New Delhi, Oct 5 : High levels of per- and polyfluoroalkyl substances (PFAS) also known as "forever chemicals" in your blood can make it difficult for you to sleep properly, which can act as a precursor to several diseases, finds a study.

Previous studies have shown that the 'forever chemicals' have contaminated water, food, and people through products such as Teflon pans, waterproof clothing, stain-resistant carpets and fabrics, and food packaging. Studies have also shown their role in cancers of the breast, ovary, skin, and uterus in women, among other diseases.

The new research led by the University of South California (USC) linked higher levels of four specific types of PFAs in the blood with disruptions to a fundamental pillar of health -- sleep.

PFAS enter the body through contact with consumer items and are even ingested with food and water. They don't break down easily and can persist in the environment for decades.

Sleep is an essential component of good health. A person must sleep 7-8 hours of sleep daily. Prolonged poor sleep may raise chronic health issues, including diabetes and Alzheimer's disease.

In the study, published in the journal Environmental Advances, the team collected blood samples and information about sleep from 144 participants, ages 19 to 24.

Out of seven types of PFAS examined, four were significantly associated with less sleep or worse quality of sleep -- PFDA, PFHxS, PFOA, and PFOS.

The young adults with higher levels of these toxic chemicals in the blood had 80 fewer minutes of sleep at night. They also had trouble falling asleep, staying asleep, waking up, or feeling tired during waking hours.

All four forever chemicals -- some of which are associated with cancer and neurological disorders from ADHD to Alzheimer's disease -- are considered "legacy PFAS."

In the study, the team also looked at the overlap between genes affected by the four forever chemicals and genes related to sleep disorders.

Out of 600-plus candidate genes, seven activated by PFAS seemed to influence sleep. This included HSD11B1 -- which helps produce the hormone cortisol that plays an important role in regulating the rhythm of sleep and wakefulness.

Another gene was cathepsin B -- related to cognitive function and memory. Disruption in this gene was linked to Alzheimer's.

/IANS