Toxic "forever chemicals" in the blood linked to poor sleep

Toxic “forever chemicals” are a major environmental problem, and a growing body of research shows they’re also a major health problem. A new study has found people with higher levels of PFAS in their blood have poorer sleep.

A group of chemicals known as per- and polyfluoroalkyl substances (PFAS) is very effective at repelling water, oil, grease and heat, so they make for excellent waterproof clothing, non-stick cookware and firefighting foam.

But that same stability means they linger in the environment more or less indefinitely, earning them the nickname of “forever chemicals.” Unfortunately they also turn up in high levels in the human body, where they’ve been linked to conditions like diabetes, cancers, immune system disruptions and others.

A new study adds another health problem to that list. Researchers at the University of Southern California (USC) have now found that people with higher levels of four types of PFAS generally have shorter and lower quality sleep.

The team collected blood samples from 144 participants, aged 19 to 24, and examined the levels of seven types of PFAS in them. This was then cross-checked with information on the patients’ sleeping patterns.

Four of those types of PFAS were found to be significantly associated with poor sleep. Patients with the highest blood levels of PFDA, PFHxS and PFOA were found to sleep about 80 fewer minutes on average than those with lower levels. Another type, PFOS, was significantly linked to problems falling asleep, staying asleep, waking up and daytime tiredness.

To find a potential mechanism behind the correlation, the team investigated which genes these four PFAS affect, and which genes are related to sleep disorders, to see if there was any overlap. Finally, they checked which proteins were found in the patients’ blood samples, to see if there were elevated levels of proteins produced by the identified genes.

From this, the researchers identified seven genes that are both activated by PFAS and influence sleep. A gene called HSD11B1, for instance, helps produce cortisol, the hormone that helps keep you alert at key times of day or during periods of stress.

“If the expression of the protein encoded by HSD11B1 is disrupted, that means that cortisol levels could also be disrupted,” said Shiwen Li, first author of the study. “That, in turn, affects sleep.”

Another gene they identified is cathepsin B. High levels of the enzyme it produces has been linked to the cognitive decline that comes with Alzheimer’s disease.

The researchers plan to continue research into the potential sleep disruptions of these forever chemicals. So far there’s little that can be done to reduce the levels of PFAS in your body, besides making regular blood donations.

The research was published in the journal Environmental Advances.

Source: USC