http://www.timesonline.co.uk/article/0,,8122-2521642.html              The Times,      December 30, 2006

Roger Dobson

Where and when you are born really does affect what happens throughout your life. But it has nothing to do with what is mapped in the stars or whether you are Taurus, Aries or Libra. It has everything, instead, to do with one star in particular, the Sun.

Research shows that the latitude of your birthplace and how much solar radiation you were exposed to in the womb affects your health, wealth, happiness, longevity and creativity. It is because one type of radiation emitted by the sun, ultraviolet (UVR), is believed to cause genetic changes in the developing baby that may have a shaping effect, either beneficial or harmful. It could explain why many of us believe that common characteristics and fates are shared by those born at the same time of year.

For example, researchers at the University of Rostock, in Germany, have analysed data to see if the month in which you are born affects how long you will live. It does. Their research found that your chances of living beyond 100 were up to 16 per cent higher than average if you were born in December, but if you were born in June, your chances were 23 per cent lower. Another study from the University of Chicago, published in the Journal of Anti-Aging Medicine, backed this up, finding that those born in December lived longer by about three years.

Where you are born can be equally influential. The area between the lines of latitude 53N and 54N, which covers much of Northern England, taking in Liverpool, seems to be particularly influential. A series of studies on the influence of latitude on wellbeing, by scientists at Maine Hospital, USA, has found that being born in Liverpool significantly increases your chances of being creative, which could explain why it has produced so many creative people: the Beatles, Beryl Bainbridge and Sir Simon Rattle all hail from the city.

It sounds bizarre, but the findings fall into a wider pattern of studies that have found links between the time and location of your birth and various traits and disorders, too, including cancer, dental health, asthma, happiness, depression, mental illness, multiple sclerosis, type 1 diabetes, rheumatoid arthritis, allergies and blood pressure levels.

The reasons for the link are not fully understood, but it has been suggested that the amount of solar radiation we are exposed to in the womb is a key influence. The amount of radiation varies according to where you are in the world, what time of year it is and cyclic changes in the sun’s behaviour. The Equator generally gets the most radiation, and in the northern hemisphere, the usual radiation peaks will be in June and July, but there will be variations from year to year according to “solar cycles”. Every 11 years the Sun goes through a cycle when the magnetic field changes and the number of sunspots grows and dwindles. This affects the amounts of radiation produced.

The Maine researchers suggest that high radiation levels either stress the immune system of embryos and foetuses or cause small mutations in their DNA, which can either predispose or protect from disease, mould brain characteristics and influence length of life.

So the reason that people born in December might live longer could be that they were conceived in March, possibly avoiding the most harmful affects of radiation early on, when the embryo is at its most vulnerable, but also avoiding very low levels of UVR that might predispose people to certain conditions. And the Liverpool “creativity” finding seems to depend on the fact that the UVR exposure associated with particular lines of latitude can have a specific physical effect; in this case, on the development of the brain.

The Maine studies focused on the way that UVR exposure varies according to latitude, and the effects this seemed to have on the characteristics and health of populations. “Where and when we are born does have an influence on our futures,” says Dr George Davis, the physician and scientist who led the studies. “This is not astrology, this is basic science. The sun has been around for a few billion years,” says Dr Davis. “It would be surprising if life did not march to its beat; 98 per cent of the time it is benevolent, but 1 or 2 per cent of the time it is destructive.”

This conclusion is backed by his research on the prevalence of 37 types of disease among more than 250,000 people in Maine. Their birth dates were checked against levels of solar activity at the time, and then compared with the diseases they had contracted. The results revealed that overall disease rates in those born at times of peak solar radiation were 28 per cent higher. Dr Davis says it is unlikely that this is a chance association because the pattern held over seven separate solar cycles in the study: “We propose that solar radiation peaks are the prime cause for genetic disruption of all life.”

The peaks affect personality as well as disease. The Maine researchers say that UVR may alter brain chemistry early in an embryo’s development, influencing traits such as creativity. They used theoretical mathematics as an indicator of creativity, and cited St Andrews University data showing that most of the world’s greatest creative mathematicians were conceived near the summer solstice.

Dr Davis and his team calculate that over the past 400 years, 54 per cent of mathematicians were born at a latitude of 53N. This could be because UVR variations are at their highest there, presenting a greater risk of disease, but also a greater chance of creativity.

The work at Maine finds support in a range of studies indicating that autoimmune conditions, such as multiple sclerosis, type 1 diabetes and rheumatoid arthritis, become more common the farther away a population is from the Equator. There is also research indicating that the prevalence of diseases and traits varies according to season of birth. People born in late winter and early spring have a 10 per cent greater chance of developing schizophrenia, while those conceived in autumn are more likely to suffer from diabetes, Crohn’s disease and asthma, according to research in the American Journal of Gastroenterology, Environmental Health Perspectives and the International Journal of Epidemiology. Conception in late spring and early summer produces an increased risk of dyslexia, multiple sclerosis, bipolar disorder, narcolepsy, seizures and autism, according to reports in the American Journal of Gastroenterology, International Journal of Epidemiology, Sleep, the British Medical Journal and Current Opinion in Gastroenterology.

One of the newest and strongest pieces of evidence for links between latitude, sun exposure and health comes from a study by researchers at University Hospital Malmö, in Sweden, who compared rates of osteoporosis in the South compared with the North. They found that for each 10-degree change in latitude there was a 0.8 per cent increase in risk of a hip fracture.

Virtually every aspect of our health and welfare can be explained according to the same theories (see panel, left). They may remain unproven for now, but for those who want to look into the future, they have a good deal more scientific credibility than horoscope charts and tarot cards.

Happiness
Happier people are more likely to have been conceived in the summer, according to a Vienna University study. Meanwhile, a study at the University of Tokyo found that people born between December and February were more likely to be disagreeable than those born at other times of the year.

Personality
Psychiatrists at the University of Umeå, in Sweden, looked at personality differences in 2,000 people and found that women born between February and April were more likely to be novelty seekers than those born in October and January. Men born in spring were more likely to be impulsive, while winter-borns were prone to be thinkers.

Intelligence
Winter-born children are bigger and brighter than those born in summer. Psychiatrists and anthropologists from Harvard and Queensland universities tracked the development of 21,000 boys and girls over seven years, and found seasonal variations in intelligence, weight, height and head size.

Exam success
Research at the University of Vienna indicates that female students born in spring and summer achieved better marks than those born in autumn and winter. Male students born in spring had worse grades than those born at other times. Women born in May had the highest exam results.

Dental disease
A Harvard University study showed that dental disease increased the farther you are from the Equator, and the coast. The researchers say sunshine, temperature, rainfall and humidity seem to be factors.

Multiple sclerosis
Studies have shown that the prevalence of MS increases with distance from the Equator. Researchers at Oxford University found that people with MS seem to be 60 per cent less likely to get skin cancer: in other words, the research suggests lower solar radiation increases the chance of MS, while lessening your chance of skin cancer.

Menopause
Sunlight and latitude at birth may affect menopause later in life. Doctors at the University Hospital Clinics of Modena, Italy, investigated 2,500 women to see if menopausal symptoms could be linked to birth dates. Those born in the autumn had the least symptoms, and those born in the spring had the most.

Prostate cancer
Countries north of the 40N latitude (passing just above Lisbon and below Naples) have some of the highest global health risks, according to a study at Wake Forest University, USA, based on 45 years of data.

Heart disease
Work at Bristol University has shown that those born in winter have a greater risk of developing heart disease, while a Southampton University study indicated that being born in the colder months of the year may increase the risk of obesity.