It’s true, moderate exposure to sunlight can have positive effects on your health. For one thing, it stimulates the production of vitamin D, which facilitates the absorption of calcium and is essential to maintaining healthy bones.1,2 But repeated or excessive exposure can damage the skin and cause its premature ageing; it also increases the risk of developing eye conditions, diseases of the immune system, and skin cancer.1,2,3
Crucially, sunlight can also have negative effects on the health and functioning of blood vessels and collagen production — potentially increasing your risk of developing spider veins4. The reason for this lies primarily in the two factors discussed below: the material spider veins are made of, and the effects of sunlight as it travels through the skin.
Capillaries and collagen
Spider veins are made up of tiny blood vessels, called capillaries, that grow close to the surface of the skin, and which are most commonly found on the face and legs 56. An important component of the capillaries’ wall is collagen: a fibrous protein which is found in the skin, blood vessels, bones, cartilage, and other organs and tissues.7,8 It’s produced by our cells in the dermis in a process of continuous regeneration and helps keep these structures firm and elastic8,9. However, its production tends to naturally decline with age10.
Role of sunlight in spider vein formation
Sunlight is made up of two main types of invisible ultraviolet (UV) radiation: UVA and UVB11. Both penetrate the skin, but UVA radiation can go deeper through the superficial layer of the skin, called the epidermis, and into the dermis2,12. This is where capillaries and collagen are found1213. When UVA radiation hits the dermis, it causes the production of free radicals (highly reactive unstable compounds which can damage cells) as well as localised inflammation and this then `switches on` the body’s own enzymes called matrix. Metalloproteinases (MMP`s), which break down the collagen14. As collagen is destroyed, the capillary walls lose strength and elasticity and become weakened, so that the pressure of blood in them is able to form bulges in the vessel wall. The capillaries then grow in the direction of the bulge. They become visible through the skin as clusters of fine blue and red spider veins or thread veins15,16,17.
Photoageing and skin damage
The phenomenon whereby collagen is destroyed by UVA radiation is generally known as photoageing14. It’s important to understand photoageing doesn’t just affect blood vessels. The skin visibly reflects the effects of photoageing by the appearance of fine lines, wrinkles, and brown spots4,14. In fact, research shows that sun exposure is responsible for 80% of the visible signs of ageing on the face.18 Despite what you might think, the damaging effects of sunlight can occur also indoors, for UVA rays are not blocked by ordinary window glass2
What are the risk factors?
Anyone can experience the harmful effects of sunlight, but some people are at greater risk and that includes anyone with fair hair and skin or with a history of having been sunburnt as well as those who regularly spend a considerable amount of time in the sun because of their job.
The risk of damage also depends on the strength of the UV radiation. This is expressed as a UV index and is measured in numbers from 0 to 11; the higher the number the greater the potential damage19. The UV index varies according to the season, weather conditions, and where you live; for example, it is higher in summer than in winter, and Mediterranean countries tend to have higher greater UV indexes than the UK19. However, it also varies throughout the day, reaching its highest values in the UK summer between 11am and 3pm20
So, how can I protect myself?
Avoiding exposure to sunlight when the UV index is at its highest is one of the most important steps you can take to reduce your risk of skin damage and the development of spider veins4. It may help to remember a simple rule, known as ‘Holloway’s rule’, which advises that the sun is likely to burn you, and is therefore very strong, if your shadow is shorter than you are tall20.
Another simple preventive measure is to use a sunscreen with a sun protection factor (SPF) of at least 30 4. It’s important to apply sunscreen generously and uniformly to achieve the desired protection.4 The recommended amount is 2 mg/cm2, for smaller quantities reduce the SPF 221. So, for example, if you apply half of the recommended amount (e.g. 1 mg/cm2) the SPF of the product you are using drops by half (e.g. from SPF30 to SPF15)21.
Damage to the skin and the blood vessel network may also be reduced by covering yourself up with suitable UV protective clothing and wearing a broad-brimmed hat4. Consider that not all fabrics have the same ability to protect from the sun’s radiation. For example lycra/elastane, nylon and polyester are more effective than cotton22. Colour, appearance and wave density are also important. In general dark, shiny and tightly-knitted garments offer greater protection22
Know how much sun is too much
Finally, if you stay in the sun, make sure you know when enough is enough. This will depend on your skin type23. If you have very fair skin that rarely tans, you shouldn’t stay in the sun more than five to ten minutes.23 But, if you have naturally dark skin and rarely burn, the maximum amount of time may be 20 to 30 minutes23.
Make sure you seek professional medical help if you are concerned about the health of your skin and veins. The above information, prepared by Nature’s Best, is not intended to replace the advice of a healthcare professional. For more information on spider veins and how to prevent them, but for more friendly advice explore our website or speak to one of our Nutrition Advisors.
1. World Health Organization. Health effects of UV radiation. Accessed 27 February 2017 from http://www.who.int/uv/health/en/
2. Wilson B, Moon S, Armstrong F. Comprehensive Review of Ultraviolet Radiation and the Current Status on Sunscreens. J Clin Aesthet Dermatol. 2012;5(9):18-23. Accessed 27 February 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3460660/
3. Stiefel C, Schwack W. Photoprotection in changing times – UV filter efficacy and safety, sensitization processes and regulatory aspects. Int J Cosmetic Sci. 2015;37(1):2-30. Accessed 27 February 2017 from http://onlinelibrary.wiley.com/doi/10.1111/ics.12165/epdf
4. Canadian Dermatology Association. What is photoaging? Accessed 27 February 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1606623/
5. Weiss R. Varicose veins and spider veins. Medscape Drugs and Diseases. 2016. Accessed 20 February 2017 from http://emedicine.medscape.com/article/1085530-overview#showall
6. NHS Choices. Varicose veins. 2014. Accessed 20 February 2017 from http://www.nhs.uk/conditions/Varicose-veins/Pages/Whatarevaricoseveins.aspx
7. Yokoi K, Kojic M, Milosevic M, et al Capillary-wall collagen as a biophysical marker of nanotherapeutic permeability into the tumor microenvironment. Cancer Res. 2014;74(16):4239-46. Accessed 27 February 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4134692/
8. Koide T. Designed triple-helical peptides as tools for collagen biochemistry and matrix engineering. Philos Trans R Soc Lond B Biol Sci. 2007;v362(1484):1281-91. Accessed 27 February 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440396/
9. DERM101. Collagen – embryologic, histologic, and anatomic aspects. Accessed 27 February 2017 from https://www.derm101.com/inflammatory/embryologic-histologic-and-anatomic-aspects/collagen/
10. Varani J, Dame MK, Rittie L, et al. Decreased collagen production in chronologically aged skin. Am J Pathol. 2006;168(6):1861-8. Accessed 27 February 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1606623/
11. Lucas R, McMichael T, et al. Solar ultraviolet radiation (p. 4). World Health Organization. 2006. Accessed 27 February 2017 from http://www.who.int/uv/health/solaruvradfull_180706.pdf
12. University of California at San Francisco (UCSF). UV radiation. 2007. Accessed February 2017 from http://www.dermatology.ucsf.edu/skincancer/General/prevention/UV_Radiation.aspx
13. MacNeal RJ. MSD Manual Consumer Version. Structure and function of the skin. Accessed 27 February 2017 from http://www.msdmanuals.com/en-gb/home/skin-disorders/biology-of-the-skin/structure-and-function-of-the-skin
14. Pandel R, Poljsak B, Godic A, et al. Skin Photoaging and the role of antioxidants in its prevention. Dermatology. 2013. Accessed 27 February 2017 from https://www.hindawi.com/journals/isrn/2013/930164/
15. Braverman IM. The cutaneous microcirculation. J Investig Dermatol Symp Proc. 2000;5(1):3-9. Accessed 28 February 2017 from http://www.jidsponline.org/article/S0022-202X(15)52851-0/fulltext
16. Pietrangelo A. Causes of spider veins. 2012. Accessed 28 February 2017 from http://www.healthline.com/health/spider-veins#Causes3
17. Mayo Clinic. Varicose veins. Symptoms and causes. Accessed 28 February 2017 from http://www.mayoclinic.org/diseases-conditions/varicose-veins/symptoms-causes/dxc-20178128
18. Flament F, Bazin R, Laquieze S, et al. Effects of the sun on visible clinical signs of aging in Caucasian skin. 19. Clin Cosmet Investig Dermatol. 2013;6:221-32. Accessed 28 February 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3790843/
20. Met Office. UV Index Forecast. Accessed February 28 from http://www.metoffice.gov.uk/uv-index-forecast#?tab=map
21. Cancer Research UK. Am I at risk of sunburn? 2015. Accessed 28 February 2017 from http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/sun-uv-and-cancer/am-i-at-risk-of-sunburn
22. Schalka S, dos Reis VM, Cucé LC. The influence of the amount of sunscreen applied and its sun protection factor (SPF): evaluation of two sunscreens including the same ingredients at different concentrations. Photodermatol Photoimmunol Photomed. 2009;25(4):175-80. Accessed 28 February 2017 from https://www.ncbi.nlm.nih.gov/pubmed/19614894
23. Gies P, McLennan A. Everyday and high-UPF sun-protective clothing. The Melanoma Letter. 2012;30(2):7-8. Accessed 28 February 2017 from http://www.skincancer.org/Media/Default/File/File/melanoma-letter-30-2.pdf
24. PubMed Health. How much sun is too much? 2015. Accessed 28 February 2017 from https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0079162/