Night Windows

Throw Open a Window to Prevent Obesity and Diabetes?

“Open your bedroom window at night to prevent obesity and type 2 diabetes.” The Telegraph reports this simple solution from an Oxford endocrinology professor. In a similar vein, the Guardian says “access to nature reduces depression and obesity.” That promise comes from a report of the Institute for European Environmental Policy.

Cool Night Air

Professor Asheley Grossman told the Telegraph about a “cool” theory for reducing diabetes and obesity:

There is some rather encouraging evidence that cooling the body, even by a few degrees, may improve or reduce diabetes. Living in a cool environment may be useful to increase insulin sensitivity and ward off diabetes.

Together with work indicating that adequate sleep can also help avoid obesity and diabetes, maybe we should all aim have a good night’s sleep in a cool bedroom with the windows open to the night breeze.

The sleep advice seems reasonable enough. Who can argue with a good night’s sleep? But the bit about a cool bedroom is a stretch. It comes from an analysis recently published by Blauw et al. They observed a small association between type 2 diabetes prevalence and higher outdoor temperatures. Bedroom temperatures were not part of the study.

Cambridge Professor Sir David Spiegelhalter offered appropriate caution:

Even if these estimates were true, it would mean a 2 degrees rise in average temperature was associated with an increased incidence of diabetes of 0.7 per cent.

In those circumstances I don’t think this would be the biggest concern.

Also, note that throwing windows open is terrible advice for people suffering from allergies.

Nature Claims

The ideas put forward in the Guardian about access to nature are a bit easier to accept. They come from a large narrative review of benefits from protecting nature and biodiversity. The Institute for European Environmental Policy commissioned the report.

It offers no sweeping claims about natural cures for obesity and other ailments. It does present a cogent case that access to nature can contribute to the health and well being of the population. Better opportunities for physical activity is one of the benefits the report describes.

Stretching the Evidence Thin

A walk in the woods, a good night’s sleep. Yes, the evidence is good that these activities have a health benefit. Stretching that evidence thin for bigger claims doesn’t help. It invites skeptics.

Click here for the study by Blauw et al and here for the report on it by the Telegraph. For the report on nature’s benefits, click here, and then here for reporting from the Guardian.

Night Windows, photograph © Betsy & Ian F-R / flickr

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March 27, 2017