News Flash: This Many Minutes of Movement May Prevent Depression, and Other Health News

Every week, we’re bringing you a roundup of the latest health and wellness news to hit the wire. This week, we look at the amount of movement needed to ward off depression, the effect that being unfit in your teens has on your middle-aged self, and how many times a day you should clean that germy smartphone.

Just this much movement may help ward off the blues

There’s no shortage of evidence that movement can have a positive impact on mood and well-being, but an innovative new study of hundreds of thousands of people published in JAMA Psychiatry and covered in The New York Times shows that 15 minutes of strenuous exercise a day such as jogging or longer bouts of walking or gardening could actually help protect people from developing depression in the first place.

The study, rather than following a certain set of exercisers and non-exercisers for years, involved tapping the UK Biobank, a database of genetic and health information for almost 400,000 men and women. From this information, they identified people who carried at least one of several gene variants believed to increase the likelihood that someone will be active. Most of these people worked out and few had experienced depression. People without the snippets of genes tended to move less and be at greater risk of depression.

Delving deeper into the data, scientists found that the ideal amount of movement to prevent depression started at about 15 minutes for the most vigorous forms of exercise. Less strenuous activities such as fast walking, housework and other movement also helped ward off the blues, but it took an hour a day to have the effect.

To further test this conclusion and make sure that depression wasn’t affecting the amount of activity in the pool, the scientists looked for gene variants related to depression and whether these people tended to be inactive. As it turns out, they were not, causing researchers to conclude that movement lowered the risk of developing depression and that depression did not affect whether people worked out.

Of course, researchers say it’s possible that the gene variant linked to being more active could play an antidepressant role, and more research is needed to clarify the linkages between movement and mental health.

No, he won’t grow out of it

If the majority of your teen’s time is spent hunched over a console playing Fortnite, there may be more at stake than you realize, according to this story in U.S. News & World Report.

A Swedish study published this month in the Annals of Internal Medicine, which followed more than 1 million boys for an average of 28 years, found that those who were inactive, obese or both as teens were more likely to have a chronic disease or be unable to work because of a disability in middle age.

Conversely, being moderately or highly fit as a teenager was related to a reduced risk for disability, whether one was obese or not. The study did not prove that being unfit or obese as a teenager causes disabilities in adulthood, only that the two are related.

However, the association is important because teens today are on average less fit and weigh more than previous generations.

“We need to increase our efforts to promote physical activity and prevent obesity starting in childhood,” said lead researcher Pontus Henriksson, a registered dietitian at the Karolinska Institute in Huddinge, Sweden.

How often should you clean your phone?

By now, you’ve probably heard that your phone is a petri dish, teeming with bacteria. Most of that bacteria is harmless, argues the epidemiologist and microbiologist in this article in Time. That said, some illness-causing germs that cause food poisoning, colds and other infections can be transferred to your phone and in turn into your body when you put food into your mouth or touch your ears, nose or breaks in your skin.

In addition to washing your hands before eating, if you use your phone all the time—particularly during eating—a daily cleanse with a disinfectant wipe is a good idea, particularly if you have a rubber phone cover, which bacteria love to cling to.

Photo credit: jacoblund, Thinkstock