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So good evening everyone welcome to this evenings seminar in the our changing world series i'm david webb i'm professor of clinical pharmacology in the university but more important to today's talk i run the hypertension service in Lothian so I'm going to to provide a short clinical perspective to the taught that follows from that Bailey and then i'll introduce Matt and then he can get into his his son so why should we worry about high blood pressure now you're fairly young audience but if you look at a full adult population about one in three will have hypertension and hypertension is globally the most important risk factor for cardiovascular disease and four and the death worldwide so I think you can see here it's right on top of the screen it's above smoking it's above excess alcohol it's about malnutrition.
It's about above infectious diseases it is the most important global problem worldwide and it just as much effects underdeveloped countries as the high-income countries so it's just not a Western problem and with the obesity epidemic and the growth of diabetes the combination is devastating this is a really significant problem for human health the problems that it causes include strokes premature dementia loss of vision heart attacks and heart failure kidney disease and heart patients with heart failure 75% them i like to have hypertension patients with stroke it's about seventy-six percent patients with heart attacks about sixty to seventy percent so you're very like much more likely to have these problems if you're hypertensive now the graph on the on the right just shows that your risk of a stroke this is about strokes same draft for high blood pressure over our class but as the age goes up your risk goes up and you'll see this is a logarithmic representation so there's a very steep increase in your risk of stroke or heart attack for increasing blood pressure.
We also know that very small changes in blood pressure can have a big difference in risk so you can see here that even a two millimeter of mercury lower which is in very small amount lower systolic blood pressure would reduce stroke mortality by seven percent and mortality from heart disease by around ten cents this is a really big difference these small differences and sort of things you can very easily change in populations so that these small changes big impacts this is a an infographic from the international society of hypertension and it makes a number of points first of all that there are around I don't where you can read it over this point is working but around nine million deaths each year from hypertension it's a massive problem and there are really simple things people can do to reduce their risk like stopping smoking eating more healthily eating more fruit and veg which contain potassium knots not sodium or salt and eating more healthily reducing weight taking exercise these are all things that people can do themselves and the other thing is that hypertension is a symptom this problem and the first time you might know about is if you have a heart attack or stroke so it's really important that you as they say here know your numbers it's easy to measure blood pressure and most people haven't had it done it's really important to have your blood pressure checked.
Even in early adulthood and they're really simple really cheap devices you can buy this particular one from on this Lots others like it.
August sell them for something like 15 pounds so it's not expensive to know what your blood pressure is and when i started as a clinician we have used to think all the rule of Harv's in hypertension the only half the people with hypertension were known about and only half of those were our any treatment and only half of those were treated to the right target to protect them from the problems of high blood pressure so if you do those sons that's twelve and a half percent get treated with full effect and this is a study that's just published this week online in the lancet that shows that nothing's changed.
Thirteen percent of those people with hypertension properly treated to target so it's a massive problem that remains unresolved.
We work in Scotland Scotland is a great place to work for heart disease and as you see here the Scottish heart survey this looked at five major risk factors so smoking excess alcohol intake for diet obesity and physical inactivity and it's a study in a 65,000 people 97.5 percent had a risk factor most what's really sad i think about this figure is that there are more people with five risk factors than with none and more people with for risk factors that sort of them were done more for them with one so we have a really unhealthy population there's a lot to be done in Scotland and as a final slide now this shows you the nation's top sellers from last year and you can see it's processed salty food hard spirits and carbohydrates and fats not not the best top sellers defined on that list so I'd like to move on with that context to our speaker tonight and that Bailey he tells me he grew up in rural lincolnshire in the village we just five farms and had high hopes of his career as a footballer he tried out for Scunthorpe United failed and is now pursuing a second career as a medical scientists began to BSC and physiology at university of manchester 1993 a PhD in renal physiology Charing Cross and westminster which is now Imperial College medical school in 1997 and he undertook postdoctoral research at the center from mythology in a note for at the central morphology at university college london and then moved onto the net.
The center for scientific research in paris between 97-2004 that you spent three years at Yale Medical School on a wellcome trust international fellowship and then moved to the University of Edinburgh to the center of cardiovasc for cardiovascular science to work with Professor John Mullin services here tonight to work on the Wellcome Trust cardiovascular research initiative intermediate fellowship scheme in 2003 and in 2008 he became member of the faculty of the university in 2010 senior lecturer and in 2014.
Reader I do a lot of work Mac he's a really good researcher and he's fun to work with.
He said been given prizes for his work from the physiological society and is a member of the kidney research UK grants committees so I'm going to hurt hand over to Matt to tell you a little bit about living in a salt saturated world do your jeans it.
Ok good evening everyone and so for the next 40 minutes or so i'm going to talk about our relationship with mineral sodium chloride salt and how that has shaped our societies and shaped our health and now this is not actually a true story.
Some people say it's that this is not a new story.
Some people say that it's a story that has shaped mankind and made us what we are.
That is ingrained within our genetic code and it's the thread that ties together our societies both ancient societies as well see our modern societies now if we go back to ancient times it really was a story of life and death.
It was the success that allowed us to leave the sea and make a good life on land and it was the economies that drove the ancient Egyptians ancient Roman ancient Greek societies now today it's still the matter of life and death but as David pointed out in his kind introduction.
The game has changed completely and instead of it being a scarce and much prized resource we're now living in the society that saturated in our bodies are not able to cope this so let's go back really to where I started with this which was a number of years ago when it came to edinboro reading this book called The Hunger for assault by Derek Denton and he said in his introduction that salt was the quintessence of life which i thought was actually very beautiful phase phrase it's not just the essence of life is the distilled essence of life the stuff of life itself and we can see this all through literature so for example you can see in Matthew ye are the salt of the earth describing a fundamental property of a human being being the very stuff that the earth is made from we can see also in the Bible the concept of the Covenant of salt the fact that you might make a binding and lasting agreement based on sharing something precious in this case sodium chloride or salt and this isn't just in judeo-christian theology this is seen all over the world for example in the Eastern religions you can see that an oath by salt is an important indeed and is considered to be life binding we know for example phrases that are in our everyday language like to be worth your salt means that actually you are worth something you worked you're doing a good job and this comes back from writings that plenty the elder made in ancient Rome talking about the practice of paying Legionnaires in cakes of salt something that really persists today in the concept of the salary a regular payment of something of value we can even see it in our geography all over the world so societies of locals that local societies that grew up based around the manufacture or the isolation of salt wrote about it in their very names so we can see this even in Scotland in the Asha coast saltcoats where they would purifying salt from the sea through to salzburg where they were mining from from the mountains and even in India where we have the village the island of salt which was very famous for several hundred years ago for for salt trade and it does indeed it does underpin a lot of our societies economic developments so for example you can see here in this picture this is the famous salt Caravan which was taking salt on Long camel trains that have been mined in here so they've been taken from swamped in this in in the Sahara Desert and bring them into Timbuktu making Timbuktu a very flourishing market economy and this was written about actually as long goes as 400 BC many economies practiced salt tax so not only the buying of the soul paying levy on top of that per capita to pay for the mining of salt and actually underpin the development of ancient wonders of the world like the tempo.
Of Artemis we hear about that was built on the proceeds of the salt tax now you might think that this is not really that relevant that these are ancient & bygone days but actually these concepts persist so this is from the BBC website 2009 we can see that the timbuk2 salt caravans are still going well they're under threat interchanging will both due to climate change and global economies but it's still very much a way of life in Mali for some some tribes there and the salt tax.
Well I think you're the pointer has as the point is died and come back and so the salt tax actually still persisted in in in relatively modern times this is the Inland salt hedge which was built by the British during the occupation of India built around 1850 at its peak around eighteen ninety four thousand kilometers long and actually a physical hedges described as been 13 to 20 feet high.
Many many meters thick built of dense course like material that just could not be passed.
Apart from certain gates along its route these gates worm and quite heavily by the British Army 12,000 soldiers at the peak and the whole point of this was to ensure that the salt tax could be livid so in order to maintain relatively high salt taxation in Bengal there was a tanned and from the salt mines here there was a tax on the the movement of assault across india and this has global economic impact gandy 1930 started protesting against this and they're big marches against the inequities of the salt tax but it's still persisted and was still in place until nineteen forty-six so still from ancient times through to modern times salt is influencing the development of our societies so from all of this we get one key concept that throughout history salt has been considered something of exceptionally high value you can see it here this is a picture of da Vinci's Last Supper and this is Judas Iscariot clutching his bag of gold and you can see in this box out here that with his elbow he's not over the salts and spilt the valuable salt all over the all over the table so in symbolic art the spilling of this valuable substance the substance that we swear oaths upon is is thought of as a hard having bring out of doom a predictor or bad things to come and we all know this where we take the pinch of salt if we split and throw it over our shoulder to dispel the devil that might be lurking there so why is this.
Well as a physiologist i got i got interested in the works of one of physiology is great philosophers this is Homer Smith he was professor of physiology new york university and in the late in the in the middle fifties nineteen fifties he published two books that had a profound impact in popular science and he posited a theory that I'll talk about in a second the first of these was a novel called the lungfish in the Padre and it's a novel that takes place in Africa about a physiologist is going to find the missing link the long Fisher fish that can live on water but equally consider can survive on land and i know it it seems a little bit far-fetched you can actually bite on major online booksellers but it was in its day a major bestseller following that in 1959 he wrote this popular science book which which said talked about our evolution as a species going from how we change from being fish to philosophers and his concept.
Is over simplified in my dr doing a diagram here it's about a fish that adapts to walking on land and his whole hypothesis was that once you do this you face a major evolutionary challenge you go from an environment where salt is hugely abundant and is is all around you to an environment where salt is very scarce and this puts extraordinary selection pressure genetic selection pressure on the organism perfect and so you're going from salt is abundant source is scarce and geographically isolated and when we talking about salt in this context we're talking about salt in solution say line sodium ions and chloride ions and why do we need these in our body we need them because they underpin hugely important physiological processes they makers what we are as David talked about his introduction they control our blood pressure the salt in our blood controls the volume of fluid in our blood and and dictates the pressure that blood is under the distribution of salt across cell membranes controls the electrical properties of that cell and allow cells and nerves and muscles to function properly so we have to control exactly physiological the normal sodium chloride in our body and once you move from this environment to this environment that becomes incredibly difficult now one of the other great philosophers is is this guy here claude bernard and he said that the process that allowed us to live this free and life on land and all mammalian species was the ability to control our internal environment allowed us to stabilize all the things that are going on.
And the solutions in which our organs were bathed and it allowed us to to perambulate across the land and to be independent of needs to control salt directly through our skin and you've all seen this kind of slide the human body is seventy percent water but this is actually not true.
It's a line its salt in water we know this when you go into a hospital with a if you're fortunate to have to get an IV drip drip is a water to drip is sodium chloride so we are salt we've adapted to salt and we carry our environments around inside walls and the processes that allowed us to do this other things that put us a challenging changing world so for Homer Smith here and Kluber not hear the major focus was on evolution of control mechanisms what mechanisms did our body put in place that allowed us to adapt to this independent life Smith focused his work almost exclusively on two aspects that the aspects that allowed the gut to reabsorb to take in salt from the food that we eat and the kidney how the kidney function to filter our blood and get rid of impurities yet keep hold of the salt that we needed to live we know however some of the work that we'll talk about a little bit later from our lab talks about other pathways and which is the kind of the input pathways to this equation so how we take salt in so we know for example that we have in hardwired hard encoded into our brain our behavioral patterns that when we become low in salt we start to have salt seeking behaviors we start to generate a hunger for assault we also know that the tongue one of the five tastes modalities of the tongue is salt the molecular processes of this we now understand a little bit better but it's a way that the body can discriminate among all of those tastes the exact taste of salt now all of these things are brought together in perfect harmony the perfect harmony physiology the perfect harmony of of control so that the salt in the salt out match and they're controlled by a variety of hormone systems and by our nervous system and these are the focus of intense research efforts and i'm not going to go into that at all anywhere today but if it works we're happy mammals the challenges keeping it working the whole concept is about balance this is what physiology is it is about balance so that the salt that we take in is matched by the salt that we excrete from our body to maintain that constant internal environment and the processes that were talking about are encoded in our DNA and we might wobble from this is my best animation by the way it really does not get any bitterness.
The point is we might wobble from day to day reminding more than we normally do but over a period of two to three wanted two days we get back into sodium balance by adjusting these hormonal or nervous controls so if we look at this prehistoric creature on the left and this elegantly sophisticated scientist on the right we ask the question what went wrong and remember that we're talking about our changing world there are many answers to this question my children give me several of them what went wrong.
The key is here if we go back into ancient civilizations we know that the daily salt intake was based around our physiological needs so we took in around about half to one gram a day now the variety of ways that we know this there are some beautiful worked on archaeological work analyzing foodstuffs analyzing contents of bowels from ancient hominids but actually even relatively recently big studies like the into salt trial which monitored global solar salt intake Cecrops the world were able to find people this is the yomi peoples from the the amazon basin of the Amazon rainforest so in the north part on the border of Venezuela and Brazil this is about 35,000 people living in a very pre industrialized society we know that their their salt intake still is around about this about half a gram per day we also measure their blood pressure and blood pressures in 95 over 60 on average compared to our normal of a hundred twenty over 80 there is no incidences of hypertension no instances of diabetes no incidences of obesity in these populations so what went wrong what changes this is the recommended upper limit of your salt intake so this is grams of salt per day there are two bars here because there are different limits the five grams a day is the World Health Organization's of pretoria belivet the six grams of days i'm sure you're familiar with is the uk's upper limit in 2012 i was part of a study that we run in little friends to measure salt intake and this was my salt into my habitual salt intake at that time sure it hasn't massively changed today i was eating between eight and nine grams of salt per day so regularly exceeding the upper tolerable limits that's recommended by health organizations and government government's so you can ask a couple of things here is this just me and my old exit down to that home so am i am I typical person well yes I am.
You look at studies like this which was published a couple of years ago in the British Medical Journal looking at average salt intake on a global level and you can see in Western Europe where somewhere here around eight or nine ground the day so I'm actually typical for my geographical location and you can see that there is somewhere spread from Central Asia all the way through sub-saharan Africa that the key message here is in all of these populations the habitual daily intake of salt exceeded whichever regulation you care to choose we're taking in too much salt about thirty percent more than we need on a world base it's around about nine grams per day and if we look at the NHS and they produced this rather snazzy salt survival guide they say look these are the figures we are eating as the UK as the UK we are eating 183 million million kilograms of salt per year which they'd rather strangely in my view say is equivalent of 18,000 london buses are not sure why that's the unit of measurement for salt intake but there you have it i think the point is it's a lot of salt and what does this actually mean.
Well let's go back to this balance diagram here where the body the physiology that the genetic code is striving to keep us in salt balance is trying to keep our internal environment constant and we're putting it under massive strain and this is david mentioned earlier on is having powerfully bad impacts on blood pressure now that is some controversy in the scientific community about how this is happening how these things this out of balance and blood pressure connect so some people would say that the the you go out of bounds only for a short period of time but you're always having to compensate for a heavy sodium load and that gives you high blood pressure some really new research is actually saying no we're chronically out of balance of what the body's doing is taking this salt that it's eating it can't excrete it so very efficiently and it's putting the salt in places that the salt shouldn't be so it's putting in our bones or in our skin.
And there's some beautiful evidences as we get older the soul concentration our skin gets higher and higher and higher and there's evidence that you can roll this back there are good outputs for health so putting in place it shouldn't be as bad but whatever the mechanism linking being out of balance to high blood pressure there is a very strong connection between this habitual overload of salt and we know you've seen stats like this it like two starts that hypertension is that it's a case of global health crisis this is the wh owes briefed on it in 2013 they said it's a public health crisis it is the silent killer.
David mentioned this unless you know your numbers you're not going to know you have it you don't feel and well until you have a cardiovascular instant like a stroke or a heart attack and this slide okay for this audience you might want you guys might all be down here in the the the low prevalence population in the twenties but once you get to my age range above and hypertension becomes a serious issue that you're worrying about and it is driven in part by things like a high-salt diet and so what causes hypertension what can we do about this well in simple terms the equations is very simple it breaks down to the interaction between our genes and the environment in which our genes operating in this case we mean assault heavy diet the problem with this is it's a tangle it's a bowl of spaghetti where do you begin how do you separate out cause and effect and how do you untangle mechanisms of a very complex disease and this is the blood pressure distribution in the general population don't know that's so that's not come out massively well but the point here is that for most people.
We're here we're operating in this region and this is where we have common genetic variants that each carrier very small effect it's really really really noisy to work in this area the measurements that you're making a very small environmental factors are difficult to control its difficult really to understand what's going on so about 20 years ago a number of people across the world notably guy called rick lifton at Yale who I was interacting with the time change the way that they thought about looking at genetics of hypertension and said okay let's not work in this middle noisy bit let's work out here.
Ok there are fewer people and the genetic variants are rare but they carry with them really large effects we can see them we can trace the effects down through families.
Let's do that and let's find out what causal genes are this is challenging to do is challenging to work with with with humans because of course is a diverse genetic background it's an uncontrollable environment is very difficult to to to get people to agree to eat a certain amount of salt in this case and of course these are all people patients with massively high blood pressure.
They all need to be treated and and they all are treated so even if you find the underlying genetic calls how did you find out how that's changing blood pressure the answer to this is you change the system and here in edinboro we've done this very well for a number of years you move from humans which are noisy and difficult to handle two genetically engineered mice genetically engineered rats the key points here is that you can then tweak the genetic code of their animal the underlying physiology is the same the evolutionary track from sea to land is the same the systems are the same you can control the genetic background you can control the environmental factors such as the salt intake and you can make studies over a long period of time so this can tell you very nicely how genes operate to control of pressures.
And I give you this is an example from from our work where we have a mouse that we tweet genetic solve and we have a diet which is similar actually to the the ancient diets that we used to live on very low salt and here systolic blood pressure is around this week then go to a period where they eat a diet that is reflects the diet that we everyday high-salt feeding and you can see what happens really nicely the blood pressure goes up and the ways we can do this is because we have amazing technologies this is called a radio telemetry device its implanted on the general anesthetic into the animal it's about the size of my little fingernail so it's very tiny device it contains a radio transmitter the new ones actually contained bluetooth connected and it records the blood pressure every minute of every day for that animal over long periods of time and allows all that data to be exported to to my computer and so we can observe animals in their natural environment to see how blood pressure is changing with salt changing we can combine this with changing the environment animals living so these for example our cages mouse House's if you like where we can control the thought we can measure certainly the water the salt meat and the sodium that they excrete in their urine and their feces so we can control we can track how blood pressures changing over time and we can tie this to the dietary challenge the animal is facebook and if we do this which we've done for a number of years we find some interesting things all of these genetic mutations from the human study then taken into animals change the way that the kidney works this is the the unit of the kidney is called the Nephilim is essentially a tube that processes salt and all of the genetic mutations change the way that this nephron process salt and this is the main way that salt leaves our body and the numbers here are huge so for example normally we filter 280 litres of blood this structure here so this is the way that the blood is filtered and impurities shared through the kidney 180 liters a day so my blood volumes around about five and a half liters and if my kidneys are working normally which hopefully they are by the end of this talk I'll filtered my entire blood one time through my kidney so if this goes slightly wrong it can have a profound impact on the amount of soldiers held within our body and so what it means when we think about why r out of balance is actually not to do with this perhaps what to do with this our kidneys are not efficient enough excreting the high amounts of salt that we taken throughout diets so is that the whole story well of course is not the whole story is a much more complicated than that because the kidneys don't exist in isolation they talked to all of the other organ systems notably Outbrain they're connected via aspects of the nervous system the brain releases a number of hormones that control for the kid the cruise control kidney function there's this to and fro between the brain and the kidney and this I think the work is now emerging suggest this interaction actually is key to understanding hypertension and understanding the impact in terms of cardiovascular disease now the reason that I go interested in this is because i read a paper by a neuroscientist colleague here at Emory University where one of the genes were interested in and we knew that it changed how the kidney work was also expressed herein the brainstem so in the ancient brain in our kind of fishy brain if you like it was expressed in very very discrete regions is only expressed in two very focused parts of the brain and when I read this work that it was the brain regions that can.
There were controlling assault appetite and will also influence in blood pressure controller and biology does not do coincidences.
So we spent some time trying to unlock what this was doing so we went back into a genetically modified approach and we modulated the jeans only in the brain and then we did this experiment we gave mice a choice.
The same choices that we face every day when you either this or you eat that so we gave them a choice in this case of taking in water or taken in sailing so very salty waters about is not quite salty seawater book pretty unpalatable we presented them always with to drinking bottles and they were complete Liberty to choose which bottle for which bottle they drank a normal mouse does this behavior it drinks eighty to ninety percent of his time from the water bottle and only take small amounts from the saltwater when we modulated this pathway in the brain stem we unlocked we amplified a hunger for assault that we could see no reason why this animal would want to eat sold but certainly did it ate and drank also from the water bottle be a perfect ramp most of its liquid intake was through the salt i have this craving this appetite for assault and what did this due to blood pressure now you've seen this before this is act these are the data actually from this study these are when the animal could only drink water in this period it could drink either water all salt and when it chose the salt to drink the blood pressure went up so this is a genetic drive for blood pressure driven by our appetite for sold the kidney function is entirely normal in this set it was rather exciting for us it broke through in a very quiet phase in british news to the mainstream media and we got headlines in the mail the times in the sub my favorite remember favorite one and I feel that I have achieved probably.
Now that my football career has failed I've achieved something because I've got a quote the ends in say scientists salt taste in jeans say scientists said the Sun the nature online character is rather nice picture of a mouse putting salt on cheez-it we were interviewed by the Chinese President down particularly big in China and also in Kazakhstan for some unknown reason and what I took from this was a momentary satisfaction that was brought down rather quickly when I looked at the online comments under the under the under the mail because sarah from Susan's error from Spain responded within half an hour of it going online with this is all to rubbish it's nonsense this is all about Jean science driving economies to make money now that the vaccine market is flooded Mitch name blanked out privacy reasons from DC was succinct in his criticism he said it's nonsense this chap add salt to his peanuts and his pretzels and he's totally fine and I resisted the temptation to get into an online them there but because actually did do Sarah and Mitch actually have a point here and and they may well do which is Mitch this is a study upper really influential study form.
Around 2,000 and it's a long-term follow-up study and these are data that I've changed to make it more easy to understood stand it followed many many patients and it categorize them into whether they could eat salt and their blood pressure didn't change so that's the salt resistant people and and and into whether people then responded to salt and the salt sensitive so people that we ate salt and blood pressure went up now what we see from this graph of two things first of all if you have normal blood pressure and your blood pressure does not change with the salt that you eat things are pretty good for you so after about twenty seven years about ninety-five percent of that group is still alive.
The redline other people with hypertension underscores David's point from earlier on that it doesn't really matter if you're salt-sensitive also resistant if you've got hypertension it's a really big cardiovascular risk factor and about forty percent of that cohort died from a cardiovascular insult during the period of this study now the interesting thing is this blue line here so this is a group of people that have normal blood pressure but their blood pressure was exquisitely sensitive to the salt that they need so if they had low salt blood pressure went down but in today's high salt societies with this high salt their blood pressure was higher than it otherwise would be and the outcomes for them were not good so around about thirty percent of that group die of cardiovascular cardiovascular disease and and the one on the way they progress to having hypertension and this is not an insignificant number so depending on the study probably influenced strongly by ethnicity around a quarter to forty percent of individuals are salt-sensitive so if we look in this room for example so say around about in this room around about 40 people also are going to have salt-sensitive blood sure and even if you're in your twenties and undergraduate and not thinking about this this is a risk factor for cardiovascular disease and the work that we're interested in now is actually saying what are the genes for salt sensitivity can we identify them can we tell you or you or me that I have salt sensitivity and can we add that advised lifestyle modifications that would have long-term cardiovascular benefits and we started this program it raised it runs and the thing that we find here former animal models so far is that the salt-sensitive genes are the old jeans their genes that have been conserved across this beautiful circle that keeps insult balance and that the same things so the same genes in our kidneys are holding onto the salt in the urine are the same genes that are in our brain that are driving us to eat salt and the same genes that are on our two expressions are tone to make us be able to discriminate salt in the food that we eat and the key thing here is in our changing world these jeans no longer fit to our environment and so when if we if we're this person here we're sailing on the sea of dietary salt will really stuck between a rock and a hard place Scylla and Charybdis we've got a brain that is driving a hunger for salt our ancient brain wants us to eat salt our kidney is massively efficient holding in that salt and that really makes it very difficult to avoid.
Dad developing hypertension over the course of your life and the damage is huge this again from the NHS tens of thousands of people dying prematurely because of cardiovascular disease and the costs in terms of society and economics are massive this is an interesting statistic reducing this salt intake by just one gram a day could save four thousand lives a year save large amounts of money for the NHS and I think we have two options here.
Option one is sarah from spain's gene science can we change the jeans option two is changing the environment so let's talk about someone changing the jeans and now why would we want to do this is because of this you can say to somebody.
The best thing that the the single best option for you is to reduce your dietary salt intake and most people will go what's option two and we can't yet released yet change gene function readily but we as their genes regulate readily in humans but we can change their function and in fact we are doing this and we have been doing this on a massive scale for a number of years through blood pressure medications and so from the statistics on 2013 we see a really large number of prescriptions given for cardiovascular disease about thirty percent of total prescriptions 65 million of those are treating hypertension or how freely or or statins to lower.
Lipid but as we saw from David slide earlier and in my my personal favor and medical journal the mail online and you can see that this is a study from Lester where they were monitoring do people take their medication by measuring the medication in the urine one in four people are failing to do this so even if we try and change the genes by giving the tablets people are not compliant with this in the long term it's complex the complex reasons underlying this part of it is it's a silent killer you don't feel and well you don't feel a need to take pills so i guess the option that we left with is changing the environment rolling back are changing will to to the to the earlier time period and and it can be successful.
This is the mouse study this is phase three of that study so we had ancient diet modern high-salt diet blood pressure goes up and when we go back to that low salt diet blood pressure comes back down after about three weeks blood pressure is back down to where it was before and there are saying the same type of data from studies in chimpanzees and also form studies in humans so it works it can be really effective so what's the problem with this you remember this one before you need this this is the regular upper limits and this is what I was eating in 2012 the next part of this study was a three-week period where we were asked to become salt aware we were asked not to eat out everyday foods but to think about the food you're eating and try and reduce our salt intake I spent three pretty challenging week students and the outcome balls.
Who was this actually I didn't know my intake by hardly anything at all so despite really trying to lower it it pretty much state.
Resolute Lee over the upper egg you later limits and from this we learned that it's really hard to reduce your salt intake why because actually most of this salt intake is not within our control so there are different estimates out in the scientific literature but about 75% of the soul the weed is already in the foods that we eat is it's part of the manufacturing process part of the process the the food is in the process food and i'll give you an example of why this is tough this is from a pizza attendance pizza from one of our major supermarket chains its manufacture its it's advertised as a healthy pizza.
The reason that it's healthy pizzas it has low fat pepper only on this pizza ok so you can go into the supermarket on real friday night when you're getting getting your vodka and pringles an account what the other thing was and and to get to get your pizza and you go no I'm going to take the healthy option i'm going to lower my i'm going to i'm going to be healthy about this i'm going to go for the spicy low-fat pepper only but look half of the pizza contains half of your daily intake for salty upper limit of your daily intake result phenomenal amounts of salt and it's not all doom and gloom and the UK government has this amazing website is really good lots of information on this and they have taken this is from the coalition government actually that took a very non alleged london on legislation based approach so it was about working with the food industry rather than imposing regulations and tariffs and it has had some success it removed in 2012 11 million kilograms of salt and it has set new targets between 17 but remember up against 18,000 london buses with assault so there's still a way to go here there are a lot of online movements now about becoming more aware of things like this this is my favorite it's be a ninja and practice stealth health and this comes from Australian actually when they study published about two years ago which was finding the children were eating six grams a day they were eating at the upper limit for adults on average and what they were deciding to do was saying actually children are an easily targeted group because their salt intake can be better controlled by their parental imports can we do education can we practice stealth so not saying you are going to be healthy but changing the foods that whenever the types of food that they have in their backup you can also see this is from the American Heart Association not sure i have to say that the salty six works it's not quite like the hateful eight but a that they were to what they're trying to do here is to say look let's increase awareness of where most of the salt is hidden annex you know the usual suspects perhaps such as pizza but it's also in the sandwiches we'd the bread particular cheese and in soups all of these are hugely hi insult and you might not be aware of this david mentioned this little there are things so this is for example from the national institutes of health its Dietary Approaches to stop hypertension the DASH diet so online you can you can go through recipe books about how you can eat diets that are calorific Lee good nutritionally good but also very low in salt and that studies show that this is very effective reduces the sodium chloride boosts of the potassium chloride and blood pressure goes down there are even a fat called paleolithic diet food movement i should say call Paleolithic diets you can fly if you type in online you'll find their website and is trying two rolls back many many millennia to say look this is this is the challenge that we're facing let's do something about it let's get away from processed food and back into a much more balanced diet ok so let's try and begin to bring this together we go from evolutionary drive that means that we value salt because it is essential for our life and it is rare we hold it as a thing of high value and it attaches itself into our economies into our cultural life both of both absolutely and symbolically and the changing world is the instead of spilling salt and then throwing it to get rid of the devil on your shoulder that salt now has become the hidden devil in all are in in all of our cupboards.
So the key thing that I would like you to do is really look out for this hidden salt because it is a changing world but we can change it back so become salta we're go for the lower salt option and with that I'll say thank you and these are the guys that are funded all our work here so thank you very much I hello thank you for your told and I wanted to ask you.
So I just to give you a bit of background I've seen I've seen this documentary on sugar for example just trying to make an analogy where they were looking at daily sugar consumption of refined sugar and they were saying that the daily recommended maximum intake should be brought down from the actual from the current values around 80 grams a day to 20 because that's actually the real amount of sugar that we should be today.
So in this in the light of this do you think the six grams a day of salt which is currently that the limit in the UK at least I think I do you think that's a real value or do you think that should be closer to three or two or less ok so that two separate that out a little bit so i think the first point you make and the analogy with sugar is a is a is a very good one I mean these so it has been said that hypertension and cardiovascular diseases are diseases of civilization is the same with diseases of things like obesity so going from scarcity to plenty changes the physiology so I think the analogy with sugars a very good one salt has tended at least in recent years not to get the same type of play and so when healthy food options are marketed they've been marketed around sugars and facts but not necessarily around Salt the second part is actually quite interesting.
So the UK government set six grams a day in canada say about 2005 there was a big media story in the BBC about the fact that they the UK government which was Labor government regarded by the time and wanted to move the recommended limit down to about 5 grams in line with the world health organization but it was not going to be achievable without significant losses across the food industry that was the BBC coverage i can't comment on the actuality of it but i think what it does do is it gets you into the fact that this is a very complex area for e3e economics certainly you can see a very nice u-shaped relationship between cardiovascular risk and salt intake and we're so if you go onto a very very low salt diet that can have adverse effects for different reasons but we're way off that and i think there's still quite a lot of room to bring that upper limit down and what the UK government's targeting at the moment is a thirty percent reduction in our daily salt intake David if you have anything you would like to have them just just to say is there a few students here that the American big bad six nothing like push takeaway take away Carrie takeaway Chinese they're not regulated in the same way as supermarkets are and you can easily 10 grams in a portion.
Thank you very much for his daughter was really interesting in and also quite disturbing but a message to share the pictures yeah message that message taken i was wondering if you could provide and following up on the last question if you will provide a little background when did this intake of salt that we have right now started to happen I mean when did this trend actually took off for talking about 40 years or 15 years and and and what's happening you know what's happening on what what's ahead of us in terms of what will happen if we actually don't start this trend or what do you think it will end up.
Yeah okay so that is the question the question when did this start happening is so more difficult to answer but there are some data out there that suggests this is something that has been occurring only in the last safe forty fifty sixty years i think increasing amounts of salt intake so you go back and to some clinical data hundred years ago.
And the the salt outputs then were much lower than they are now but of course the ways the numbers of patients that would be measured was quite small so it's uncertain but i think you said i think is relatively recent and it's been driven by convenience foods and high food processing so a change in the way that we relate to the food that we eat so most of the time and I know in my life when you going into the supermarket's you're not making things from scratch so you're often on a way of things that you're putting together for dinner so you might have for example past with the past source that you haven't made the constituents of and this is something that didn't happen even with my parents and it certainly didn't have my grandparents so I think it's a relatively modern phenomenon the good news about is something we're becoming increasingly aware of it relating back to the topic about them sugar and obesity think generally will be becoming more aware of the things that we having high impact on our cardiovascular health where do we go from here this is my view that the burden is disproportionately distributed so it is a socio-economic component to this because one of the ways that food is driven to people that aren't quite so well office through value meals or essential ranges or whatever and these are the ranges which tend to behind sugar high in fat and high high insult.
So I think we're in a phase of the moment where there is more notice about it.
Things can be changed but the way it's changing is not evenly distributed across society and I remember actually David through the beach at David the back remember the the the at your annual awards day speaking to a group of people from Glasgow who had been talking about the availability of fresh food fruit stuffs within the region that they lived in in west of scotland and finding actually it was really difficult for people to access this kind of things because actually the local stores were no longer shot stocking them and to go to the larger supermarkets was an economic challenge so so i think that that's where we're out of them.
Thank you for the talk I'm just wondering how is salt beans become so cheap nowadays talk about it being such a valuable resource as latest 1944 tease but now obviously gets I killed our salt about two pounds is yeah it's actually actually I don't know the answer to that question i mean so when I when I look back I and I guess is locked up in the manufacturing process so when I when I look back at the descriptions of how salt was mined or dried out from marine seawater you're looking at a very labor-intensive small-scale operation and even your even persisting until the kind of the nineteen forties I i assume but don't know the answer that that it has just been part of a improve manufacturing process so that you scale up you automate so it doesn't become so person heavy and the price you get economies of scale and the price goes down but i don't know exactly hey yeah there's wondering what is a realistic amount of salt that you would have upper day that you would say and then the second question was would it be possible to not have any salt at all for a day and that affect your blood so to answer the first question I was hoping in the phase of the study that I was doing myself so I should tell you how we how I measure how you measure salt intake it's not really threw food diaries because these are very unreliable and unless you're in a situation where you can control exactly that the the food that was presented to an individual and ensure they eat all that food is very difficult to gauge what people are eating so what they want what is tended to be done is it is a urine collection so you collect your urine / 24-hour period several times and you measure how much salt is in that urine and that gives you a good indication of the amount of salt that you've ingested within a 24-hour period preceding that having done this over a period of myself over a period of several weeks i learned that it's quite weird thing to do because you have to go around with a big round pot full of pee look at work why do I think otherwise people would think I was we're talking a nice spot so anyway when I did that I of the study I was hoping that i will get down to 26 grams a day and I didn't so I would think that we should be able to get down to six grams a day but it is really really challenging we were giving up actually to do this study again and we think you're thinking of ways about being more interactive with our dietary advice just want to say thank you so much that was really good and I were confident occation and and my project is covering the whole country and would be very interested and perhaps if that's too much to ask now it would like to talk to you afterwards and see what your advice would be to employ include and awareness of salt in our diet for in children and education that actually that would be great because for me if I'm looking for somebody with your skills about how we doing that kind of stuff in two hours i'm already eating the sugar and actually might make Rangers quite broad but i haven't include specifically a salt that much and i would love to include I've that's ok perfect we can talk afterwards I can go and give you my contact details XO the second thing was i would like to give salt such a bad name because we also give him and also the aspect of food preservation so we also see children actually thanks to salt we managed to preserve food in history we didn't have fridge absolutely options that the only thing about them and the other thing that I struggle sometimes and I have a red discuss the Food Standards Scotland but and i'm still in a battle but i'm i'm i'm trying to find wasted to do this is food labeling basically as much as you said about salt and how hard it is to really prevent eating salt because of the heat assault and is the same with sugar but in the food labeling and the standard is for an adult honor 2,000 calories where was children a pin John the each group the salt intake should be less so let's say for 46 years old child we should be recommending actually perhaps three grams of salt no 6 which means if the in the label if we go for the traffic light where is amber for our child is already are red and it gets confusing for parents and i called and talked to fit sounds we need to do something about this and they sell too complicated we can't do that so I'm trying to engage with the universe together for Chris Griffin and try to convince them that parents could do with something around the city this is a yeah i'm absolutely in agreement with this I'm enlisted when we go back to the ninja and the stealth health and she's driven by exactly this is how how can you help parents to make the right choices for their children no no I'm really agreement that I understand a lot of us a lot of salt has idea added to it this is cut the incidence of disease later I d deficiency.
I just want a healthy balance the idea deficiency with salts with an excess salt or salt become a much greater problem now in a higher priority should be maybe adding I'd into something else is there a way to balance both i think so i think i would think that the you can balance both more easily i mean you you look at you look at this a movement of adding things like idea nor in America particularly adding vitamin complexes to milk so that there is this thing and all of this has profound health benefits so that you could either think of an alternative but some of the conversations had more recently is about changing the types of things that we use to flavor food with so maybe going away from purified salt we know about things like rock salt and sea salt etc etc but actually into all the flavorings that are more that they engaged the time in the brain in the same way that salt does but don't have the cardiovascular impact on map so i think you can achieve it and there is certainly within the food industry and a couple of conversations in that industry that I've had our people are actively looking at trying to answer that question is there any difference between salt in like reiterations or drinks and sorted food soon you want among over it was eerie forbid inter-affiliate ara and they always need to feel better but is there any result text out okay yeah so okay to a little bit of background without so when I was at Yale one of the people there one of the groups that had worked with developing one of the rehydration drinks and was funded through that and actually engages the physiological process so when you're engaged in high-intensity sport you're losing a lot of salt through sweat so it's actually about that's why you get your salt appetite when you're hungover the thing that alcohol does is it dehydrates you because you inhibit an enzyme in the brain that holds water in the body so you start to be a lot of salty water out and you get very dehydrated so this is the kind of physiology in action is that your you've had some perturbation to the system you become salt depleted and yours your body is seeking out to get that together outsole back in to your body is there any difference between one of these fluid drinks and out and all this other types of salt intake at base not really they tend to be sodium chloride they tend to be potassium this calcium and things in there and the only difference is about how you take them so if you drink these drinks without having a physiological need you're taking excess salt and excess calories so they own their design particularly to work in response to losing salts for exercise you actually saw the same when I was when I was a university works in the summer in in the steelworks and scandal on one of the jobs that you did there was is called furnish wrecking and you went inside and strip the blast furnace lining they turn the furnaces off but they were still massively massively hot and you could only work in therefore i think it was half an hour on half an hour off and they used to bring galvanized buckets of the saltiest orange juice that was a color not known to nature so kind of pre sports drinks essentially and it was all about replacing the soul that you lost you in the work so it's that's physiological salt replacement but without basis the same salt.
There's been a lot on the net but they're aforementioned Himalayan rock salt.
Well what they're actually saying is it's very good for your bones so and i give up eating solid food but now i bought some and I've started adding it to some meals so wondering why using that the access so gets into your bones and you sort of it's bad for your bones so now this is sort of completely conflicting advice that one's new yes i think so I so I guess to pass this i am aware of the Himalayan rock salt I haven't looked into this yeah yeah absolutely.
But there are lots of things like that appear and the scientific basis for that cannot often be the strongest in this case I don't know this is one thing I've just had my blood pressure taken it's absolutely perfect the doctor was really impressed with it so so there are two there again with two aspects of these and one of the things i was trying to get across in the talk is that the on a population level this reducing salt is a good thing on an individual level it will depend on your individual needs because there are people for example that have genetic disorders that make them lose salt from the body and they tend to have lower blood pressure and they tend to need to get a very strong salt appetite so overall reducing Salty's is for population has it will have a very good cardiovascular outcomes for the population on an individual basis it will depend on your underlying genetics and that's part of the things that we and other groups are trying to do to be able to say to individuals are you going to be assault loser or do you need to reduce your salt the Himalayan stuff I can't depend on what kind of salt you too.
Yes the soldiers it's a calcium so just say it might not be so troublesome exactly sodium salt is that sells its bathroom I think we should call it a day there.
Thank you very much like a will join them shortly.
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