Examination of Witnesses (Questions 89
- 99)
TUESDAY 2 NOVEMBER 2004
PROFESSOR JOHN
MATHERS, DR
FRANS VAN
DER OUDERAA
AND PROFESSOR
ELIZABETH KAY
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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