Spotlight on Microplastics, Chemical Additives and Weight Gain

Over the years we have published numerous pieces highlighting scientific studies that focus on the connection between synthetic and industrialized chemicals in our food and products and weight gain/obesity. (*See some recent articles below.)  This post focuses on the link between microplastics–and the chemicals they contain–and serious health outcomes, including weight gain/obesity.

What are microplastics anyway?

The source of most common microplastics is from degradation of larger plastics–drinking bottles, plastic grocery bags, etc.  Through weathering, a process including erosion, abrasion, oxidation, and decomposition, these plastics break down in the environment into microplastics – officially any plastic particles smaller than 5 millimeters in size.  Additional types of microplastics come from microfibers or synthetic textiles, plastic fragments and pellets, as well as microbeads used in cleaning products and cosmetics.  Plastics, and their degraded form microplastics, are abundant in landfills and bodies of water (marine, fresh water, wastewater, etc.) worldwide.

Where does the exposure to microplastics come from?

The average person in the U.S. is exposed to anywhere from a few milligrams to several milligrams of microplastics everyday. According to scientists, the most common sources of microplastics exposure are inhaled indoor air and dust, drinking water and packaged beverages and foods, cosmetics and textiles. (Plastic-bottled water consumption is currently the second-greatest source of exposure to microplastics worldwide.)  While most plastic food packaging, as well as whole foods, have yet to be tested, scientists have demonstrated that seafood and sea salt are sources of microplastics.  Additionally, clothing and other fabric-based household goods like curtains, bedding and furniture upholstery that are made of synthetic fibers (polyester, nylon, acrylic–and variations thereof) contain microplastic particles in the microfibers which are released during use, entering the airspace, and again during laundering, entering the wastewater system.

What do microplastics have to do with weight gain/obesity?

The following is an excerpt from the U.S. National Institutes of Health (NIH) and National Institute of Environmental Health Sciences (NIEHS) entitled, “Microplastics May Increase Risk for Obesity


Health Effects of Exposure to Microplastics

“The persistent exposure to microplastics and plastic additives raises significant health concerns. While most microplastics are excreted through feces, particles smaller than 150 micrometers can cross into the intestinal epithelium. Particles under 20 micrometers can reach organs, such as the lungs and liver, through systemic circulation. Further, inhalation exposure can lead to direct deposition of microplastic particles in lungs. Microplastics that are between 0.1 and 10 micrometers can even cross the blood-brain barrier and the placenta.


Microplastics and Obesity

The results of a new NIEHS scientific study have revealed that human exposure to microplastics and plastic chemical additives may be linked to an increased risk for obesity by affecting metabolism and promoting the growth of fat cells.

While the health risks of microplastics in humans are not fully understood, laboratory animal and cell culture studies suggest that these chemicals can encourage obesity through several mechanisms…

Microplastics fewer than 20 micrometers that penetrate the cell membrane can cause an immune response and potentially cell damage. Microplastics induce oxidative stress and alter energy and fatty acid metabolism. Accumulation of microplastics in the liver and kidney has also been shown to boost the growth and accumulation of fat cells and disrupt energy balance, which ultimately can affect body weight.


Plastic Chemical Additives Add to the Risks of Weight Gain/Obesity

In addition, plastic additives (chemicals such as heat and UV stabilizers, plasticizers, and flame retardants) can contain harmful chemicals, which can act as co-contaminants in microplastics. Many of these plastic additives, including organotins, phthalates, bisphenols, and toxic metals, affect fat cell growth as well as the proteins that regulate lipid and glucose metabolism. Bisphenol A (BPA), commonly used to make certain types of plastics, is known to affect the endocrine system and the body’s hormonal balance, which can impact metabolism and weight gain.”


“The World Health Organization estimates that obesity has nearly tripled since 1975. While obesity has increased, so has exposure to microplastics and plastic chemical additives, suggesting an association between the two.”

What can you do?

Completely avoiding microplastics is not possible.  The situation is similar to completely avoiding other toxins like PFAS/PFOA/PFOS, Phthalates, Parabens, etc. that are ubiquitous these days in our food, products and environment.  You can minimize your exposure to microplastics, however.  This can be achieved by avoiding highly processed, prepared and pre-packaged meals, drinks and snacks and replacing them with fresh, whole foods and ingredients you prepare yourself.  You may also want to minimize the amount of seafood and sea salt you ingest.

Additionally, you can also research which cosmetic manufacturers specifically state their products are free of microplastics.  This can be tricky business–one EU organization found that 87% of the top 10 most popular brands of cosmetics tested contained microplastics. (Nivea was free of microplastics–at least the products sold in the EU. See the report here:  Plastic: The Hidden Beauty Ingredient.) In Germany, The BUND (German Association for the Environment and Nature Conservation) has compiled a list of cosmetics that contain microplastics sold in that country (the BUND purchasing guide), but finding such a compilation in the U.S. can prove to be difficult.  What you can do is become a label reader and check your lotions, potions and makeup for the following plastic ingredients.  The list has been compiled by Greenpeace:

Acrylate copolymer (AC)
Acrylate Crosspolymer (ACS)
Polyamides (PA, Nylon)
Polyacrylates (PA)
Polymethyl methacrylate (PMMA)
Polyquaternium (PQ)
Polyethylene (PE)
Polyethylene glycol (PEG)
Polyethyleneterephthalate (PET)
Polypropylene (PP)
Polypropylene glycol (PPG)
Polystyrenes (PS)
Polyurethanes (PUR)


You can also choose to switch to natural fibers and avoid purchasing clothes and household textile items made of synthetic fibers that contain microplastics.

* Some of our recent posts on scientific findings linking synthetic/industrialized chemicals and weight gain:

Weight Gain and Chemicals: Science Hones in on the Connection

Obesity Link with Chemicals in Food, Products under Scrutiny from scientists

Increased weight gain linked with common chemicals

Food Packaging Chemicals Linked to Weight Gain

Its Harder to Stay Thin Now: Millennial Spread and Food Additives

The results of a scientific study on weight gain demonstrate that it is harder for adults today to maintain the same weight as those 20 to 30 years ago did, even at the same levels of food intake and exercise. In other words, people today who eat and exercise the same amount as people 20 years ago, are still fatter–and additives in food and prescription drugs may be the culprit.

Food Hacker BOOKCOVER-CFL  Learn how to find and avoid toxic chemicals of concern in your food, products and environment linked in scientific studies to health problems, including weight gain and obesity.  Get our book,  The Food Hacker’s Handbook HERE.

w  Sign up for your own individualized consulting and coaching program to learn where chemicals of concern linked to obesity are hiding in your life and how to avoid them.

Journal reference: Kurunthachalam Kannan & Krishnamoorthi Vimalkumar, A Review of Human Exposure to Microplastics and Insights Into Microplastics as Obesogens, Frontiers in Endocrinology Journal, 2021 Aug 18; 12:724989, PMID: 34484127, PMCID: PMC8416353.                                       

DOI: 10.3389/fendo.2021.724989