People who are permanently exposed to certain chemicals may be at higher risk of developing multiple sclerosis (MS), according to a new study.

No one knows why, but it may help explain why the prevalence of MS has increased over the past 30 years. increased An average increase of 26% worldwide. In some countries, the number of infections has more than doubled since 1990.

MS is autoimmune disease A central nervous system disease with no specific cause or cure.

This new study conducted in Sweden suggests that chemicals may be a forever overlooked factor.

Related: Scientists discover there may be two different subtypes of multiple sclerosis

Decades of research have linked MS risk to several genetic variations and several important environmental exposures. epstein barr virus.

Some studies are considering the potential role of permanent chemicals, more formally known as per- and polyfluoroalkyl substances (PFAS).

Using Swedish health data, researchers measured 24 PFAS compounds in the blood of 907 patients recently diagnosed with MS and 907 healthy controls. They also considered seven byproducts from other permanent chemicals called polychlorinated biphenyls (PCBs).

Ultimately, participants with high levels of these chemicals in their blood had a significantly higher risk of multiple sclerosis.

Some of the strongest associations arose from combinations of PFAS compounds and/or their byproducts, rather than a single chemical alone.

‘toxic synergyThe complications of eternal chemicals are something scientists have long warned about.

“This result shows that when trying to understand the effects of PFAS and other chemicals on the human body, we need to consider mixtures of chemicals, not just individual substances, because people are commonly exposed to multiple substances simultaneously.” say Lead author and medical researcher Aina Vaivade from Uppsala University in Sweden.

Since the mid-20th century, timeless chemicals like PFAS have been used in a wide range of products, including nonstick pans, stain-resistant fabrics, firefighting foam, and a wide range of cosmetics.

Today and forever, chemicals are almost everywhere: in water, drink, food, our guts, our blood, our brain;they can Penetrates through our skin Via cosmetics.

To make matters worse, research findings are increasingly revealing Adverse health effects It is associated with specific concentrations of certain chemicals.

Of the over 12,000 PFAS chemicals produced; only twoPFOA and PFOS, Show clear links to cancer and birth defects. Although both are now being phased out in many countries, including the United States, they remain a persistent threat to this day because they take a long time to break down naturally in the environment.

The current study showed that participants with high levels of PFOS or either of two PCB byproducts (4-OH-CB187 and 3-OH-CB153) were particularly likely to develop MS.

“We found that several individual substances were associated with an increased probability of MS, including PFOS and two hydroxylated PCBs.” explain Lead author Kim Kurtima, a clinical chemist from Uppsala.

“People with the highest concentrations of PFOS and PCBs were approximately twice as likely to be diagnosed with MS than those with the lowest concentrations.”

Both PFOS and OH-PCBs can cross the blood-brain barrier and can infiltrate immune cells in the central nervous system.

If these chemicals induce oxidative stress, researchers believe that they can impair the brain’s antioxidant defenses, which could be the cause. Muscle weakness, numbness, or visual disturbances often associated with MS.

Curiously, Kultima and colleagues found that patients with genetic mutations that put them at low risk for the disease were actually much more likely to develop MS if they had been exposed to higher levels of PFOS.

In fact, with increased exposure to PFOS, participants with this genetic mutation had a more than four-fold increased risk of developing MS.

“This shows that there is a complex interaction between genetics and environmental exposures that is related to the probability of MS.” explain Kurtima.

“Therefore, we believe it is important to understand how environmental pollutants interact with genetic factors, as this may provide new knowledge about the development of MS and may also be relevant to other diseases.”

This study environment international.