a nearby tree and jumped onto the man as he ran past, a phenomenon known as side flash. This triggered muscle contractions that threw him eight feet. The man's burns ran in two lines up his neck, across the sides of his face and entered his ears. They corresponded to the position of his headphones when the accident happened. Although Eric Heffernan and his colleagues who described the case are at pains to emphasise that iPods aren't a specific risk factor for being hit by lightning, in this instance the combination of sweat, metal wires and headphones channeled the electricity into the patient's head. The sudden heating effect caused by the dischage into the ears caused rapid expansion of the air in the auditory canal, bursting the patient's ear-drums.

It's not known what he was listening to on the iPod at the time the bolt hit, but my money's on Pink Floyd's Delicate Sound of Thunder...

15th Jul 2007

Analysing Voices And Accents

Chris - What is your voice and how does it work?

Kirsty - The voice is a bit like an instrument when we produce a vowel sound where we have the mouth and throat (the vocal tract) acting as a resonator. We have air coming from the lungs making the vocal chords vibrate very rapidly and the vocal tract will emphasise some frequencies a bit like the te body of a flute or clarinet.

Chris - You have a bit of a twang that says... down under. You sound a bit different to me, why is that?

Kirsty - Different language communities have agreed different targets for what the sounds of language should be and how they are going to realise them. Comparing a british and Austrailian accent the vowels sounds are different, eg the a sound in park is differnt. I produce it with my mouth and toung a bit higher and with a bit more nasalisation.

Chris - It is all learned isn't it?

Kirsty - Yes, it is agreed by the community and you learn your accent as a child.

Chris - I can begin to do an austrailian accent... G'day mate... but Rory Bremner does this brilliantly and sounds like tony blair etc. So when I try to sound like you what am I having to do? Is it like changing you accent?

Kirsty - Within a language community, it isn't really adopting an accent it is copying more individual habits, if you are trying to change your accent you are trying to change your linguistic targets to those of eg. Austrailians.

Chris - Kat has brought in some instruments. You are going tou use these to illustrate the difference between a man and a woman's voice.

Kirsty - We are going to show the difference between the resonances in a shorter female vocal tract and a male.

Kat - I have a B flat clarinet which sounds like this...

Kat - And a bass clarinet which sounds like this ... much deeper

Kat - So it is the same timbre of sound but the bigger one is much deeper.

Chris - so it this like the difference between a male and female voice?

Kat - It is in the sense that the female vocal tract is shorter than the male one, but the different vowel sounds involve changing the shape of the resonantor using the tongue and lips rather than changing its length.

Chris - Does this mean that really good singers have exactly the right head anatomy to sound really nicest resonances?

Kat It is to do with the head anantomy and also the control that such people have developed over the years.

Chris - How would you analyze a voice?

Kirsty - This is where a witness has heard a voice at a crime scene and thinks that they could recognise it again. So a bit like an identification line up.

Chris - Can we do this by computer, as the stress of a situation could distort someone's memory?

Kirsty - This type of evidence is only used in a very limited set of conditions, the witness would have had a resonable amount of exposure to the voice in question.

Chris - How can you use a computer to help an identification?

Kat - In forensic situations when you have a recording of a voice you can use a computer to do an analysis of a recording, this is normally a different situation as you rarely have a tape recorder running when you are attacked.

Kat - What are the most identifyable parts of the voice?

Kirsty This is a big problem for us, and actually we spend more time pointing out the problems with voice identifications than making them. There is no 100% reliable technique for identifying people from a recording of their voice. We just put together a whole series of indicators.

December 2006

People who don't Feel Pain

Chris - Geoff recently published a paper on people who seem to congenitally, in other words have a genetic preponderance, not to be able to feel pain. So tell us about these people.

Geoff - We came across a bunch of children who were reported never to have felt pain. At first we didn't believe that this was the case, but we slowly saw a number of these children and they and their parents reported that they'd never felt pain of any type throughout their lives; whether they'd fractured bones, burnt their skin, scalded themselves drinking boiling water. It was a huge problem for the parents bringing these children up and later on for these people for when they became older children, teenagers and later adults. Furthermore, there was nothing that we could find wrong with their nervous system. They had normal intelligence, they had normal nerves, the nerves seemed to conduct signals normally, their brain seemed to be put together normally, and it didn't make any sense by the current theories of how pain is controlled. So we set about trying to find if there was a genetic disease that they had, because it wasn't all people in the family that were affected by this condition; it was just some members. So we used three families where the parents were first cousins, so-called consanguineous relationships. Using those three families we mapped the condition down to a gene called SCN9A, and in each of our three families we found a different fault in that gene that abolished its normal function.

Chris - Where is that gene turned on? What cells carry that gene and switch it on?

Geoff - It's not entirely clear at the moment. It's probably expressed in a number of parts of the brain and in a number of different types of nerves, but it's very highly expressed in the pain sensing nerves. It probably has a redundant function elsewhere, but in the pain sensing nerves it seems to be expressed only at the very tips of those nerves and it's at the tips that pain is sensed.

Chris - So what does it do? How does it work?

Geoff - All pain is tissue damage, so it's very important that a species knows it's being damaged and can stop itself from being damaged. It seems there are a whole series of proteins that detect various types of damage, be it hot, cold, pressure, etc. These seem to be integrated together by this SCN9A, which seems to be an amplifier that takes these small initial tissue damage signals and turns them into a much larger sodium impulse and a nerve can fire. The brain can then sense that there's tissue damage going on and avoid it.

Chris - So it's almost like an engine. You turn the key but the engine doesn't start, and what you've got in your nerves is lots of starter motor activity but there's no firing of the engine.

Geoff - Absolutely right.

Chris - So why should these families have this? What's happened? Where did this change come from?

Geoff - I guess it's just the random mutation that happens in the human genome. Unfortunately if the mutation happens in an essential gene, it's going to give rise to damage.

Chris - Why is it so uncommon?

Geoff - I don't know. Some diseases are desperately rare and some are common. We usually use the excuse that if the disease is common, there must be some benefit to carrying that disease, but it's very unclear. Probably this gene's very important and any mutation in it is not well tolerated and is usually got rid of as time goes by.

Chris - Now you mentioned that the people who you spotted that had this problem couldn't feel any pain. They had inbred within their families so that means one person was carrying one dodgy copy of the gene and they got together with someone with another dodgy copy. When you put the two together, you end up with two dodgy copies of the gene, which is why they can't feel pain.

Geoff - Yes, that's absolutely right. We all have two copies of most genes. Just having one faulty copy is fine because as long as you've got one good copy of the gene telling the body what to do, everything seems alright. The parents of these children have no problems at all with their pain sensation.

Chris - But what I'd like to ask Geoff is that if you normally have two copies of this gene and they're working and switched on, does this mean that if I married someone who has one copy working and had children with them, that you'll get kids that only have one copy of the gene working and therefore they'd be less sensitive to pain than I would be?

Geoff - No that doesn't seem to be the case. Most diseases like this are called recessives and carriers of recessives are very common in the general population. Carriers have no minor features of the disease they carry; they're just normal. So we don't think it matters if you carry a fault in this gene. We have extended our studies as we discussed prior to this programme, looking at changes in the gene that occur called SNIPs - variants that go in almost all genes.

Chris - So that's just natural variation people have in the population. It doesn't switch the gene off, it just means it maybe works slightly differently from one person to the next.

Geoff - Well we've asked that very question. Is there any link between the degree of pain people feel and changes in this gene which occur in the normal population. And it seems that this gene is one of about three or four genes where small changes in its function change our pain thresholds.

Chris - So if you've got a gene that only seems to make a difference to your nervous system when it's in a pain-conveying nerve fibre, does this gene explain why some people for instance have an incredibly high pain threshold, while other people seem to wince at a gnat flying past them?

Geoff - I think it does and it could be one of the explanations. There's a number of genes now that have been found to alter people's susceptibility to pain. Initially people were thought to lack moral fibre et cetera, but it seems that there's a strong genetic basis to feeling pain differently. It's always been the case that some children cry when blood's been taken and people say that they're not being brave. Some women need a lot of pain control when they're having babies while others need very little. It now actually seems that these people have different abilities to tolerate pain.

Chris - What were the consequences for the people in Pakistan in the families you studied?

Geoff - Much greater than being rather stoic.

Chris - Because it seems rather exciting because when I go running, it's actually the pain of being grossly unfit that holds me back. Could these people become super athletes for example because they can't feel that they've got this heart-wrenching stitch and their legs are about to collapse and feel as though they're gasping for oxygen?

Geoff - We thought along the same lines as you, that pain was holding us back from being able to do better things. But in fact no, pain is actually there for a very very good purpose. Pain is telling you that you're working too hard and starting to cause tissue damage, and if you carry on you'll either break bones, tear muscles or fall down exhausted. These children and some adults we've now met with this condition have none of those restraints on their body and so they continually damage themselves.

Chris - They do dangerous things.

Geoff - Not necessarily. They don't deliberately do dangerous things. When they're children they'll do stupid things because they don't know to stop running into walls and jumping off high areas.

Chris - One of them jumped off a roof and died, didn't he?

Geoff - Yes that's right and he did that on his birthday because he'd had none of the restraints the rest of us have to stop us doing dangerous things. He was just trying to give his friends a great show on his birthday. We've met some adults with this condition now and they'll tell terrible stories about the types of injuries they've put up with because they didn't want to not go on a school trip or appear unusual, and yet they'd have broken major bones and not be able to stand up. They'd have burnt their lips on boiling water.

Chris - They'll do things like walk on fire, and literally do it without any jiggery pokery or tricks. They can walk on hot coals and things.

Geoff - They will and they won't feel pain, but they'll do as much damage as if you did it.

Chris - So we've proved that it can be bad if you have all your pain turned off all the time, but it strikes me that you've found something incredibly interesting because there are lots of people who in their lives have to go through incredibly painful things. Anaesthetics are not brilliant, are they? They're very non-specific, they cause lots of side effects and if you take things like morphine or heroin for pain killers they can switch down your heart and breathing so that people die of heart and respiratory depression. If you've got something that has the power to inactivate just this part of your nervous system, can we exploit that to make an amazing drug?

Geoff - I certainly hope so.

Chris - You have a patent on it already I suppose!

Geoff - No we don't have a patent on it at all. We haven't exploited this result at all and are interested in it academically. Others hopefully will and I know that drug companies are already looking at this sodium channel and many other similar ones. The hope is that if people who have none of this protein feel no pain but don't have other side effects, then if you block this protein in a normal person, they'll have a pain killer without side effects. That's exactly the hope that drug companies are now working on.

Chris - Is that feasible?

Geoff - We think so. The problem is that there are about eleven of these sodium channels and they are very similar to each other. So the problem's going to be getting drugs that are totally specific to just one of these sodium channels and doesn't spill over and block other sodium channels.

February 2007

The Wine Diet: Is Red Wine Good For You?

Chris - One of the things you've risen to prominence for Roger is sussing out what's in red wine that makes it good for us.

Roger - Absolutely, that's been my work for the past six or seven years. I've focused on finding out what is in wine that improves blood vessel function and protects from heart disease.

Chris - So how did you go about that and what is the bottom line? Is it good for us?

Roger - All the evidence points to it being good for us. But it may be that certain types of wine are much better than other wines. What we did from a laboratory point of view is we studied exactly what substances in wine could change blood vessel function. In parallel with that we were looking at areas where people were living longer and drinking wine. And we saw that the wines in these areas were richer in a substance we identified, procyanidin, which is a flavanoid polyphenol. People would know them as anti-oxidants but in terms of the effects that we were looking at, this causes a profound change in blood vessel function.

Chris - There is a phenomenon called the Mediterranean Effect isn't there for people from the Mediterranean basin. And the French paradox as well. There are French people who manage to have an atrocious diet, smoke like chimneys, and live to be 500 years old. No one really understood how they did it, and what you're saying is that it's the red wine that they're drinking.

Roger - Exactly. The Mediterranean diet sprung out of research called the seven country study. That showed that people living on the island of Crete were living longer with less heart disease despite a fairly high fat diet. But an important part of their diet was to drink regular wine. Now I started to look at Sardinia because the highest concentration of centenarians were based on this island in terms of European population, and I found that their wines were richer in Procyanidins than wines from other areas. The Cretan wines were also particularly rich in this particular polyphenol. And so I then looked at the French population. And there's a regional variation in heart disease across France. And there's also a regional variation in terms of longevity. And what I found was that people living in South West France were drinking wines which were very rich in these polyphenols. But the interesting thing about this and the French paradox, is that this is one of the areas of France where they eat some of the fattiest foods. And so I became convinced that a) Wine should be part of a healthy diet, and b) some of the nutritional advice being pushed on the general public was actually not based on fact.

Chris - Is there a conflict of interest here Roger, because you're a wine connoisseur aren't you?

Roger - I wouldn't like to say I'm a wine connoisseur. Obviously we all like to have excuses for our habits. What I was, was somebody who was religiously following a low fat diet. And I suddenly started looking at the science of low fat diets, and realised that actually, if you wanted to have a healthy cholesterol level, it was the type of fats you ate, rather than having a low fat diet. Low fat diets are often boosting over-purified carbohydrates into people's food, and sugar into people's food. And that was actually changing their heart disease risk in an unfavorable way. And so this drove me to write a book to explain what it is about eating healthily that everybody should understand. It doesn't matter whether you're thin or fat. Wine can be part of it, but the food you eat is so crucial to your overall wellbeing.

Chris - Let's just focus in on the wine story for a second. You saw this effect, which was distributed across France, and the effect rose specifically in South West France. So what was going on there that meant that people, despite an atrocious diet, were protected? Presumably it wasn't just genetic.

Roger - I wouldn't say their diet was atrocious, it was just different. Essentially they were growing a grape down there called the Tannat grape that was very very rich in these protective polyphenols. But other wines are also good for you.

Chris - Is it just red wine though Roger? Because lots of people say you have to drink red wine, white wine's no good. Beer's no good.

Roger - Well, let me provide you with some evidence. Alsace has the lowest longevity in France. And it has some of the highest heart disease. That's a white wine drinking area.

Chris - So it is specific to the colour. Red wine grapes impart the protective chemicals.

Roger - Exactly.

Chris - What are those chemicals, how do they work and how does the grape make them?

Roger - Actually white grapes also have them. The difference between white wine and red wine is really the way in which the wines are made. The white wine is the fermented juice of the grape, where red wine is the fermented juice with the seeds and skin present. So the longer the time of the fermentation with the seeds, the more extraction of these polyphenols that you have. And so the higher the levels.

Chris - Ok so we know wine has this stuff in it. How do we actually get this stuff to where it needs to go, the blood vessels? Why does if affect your risk of vascular disease? How does it work?

Roger - Essentially, if you imagine that blood vessels are a tube, and they have a lining which is protective. It's important that they function in a healthy way. Now the chemicals in wine are able to boost the healthy characteristics of this lining. So that you reduce your risk of heart disease. Many people may be aware that chocolate has also been said to be helpful. Now the point about chocolate is that dark chocolate has the same polyphenols in, as a good red wine. As so for non wine drinkers, if they want to get these polyphenols into their diet from other sources then dark chocolate becomes a possibility.

Helen - So I bet people out there are dying to know. Can we say in a snapshot, what should people be eating? And how many glasses of red wine should I be drinking? Is there enough in one glass?

Roger - If you look at a glass of average supermarket wine there isn't probably enough to have much benefit. But with time we're going to change people's awareness of wine and also the way that it's labeled. If there was more details about the wine making process, one could read the label and think that if it's been fermented a long time it's much more likely to have a higher level of these compounds. But there's no information on wine. How much should you drink? All the scientific evidence about reduced heart disease actually reflects a consumption level that is similar to what government guidelines recommend. So for a woman that's no more than one to two small glasses per day, 125 mL. For a man, two to three glasses is ok. But an important factor about people benefiting from wine consumption is that it's part of a lifestyle pattern. It's not going to the pub and shoving down a few glasses of wine and then thinking, "I've got all the benefits". Because studies have shown that people who drink without food are more likely to have high blood pressure. High blood pressure increases your risk of heart disease and it increases the risk of a stroke. So it's important to understand fully, the lifestyle combinations.

See also Roger Corder's book "The Wine Diet", which will point you in the direction of the healthiest red wines to have at dinner time.

January 2007

The Secret Sounds of the Oven Shelf

The kitchen has always seemed an unlikely place to find a musical instrument - until now. This week Derek and Dave are with Matt and Nick at Hinchingbrooke School in search of the hidden harmonies of the oven shelf. Prepare to be amazed!

What you need

An oven shelf (make sure it's not hot!)                    

2 pieces of string, each about 1 metre long

Wooden spoon, or pen

A friend to help you

What to Do

What may Happen

When you listen to the oven shelf being hit normally, you can hear a ringing sound. However when your fingers are in your ears, the sound you hear is much lower - a bit like a huge gong - and really nothing like an oven shelf usually sounds.

What is going on?

First of all we have to understand that sound is all about vibrations. When somebody speaks, their voicebox vibrates, and this makes the air around it vibrate. These vibrations carry information about what someone has just said. When these vibrations reach your ear, they make your eardrum vibrate and this is processed by your brain as sound. The amount of energy (or the volume of the sound) that manages to make the journey from voicebox to ear depends on what the sound is travelling through and what kind of sound it is.

In the case of speaking to a friend or when you listen to the oven shelf, the vibrations must travel through air. Air is really sloppy, fluid and not very stiff. Water is quite similar - if you put your hand in water and slowly move it around, the water feels very soft and fluidic. However, if you slap the water then it suddenly feels very hard and stiff. This is because the water doesn't have time to get out of the way so it has to form waves. Although it is not quite so obvious, this is the same for air. If you move something through it very quickly, the air feels stiffer and it's much harder to move through it, so high frequency vibrations will transfer more energy intto the air.

The ability of sound to reach someone's ear also depends on the ability of the air next to the ear drum to vibrate. In the same way as a high frequency (pitch) vibration can transfer more energy to the air from the oven shelf because it has less time to get out of the way, a high frequency sound will transfer more energy from the air to your eardrum so the sound loud. Low frequency sounds vibrate the air much more slowly, and so the air seems relatively more sloppy and doesn't transfer energy so well so they sound much quieter. So both low and high frequency sounds are produced by the oven shelf but it's only the high frequencies that vibrate the air by your ear drum much so the shelf sounds tinny and high pitched.

In order to hear the low frequencies, you need to create a stiff connection between the oven shelf and your ears. The string wrapped around your fingers provides this connection. The string is taut and stiff and can transmit both high and low frequencies. When you add the high and low frequencies together, the oven shelf suddenly sounds like a gong.

What about in the real world?

This is why your voice sounds different to everyone else and when you hear it recorded. Everyone else just hears you though the air, but you hear yourself through the bones in your skull as well, so different pitches will reach your ears than other people's.

Written by Dave Ansell