The ominous presence of ‘forever chemicals,’ long known for their carcinogenic properties and connections to chronic illnesses and fertility issues, has now been linked with a serious neurological disorder. These chemicals, scientifically referred to as PFAS, have been found to significantly elevate the risk of developing multiple sclerosis (MS), particularly in individuals with a genetic predisposition.

PFAS are aptly nicknamed ‘forever chemicals’ due to their persistent nature, as they remain lodged within the body and the environment for exceedingly long periods, potentially spanning decades or even centuries. Recent research indicates that individuals with elevated blood levels of these chemicals may face up to a fourfold increased risk of MS.

Multiple sclerosis is an enduring autoimmune disease affecting close to a million people in the United States. It occurs when the immune system mistakenly assaults the myelin sheath, a protective layer around nerves in the central nervous system, severely hampering communication between the brain and the rest of the body.

This disruption leads to debilitating symptoms such as extreme fatigue, numbness, vision impairment, and difficulties with mobility, often culminating in progressive disability over time.

Particularly concerning is the discovery that high concentrations of two specific PFAS chemicals, PFOS and PCBs, are strongly associated with an increased MS risk. Alarmingly, exposure to PFOS can nullify the protective benefits of a gene that usually guards against MS.

For those carrying this protective gene, the presence of high PFOS levels in the bloodstream can still lead to a more than fourfold increase in the likelihood of developing MS, underscoring the profound impact of these pervasive environmental toxins.

Forever chemicals are synthetic ingredients engineered to be extremely stable and resistant to heat, water, oil and stains. They have been used for decades in nonstick cookware, forming the coating on pans to prevent food from sticking.

They are also used in some grease-resistant plastic food containers, as well as in waterproof, water-resistant, and stain-resistant fabrics.

Forever chemicals are human-made compounds designed to resist heat, water, oil, and stains. For decades, they have been used to create the nonstick coating in common household cookware (stock)

These harmful forever chemicals, including MS-linked PFOS and PCBs, leach into the food and enter the body, resulting in a direct route of significant exposure to the hazardous chemicals, which have been linked to several health issues, including cancers of the prostate, kidney and testicles, low birth weight, liver damage, developmental delays in children and thyroid disease.

Swedish researchers analyzed data from a major Swedish health study conducted between 2005 and 2015.

They recruited 907 people in their 30s and 40s who had recently been diagnosed with MS. For each MS patient, they found 907 matching individuals identical to the cases in key ways: same age, sex and geographic area in Sweden.

All of them gave blood samples and completed detailed surveys on their lifestyle and environment. Scientists then tested their blood for 31 industrial chemical pollutants, including PFAS and similar compounds such as OH-PCBs.

Researchers calculated participants’ past sun exposure, as sunlight triggers the synthesis of vitamin D when it hits the skin, which modulates the immune system in a way that reduces the risk of MS.

They also identified key genetic markers, specifically variants in the immune system’s HLA genes known to influence MS risk.

The researchers divided chemical exposure levels into four groups: Quartile 1 was the lowest, Q4 was the highest.

Elevated blood levels of three specific pollutants, PFOS (a common PFAS) and two OH-PCBs (4-OH-CB187 & 3-OH-CB153), were each independently linked to an eight to 10 percent higher odds of having MS.

Each graph shows odds of having MS with greater exposure to PFOS, 4-OH-CB187 and 3-OH-CB153. They show that MS risk does not increase in a straight line with exposure. Instead, the odds rise more sharply at higher exposure levels. The shading represents the statistical uncertainty in the estimate. A wider band means less certainty; a narrow band means high certainty. The true effect likely lies within this shaded zone 

For PFOS and one OH-PCB, only people in the top 25 percent exposure group, Q4, had roughly double the risk of having MS of the lowest-exposure group.

The researchers tested how chemical exposure interacted with key HLA immune system genes and found a significant gene-chemical interaction. HLA-B*44:02 protein is a known protective gene that reduces a person’s baseline risk of MS.

PFOS exposure promotes a state of chronic, low-grade inflammation. This inflammatory chaos drowns out the calming signals normally sent by the protective HLA-B*44:02 protein.

As a result, the immune system becomes imbalanced, producing an overabundance of attack cells and a shortage of regulatory cells, which cripples the gene’s ability to protect against MS. 

People with this protective gene but also with high PFOS levels had a more than four-fold higher risk of MS. In people without the protective gene, only the very highest PFOS exposure increased risk, by about 60 percent.

When the researchers analyzed the combined effect of all the PFAS and OH-PCBs together, they found a strong and significant link to higher MS odds.

This biological mechanism, chronic inflammation, immune dysregulation and disruption of immune tolerance, is a general pathway that can make someone vulnerable to multiple autoimmune conditions, not just MS, including lupus and rheumatoid arthritis.

Aina Vaivade, a PhD student at Uppsala University in Sweden and first author of the study, said: ‘The results show that when attempting to understand the effects of PFAS and other chemicals on human beings, we need to take mixtures of chemicals into account, not just individual substances, as people are generally exposed to several substances at the same time.’

The study was published in the journal Environment International.