The Alarming Impact of Microplastics on Human Health

Yesterday’s post described the problems than pollution and chemicals are associated with in children.

Today’s post reviews data that microplastics accumulate in the brain and are associated with dementia in adults. A thorough review of this topic from Eric Topol 2/3/25: The Microplastic Concerns Elevate—To the Brain

Some excerpts:

Background: Last March a landmark prospective study of microplastics found nearly 60% of patients undergoing an artery operation (carotid endarterectomy) 58% had microplastics and nanoplastics (MNPs) in their plaque. Their presence was linked to a subsequent 4.5 -fold increase of the composite of all-cause mortality, heart attack and stroke…A multi-center study from China showed microplastics were present in the semen and urine of all 113 men assessed and were associated with reduced sperm count and semen quality The CDC data indicate they are likely present in the bodies of all Americans. As you know by now, MNPs are pervasive in our air and water, there’s currently an annual output of 400 million tons of plastics, and the burden of MNPs is expected to double by 2040 if nothing is done to change course.

The main sources of MNPs

The New Study

As reported in today’s Nature Medicine, Alexander Nihart and colleagues assessed concentrations of MNPs in the brain, liver and kidney…To emphasize, the MNP concentration in the brain was 7-30 times greater than the concentration in the liver or kidneys...the increased concentration of MNPs was considerably greater in the people with dementia. Even at the most recent, higher MNP concentration, the brains without dementia averaged ~5,000 μg g−1 whereas the brains from individuals with dementia has MNP concentrations that were 2 to 10-times higher…

Another study published on 22 January in Science Advances demonstrates, in the mouse model, that MNPs in the bloodstream cross the blood-brain-barrier, activate the immune system (schematic below) and result in stagnation of blood flow, culminating in blood clots, also resulting in neurological abnormalities…

Some practical tips were, however, provided: “Reducing exposure to microplastics is feasible, by avoiding food and drinks packaged in plastics, using less synthetic fabric and cleaning up household dust. Heating plastic containers leaches lots of microplastics, so avoiding microwaved ready-meals and plastic kettles should help too.”

The essential point of this post is that the striking brain accumulation of MNPs is paralleled by the overwhelming accumulation of evidence for their toxicity to human health. 

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