Select Committee on Science and Technology Minutes of Evidence

Examination of Witnesses (Questions 89 - 99)



  Q89  Chairman: May I welcome you very warmly indeed to this Committee. As you know the topic is the scientific aspects of ageing. What we would like to do is to give you the chance to say the sorts of things you want to say but equally we will do that significantly by asking questions and we will move around the table quite a bit. If you feel there is any point where we have not been pressing where we ought to have pressed and you want to add or extend the question, please feel free to do so. Equally if after the session you wanted to amplify any point or send any further information in or comment in in writing or e-mail we would be very happy to receive that. The members of the Committee round the table have name tags in front of them so I will not take time to go round. I suspect you know Professor Kirkwood who is our scientific adviser. The first question, a fairly general starting point and an opportunity for each of you perhaps to introduce one of the main themes that you might wish to push, has to do with the effect of nutrition on health throughout one's life, and I wondered if you would like to expand a little bit on what particular aspects of nutrition you consider especially important with regard to its impact on the ageing process. For example, supposing you were to be weighing it against genetic factors, is it 100/0 or 50/50? Do you have any estimate on that with which you can help the Committee?

  Professor Mathers: Nutrition can affect the function of cells and tissues at any stage in life and I think we are looking at ageing as part of a continuum. It is difficult to put a precise figure on what contribution a single factor might make. Clearly if you look at something like length of life, nutrition makes a contribution as does genetics and I think the best estimates are that genetics contributes about 25 per cent of the variability in longevity so non-genetic factors make up the rest of it. Nutrition and other aspects of lifestyle will contribute to that.

  Professor Kay: Nutrition has a double effect with oral health and we are very grateful that oral health is being included in the remit of this Committee; very grateful indeed. First of all, life time nutrition affects how your oral health turns out when you are elderly and it is mostly exposure to sugar and exposure to fluoride that will affect the amount of dental decay that you end up with. The amount of dental decay you end up with will affect whether you have teeth in your elderly years and at that point, when you have lost a significant number of teeth, it then affects what you are able to eat. Specifically it reduces the amount of vitamin C that people consume and the amount of fruit and vegetables they consume, and all the knock-on effects that that might have.

  Dr van der Ouderaa: Nutrition is obviously a very important factor in the context of people's ageing trajectories and everybody has a trajectory which is defined by genes, by lifestyle, by behaviour and by the environment. As Professor Mathers indicated, about 25 per cent of people's ageing trajectory is in principle defined by the genes. However, that is malleable and it is dependent on lifestyle and nutritional behaviour. There is very strong data from epidemiology and in particular the excellent EPIC-Norfolk study by the University of Cambridge which shows that high fruit and vegetable nutrition reduced the prevalence of disease by up to 50 per cent for cardiovascular disease and a similar percentage for mortality in the period of eight years that the two studies were done. There is a similar study done by the EU called the Senega Study which was done in the 1990's which shows that the combination of lifestyle and nutrition for an optimum nutrition and lifestyle person versus a non-optimum lifestyle nutrition makes about an eight to nine year difference. So you can extend healthy ageing by the right lifestyle and the right nutrition by that sort of period, which is over life quite a significant number. However, on the other extreme, if you have someone who chain smokes, has a sedentary life and has high stress shift work, then a couple of pieces of broccoli and two oranges are not going to save this person. You have to look at all these things in the context of the whole picture of lifestyle and environment.

  Q90  Chairman: Can I ask a supplementary that has two elements to it? One is, generally, how strong is the evidence that you would bring to bear on the nutritional impact? But a particular aspect of that, it was stressed that ageing is an extensive process and it may well start on day one of one's life, what about the evidence of early nutrition and childhood nutrition which is not easily available for those reaching mature years?

  Professor Mathers: That is a very interesting area and there is very active research going on at the moment. There is a lot of evidence that early life nutrition—that is nutrition in the womb as well as nutrition in the first year of life—can affect diseases of middle age and later life and that evidence is really quite strong. However, it does not preclude the effect of nutrition at later stages and I think we should be concerned with nutrition from conception all the way through.

  Dr van der Ouderaa: There is brilliant work done by Professor Barker at Southampton which states that even before conception, at the time of conception and the whole life of the foetus and then infancy, that period is extremely important from a nutrition point of view. Malnutrition at that stage will relate to higher rates of diabetes, blood pressure and cardiovascular disease in later life. In low birth weight babies the growth trajectory in infancy is extremely important to change the perspective so if a low birth weight baby grows very quickly the chances of getting a disease in later life of a coronary or vascular nature are much higher than in the low birth weight baby who gains weight very slowly. The environmental factors are extremely important and the nutrition in this particular case, at the very early age is extremely important and is well documented by British groups.

  Q91  Chairman: Longitudinal evidence is available on this because clearly if we were to see the whole cycle you are talking about events of 70 or 80 years ago.

  Professor Mathers: That is really part of the problem with this hypothesis, that most of what we have are cross-sectional data. We have data on birth weights or weights at age one and so forth and then we have information on people in middle age or later. The data that follow individuals from birth all the way through are rather sparse and in fact most of them are being conducted in India by the Southampton Group and they have some very nice studies there following people from birth and looking at their nutrition. Currently with MRC funding they have undertaken a nutrition intervention study in that setting.

  Professor Kay: In terms of oral health the evidence is extremely strong, that what you eat and your exposure to sugar throughout life affects your oral health. That is not randomised controlled trial data obviously, it is ecological data but it certainly meets the criteria of the causality, and that is the nature of the disease.

  Q92  Lord Drayson: What is the role of the food industry in addressing the links between nutrition and healthy ageing? How much interest is there in developing functional foods, for example? Or foods particularly targeted at the more elderly section of the population?

  Dr van der Ouderaa: This is a very complex area. In the first instance because it is not very clear what precisely the market is so we have done a fair amount of market research and there is a great deal of difference between people of 50 to 65, 65 to 75 and 75 to 90 from a needs point of view but also from a communication point of view. One of the most important things for us as a company is to understand how you communicate with people who are older, because the one thing you do not want to tell them and they do not want to hear from you is that they are elderly people. Then we have done as a company a fair amount of research on functional foods which is quite successful and one of the key examples is, for instance, the recent addition of phytosterols to margarines and to yoghurts which in principle gives a 10 per cent lowering of cholesterol levels. It does not sound much but in actual fact it is quite a significant effect. If you were to apply this to the whole of the British population between 30 and 74 you would have a 10 year time scale reduction of cardiovascular death by a quarter of a million people. The key thing that one needs to understand about foods is that since the whole population takes foods every day, the effect of small effects of the foods—which are smaller effects than from drugs—is, on a population basis, quite a big effect. Another important thing is to make sure that we take out the negatives so, for instance, our company has taken the lead in removal of trans-fatty acids from saturated fat and reducing saturated fat per se which again is a cardiovascular benefit measure. As an industry and as a company in particular we are also busy reducing the salt levels. That is a little bit tricky because if you do it too quickly that affects the acceptability of products and then there is no point in it. There is a fair amount of work in the context of the oxidative damage theory of ageing; we are looking into the effect of flavonols and anti-oxidants. There is evidence, for instance from the EPIC Study, that high levels of fruit and vegetables have this quite extensive benefit. How to communicate this to the population is quite a difficult issue which I do not think the industry as a whole has cracked yet.

  Professor Mathers: From the perspective of academic research there has been a lot of interest in potential benefits of functional foods and one of the things that has troubled people is getting real evidence of efficacy alongside evidence of safety. I think that is coming and it may be stimulated by EU legislation around food labelling which I understand is on its way. But related to that is an issue around inequalities because in all probability such foods are likely to be more expensive than the standard foods so the people who are likely to benefit are the people who are least in need, perhaps, of those special foods.

  Q93  Lord Turnberg: There has been quite a lot of interest in folic acid supplementation in the belief that it reduces the incidences of coronary artery disease. What is your view on this?

  Professor Mathers: The best evidence of course of folic acid is in the prevention of neural tube defects, and that is where there are really good randomised controlled trials. There is supportive evidence for the idea that folic might protect against cardiovascular disease but the trials are not yet finished; there are trials on the way to try to prove that. There is no doubt that raised homocysteine concentrations is an independent risk factor for heart disease and folate may lower homocysteine and therefore lower risk of CVD. However, until we have the RCT trials finished we will not know.

  Dr van der Ouderaa: There is quite interesting data from the Nun's Study from the Mid-West United States carried out by Professor David Snowdon that there is a relationship between folic acid in the serum and dementia risk. You could post-rationalise this from the point of view that folic acid reduces homocysteine in people who have a specific genetic permutation in the folate reductase enzyme and because of the lowering of the cardiovascular risk you get the additional dementia risk. This is found in nuns of relatively high age, of 95-plus.

  Q94  Lord May of Oxford: I have a question which is inherent in the question we are asking—what is the role of the food industry in addressing the links between nutrition?—Not wishing to be cynical, I would have thought that the role of the food industry was selling food and that would explain the fact that it is relatively hard (although it is slowly changing) to get low salt versions of various things on the grounds that people on the whole are more inclined to buy things with salt in them. I would like to go back more to the root of the question and ask you to what extent do you feel the food industry should be held responsible for having a degree of interest in healthy foods as distinct from simply selling it?

  Dr van der Ouderaa: I think we have a great responsibility to help with the health of the nation. In Unilever this goes back to William Hesketh Lever in the 1890's—he was a salesman of bars of soap—saying that his vision was to contribute to the health of the people and I think that vision is still within the company. In the first instance our role is precisely as you say, to make sure that we give people safe, healthy foods from a microbiological point of view and foods that are nutritious so that you avoid deficiencies, in particular vitamin deficiencies.

  Q95  Lord May of Oxford: The majority of things on the supermarket shelves have added salt. That is not done for nutritional reasons surely. It may, in fact, be anti-nutritional reasons; it is done for other reasons. I am not even criticising it necessarily because your aim is to sell the things people want to buy which are not necessarily the same things that are healthy. I would have thought it was possible to defend the view that because the food industry—demonstrably, in my view—does not take a primary responsibility in delivering nutritious food, you really have to defend the indefensible or say that it is not true at all.

  Dr van der Ouderaa: The food industry as a whole is trying to lower salt levels; I am not sure if I am defending the indefensible but I do think they have a responsibility.

  Professor Kay: Could I just add that exactly the same argument applies to sugar.

  Professor Mathers: From my perspective I do think that the food industry does need to do more about reducing salt intakes. There are just some practical issues about how to do it.

  Q96  Lord Soulsby of Swaffham Prior: What is the role of the British Dental Association and of oral health practitioners and related industries in this issue?

  Professor Kay: The British Dental Association is the professional association and trade union of dentists in this country. Amongst its missions is promoting the oral health of the population, hence our presence here. We are not a research organisation but we do link, as far as we can, with oral health promoting industries who sell products that promote oral health. We link with them as much as we can in order to try to raise the profile of oral health. Unfortunately, although it has such a profound effect on the psycho-social welfare—particularly of the elderly who have poor oral health—it tends to be a poor relation in terms of the notice the public take and the research funding.

  Q97  Lord Soulsby of Swaffham Prior: I can anticipate that you do not undertake research but do you promote it? Do you made representations to government to say that this is an area that must be looked into and areas like that?

  Professor Kay: The BDA are very strongly supportive of evidence-based practice because obviously the advice we can give to our members is as a results of the research that is going on. We also like to take that the other way, in that we feel quite profoundly that it is the actual carers of people—the people who are trying to deal with the very difficult problems in the very elderly population and their dentition—who should be leading the research agendas. So it is their questions, the difficulties that they face, that should be telling us where we ought to be going with the research that is going on out there.

  Q98  Lord Soulsby of Swaffham Prior: Is there any burning question that the British Dental Association has that the Government should do something about?

  Professor Kay: Last year we published a report on Oral Healthcare for Older People which may be of interest to this Committee because it is one the key policy issues that we are interested in. Please stop me if I am going too deeply into this but there is a big issue at the moment because the very elderly come from a population in whom, around 1948, it was common to have all your teeth removed at the age of 20, 25 or when you got married. So we have a population of very elderly who have worn dentures for 50 or so years and they are technically extremely difficult to treat because the bone resorbs and it is very difficult to provide dentures. The next cohort is a highly diseased population that have had a lot of dentistry available to them so they have very highly restored mouths, and very complex restorative problems towards the end of life. The difficulty with that group is that we have to keep restoring those dentitions because at 75, 80 and 85 you simply cannot adapt to suddenly have no teeth and using a denture. At 21 you can do it, but it is a very, very difficult problem for the elderly. We have a cohort coming up who are going to need quite intensive restorative care to keep them going into old age.

  Q99  Chairman: Does the Association have any evidence one way or the other on whether the evident shortage of dentists in certain parts of the country who will provide effectively free health care is causing a disproportionate problem for old people because on the whole they are poorer—whatever bracket of income—than their younger peers so is this a special problem?

  Professor Kay: The older elderly—if I can call them that—have had dentures for a long time. That goes with negative attitudes towards oral health and if you have no teeth you do not feel the need for dentistry. They are very typically non-attenders because they have no perceived need. You can accept that as, "Oh, good, we don't have to provide treatment for them" or feel that this is a very vulnerable group who need to be looked after. There are risks of oral cancer et cetera so they should be screened, but by nature of their age and mobility they would find probably find access to a dentist difficult. Their treatment costs would not be high. The next group—the next cohort down, if you like—the pre-elderly or the young old, their treatment costs are likely to be high as they go into old age, probably beyond a state pension.

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