Are we really dying for a tan?
BMJ 1999; 319 doi: https://doi.org/10.1136/bmj.319.7202.114 (Published 10 July 1999) Cite this as: BMJ 1999;319:114
All rapid responses
Dear Sir
We note with interest the article by Ness et al (1) on the risks and
benefits of sunlight exposure, which will also influence cutaneous vitamin
D production.
Epidemiological evidence links an increased incidence of common
cancers, such as breast, colon and prostate, with decreased sunlight
exposure. The influence of vitamin D, retarding cancer progression, is
given weight by numerous studies in vitro and in animal models, which have
shown inhibition of cancer cell growth, angiogenesis and metastasis (2).
Phase I and II trials of vitamin D analogues in the common cancers are
underway.
There is increasing evidence, too, that vitamin D deficiency may
predispose to insulin resistance and therefore increase the risk of
vascular disease (3).
However, increased exposure to sunlight is not without its hazards.
Some of the benefits of vitamin D, without the potential risks of sunlight
exposure, might be gained through a policy of dietary supplementation. In
order to answer the question of whether vitamin D supplementation is of
benefit, we are recruiting participants to a large, randomised controlled
trial of calcium and/or vitamin D in the secondary prevention of
osteoporotic fractures. Six thousand five hundred participants, 70 years
of age and over, are being recruited from 15 centres throughout the UK
over two years. The RECORD trial is funded by the Medical Research
Council. We are using this trial not only to test for the prevention of
fractures, but also to examine further hypotheses relating to vitamin D,
and by implication sunlight exposure in the form of ultraviolet B
irradiation.
Thus, we are using the UK cancer registry to examine whether vitamin
D, given in the RECORD trial, influences cancer presentation.
Additionally, we are collecting information on the development and
progression of diabetes in participants in the RECORD trial. We are also
examining death certificates for cardiovascular and cerebrovascular
disease.
The large size of the RECORD trial allows us to examine these
additional hypotheses, in the age group which is most affected by cancer,
vascular disease and vitamin D deficiency. The recent National diet and
nutrition survey of people aged over 65y (4) has clearly shown that food
sources contribute only 38-41% of the reference nutrient intake in this
age group, which only serves to emphasise the important contribution made
from sunlight. Hence in 2003, when the RECORD trial is completed, we
should have answers and insights to many of these important public health
issues.
Yours sincerely
Alison Avenell for the RECORD trial
MRC Training Fellow in Health Services Research
Health Services Research Unit
University of Aberdeen
Foresterhill
Aberdeen AB25 2ZD
a.avenell@abdn.ac.uk
The RECORD Project Management Group comprises: FH Anderson,
Southampton General Hospital; MK Campbell, Health Services Research Unit,
University of Aberdeen; C Cooper, MRC Environmental Epidemiology Unit,
Southampton General Hospital; C Donaldson, Departments of Economics and
Community Health Sciences, University of Calgary, Canada; RM Francis,
Freeman Hospital, Newcastle upon Tyne; W Gillespie, Dunedin School of
Medicine, New Zealand; A Grant, Health Services Research Unit, University
of Aberdeen; CM Robinson, Royal Infirmary of Edinburgh; DJ Torgerson,
Centre for Health Economics, University of York; A Wallace, Queen’s
Medical Centre, Nottingham.
1. Ness AR, Frankel SJ, Gunnell DJ, Davey Smith G. Are we really
dying for a tan? BMJ 1999; 319: 114-6.
2. van Leeuwen JP, Pols HA. Vitamin D: anticancer and
differentiation. In: Feldman D, Glorieux FH, Pike JW, editors. Vitamin D.
San Diego: Academic Press; 1997. p. 1089-105.
3. Boucher BJ. Inadequate vitamin D status: does it contribute to the
disorders comprising syndrome ‘X’? Br J Nutr 1998; 79: 315-27.
4. Finch S, Doyle W, Lowe C, Bates CJ, Prentice A, Smithers G et al.
National diet and nutrition survey: people aged 65 years and over. Volume
1: report of the diet and nutrition survey. London: The Stationery Office;
1998.
Competing interests: No competing interests
RE "Are we really dying for a tan?"
Editor - The provision of the advice that sunburn should be avoided,
as a proven factor increasing the incidence of avoidable skin cancers of
especial virulence, is not in question.
What we should be questioning is
whether avoidance of undue exposure to sunlight, upon which we in this
country largely depend for our vitamin D,together with the provision of
advice on the avoidance of an excessive intake of fat,i.e. of just the
foods that contain vitamin D, might be increasing the risk of vitamin D
insufficiency and of the many health problems associated with that
condition. Indeed many groups in the western world continue to develop
vitamin D insufficiency including children, Asians and the elderly 1-3
Since vitamin D does more than protect the bones and such deficiency is
avoidable it is important to define these risks. For example unborn babies
grow less well in the presence of maternal vitamin D deficiency4,5 and
insulin secretion is reduced in response to oral glucose; glucose
intolerance and diabetes can then develop, both being known to be increase
the risk of ischaemic heart disease (IHD) which would contribute further
to the postulated direct increases in risk of ischaemic heart disease
reviewed by the authors.6,7 Vitamin D also promotes a healthy immune
defence system and reduces the risks of infections such as tuberculosis.8
Recent advice on sensible and healthy eating suggests that no more than 5
eggs should be eaten per week and that all of us, and especially those
with raised lipids (even a minor degree at screening), should reduce
overall fat intake. Such advice generally applies to vitamin D
supplemented poly- and mono - unsaturated fat spreads as well as to animal
fats. Advice that one should 'eat more fish' does not always specify oily
fish and not every dietary advisor is aware that some oily fish, such as
the Atlantic salmon, are a poor source of vitamin D. Vitamin fortified
cereals are becoming available but few, and certainly not the cheaper
ones, contain added vitamin D. Milk is a poor source of this vitamin and
the use of skimmed or semi-skimmed reduces vitamin D content still further
whilst milk fortified with vitamin D is not widely available in the UK. It
would seem desirable, therefore, to ensure that the public is informed on
how best to maintain an adequate intake of vitamin D within the diet. The
implication of the above paper must be that work to determine the cost
benefits of such dietary advice would be both appropriate and timely. This
is especially important whilst there are as yet no ways to ensure adequate
exposure rates to sunshine which can be said to be 'safe' for the skin
though the development of cheap, accurate and user-friendly UVA/B metering
devices for general use will be helpful. 9,10 We as a community, and our
Health Service research funding bodies and 'professionals', should not
allow these matters to be neglected simply because of the outcry from
those who rightly fear a return to an uninformed approach to the risks of
exposure to sunlight.
1 Wharton BA. Low plasma vitamin D in Asian toddlers in Britain; if
in doubt give vitamins; consider iron too, and remember other vulnerable
children Brit Med J. 1999;318:2-3
2. Solanki T, Hyatt RH, Kemm JR, Hughes EA, Cowan RA. Are elderly Asians
in Britain at a high risk of vitamin D deficiency and osteomalacia? Age,
Ageing 1995;24(2):103-107
3. van der Wielen RP, Lowik MR, van den Berg H, de Groot LC, Haller J,
Moreiras O, van Staveren WQA. Serum vitamin D concentrations among
elderly people in Europe. Lancet 1995;346:207-210
4. Marya RK, Rathee S, Lata V, Mudgel S Effects of vitaminD
supplementation in pregnancy Gynaec & Obst Invest 1981;12(3):155-161
5. Maxwell JD, Ang L, Brooke OG, Binn R Vitamin D supplementation enhances
weight gain and nutritional status in pregnant women Br J Obst & Gyn
1981;88(1):987-991
6. Boucher BJ, Inadequate vitamin D status: does it contribute to the
disorders comprising syndrome 'X'? Brit J Nut 1998; 315-327
7. Boucher BJ, Mannan N, Noonan K, Hales CN, Evans SJW Glucose intolerance
and impairment of insulin secretion in relation to vitamin D deficiency in
east London Asians Diabetologia 1995;38(10):1239-1445
8. Douglas AS, Strachan DP, Maxwell JD Seasonality of tuberculosis: the
reverse of other respiratory diseases in the UK. Thorax 1996:944-946
9.Munakata N, Ono M, Watanabe S. Monitoring of solar-UV exposure
among schoolchildren in five Japanese cities using spore dosimeter and UV-
coloring labels. Jpn J Cancer Res 1998;89(3):235-245
10. Knutshke P, Barth J. Bilogically weighted personal UV dosimetry. J
Photochem Photobiol B. 1996;36(1):77-83
Competing interests: No competing interests
We were interested to read the comments of Ness and his colleagues
questioning the acceptance of sunlight as being bad for health (1). The
criticism of the article which has followed in the lay press underlines
how the authors have dared to question one of the axiomatic tenets of
modern preventive medicine: that sunlight exposure is one of the major
avoidable causes of cancer and should be ranked alongside cigarette
smoking in the demonology of medicine. It is therefore surprising that
the authors did not consider the evidence that, far from causing cancer,
sunlight exposure might actually be a potent agent for its prevention.
Several studies have examined the relationship between sunlight
exposure and internal malignancy. Several of these give sufficient
information to allow the effect of changing sunlight exposure on the
expected rate of malignancy to be estimated. All the studies demonstrate
a negative relationship of similar magnitude (table), particularly for
breast and colon cancer.
___________________________________________________________
Author Site Country Change in incidence
for 10% decrease
in sunlight at
mean exposure
___________________________________________________________
Garland, 1980 (2) Colon USA +12%
Garland, 1990 (3) Breast USA +6%
Gorham, 1990 (4) Breast USSR +10%
Emerson, 1992 (5) Colon USA +7%
___________________________________________________________
In 1995 there were approximately 30 000 new cases each of breast and
large bowel cancer in the UK and about 30 000 deaths from the two tumours
combined. Taking the most conservative of the above estimates from these
studies would suggest that a 10% decrease in sunlight exposure might lead
to a 6% increase in these figures. This would approximate to 1 800 extra
cases of each of the tumours and 1 800 extra cancer deaths. This latter
figure exceeds the total number of deaths due to malignant melanoma, which
are unlikely to be totally prevented by such a modest reduction in
sunlight exposure.
Thus, it can be seen that reduced exposure to solar radiation far
from preventing cancer may have the opposite effect. Further research is
urgently needed to determine whether this is the case. If this is
confirmed it will be necessary to determine what aspect of sunlight
protects against cancer. Vitamin D or its metabolites may play an
important role in this, offering hope for a strategy of moderating
sunlight exposure to minimise the risk of skin cancer but replacing
vitamin D to prevent internal malignancy.
Peter L Selby
Lecturer in Medicine, Honorary Consultant Physician
E Barbara Mawer
Professor
Department of Medicine
Manchester Royal Infirmary
Oxford Road
Manchester
M13 9WL
1. Ness AR, Frankel SJ, Gunnell DJ, Smith GD. Are we really dying for
a tan? BMJ 1999;319:114-6
2. Garland CF, Garland FC. Do sunlight and vitamin D reduce the likelihood
of colon cancer. Int J Epidemiol 1980;9:227-231
3. Garland FC, Garland CF, Gorham ED, Young JF. Geographic variation in
breast cancer mortality in the United States: A hypothesis involving
exposure to solar radiation. Prev Med 1990;19:614-22
4. Gorham ED, Garland FC, Garland CF. Sunlight and breast cancer incidence
in the USSR. Int J Epidemiol 1990;19:820-824
5. Emerson JC, Weiss NS. Colorectal cancer and solar radiation. Cancer
causes and control. 1992;3:95-99
Competing interests: ___________________________________________________________Author Site Country Change in incidence for 10% decrease in sunlight at mean exposure___________________________________________________________Garland, 1980 (2) Colon USA +12%Garland, 1990 (3) Breast USA +6%Gorham, 1990 (4) Breast USSR +10%Emerson, 1992 (5) Colon USA +7%___________________________________________________________
Editor - 'Health educators should weigh up explicitly the potential
risks and benefits of reduced exposure to sunlight.¹ One of the
important benefits is synthesis of vitamin D in the skin - the principal
source of this vitamin, which is essential to bone health.
There are at present 60 000 cases of fractured femur each year in the
UK, with an early mortality rate of 25%. The mortality rate of femoral
fracture rate is about 15 000 per annum. In contrast, the mortality
attributed to malignant melanoma in 1995 was less than 1500. Although
vitamin D is less readily synthesised in elderly people, particularly in
northern latitudes, there is nevertheless some advantage in exposing the
skin to ultraviolet light. Recent research has shown that the use of
sunscreen may reduce but does not abolish this effect²,³.
It is essential to communicate to patients and health educators the
potential advantages of exposure to sunlight.
Jean Coope
Retired general practitioner
Bollington
Macclesfield
Cheshire
1 Ness A R, Frankel S J, Gunnell D J, Smith G D. Are we really dying
for a tan? BMJ 1999; 319: 114 - 6.
2 Marks R, Foley P A, Jolley D et al. The effect of regular
sunscreen use on vitamin D levels in an Australian population: results of
a randomised control trial.
Arch-Dermatol 1995; 131(11): 1337 - 9.
3 Farrerons J, Barnadas M, Rodríguez J et al. Clinically prescribed
sunscreen (sun protection factor 15) does not decrease serum vitamin D
concentration sufficiently either to induce changes in parathyroid
function or in metabolic markers. BJDerm 1998; 139: 422 - 7.
Competing interests: No competing interests
Ness et al(1) have performed a valuable service in challenging
preconceptions. Their assessment, though, of the balance of risks and
benefits associated with sun exposure does somewhat understate the latter.
There is evidence, for example, that regular sun exposure is associated
with reductions in mortality from internal cancers(2), and conversely that
sunlight deprivation is associated with an increase in incidence of cancer
of the breast, colon and prostate. A prospective study(3) of nearly two
thousand men in Chicago found a 50% reduction in the incidence of
colorectal cancer associated with an increased dietary intake of vitamin
D, but generally sunlight activation is the most potent source of vitamin
D.
The effects of vitamin D on cancer incidence and mortality may be
attributable to vitamin D3 derivatives such as 1,25-dihydroxyvitamin D3,
which induces differentiation of neoplastic cells and impedes their
proliferation. Similarly, vitamin D metabolites have induced
differentiation of leukaemia and lymphoma cells, and brought about
remissions in lymphoma patients with high levels in tumour tissues of
vitamin D metabolite receptors.
As Ness et al. indicate, the nature of the association between
sunlight and the development of malignant melanoma is complex.
Intermittent, intensive sun exposure for short periods is clearly
associated with increased risk, particularly for light-skinned people, and
in Australia sunburn before the age of 10 is well established as a risk
factor for melanoma later in life, but regular outdoor occupational
exposure is associated with a decreased risk of melanoma(4).
The risk of contracting melanoma in areas such as Queensland, with
the world’s highest reported incidence rates, is much higher among the
middle class population whose sunlight exposure is largely confined to
relatively brief holiday periods, than among those such as agricultural
workers who sustain high levels of natural sun exposure over prolonged
periods. The risks among the former group may be compounded by the use of
sunbeds and sunlamps, the use of which is known to be major risk factor
for melanoma(5).
It is thus not sunlight per se which constitutes the major risk
factor for melanoma, but unwise exposure following the unnatural life
style practices that all too often precede it.
References
1) Ness AR, Frankel SJ, Gunnell DJ, Davey Smith G. Are we really
dying for a tan? BMJ 1999; 319: 114-116.
2) Ainsleigh HG. Beneficial effects of sun exposure on cancer mortality.
Preventive Medicine 1993; 22(1): 132-40.
3) Garland CF. Garland FC. Gorham ED. Can colon cancer incidence and
death rates be reduced with calcium and vitamin D?. American Journal of
Clinical Nutrition 1991; 54(1 Suppl): 193S-201S.
4) Elwood JM. Melanoma and sun exposure: contrasts between intermittent
and chronic exposure. World Journal of Surgery 1992; 16(2): 157-65.
5) Armstrong BK. Kricker A. Skin cancer. Dermatologic Clinics 1995;
13(3): 583-94.
Competing interests: No competing interests
Letter To BMJ In Reply To 'Are We Really Dying For A Tan?' Ness Et Al 10th July 1999
Debating the content of health education messages, the scientific evidence on which they are based, and their likely effects, both bad and good, is important provided that the debate is constructive and based on a sound literature review. Unfortunately the article by Ness et al 1 et al inadequately addresses the debate about sun protection.
The article opens with the statement that certain professionals embrace the notion that 'sunlight is bad for health'' implying that the message has been to avoid sun exposure. This mis-represents the advice given which includes 'avoiding excessive sun exposure' and 'encouraging gradual sun exposure' 2.
No short article can do justice to the extensive research, both epidemiological and experimental, into the role of ultra-violet radiation (UVR) exposure in the aetiology of skin cancer. The limitations and uncertainties about our understanding of the problem have been the subject of international, inter-disciplinary debate. The dilemma facing those who wish to prevent extensive morbidity from skin cancer, and rising mortality from melanoma, is that effective primary prevention may take 20 years or more to reduce the incidence of disease. As for the prevention of other diseases, there has been much pressure to promote life style and dietary changes.
The authors suggest that early detection and treatment may be more beneficial than primary prevention to reduce melanoma mortality, but in countries with a low incidence of melanoma we have yet to agree on a cost-effective strategy for early detection3 4. Nor do the authors address the psychological and financial costs of diagnosis and treatment.
Primary prevention undoubtedly bring costs as well as benefits, no differently than for other prevention strategies. However, there is insufficient evidence at this stage for Ness et al2 to suggest that recommendations on sun exposure should be promoted to prevent one disease at the expense of another. It may well be that greater understanding of the problem will enable advice development of recommendations on sun exposure that can benefit more than one condition.
It is essential that people should have the opportunity to make a fully informed choices about their life styles, and decisions on prevention based on the best available evidence. While the paper raises important questions about how best to prevent skin cancer, from an epidemiological view point the paper is disappointing because it has not adequately reviewed all the health issues and because it has misrepresented at least two papers2 5.
JANE MELIA
Cancer Screening Evaluation Unit,
Institute of Cancer Research
15 Cotswold Road
Sutton
Surrey SM2 5NG
References
1. Ness AR, Frankel SJ, Gunnell DJ, Davey Smith G. Are we really dying for a tan? BMJ 1999;319:114-116.
2. Melia J. Skin cancer. Health and Hygiene 1995;16:153-158.
3. Sinclair R. Commentary: Start with the KISS principle. BMJ 1998; 316:38-39.
4.Melia J. Changing incidence and mortality from cutaneous malignant melanoma. the reasons are not yet clear. BMJ 1997;315:1106-1107.
5. Marks R, Foley PA, Jolley D, Knight KR, Harrison J, Thompson SC. The effect of regular sunscreen use on vitamin D levels in an Australia population. Arch.Dermatol. 1995;131:415-421.
Competing interests: No competing interests
Sir,
The article by Ness et al1 may have created publicity
for the BMJ but
is it really this type of publicity that the BMJ needs? The
article is in
the section 'Education and Debate'. No debate is encouraged
in that only
the opinions of Ness et al are given journal space. To my
knowledge none
of those involved in advocating a safe sun approach to life
have been
asked to offer their opinion in an adjacent article. It is
also important
to note that Ness and colleagues have contributed absolutely
no original
data to this debate at any time. No original data from the
Bristol Group
is reported in the article and they themselves have never
published in
this field. Thus reports in the tabloids on Friday on "new
research from
Bristol" are meaningless.
<P> Furthermore they have misquoted others. Those of us
who have an
interest in prevention and early detection of skin cancer,
particularly
malignant melanoma, have a longstanding interest in vitamin
D levels
particularly when we are working with small children and
older
individuals. We regularly offer the public a balanced view
and have also
carried out studies to determine whether or not sensible use
of sunscreen
is associated with the drop in vitamin D levels. I find it
a very
disturbing aspect of this article that Ness and colleagues
have totally
misquoted the work of Robin Marks and his colleagues from
Australia2 who,
in 1995, carried out an excellent study in older individuals
and published
in the Archives of Dermatology reassuring evidence that use
of sunscreen
was not associated with a fall in vitamin D levels. This is
incorrectly
reported in Ness et al's paper as giving worrying concern of
falling
vitamin D levels in patients using sunscreen. This is a
major error which
obviously should have been spotted by the authors themselves
and
preferably also by an informed referee. The data on
coronary disease
levels and vitamin D is irrelevant until it is recorded that
safe sun
advice is associated with a significant fall in vitamin D
levels.
<P> The UK public could do without this kind of so-called
debate at the
present time. We are currently even in Scotland enjoying a
period of
extremely warm sunny weather. I have just returned from my
children's
clinic where I saw a 4 month old baby who required hospital
admission at
the weekend because of sunburn and blisters on the child's
forehead. When
asked about the problem, the mother quoted the fact that she
had read in
her newspaper on Friday that it was now proven that sun was
good for small
children. I would be interested in Ness et al's comments.
<Yours sincerely
<Rona M MacKie CBE, FRCP
<P> 1. Ness AR, Frankel SJ, Gunnell DJ, Davey Smith G. Are
we really
dying for a tan? Br. Med. J. 1999; 319: 114-6.
<P>2. Marks R, Foley PA, Jolley D, Knight KR, Harrison J,
Thompson SC. The
effect of regular sunscreen use on vitamin D levels in an
Australian
population. Arch Dermatol. 1995; 131: 415-21
Competing interests: No competing interests
In a recent commentary, Ness and colleagues [1] questioned the advice
given by public health authorities to reduce exposure to sunlight .
Without quantifying both the risks and the benefits of sun exposure across
the population, the authors reasoned, isn't it unethical to advocate a
change in behaviour? They then conducted a brief review of known harms and
possible benefits of sunlight exposure, and concluded that increased
exposure to the sun might actually be beneficial when assessed on a
population basis. Predictably, the article has created a storm in the lay
press, greeted with joy and horror in roughly equal measures: but what of
its scientific content?
The question posed is certainly reasonable, however the article is
flawed by superficial interpretation, a disturbing tendency to equate
conjecture with evidence and an Anglo-centric view which fails to
appreciate the adverse effects of sun-exposure experienced by people
living in other parts of the world. For example, the authors acknowledge a
causal role of sunlight in the aetiology of most types of skin cancer, but
claim that mortality gains for melanoma by reducing exposure to the sun
will be small. And anyway, since avoiding the sun is such a terribly
bothersome and humourless strategy for preventing melanoma, a 'better'
public health approach might be to train the public to consult doctors at
an earlier stage in the disease process. Even in countries with low rates
of melanoma such as England and Wales, these claims are contentious; when
applied to the sun-ravaged populations of Australia, New Zealand and low-
latitude USA, they are incomprehensible.
Two possible benefits of sunlight exposure were expounded : a
reduction in coronary heart disease and improvements in mood and well-
being, although the evidence proffered for either claim was extremely
weak. Assuming that high levels of sunlight exposure convey a public
health benefit, then at the very crudest level one might predict fair-
skinned Australians to enjoy lower cardiovascular mortality and fewer
suicide events than their northern European cousins. However, death rates
for heart disease among Australian males in the MONICA cohorts are higher
than for Iceland, Denmark or Sweden [2], and suicide rates in Australia
are among the highest in the world [3]. Moreover, people who migrate from
the relative darkness of England, Wales and Ireland to the sun-drenched
shores of Australia commit suicide at higher rates than their countrymen
who remain behind [4]. If high levels of sun exposure really do lower the
risk of heart disease and suicide, then one explanation for these
contradictory findings is that other risk factors which negatively
confound the association with sunlight must be over-represented in
Australia. More likely is that exposure to sunlight has a negligible
effect on the occurrence of these health outcomes.
Most would agree that simple health education messages are blunt
tools for addressing complex health problems, but one wonders at the
consequences of the high-profile strategy adopted by Ness and colleagues.
The distilled message of the article (intended or otherwise) that
'sunlight is good for you' will echo far beyond the lush pastures of Avon
valley into dusty, sunburned townships half a world away. It is here that
the damage will be done.
So as the authors smugly recline on their deckchairs in the noonday
sun (no doubt humming Noel Coward ditties), I sincerely hope their skins
are saved by yet another wet British summer.
1 Ness AR, Frankel SJ, Gunnell DJ, Davey Smith G. Are we really dying
for a tan? Br Med J 1999;319:114-6.
2 Tunstall-Pedoe H, Kuulasmaa K, Amouyel P, Arveiler D, Rajakangas
AM, Pajak A. Myocardial infarction and coronary deaths in the World Health
Organization MONICA Project. Registration procedures, event rates, and
case-fatality rates in 38 populations from 21 countries in four
continents. Circulation 1994;90:583-612.
3 La-Vecchia C, Lucchini F, Levi F. Worldwide trends in suicide
mortality, 1955-1989. Acta Psychiatr Scand 1994;90:53-64.
4 Burvill PW. Migrant suicide rates in Australia and in country of
birth. Psychol Med 1998;28:201-8.
Competing interests: No competing interests
Your recent media release on “Sensible health warnings to stay out of
the sun may also be denying some people the benefits it provides” causes
me great concern. This is because it fails completely to understand the
message which photobiologists and dermatologists are seeking to put to the
public in relation to care in the sun, and it also portrays a similar lack
of understanding by the authors of the nature of sunlight. This may be
explained as follows.
It is clear that sunlight is absolutely vital to the existence of the
human race, as the authors imply, but the warmth and light of sunlight are
the only rays we need, and ultraviolet radiation exposure is definitely
harmful to human skin, although usually not noticeably so in the early
years of life; now that we are living longer, however, such exposure has
become of very significant concern, in that it causes the condition of
photoageing in virtually all subjects, even the dark skinned, namely a
dry, itchy, often eczematous, wrinkled, blotchy, unpleasant looking skin,
and skin cancer in a very significant minority, but a minority in whom
such cancer could be prevented, and is being prevented in countries such
as Australia where ultraviolet avoidance programmes have been in place for
a number of years. Our message is therefore to minimise exposure to solar
ultraviolet radiation but not of course to solar infrared and visible
radiation, an aim which is now fairly readily achievable. It is thus not
felt that sunlight should be avoided altogether and the authors of article
are apparently mistaken in that belief.
They also state that mental health is improved by lying or sitting in
the sun and that the depression of seasonal affective disorder may be
improved by sunlight exposure – but this is by exposure to the visible
radiation from sunlight through the eye, not to ultraviolet radiation
through the skin. They further say that the avoidance of sunlight reduces
vitamin D production, quoting an article by Marks et al1, which in fact
states the opposite. In addition, vitamin D is very readily available in
the normal diet and there is therefore no evidence whatsoever that
ultraviolet radiation avoidance leads to vitamin D deficiency and
secondarily to coronary heart disease. The authors state too that skin
cancer rates are not very high and that perhaps only a little skin cancer
will be prevented by avoiding sunlight; any skin cancer is detrimental to
the sufferer and costly to health services, however, particularly because
if ultraviolet radiation is exposure is reduced, skin cancer rates too
would be expected to reduce, as is already happening in Australia.
Finally the authors do not mention at all that most people, even the
darker skinned, develop the very annoying disorder of photoageing
mentioned above and that ultraviolet radiation avoidance would also
prevent that and the expense of treating it.
The ultraviolet radiation in sunlight is strong in the middle of the
day in summer and in Mediterranean and tropical climates, and damage from
such radiation can readily be prevented by covering up at that time,
seeking the shade and using high protection sunscreens on the still
exposed skin. Before about 11 o’clock and after about 3 o’clock therefore
in Britain and abroad, even on hot and sunny days, people may enjoy
sunlight with much less concern because the ultraviolet intensity at that
stage is relatively weak; if they wisely use sunscreens in addition at
those times, they are even less at risk.
In summary, the public health message should be that people need to
minimise ultraviolet radiation exposure by covering up, seeking shade and
using sunscreens in the middle of the day in summer or in sunny climates,
even on cloudy or cool days, and enjoy the sunlight even if warm and
bright while still using a sunscreen at other times; they should of course
also use high protection sunscreens carefully in the middle of the day if
they must be out then. Thus, ill-advised messages based on incorrect
information and a lack of understanding of the nature of sunlight are
positively harmful to the public wellbeing, and I believe that publication
of the article in question has been extremely misleading.
Yours sincerely
J L M Hawk
Consultant Dermatologist and
Professor of Dermatological Photobiology
1Marks R, Foley PA, Joffey D, Knight KR, Harrison J, Thompson SC
The effect of regular sunscreen use on vitamin D levels in an Australian
population. Arch. Dermatol. 1995; 131:415-21
Competing interests: No competing interests
The real hazards of excessive sun exposure and the difficulty in treating
EDITOR – Ness et al’s recent article ‘ Are we really dying for a
tan?’ is misleading and undermines he valuable work which has been done to
increase public awareness of the
deleterious effects of excessive sun exposure, particularly the
development of cutaneous malignancies.1 There are more than 50,000 new
cases of cutaneous malignancies diagnosed in the UK each year, with more
than 2,000 deaths and considerable morbidity . The authors highlight the
inconsistencies between malignant melanoma and sunlight exposure and
suggest ‘effective options’ for reducing the incidence of melanoma without
reducing sun exposure by increasing diagnostic awareness and early
treatment. They
then discuss more ‘benign’ forms of skin cancers i.e. basal cell and
squamous cell carcinomas which they feel may be a cause of minor
morbidity.
Although there are some inconsistencies in the literature, there is
strong evidence to suggest that excessive sun exposure is a major cause of
melanoma. 2 Melanomas can be difficult to detect in the initial stages
and have often metastasised by the time a patient is seen by a
dermatologist.
To imply that mortality could be reduced by increasing diagnostic
awareness and ‘access to treatment’ rather than by avoiding excess sun
exposure is foolhardy. There are already many campaigns to increase early
diagnosis of
melanoma and removal of suspected melanomas is always a treatment
priority.
While basal cell carcinomas very rarely metastasise, squamous cell
carcinomas can do so. A recent meta-analysis showed an overall 5 year
metastasis rate of 5.2%, with a recurrence rate of 3.7-10%.3 How
difficult to manage these ‘benign’ skin cancers can sometimes be is
illustrated by the case of a 68 year old man who recently re-presented to
the dermatology clinic. He lived for nine years in Brazil (1953-1962),
working in an office during the day but spending most of his leisure time
outdoors. He has had a total of eight squamous cell and basal cell
carcinomas removed from his face, two from his hand, and has multiple
pre-malignant skin lesions. He also has severely photodamaged skin. Most
notably, an aggressive squamous cell carcinoma affecting his right ear
recurred twice after excision and was then treated with radiotherapy.
Following its third recurrence, he required total removal of the pinna. A
prosthesis was fitted but he has now developed a basal cell carcinoma on
the tragus, where the prosthesis is attached (fig.1).
Public awareness of the real dangers of excessive sun exposure needs
to be maintained by repetition of a consistent message from medical and
health education authorities. Prevention of skin cancers is better than
cure, which is often difficult and may be impossible.
1 Ness R A, Frankel SJ, Gunnell DJ, Davey Smith G. Are we really
dying for a tan? BMJ 1999; 319:114 – 6. (10 July)
2 Osterlind A, Tucker MA, Stone BJ. The Danish case-control study
of cutaneous malignant melanoma. The importance of UV-light exposure.
Int J Cancer 1988; 42:319-24.
3 Rowe DE, Carroll R J, Day CL. Prognostic factors for local
recurrence, metastasis, and survival rates in squamous cell carcinoma of
the skin, ear and lip. J Am Acad Dermatol. 1992; 26: 976-90.
Dr CW Jackson Specialist registrar dermatology
Dr LE Rhodes Consultant dermatologist
Department of Dermatology, Royal Liverpool University Hospital, Liverpool,
L7 8XP
Editorial note
The patient gave written consent to the publication of the above mentioned material
Competing interests: No competing interests