Sleeping with even a little bit of light isn't good for your health, study shows

Just a night or two of exposure to faint light is enough to raise your pulse and increase insulin resistance - factors that increase the risk of heart disease and diabetes, researchers find.

The findings tie into a broader body of evidence that indicates being exposed to light at night may be harmful in a variety of ways and could predispose people to chronic diseases.

• An extensive study showed that unlike those who spent nights in the dark, the test group exposed to the light had elevated heart rates throughout the night.
• They also had increased insulin resistance in the morning, meaning they had more trouble getting their blood sugar into a normal range.
• Artificial light at night can suppress melatonin levels, and scientists have found a link between the disruption of melatonin and several diseases, including cancer and diabetes.