Those of us familiar with the evolutionary medicine model have come to question many of the conventional public health recommendations and, along with them, the complete sun avoidance. Dr Anastasia Boulais will describe the delicate balance between the benefits and risks of sun worshipping based on current evidence. The talk will focus on particular patterns of sun exposure which may increase the risk of formation of cutaneous melanoma. Other factors, such as diet, vitamin D status and even training patterns, contributing to that risk will be discussed. Anastasia will conclude with an overview of protective lifestyle factors.

1. IS SUN WORSHIPPING INCREASING
YOUR RISK OF MELANOMA?
Dr Anastasia Boulais
Ancestral Health Symposium
Atlanta 2013

2. FAT MAKES YOU FAT

3. FAIL!
Dr Anastasia Boulais AHS13

4. BUTTER CAUSES HEART ATTACKS
Dr Anastasia Boulais AHS13

5. FAIL!
Dr Anastasia Boulais AHS13

6. THE EVIL ORB IN THE SKY
IS OUT TO GIVE YOU
LETHAL CANCER

7. FAIL?
Dr Anastasia Boulais AHS13

10. Australia: World Leader in Melanoma
• CMM – cutaneous malignant melanoma (not “skin cancer”)
• Highest incidence in the world
• 10% of all cancers
• 1 in 17 Australians will develop melanoma before the age of
85
• 3.4% of all cancer deaths in 2010
• 1980 – “Slip, slop, slap” campaign
• 1986-2006 – Melanoma rates double
Dr Anastasia Boulais AHS13

11. PRO AGAINST
1. Known cellular mechanism
1. Lower incidence in outdoor workers vs.
indoor workers
2. Increased incidence with latitude
2. CMM more prevalent on less sun-exposed
sites
3. Increased incidence in sunbed use
3. Negative correlation between chronic
exposure and incidence of CMM
4. Association with sunburns 4. Vitamin D inhibits growth of tumours
5. Sun exposure > atypical naevi >
strong risk factor for melanoma
5. Increased melanoma survival with higher
sun exposure history
6. Sunscreens have not been found to
decrease CMM incidence

12. Does sunlight cause melanoma?
Does food cause heart disease?
Dr Anastasia Boulais AHS13

13. ultraviolet
visible
UVA
UVB
UVC
UVA UVB
UVC
ozone
Dr Anastasia Boulais AHS13

14. UVA SKIN PENETRATION
• UVA – longer wavelength
with deeper skin
penetration.
• Low erythema potential
• Not absorbed by ozone layer
• Immediate & Persistent
Pigment Darkening (IPD/PPD)
• UVA tan via oxidation of
melanin precursors in basal
cell layer, not an increase in
melanin content.
Dr Anastasia Boulais AHS13

15. UVA RADIATION
• Indirect DNA damage via formation of ROS  oxidative stress
• No significant photoprotection
• Breaks down Vitamin D bound to VDR
• Induces NO¯ formation
• Inhibits UVB-induced immunosuppression
Dr Anastasia Boulais AHS13

16. Dr Anastasia Boulais AHS13
- PROTEIN DAMAGE
- LIPID DAMAGE
- DNA DAMAGE

17. Sunbeds give off 5-10x more
UVA than experienced at solar
noon in Southern Europe

18. UVB SKIN PENETRATION
• UVB – poor skin penetration.
• High erythema [burn] potential
• Partially absorbed by ozone
layer
• Delayed tanning (DT) 3-7 days
post exposure lasts for weeks
• UVB tan via increased
synthesis of melanin and
increased melanocyte density
Dr Anastasia Boulais AHS13

19. UVB RADIATION
• Direct DNA damage via formation of cyclobutane pyrimidine
dimers [CPD] and 6-4 photoproducts [6-4PP]
• Delayed tan = photoprotection
• Skin adaptations: hyperkeratosis and thickening of stratum
corneum
• Vitamin D production
Dr Anastasia Boulais AHS13

20. Source: Lester M.Davids “Recent Advances in the Biology, Therapy and Management of Melanoma”
Published Feb 2013 under CC BY3.0 license

21. Irradiation
Solar Zenith
Angle (the
shadow rule)
Latitude
Time of the year
Time of dayElevation
Ozone
concentration
Dr Anastasia Boulais AHS13

22. UVB PARTIAL OZONE ABSORPTION
Las Cruces , NM
32.6° north latitude
June 21
Clear day
Midday
Current ozone level
Seattle, WA
47.7° north latitude
June 21
Clear day
Midday
Current ozone level
1.24x more UVB
Source: http://uvb.nrel.colostate.edu/UVB/publications/uvb_primer.pdf

23. MELANOMA ACTION SPECTRUM?
“…the available evidence points away from pyrimidine dimer
formation by UVB and toward oxidative damage caused by
longer *UVA+ wavelengths.”
Lund et al (2007) Melanoma, long wavelength ultraviolet and sunscreens: Controversies and potential resolutions,
Pharmacology and Therapeutics
UVA UVB
INDIRECT
DNA DAMAGE
DIRECT
DNA DAMAGE

24. INNATE PROTECTION AND REPAIR
1. Delayed Tanning photon absorption
2. Skin adaptation
3. Melatonergic Antioxidant System
4. Nucleotide Excision Repair
5. Endogenous + exogenous ROS quenchers
6. Vitamin D – potent immunomodulator
Dr Anastasia Boulais AHS13

25. MELATONERGIC ANTIOXIDANT SYSTEM
• Melatonin is produced in pineal
gland, bile fluid, BM, CSF, ovary,
eyes, lymphocytes, gastric mucosa
and skin
• Antioxidant – strong scavenger of
UV-induced ROS
• Modulates UV-induced apoptosis
• Tumour growth inhibitor
Dr Anastasia Boulais AHS13

26. NUCLEOTIDE EXCISION REPAIR
• XPA [Xeroderma Pigmentosum Group A]
– A critical protein involved in DNA damage recognition
• XPA is a rate-limiting factor in excision repair controlled by a
circadian clock
• In [nocturnal] mice: CPD + 6-4PP repaired faster in 4pm group
(XPA zenith) vs. 4am group (XPA nadir)
• In humans this peak repair rate would coincide with the
morning hours up to around solar noon.
Dr Anastasia Boulais AHS13

27. CIRCADIAN RHYTHM FTW!
Dr Anastasia Boulais AHS13

28. INCREASED UVA TO UVB RATIO
↓ erythema
↑ oxidative stress
↓ melanin production
↓ Vitamin D production
↑ Vitamin D breakdown
↓ protective skin adaptation
A tan with no photoprotection

29. EXOGENOUS ANTIOXIDANTS AND
PRO-OXIDANTS
Antioxidants
• Carotenoids
– Beta-carotene
– Lutein
– Lycopene
• Flavonoids and Polyphenols
– Tea and cocoa polyphenols
– Herbs and spices
• Ascorbic acid
• Vitamin E (tocopherols)
Pro-oxidants
• Increased risk with high PUFA diet (RR 2-4),
high linoleic acid (RR 2.16) and cod liver oil
(RR 2.9)
• Recall: Sunbed RR 1.2
In vitro studies
Epidemiological evidence
Human RCTs (erythema)
Dr Anastasia Boulais AHS13

30. PHYSIOLOGICAL STRESS?
• Increased number of atypical naevi in marathon runners
• Training HR, training velocity and physical strain index
• Cortisol?
• Oxidative stress?
• Impaired carcinogenesis repair?
Dr Anastasia Boulais AHS13

31. Dr Anastasia Boulais AHS13

32. Dr Anastasia Boulais AHS13
THERE’S NOTHING
HEALTHY ABOUT A TAN?
HIGH INTAKE OF PRO-OXIDANTS
LOW VITAMIN D STATUS
PHYSIOLOGICAL STRESS
CIRCADIAN RHYTHM
DYSRUPTION
POOR INTAKE OF ANTIOXIDANTS
HIGH UVA/UVB RATIO
GENETICS MELANOMA RISK

33. Know your risk…
Eat well
Sleep better
Enjoy movement
Manage your stress
Smart sun exposure

34. BIBLIOGRAPHY
1. Juzeniene A, Moan J (2012) Beneficial effects of UV radiation other than via vitamin D production. Dermato-Endocrinology,
4:2, 109-117
2. Desotelle J, Wiling M, Ahmad N (2012) The Circadian Control of Skin and Cutaneous Photodamage. Photochemistry and
Photobiology, 88: 1037-1047
3. Boniol M, Autier P, Boyle P, Gandini S (2012) Cutaneous melanoma attributable to sunbed use: systemic review and meta-
analysis. BMJ 345: e4757
4. Gaddameedhi S, Selby C, Kaufmann W, Smart R, Sancar A (2011) Control of skin cancer by the circadian rhythm. PNAS
Online
5. Weinstock M (1996) Controversies in the role of sunlight in the pathogenesis of CM. Photochemistry and Photobiology
63(4)
6. Vinceti M, Pellacani G, Malagoli C, Bassissi S, Sieri S, Bonvicini F, Krogh V, Seidenari S (2005) A population-based case-
control study of diet and melanoma risk in Northern Italy. Public Health Nutrition 8(8) 1307-1314
7. Veierod M, Helle D, Aake P (1997) Diet and risk of cutaneous malignant melanoma: a prospective study of 50,757
Norwegian men and women. Int. J Cancer: 71, 600-604
8. De Giorgi V, Gori A, Grazzini M, Rossari A, Oranges T, Longo A, Lotti T, Gandini S (2012) Epidemiology of melanoma: is it
still epidemic? What is the role of the sun, sunbeds, Vit D, betablocks, and others? Dermatologic Therapy, 25: 392-396
9. Godar D, Landry R, Lucas A (2009) Increased UVA exposures and decreased cutaneous Vitamin D3 levels may be
responsible for the increasing incidence of melanoma. Medical Hypothesis, 72:434-443
10. Richtig E, Ambros-Rudolph C, Trapp M, Lackner H, Hofmann-Wellenhof R, Kerl H, Schwaberger G (2008) Melanoma
markers in marathon runners: increase with sun exposure and physical strain. Dermatology 217:38-44
11. Lund C, Timmins G (2007) Melanoma, long wavelength ultraviolet and sunscreens: controversies and potential resolutions.
Pharmacology and Therapeutics, 114: 198-207
12. Shapira N (2010) Nutritional approach to sun protection: a suggested complement to external strategies. Nutrition Review,
68(2) 71-86
13. Rosso S, Sera F, Segnan N, Zanetti R (2008) Sun exposure prior to diagnosis is associated with improved survival in
melanoma patients: Results from a long-term follow-up study of Italian patients. European Journal of Cancer, 44: 1275-
1281
14. Agar N, Halliday G, Barnetson R, Ananthaswamy H, Wheeler M, Jones A (2004) The basal layer in human squamous tumors
harbors more UVA than UVB fingerprint mutations: A role for UVA in human skin carcinogenesis. PNAS 101(14): 4954-4959
15. Miyamura Y, Coelho S, Schlenz K, Batzer J, Smuda C, Choi W, Brenner M, Passeron T, Zhang G, Kolbe L, Wolber R, Hearing V
(2011) The deceptive nature of UVA-tanning versus the modest protective effects of UVB-tanning on human skin. Pigment
Cell Melanoma Res 24(1); 136-147
Dr Anastasia Boulais AHS13