Hello! This week’s Health newsletter focuses on microplastics in the brain, the first 10 minutes of exercise, a better way to wake up ... and the case for taking off your shoes in the house. Plus, will this new blood test replace colonoscopies?

PHOTOGRAPH SAMUNELLA, SCIENCE PHOTO LIBRARY 

A startling study has found microplastics and nanoplastics accumulate at higher levels in the human brain than in the liver and kidneys—and at significantly higher concentrations over the last eight years. There are particularly alarming findings for people with dementia.

Related:

--In a first, microplastic particles have been linked to heart disease
--How much harm do microplastics cause?
--What are the signs of dementia—and why is it so hard to diagnose?

PHOTOGRAPH BY ANDY MANN, NAT GEO IMAGE COLLECTON 

PHOTOGRAPH BY ROBERT MADDEN, NAT GEO IMAGE COLLECTION 

Does kicking off shoes at the door really keep germs—and illness—at bay? Or is it just a legend? Science finally has an answer.

Related: 

--Kids are losing fine motor skills, and screens may be to blame
--Here’s why handwriting still matters

PHOTOGRAPH BY JOEL SARTORE, NAT GEO IMAGE COLLECTION 

New research is focusing on the importance of the first 10 minutes of exercise. What happens during that time? 

A. Blood flow changes
B. Your brain becomes more alert
C. Your heart rate spikes
D. All of the above 

Today’s Soundtrack: Little Girl Blue, Nina Simone

Today’s newsletter was edited and curated by David Beard and produced by Alisher Egamov. Thanks for reading! Have a suggestion? Let us know.