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Sun Screen Lotions Really Work
Australian Trial Demonstrates Importance Of Using Sun Block
In the first ever randomized trial to evaluate sunscreen lotions effectiveness at preventing melanoma the results provided proof that sunblock is in fact a very effective protection against the damaging effects of excessive sun exposure.
Until this trial the use of sunblock was considered controversial because some thought it really didn't work and others considered it just encouraged fair skinned people to spend too long in the sun.
The Sun Screen Trial
The Queensland Institute of Medical Research (QIMR) study was based on a survey based in the town on Nambour, an inland town an hour or so north of the city of Brisbane where summer is pretty much all year round.
Professor Adèle Green who leads the Cancer and Population Studies Laboratory (Brisbane University) co-opted 1,621 randomly selected local people to participate in her trial that ran over a period of four years from 1992 until 1996. The people were arbitrarily split into two groups.
The Two Groups
Group One was instructed to just continue to use sunscreen as they usually did and Group Two was supplied sunscreen lotion and asked to apply it liberally every time they went outside for more than a brief time.
It is important to note that Group One were not asked to do anything. There were a control group left to carry on as they usually did. If they were already using sun block so be it and if they were not using it or were only using it occasionally they were left to just carry on as usual. They were not instructed to change anything about their daily lives.
The people in Group Two were asked to make a change. They were supplied sun block and asked to apply it regularly and liberally for the entire four year period.
The groups were selected randomly so as to eliminate anomalies such as fair skin people being more likely to assiduously apply sunscreen lotion than those was a naturally darker skin.
At the time the study was commenced the only sun block lotion available was SPF 15. The trial ran for only four years so the results demonstrate a significant carry over benefit.
The Result
In the 15 years after the trial, the people in Group One had developed twice as many melanoma lesions as Group Two while squamous-cell carcinoma tumours were 40% reduced in Group Two.
Sun Lotion Use Vindicated
As the three most common skin cancers are linked to sun damage to skin the results of the trial by the Queensland Institute of Medical Research (QIMR) are particularly useful in allaying fears about prolonged sun exposure if sun screen lotion is used liberally and frequently.
There is now some certainty that the regular application of sun screen lotion of itself provides a good degree of protection against melanoma and other sun induced skin cancers.
However, in adult hood, sun screen lotions are less effective against basal-cell carcinomas because they are usually initiated by sun exposure during childhood. By adulthood the skin damage is likely to be already done with some skin cells already initialized to later become basal-cell carcinomas and may do so after sun exposure during adult hood.
The use of sun screen lotions in adulthood may stop or slow down the development of basal-cell carcinomas but the only real protection against this form of cancer is the use of the sun screen lotion during childhood.
After The Trial
Fifteen years after the trial stopped the participants were all checked and it was found that the regular generous use sun block lotion had reduced the numbers of skin cancers markedly in the group that had been supplied with SPF 15 sun screen lotion and encouraged to use it liberally.
The Cause Of Skin Cancers – A (very) Brief History
The main cause of skin cancers is excessive exposure to sunlight. Once most fair skinned peoples of European stock lived in a part of the world where winters were long and the days were short.
Fair skin is most efficient at manufacturing Vitamin D which is essential for our wellbeing so the most effective way of ensuring we got enough Vitamin D for our healthy survival was to have a pale skin that efficiently manufactured Vitamin D during the relatively rare occasions when we were out in the sun.
Over the generations the pale skinned ones migrated to, and decided they liked, parts of the world with warm sunny climates. The climate of their homeland also gradually warmed up with summers becoming longer and sunnier.
Unfortunately these people still have fair skin unsuited to regions with lots of clear bright sunny days and are susceptible to sun burn and invisible skin damage directly caused by ultraviolet radiation from the sun. People with European ancestry have never developed any natural sun protection such as a darker skin color.
Skin Cancer Facts
Although excessive exposure to the sun during childhood can cause or set up skins cancers for later development, adults (Over 18) still have almost 80% of their lifetime exposure to sun ahead of them making the use of sun screen lotions a very sensible option for adults.
Every year two million people in the U.S. are diagnosed with over 3.5 million skin cancers.
About 90 percent of all basal-cell carcinoma's or squamous cell carcinoma's are caused or strongly linked to exposure to ultraviolet radiation from the sun. (A similar percentage of the changes to a persons skin associated with aging are also due to exposure to the sun.)
During the course of their lifetime, one fifth (1/5) of all Americans will develop a skin cancer with two million eight hundred thousand new basal-cell carcinomas alone diagnosed annually in the US.
Around 45% of all Americans who live to the age of 65 will have either one or the other of basal-cell carcinoma or squamous cell carcinoma's during their life. Many will have both types of cancer. Seven hundred thousand squamous-cell carcinomas are diagnosed each year in the U.S. and about 2,500 deaths Americans die from them every year.
Skin Cancer More Common Than You Think
Skin cancer in the U.S. is more common than any other type of cancer – this includes lung cancer, breast cancer, prostate cancers, and colon cancer.
In my Health Blog I have more facts about and some photo's of the three most common skin cancers: Basal Cell, Squamous Cell and Melanoma cancers.
I also have some information about why the Ozone Layer in the upper atmosphere is very important to our health.
I suggest you have a look. You might also be interested in another article I wrote about skin cancer.
Thanks for reading my article.
Ian Miller - Health Writer
About the Author
For several years I have been concerned about the increase of lifestyle diseases such as diabetes, heart disease and cancers.
I am also concerned about an increasing number of unfit people in modern western societies. I decided to write about health and wellness matters as I feel very strongly that we, as a society, are going to facing huge problems in future years dealing with a bulge of health problems that will strain our health services to breaking point.
I have had some work experience in the health field but I also do a lot of research which I combine with some pretty pragmatic down to earth life experiences to produce readable commonsense health information.
I have a blog health site, www.ClearSkyHealth.com, where I publish my articles. I look forward to readers feedback and welcome suggestions for future topics. If you have a question I will endeavor to answer it for you.