Sunlight leads to protection against cancer and other illnesses

Discussion in 'Health and medical' started by Habshi, Jan 25, 2004.

  1. Habshi

    Habshi Guest

    The hijab and burqa are stupid outfits and should be banned in children under 18 as a form of
    child abuse. excerpt Sunny D It's the great cancer cover-up. Panicked into avoiding sunlight by
    health experts, we are now dying in our thousands from diseases linked to deficiencies of vitamin D.
    But still the exaggerated warnings come. Oliver Gillie reveals how sunbathing can save your life 25
    January 2004

    How many times have you heard it: "There's no such thing as a healthy tan." Second only to "smoking
    kills", avoiding the sun is the health advice that has most permeated our conciousness. Young and
    old, rich and poor, everyone knows that exposure to the sun puts us at risk of skin cancer. But does
    it? What if the advice we've been given to avoid the sun is wrong? What if hiding your skin from
    those seductive rays is putting your health in danger?

    While every summer cancer charities and skin experts launch their annual campaign to persuade
    people, against their natural inclination, to cover up and stay out of the sun, there is growing
    evidence that lack of exposure to sunlight is responsible for a multitude of disease from multiple
    sclerosis and diabetes to several types of cancer and schizophrenia. And it's all down to a
    deficiency of vitamin D - some 90 per cent of which we get from sunlight.

    Most medical researchers have been slow in recognising the potentially lethal consequences of
    vitamin D deficiency. In part this is because vitamin D is not the only trigger for these diseases.
    However in the British Isles with our long winters and cloudy summers, it seems that insufficient
    exposure to the sun can make the difference between illness and health, between life and death.

    Dr Peter Selby, lecturer in medicine at Manchester Royal Infirmary, says: "Reducing exposure to
    solar radiation, far from preventing cancer, may have the opposite effect." He points out that a 10
    per cent decrease in exposure to sunlight would not greatly reduce skin cancer but could lead to a 6
    per cent increase in certain other cancers. And these extra cancer deaths, he points out, would
    exceed all the deaths from skin cancer put together.

    In the UK about 14,000 women a year die of breast cancer - some 40 per cent of these may be caused
    by deficiency of vitamin D, estimates William Grant, a NASA scientist who has become an expert in
    vitamin D epidemiology. He calculates that 12-15% of all cancers in the UK, apart from lung cancer,
    are linked to vitamin D deficiency. That adds up to some 20,000 cancer deaths a year in the UK
    resulting from too little exposure to the sun, compared with only 2,000 deaths per year from skin
    cancer of all kinds - not all of which are caused by too much sun. Melanoma, the commonest skin
    cancer (1,600 deaths per year) may also be caused by diet, overweight and lack of exercise.

    Multiple sclerosis is almost unknown in Europeans who are born in South Africa and so in the old
    days, when doctors worried about the rigours of weather, people with MS were often advised to move
    to a sunnier climate. Many studies have since shown that MS is more common in cold northern
    latitudes than it is in sunnier places. In a pioneering study in the 1960s, Professor Sir Donald
    Acheson, now Dean of Southampton Medical School, found that MS in US war veterans was most closely
    related to the amount of December sunlight in their place of birth. Winter sunshine, which we now
    know can make a crucial difference to vitamin D stores, was implicated.

    But Acheson's ideas fell on stoney ground. "Sunshine? More like moonshine, what absolute poppycock,"
    one senior colleague remarked in a public put down. It was an idea before its time and the work
    remained a curiosity, largely forgotten until now.

    Over the next 40 years several quite different diseases were found to be linked geographically with
    MS. Deaths from cancer of the colon and cancer of the prostate were found to be most frequent in the
    same countries where deaths from MS are most often seen. These were the least sunny northern
    countries of Europe and the least sunny northern states of the US. Dental decay and rickets were
    also found to be most common in these areas. And strangest of all, schizophrenia, an extremely
    disabling mental illness, was found to be more common in the colder northern states of America and
    in colder northern districts of Italy. While Parkinson's disease, another nervous disorder (causing
    primarily tremor and stiffness), had a similar geographical distribution.

    Theories abounded. Sunlight was too obvious an answer for many researchers. Nor did anyone dare
    suggest that such different nervous diseases as schizophrenia, Parkinson's disease and MS might all
    have the same ultimate cause. Perhaps, they proposed, the diseases were caused by viruses? People in
    the north eat more fat, perhaps that was causing these diseases? Maybe it was all a matter of
    heredity. The research was like a giant jigsaw puzzle with thousands of pieces. But many important
    pieces were missing, and thousands of pieces from other jigsaws were muddled up in the same box.
    Nevertheless, piece by piece connections were made and the jigsaw began to fit together.

    According to one school of thought, MS is a hereditary disease of northerners, possibly borne round
    the world by Vikings. Researchers rushed to find the MS gene. But now Australians, who over the
    years have received the most dire warnings to keep out of the sun, have found that MS is six times
    less common in tropical Queensland than it is in Tasmania which has much less sun, particularly in
    winter. Genetics could not explain the difference: the people of Tasmania and Queensland have the
    same Anglo-Irish and European ancestors. Children in Tasmania who did not develop MS were more
    likely to have spent two to three hours a day playing outdoors in summer during weekends and
    holidays. Maybe these diseases can be prevented by playing in the sun. Fun in the sun, could the
    answer be so simple?

    Then came a breakthrough. MS is caused by patches of damage in parts of the brain and spinal cord
    leading to severe disability and eventually paralysis. The symptoms come and go. People with MS may
    improve for a while and then relapse for no apparent reason, until now. Brain scans of people with
    MS investigated by a team of scientists in Germany have shown that the number of MS lesions increase
    during winter when the amount of vitamin D in the body declines.

    And other pieces of the jigsaw were falling into place. In 1992 Gary Schwartz, a researcher at the
    University of Pittsburg, suggested that the common factor linking MS and prostate cancer could be
    vitamin D. Schwartz showed that consumption of cod liver oil (a good source of vitamin D) in youth
    reduces the risk of prostate cancer in old age. Finally evidence linking prostate cancer directly
    with sunlight came two years ago from Professor Richard Strange and colleagues at Keele University.
    They found that men in North Staffordshire with prostate cancer had had substantially less exposure
    to the sun than men who did not have prostate cancer. On average, men who had least exposure to the
    sun developed prostate cancer four years earlier than men who had more exposure. Regular foreign
    holidays and sunbathing were found to protect against the disease.

    Northern Europe is not man's natural environment. Recent studies of human DNA tell us that man
    evolved in Africa. Small bands of people left the African continent some 80,000 years ago following
    the southern coast of Asia, and eventually colonising what is now Iraq and Iran. These people, who
    were almost certainly dark skinned, moved into Europe via Turkey, the Black Sea and the
    Mediterranean as the northern ice cap retreated some 50,000 years ago. The story of this epic human
    journey has been reconstructed from modern DNA studies and is told by Oxford professor Stephen
    Oppenheimer in his authoritative book "Out of Eden".

    The virgin territory of Europe must have supplied plentiful food in summer but in winter not only
    was food in short supply, low levels of vitamin D must have increased the susceptibility of these
    pioneering bands of people to disease and reduced their fertility. Dark skin takes six to 10 times
    as long as white skin to make a given quantity of vitamin D and so those with lighter skins would
    have had an advantage as the pioneers moved north.

    The importance of skin colour for human survival outside the Tropics has been shown by Dr Nina
    Jablonski of the California Academy of Sciences in San Fransisco and George Chaplin of Manchester
    Metropolitan University. They found that skin colour of 180 different indigenous peoples is linked
    closely to the amount of autumn and winter sunlight where they live. Not only do native peoples
    everywhere have paler skins the further they live from the equator, but women and children in the
    human groups studied by Dr Jablonski always had paler skins than men, a neat adaptation to provide
    the maximum vitamin D that is needed for fertility in women and growth in children.

    Northern Europe was the end of the line for the successive waves of people travelling through Turkey
    and the Balkans after the ice age. It was further north than man had ever lived before and the
    cloudy maritime climate of the British Isles and other countries bordering the North Sea have
    reduced sunlight even in summer. And so Europeans evolved a pale skin that enables the first weak
    rays of spring sun to be used to make vitamin D. This enables body stores of the vitamin depleted
    during winter to be replaced at the earliest opportunity, while tanning provides some protection as
    sunlight becomes stronger over the summer. For thousands of years into historic times, Europeans
    living an outdoor life in the countryside do not seem to have suffered from obvious vitamin D

    But in the past 400 years, when large numbers of people began to congregate in towns and cities a
    severe problem of vitamin D deficiency developed. In 1650, treatises were written on rickets, the
    bone deforming disease of children that became known as the English disease. The disease was most
    common in cities, where narrow streets and air pollution prevented the penetration of the sun.
    Children developed deformities of the legs which made it difficult for them to walk and women
    suffering from the disease had flat deformed pelvises which caused difficulty in childbirth.

    The link between rickets and lack of sunlight was not made until 1822 when a Polish doctor noted
    that children living in Warsaw frequently suffered from the disease while children living in the
    surrounding countryside did not. He recommended fresh air and sunlight. In 1889 the British Medical
    Association reported that rickets, common in cities, was unknown in rural areas. A year later
    another British doctor reported in the Practitioner that rickets did not occur among the poor living
    in the city slums of China and India and concluded that exposure to sunlight would prevent the
    disease. It would be another 30 years before these ideas began to be accepted.

    The demonstration in 1919 that ultra-violet light from a mercury arc lamp could cure rickets in
    children provided dramatic scientific "proof" that rickets was caused by lack of sunlight. At about
    the same time it was shown that cod liver oil (which is now known to be rich in vitamin D) could
    cure rickets in dogs raised exclusively indoors. It took a few more years for scientists to
    chemically identify vitamin D and show that it was responsible for the ability of cod liver oil to
    cure rickets. By the 1930s vitamin D was being added to foods such as margarine and rickets became
    relatively rare.

    The discovery of vitamin D was an early triumph of modern science which caught the public
    imagination and fed the craze for city people to seek health in the open air. Cycling, rambling and
    youth hostelling all became immensely popular between the two world wars - a movement which reached
    a summit of sorts with the invention of the bikini by a French engineer in 1946. The full delight of
    sun on naked skin was re-discovered and forty years of carefree sunbathing followed before the
    spectre of skin cancer cast its pall over summer fun.

    Nicolai Gogol's short story Dairy of a Madman (1834) is one of the earliest and most complete
    descriptions of schizophrenia. Brief accounts of the disease had appeared in Paris and London in
    1809 but, with the possible exception of the character Poor Tom in Shakespeare's King Lear, earlier
    descriptions of schizophrenia do not seem to exist. Schizophrenia appears to have been virtually
    unknown before 1800 while most other psychiatric and nervous diseases such as epilepsy are described
    in the Old Testament or other early historical works.

    These literary observations made by Dr Eric Altschuler of the Brain and Perception Laboratory at the
    University of California provide historical support for a theory that schizophrenia may be caused by
    a deficiency of vitamin D during pregnancy. Schizophrenia, it seems, emerged as a new disease with
    the great expansion of modern European cities, at much the same time as rickets began its most
    devastating phase.

    For many years geneticists claimed that schizophrenia was an inherited disease and poured scorn on
    other ideas. But they were at a loss to explain why people with schizophrenia had winter birthdays
    more often than would be expected. Extra vitamin D is required in the last three months of pregnancy
    to support the rapid growth of the baby. When the level of the vitamin is low, as occurs most
    frequently in winter, there may not be enough to provide for normal development of the brain or
    other organs causing more winter births of people with schizophrenia.

    The nervous system of the developing baby may be damaged in other ways by vitamin D deficiency.
    Other diseases which occur more frequently than would be expected in babies born in winter or early
    spring are autism, Alzheimer's disease, Parkinson's disease, and MS. The cause of these diseases is
    still being hotly debated by experts but vitamin D deficiency is one theory that is gaining
    increasing support. Like schizophrenia, these diseases may appear to be more strongly inherited than
    they really are because family members influence each other in the way they seek or avoid the sun.

    Schizophrenia is one of several diseases that has been found to be more common among dark-skinned
    people than among whites in Britain. Diabetes, multiple sclerosis, autism and rickets have also been
    reported to be more frequent among immigrant families who came to Britain from Tropical countries.
    First generation immigrants born in the Tropics are no more vulnerable to schizophrenia than native
    British whites, but the disease is more frequent among their children than among white British
    people, according to several research studies led by Professor Glynn Harrison at the University of
    Nottingham, Dr Dinesh Bhugra at the Institute of Psychiatry, London, and others.

    Many explanations, including prejudice, psycho-social stress and inheritance have been considered,
    but they do not explain the facts. Investigators have repeatedly pointed to the consistency of their
    findings and concluded that an environmental factor must be responsible. Now in the light of other
    research it seems obvious that deficiency of vitamin D, caused by the slow absorption of ultra-
    violet light by black skin and low levels of sunlight in northern climates, is the most likely
    explanation for the increased incidence of these diseases in immigrant families.

    Not only are more people with schizophrenia born in winter, the number of people born each year who
    later develop the disease varies from year to year in a way that cannot be explained by chance.
    Investigations by Dr John McGrath and others at the University of Queensland have linked this
    variation in births of schizophrenic people with the amount of sunlight around the time of their
    birth. The observations fit in neatly with new findings that show the importance of vitamin D for
    growth of cells and for the development of the brain.

    Dr McGrath, an Australian who is currently working at Harvard University, says: "Queensland, where I
    live, is in the Tropics so we get strong sun all the year round. I try to sit out in the sun every
    day and when I go to the beach with the children we have a half hour of exposure to the sun before
    we put on any suncream. Sunlight is specially important for pregnant and nursing mothers."

    Babies in Finland often used to be given very large doses of vitamin D in the first year of life and
    now Dr McGrath, working with Finnish doctors, has shown that men who were given these large
    supplements as babies are less likely to develop schizophrenia than men who were not given the
    supplement. This same group of men given vitamin D as babies have been found to be less likely to
    develop diabetes before the age of 30. And in the UK people with this type of juvenile diabetes
    (known as diabetes type 1) are more likely to be born in the winter or early spring months when
    vitamin D is in short supply.

    In juvenile diabetes the beta cells in the pancreas that normally produce insulin do not develop
    properly and are attacked by the body's own immune system. Deficiency of vitamin D is probably what
    causes these cells to develop abnormally, triggering the assault. Now a dramatic demonstration that
    vitamin D can rescue beta cells that are being attacked in this way is likely to sway scientific
    sceptics. Two independent trials conducted in Rome and Munich have shown that giving vitamin D to
    children when diabetes is first diagnosed can save the beta cells, at least temporarily, and delay
    development of the disease.

    But these trials of the health benefits of vitamin D supplements are exceptional. Few trials have
    been made of vitamin D for treatment of diseases other than bone disease because the vitamin cannot
    be patented and drug companies cannot justify expensive trials which will not lead to profits.
    However trials of several compounds similar to vitamin D have begun recently for treatment of cancer
    because these compounds can be patented.

    Crucial pieces of the jigsaw puzzle now seem to be in place and a consistent picture has emerged
    although many researchers remain sceptical, especially those who have spent most of their lives
    committed to other theories. The sceptics point to technical difficulties in the scientific evidence
    and the lack of final proof that vitamin D is the cause of most of these diseases. But the weight of
    so many different studies demonstrating or suggesting the health benefits of sunbathing and vitamin
    D supplements can no longer be overlooked.

    Yet every year doctors repeat the mantra: "There is no such thing as a healthy