Examination of Witnesses (Questions 169-179)
26 JUNE 2003
PROFESSOR SIR
GEORGE ALBERTI,
DR GEOF
RAYNER, PROFESSOR
JULIAN PETO,
PROFESSOR HUBERT
LACEY, PROFESSOR
JANE WARDLE
AND DR
TIM BARRETT
Chairman: Colleagues, could I welcome
you to this session of the Committee and welcome our witnesses.
Before we begin, could I welcome Paul Burstow, who is making his
debut at the Committee today: we are very pleased to see you here.
I think it is appropriate to pay tribute to your predecessor Sandra
Gidley, who was a first-class member of the Committee who was
responsible for initiating certain inquiries. We are very grateful
for her efforts. I am sure you will follow her lead in many ways.
We are very pleased to see you here.
Dr Taylor: May I add my comments. I appreciate
her work as a pharmacist. I think in government as a whole there
is a lack of professionals in positions of authority.
Chairman: Apart from lawyers, of course!
John Austin: And teachers.
Jim Dowd: Lawyers, lecturers and social
workers.
Q169 Chairman: Thank you. Could I
ask the witnesses briefly to introduce themselves to the Committee.
Dr Barrett: I am Dr Timothy Barrett.
I am a paediatrician at Birmingham Children's Hospital, responsible
for a clinic of about 350 children with diabetes and I am a senior
lecturer in the University of Birmingham doing research into diabetes
and genetics.
Dr Rayner: My name is Geof Rayner.
I am Chair of the UK Public Health Association but also representing
the Faculty of Public Health Royal College of Physicians.
Professor Peto: I am Julian Peto,
Head of Epidemiology at the Institute of Cancer Research and I
also have a part-time Chair at the London School of Hygiene and
Tropical Medicine.
Professor Lacey: My name is Hubert
Lacey. I am Professor of Psychiatry at St George's. I run the
St George's Eating Disorder Service. It is not only the largest
in the UK but probably the largest in the English speaking world.
It deals mainly with anorexia and bulimia nervosa—with a
small offshoot into obesity, because of lack of funding.
Professor Wardle: I am Jane Wardle.
I am Professor of Clinical Psychology in the Department of Epidemiology
and Public Health at University College and I am Director of Cancer
Research UK's Health Behaviour Unit there. As part of my role
there, I do research into obesity, including beginning to run
some treatment studies for paediatric obesity.
Professor Sir George Alberti:
I am George Alberti. I am emeritus Professor of Medicine, Newcastle,
and Senior Research Fellow at Imperial College. I am also the
Trolley Tsar—sorry, the National Director for Emergencies
Access, and President of the International Diabetes Federation.
I have worked in diabetes for the last several decades, and also
ran a very unsuccessful obesity clinic for many years!
Q170 Chairman: Obviously, from the
evidence we have had from a range of witnesses, the obesity problem
has been something that has been emerging for some considerable
time. Why has it taken so long for us to wake up politically to
address the issue?
Professor Sir George Alberti:
I suppose because it has insidiously crept in. My own experience,
talking to an ex-minister while she was a minister, is that she
did not want to know. She did not want to tell the public a very
simple thing: "Eat less." That did not seem to be a
great vote-catcher. Medically I think we have been enormously
unsuccessful at altering people's habits and it has just sort
of crept in. It is only as we have begun to see epidemics of the
consequential diseases that it has really begun to grab hold of
people.
Q171 Chairman: You are saying that
it is a politically difficult issue for governments to address.
Professor Sir George Alberti:
Yes.
Q172 Chairman: For the reasons you
gave.
Professor Sir George Alberti:
Yes.
Professor Lacey: I think there
is another clinical reason, Chairman, which is that as a group
clinically they are not liked: people do not find them attractive
to work with. They are often subject to stigma, not only from
the general population but also, to a degree, from professionals
too. I would agree with Professor Alberti, the other reason professionally
is that they are very difficult to respond to treatment.
Dr Rayner: I would add that I
think it is society looking at itself, really. We are talking
about basically the medical consequences. Obesity and super-obesity,
but overweight as well, these are consequences of changes in society.
We are actually very poor at recognising the powerful cultural
change that has happened in this country. And it is happening
worldwide. We are not talking just about a UK epidemic. All the
reasons that you have been presented with, from changes in dietary
patterns to the reduction of physical activity, these are big
changes in society. We need big explanations. When you have big
explanations which you cannot pinpoint exactly then it is very
difficult to see what you can do about it. What do we do about
it? If there was a magic pill or bullet or something, but there
is not, so we actually have to face up to these big cultural changes
and we do not have solutions. We call it a lifestyle illness or
lifestyle pattern which explains it, but actually it is our society
changing. How do we deal with that?
Professor Peto: In relation to
cancer, cancers tend to be studied individually because the causes
of different cancers tend to be different. Although it has been
known for a long time that breast cancer and endometrial cancer
are associated with obesity, it was not until quite recently,
when very large American cohort studies, particularly studies
of non-smokers, were done, that it was realised what a large contribution
overall cancer mortality was making to the effects of obesity,
that a whole range of cancers are actually affected. The risks
are not huge, and they only emerge in very large studies, but
in this particular one, a very large cohort study, it has emerged
quite suddenly that among non-smokers obesity was by far the largest
avoidable cause of cancer. Heart disease and diabetes obviously
have been recognised for a long time, but the realisation that
it was a major contribution to cancer has really only emerged
quite recently.
Q173 Chairman: We will obviously
talk about the public health sector later on and public health
steps that might be taken, but, looking back at how the trends
have emerged over the years, what ideally might have happened,
say, some years ago that could have prevented us being where we
are now? What should have happened and at what point? Who should
have been responsible for doing something?
Professor Sir George Alberti:
I think a massive public education programme—there is one,
it has got through to a few people, but I think it has never been
emphasised adequately—and tackling the food industry head
on.
Chairman: We will get into the specifics
later on, so perhaps we should not pursue that further.
Q174 Julia Drown: I want to ask Sir
George Alberti about diabetes in particular. Obviously we are
seeing huge increases in the number of people with diabetes. Could
you briefly outline to us what the evidence is on the role of
weight gain in diabetes and whether that is disputed or generally
accepted.
Professor Sir George Alberti:
Number 1, it is generally accepted. We have seen worldwide, in
a number of societies, a parallel increase in overweight, obesity
and diabetes. Just as an example, I have studied diabetes and
obesity in East Africa—as one does—and in the rural
areas there were less than 1% of people over the age of 15 with
diabetes and less than 2% overweight. Move into the city, and
we are up to 20-25% overweight and 8% diabetes: an eight-fold
increase. Some of the populations who have become wealthy very
rapidly, like the American Indians in Arizona, where they were
given the worst bit of land, as you know, oil wells were found,
so they became very wealthy, stopped working, became very overweight,
and half the adults in that population have diabetes. It is the
same on the South Sea island of Nauru, which was basically a large
coral reef of bird droppings, which was mined as fertiliser. Overnight,
in the fifties, it became the second richest country in the world
and the people are very overweight, life expectancy is falling,
and diabetes is the main accompaniment of that. You cannot separate
it completely from physical inactivity. Each of them, independently,
has a two-, three-, four-fold increase in risk. There was a very
good prospective study of nurses in the United States which showed
that, if your body mass index was 22 (that is, nice and skinny
like I am) and you compared yourself with those people with a
body mass index of 35 (which is pretty obese), there was a 92-fold
increase in risk of diabetes. I think it is very, very solid.
With the additional impact of physical activity, which is probably
equally important—or physical inactivity. Society is pushing
both physical inactivity and overeating as well, or eating the
wrong things.
Q175 Dr Taylor: Could we go back
to the links between obesity and cancer, really to Professor Peto—and
I must say that the paper we have had from Cancer Research—which
is precisely one side of a sheet of paper—is absolutely
splendid because it is the sort of length that we can actually
digest. This does tell us that about one in eight of cancer deaths
in non-smokers is due to being overweight or obese, so it is a
real problem. It also goes on,"... the link between obesity
and cancer has been poorly acknowledged." Could you give
us any idea of the mechanisms of this link? Is that a possible
question or just not known?
Professor Peto: One straightforward
one is that there is a correlation between obesity and circulating
levels of things that are associated with cancer risk. I mean,
hormones—oestrogen, particularly in post-menopausal women,
which certainly would contribute to breast and cancer of the uterus.
Insulin, of course, in relation to diabetes. What its relation
to cancer is, I do not know, but IGF-1 (insulin-like growth-factor
type 1) is emerging as an important circulating correlate of cancer
risk for a whole range of cancers. That is correlated with obesity.
So there are endogenous processes associated with obesity which
certainly correlate with cancer risk in the general population.
In relation to oesophageal cancer, which is quite an important
cancer, there is gastro-oesophageal reflux which is likely to
increase the risk of oesophageal cancer. Cancer of the gall bladder
is trivial, but gall stones are associated with obesity and with
cancer, so in that particular site there is a plausible mechanism.
We are talking about cancer mortality not incidence and the relationship
with obesity seems to be stronger with the death rate than with
the incidence rate. The reason for that is probably that very
obese people are diagnosed late. Whether or not, once the cancer
is there, obesity has any effect on the course of the cancer is
not known, but they are certainly likely to be diagnosed late—there
is direct evidence of that—and, once you have got cancer,
you are more likely to die of it if you are obese because you
are diagnosed at a more advanced stage.
Q176 Dr Taylor: That brings us back,
I think, to the point Professor Lacey raised, that doctors as
a whole probably are less interested in the really obese and they
are more difficult to examine.
Professor Peto: I think they are
more difficult to examine. I do not think doctors do not examine
them because they are not interested in them, I think that would
be going a bit far. But, I mean, you are a doctor, there is .
. .
Q177 Dr Taylor: Yes.
Professor Peto: There is one other
point which may not be negligible: excess energy. First of all,
increased body size. One might expect it to be associated with
cancer on arm-waving grounds: cancer originates in a single cell;
if there are more cells dividing more quickly, you might expect
the cancer rate to be increased. That is an arm-waving argument.
It probably has some validity. Of course, in relation to colon
or rectal cancer, it is pretty obvious that the chemistry of stools
is affected by what you eat and whether you overeat. Again, there
is an arm-waving argument. The explanations range from being really
rather specific and well-established, to being speculative and
plausible. But they are scientifically reasonable.
Q178 Dr Taylor: So you have mentioned
the breast, endometrial cancer, oesophageal cancer, colonic cancer.
Other cancers?
Professor Peto: Cancer of the
oesophagus, you mentioned that. That is an important one. I do
not know whether the insulin relationship has anything to do with
the pancreas, but pancreatic cancer has emerged consistently in
studies as being linked to obesity. The one important cancer where
the evidence is, I suppose, dubious and I think it is probably
more likely to be due to survival than incidence, is prostate
cancer. There is a significant link with prostate cancer in a
big American study, but it is not clear whether that is ... That
is not as marked as the other ones, although it is statistically
significant. It remains to be seen whether that is a real effect.
Q179 Dr Taylor: Is the link generally
with obesity or is there any link with people who suddenly put
on a vast amount of weight?
Professor Peto: The data on that
are really inadequate. It is not known. There is not very good
evidence that losing weight rapidly reduces the cancer risk. I
mean, that is irrelevant from a public health—
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