Do Eyeshades Protect Against Obesity and Cancer?

In Newsweek last December, science writer Sharon Begley pulled together research showing that lab animals and pets are getting fatter, just like people: “In Macaques, living in research colonies, average weight gain rose about 10 percent per decade. Chimps in the lab had a 14-fold increase in obesity, with weight increasing 34 percent per decade. Pet cats: a 38 percent increase in obesity, with weight up 10 percent per decade. Pet dogs: a weight gain of just 3 percent. Those alley rats: a 21 percent increase in obesity. Government lab mice: weight gain of 12 percent per decade.”

Such data from animals suggest that the human obesity crisis is not only the result of our consuming larger portions of food and our sedentary lifestyles. The problem may be more complex.

Begley notes new research showing that bacteria in our gut affect how many calories we extract from food. So a shift in bugs could be making us fatter. So could our lack of sleep, which stimulates appetite hormones, or better heating and air conditioning, which means we burn fewer calories. Or endocrine disruptors like BPA in plastics. Writes Begley, “It’s time to expand the set of possible suspects.”

About the same time as Begley’s article, the online edition of the Proceedings of the National Academy of Sciences added another powerful accomplice for weight gain: persistent exposure to light at night. Experimenting with mice, researchers at Ohio State University discovered that mice exposed to a relatively dim light at night over eight weeks had a body mass gain that was about 50 percent more than mice that lived in a normal light/dark environment, despite the fact the all the mice ate the same amount and had the same amount of activity.

The researchers report that mice living with lights on at night would eat at times they normally wouldn’t. In another study, mice exposed to light at night but that had food availability restricted to normal eating times gained no more weight than did mice in a normal light/dark cycle. “Something about light at night was making the mice in our study want to eat at the wrong times to properly metabolize their food,” said Randy Nelson, co-author of the study and professor of neuroscience and psychology at Ohio State.

Further studies with mice confirmed that mice living in dim light at night not only gained significant body mass within the first week but also showed higher levels of epididymal fat (adipose fat deposits within the abdominal cavity) and impaired glucose tolerance—a marker of pre-diabetes. The researchers believe that light at night, however dim, could disrupt levels of the hormone melatonin, which is involved in metabolism.

Light pollution is everywhere, and so it could be fattening pets, research animals, and us, too. But let’s expand this inquiry even wider:

In January, the journal Chronobiology International reported on a ten-year study from Haifa University in Israel showing that habitual exposure to light at night in the bedroom — such as from night lights, television sets, and outside light pollution — increases risk of developing breast cancer by 22 percent. Previous studies have shown that shift work at night is associated with increased risk of breast cancer, but this was the first major study showing the dangers of light while sleeping.

As with the fat mice, the culprit for breast cancer seems to be melatonin disruption. According to the researchers, melatonin not only modulates estrogen levels but acts directly as a first line of natural defense against cancer. Fortunately, the researchers write, “simple solutions exist, such as the installation of window blinds in the bedroom, and also by the use of eye covers while sleeping.”

If eyeshades and window blinds may be a good, frontline defense against breast cancer, they may also work against obesity.

Nevertheless, let’s keep this investigation wide open. What if the problem is not just the fields of energy we can see — the light pollution — but the electromagnetic energies that connect all the gizmos and gadgets of modern life? It’s a frightening question, but it may also have a simple solution: see “Barefoot Healing” Article.