Could microplastics cause Alzheimer's?

The worsening microplastic pollution

August 2023. Research results on microplastics that have entered the body were published in the International Journal of Molecular Science, showing the danger of microplastics posing serious effects on the human body, including Alzheimer's disease.

Plastic pollution is widespread around the world.
In particular, microplastics, which are tiny particles of plastic, are transported by air and water currents and have spread to all parts of the world. They have entered the air, water, and food chain, and their effects are finally beginning to affect humans .

The impact of microplastics on humans and mammals

Research into the various effects of microplastics has only just begun in various countries. In particular, the negative impact on the environment and marine life is widely recognized and research is underway.

However, there is a lack of research into the effects of nicotine on the health of humans and mammals. This is why this study was conducted by a research team led by Professor Jaime Roth of the University of Rhode Island.

• Neurobehavioral effects and inflammatory responses caused by microplastics
• How widespread are microplastics in the body?
• Potential for microplastic accumulation in brain and other tissues

The study found that microplastics are widespread not only in the natural environment but also in the bodies of mammals.

Microplastics cause abnormal behavior

In the study, young and old mice were given different amounts of microplastics through their drinking water for three weeks, after which changes in the mice's behavior and in biomarkers in the liver and brain related to the immune system were observed.

They found changes in behavior and immune markers in liver and brain tissue, and the mice behaved strangely even though they hadn't ingested large amounts of microplastics.

Clear changes were observed in a short period of time. The abnormal behavior was particularly evident in the aged mice, and was similar to that of patients with Alzheimer's disease or dementia.

Microplastics reach every organ

The study also looked at different tissues in the mice.

They examined the brain, liver, kidneys, digestive system, heart, spleen, and lungs, and found microplastics in all organs, including the brain, as well as in the urine and feces.

In the experiment, microplastics were administered through drinking water, so detection in the digestive system, liver and kidneys was expected.

However, it was found to be present in the heart, lungs and brain, and bioaccumulation had already begun. Professor Ross, who led the study, said he was surprised that the substance could reach and accumulate in every corner of the body.

Deep in brain tissue

The fact that microplastics ingested through drinking water have reached the brain is an unexpected result, as it is extremely difficult for external substances to penetrate the blood-brain barrier .

The blood-brain barrier acts as a protective barrier to stop viruses and bacteria from entering the brain. The blood-brain barrier is tightly regulated, allowing normal protein concentrations in the central nervous system and spinal cord.

However, it has been shown that microplastics can cross the blood-brain barrier and penetrate deep into brain tissue where they would normally not be able to reach.

Decreases in important proteins

The researchers also showed that by reaching brain tissue, it may be possible to induce a reduction in a protein (GFAP) that supports cellular processes in the brain.

"Reductions in GFAP have been linked not only to depression but also to the early stages of several neurodegenerative diseases, such as Alzheimer's disease. We were very surprised to find that microplastics induce changes in GFAP signaling."

Professor Ross says his future research will investigate these findings further.

"We want to understand how plastics may affect the brain's ability to repair itself and how they may lead to neurological disorders and diseases such as Alzheimer's."

"No one really knows how long these microplastics stay in the body. As we age, do we become more susceptible to inflammation caused by microplastics? Can we easily remove them from the body? How do our cells respond to these foreign particles? We just don't know."

What can we do?

In Japan, where the population is rapidly aging, the impact of Alzheimer's disease and dementia cannot be ignored.
What if microplastics and nanoplastics are contributing to these diseases?
With that in mind, we want to do whatever we can to help. The following are some of the things that are said to emit large amounts of microplastics in our daily lives:

• Tyres (wear and tear emissions)
• Clothes made from synthetic fibers
• Artificial Turf
• Fragments of deteriorating plastic products
• Cosmetics and personal care products

It may be difficult to completely eliminate everything from your life right away, but you can choose your clothes and cosmetics based on the materials and ingredients they contain.

In particular, cosmetics and personal care products contain microplastics that are made in micro and nano sizes from the start, meaning they are made in sizes that make them impossible to recycle.

Why not start by reviewing the cosmetics you use every day?