Does living in a sunny place reduce the risk of a child developing ADHD?
Correlational data only. Interpretation speculative.
The percentage of the variance in ADHD explained by sunlight (correlations around .7) was extremely high but that is to be expected of ecological correlations.
Individuals were not examined. High sunlight AREAS and high ADHD AREAS were correlated. Are high sunlight areas simply less likely to REPORT ADHD? Could be. The study may simply show that plenty of sunlight makes you Pollyanna-ish
Children who live in sunny areas may be less likely to suffer from ADHD, a new study suggests.
Dutch researchers have found that very sunny regions have a lower prevalence of the condition, suggesting that high sunlight intensity may exert a 'protective' effect.
Researchers came to the conclusion after analysing maps that showed the U.S. states (and nine other countries) most affected - and how sunny they were.
Even after taking into account other factors that are known to be associated with ADHD, they found there was still a relationship between solar intensity and how many children suffered from the condition.
To test their theory further, the researchers also looked at whether there appeared to be relationship between sunlight exposure and autism or major depressive disorders - but there was not.
The data maps were released by the U.S. Centers for Disease Control and Prevention and the U.S. Department of Energy.
Study leader Martijn Arns, of Utrecht University in the Netherlands, suggests that our biological clocks may help explain the apparent connection with sun exposure.
Sleep disorder treatments intended to restore normal circadian rhythms, including light exposure therapy, have been shown to improve ADHD symptoms.
He suggests one solution in less sunny areas could be to install more skylights in classrooms and schedule playtime to get maximum sun exposure.
And that with our heavy use of tablets, smartphones and PCs - which disrupt sleep - manufacturers should develop colour-adjusted screens to filter out disruptive blue light.
ADHD is the most common childhood psychiatric disorder, with an average worldwide prevalence of about five to seven per cent, but it also varies greatly by region.
Symptoms include an inability to focus, poor attention, hyperactivity, and impulsive behavior, and the normal process of brain maturation is delayed in children with ADHD. Many people also report sleep-related difficulties and disorders.
Scientists do not know what causes it, but genetics play a clear role. Other risk factors have also been identified, including premature birth, low birth weight, a mother's use of alcohol or tobacco during pregnancy, and environmental exposures to toxins like lead.
The research is published in the current issue of Biological Psychiatry.
Commenting on the findings, editor Dr. John Krystal, said: 'The reported association is intriguing, but it raises many questions that have no answers. 'Do sunny climates reduce the severity or prevalence of ADHD and if so, how? Do people prone to develop ADHD tend to move away from sunny climates and if so, why?'
Geographic Variation in the Prevalence of Attention-Deficit/Hyperactivity Disorder: The Sunny Perspective
By Martijn Arns et al.
Attention-deficit/hyperactivity disorder (ADHD) is the most common psychiatric disorder of childhood, with average worldwide prevalence of 5.3%, varying by region.
We assessed the relationship between the prevalence of ADHD and solar intensity (SI) (kilowatt hours/square meters/day) on the basis of multinational and cross-state studies. Prevalence data for the U.S. were based on self-report of professional diagnoses; prevalence data for the other countries were based on diagnostic assessment. The SI data were obtained from national institutes.
In three datasets (across 49 U.S. states for 2003 and 2007, and across 9 non-U.S. countries) a relationship between SI and the prevalence of ADHD was found, explaining 34%–57% of the variance in ADHD prevalence, with high SI having an apparent preventative effect. Controlling for low birth weight, infant mortality, average income (socioeconomic status), latitude, and other relevant factors did not change these findings. Furthermore, these findings were specific to ADHD, not found for the prevalence of autism spectrum disorders or major depressive disorder.
In this study we found a lower prevalence of ADHD in areas with high SI for both U.S. and non-U.S. data. This association has not been reported before in the literature. The preventative effect of high SI might be related to an improvement of circadian clock disturbances, which have recently been associated with ADHD. These findings likely apply to a substantial subgroup of ADHD patients and have major implications in our understanding of the etiology and possibly prevention of ADHD by medical professionals, schools, parents, and manufacturers of mobile devices.
Is a high-fat diet GOOD for the heart? Doctors say carbs are more damaging to the arteries than butter or cream
The great backflip has begun
Cutting back on butter, cream and fatty meats may have done more harm to heart health than good.
Experts say the belief that high-fat diets are bad for arteries is based on faulty interpretation of scientific studies and has led to millions being ‘over-medicated’ with statin drugs.
Doctors insist it is time to bust the myth of the role of saturated fat in heart disease, which was based on faulty interpretation of scientific studies.
Some western nations, such as Sweden, are now adopting dietary guidelines that encourage foods high in fat but low in carbs.
Cardiologist Aseem Malhotra says almost four decades of advice to cut back on saturated fats found in cream, butter and less lean meat has ‘paradoxically increased our cardiovascular risks’.
He leads a debate online in the British Medical Journal website bmj.com that challenges the demonisation of saturated fat.
A landmark study in the 1970s concluded there was a link between heart disease and blood cholesterol, which correlated with the calories provided by saturated fat.
‘But correlation is not causation,’ said Dr Malhotra, interventional cardiology specialist registrar at Croydon University Hospital, London.
Nevertheless, people were advised to reduce fat intake to 30 per cent of total energy and a fall in saturated fat intake to 10 per cent.
Recent studies fail to show a link between saturated fat intake and risk of cardiovascular disease, with saturated fat actually found to be protective, he said.
One of the earliest obesity experiments, published in the Lancet in 1956, comparing groups on diets of 90 per cent fat versus 90 per cent protein versus 90 per cent carbohydrate revealed the greatest weight loss was among those eating the most fat.
Professor David Haslam, of the National Obesity Forum, said: ‘The assumption has been made that increased fat in the bloodstream is caused by increased saturated fat in the diet … modern scientific evidence is proving that refined carbohydrates and sugar in particular are actually the culprits.’
Another US study showed a ‘low fat’ diet was worse for health than one which was low in carbohydrates, such as potatoes, pasta, bread.
Dr Malhotra said obesity has ‘rocketed’ in the US despite a big drop in calories consumed from fat. ‘One reason’ he said ‘when you take the fat out, the food tastes worse.’
The food industry compensated by replacing saturated fat with added sugar but evidence is mounting that sugar is a ‘possible independent risk factor’ for metabolic syndrome which can lead to diabetes.
Dr Malhotra said the government’s obsession with cholesterol ‘has led to the over-medication of millions of people with statins’. But why has there been no demonstrable effect on heart disease trends when eight million Britons are being prescribed cholesterol-lowering drugs, he asked.
Adopting a Mediterranean diet after a heart attack is almost three times as powerful in reducing death rates as taking a statin, which have been linked to unacceptable side effects in real-world use, he added.
Dr Malhrotra said ‘The greatest improvements in morbidity and mortality have been due not to personal responsibility but rather to public health.
‘It is time to bust the myth of the role of saturated in heart disease and wind back the harms of dietary advice that has contributed to obesity.’
Dr Malcolm Kendrick, a GP and author of The Great Cholesterol Con, said Sweden had become the first western nation to develop national dietary guidelines that rejected the low-fat myth, in favour of low-carb high-fat nutrition advice.
He said ‘Around the world, the tide is turning, and science is overturning anti-fat dogma.
'Recently, the Swedish Council on Health Technology assessment has admitted that a high fat diet improves blood sugar levels, reduces triglycerides improves ‘good’ cholesterol - all signs of insulin resistance, the underlying cause of diabetes - and has nothing but beneficial effects, including assisting in weight loss.
‘Aseem Malhotra is to be congratulated for stating the truth that has been suppressed for the last forty years’ he added.
Timothy Noakes, Professor of Exercise and Sports Science, University of Cape Town, South Africa said ‘Focusing on an elevated blood cholesterol concentration as the exclusive cause of coronary heart disease is unquestionably the worst medical error of our time.
‘After reviewing all the scientific evidence I draw just one conclusion - Never prescribe a statin drug for a loved one.’