Bayou Health | Plastics Around Us & Within Us

by Shannon Dahlum, FDN-P

Plastics are ubiquitous in the environment and in our daily lives. From plastic bags to water bottles to food packaging, plastics are pervasive. They’re present in many of the products we apply to our skin, and even our stretchy yoga pants are made with them. Once plastics are produced, they never go away. They will slowly break down into smaller particles over time until they’re too small to be seen, but they’ll always be here. In fact, every molecule of plastic produced since 1907 (when the first fully synthetic plastic was produced) is still present in our environment. Because of that, these plastics are now also preset within our bodies.

Plastic bags that make their way into the ocean break down due to constant motion and UV light in about 20 years. Plastic bottles take about 450 years to decompose in the ocean, and plastic fishing lines take around 600 years. Even after breaking down into molecules that are too small to be visible, however, they’re still present in the ocean. Because of these plastics in the ocean, microplastics also present in our sea salt, according to a study published in the journal of Environmental Science & Technology.

In a study released in May of this year, researchers measured the micro- and nonoplastics present in the livers, kidneys, and brains of deceased individuals. Samples were collected and measured from a group of cadavers in 2016, and the process was repeated again on a new set of cadavers in 2024. All organs exhibited a significant increase in micro- and nanoplastics from 2016 to 2024, and brain samples exhibited much higher concentrations than both liver or kidney samples. These results demonstrate that these plastics are selectively accumulated in the brain and that concentrations are rising in the population over time.

The most prevalent type of polymer found in these organs was polyethylene, also known as PET. PET is a clear, durable, versatile plastic that is used in almost all single serving and two liter beverage containers in the US. It’s also commonly used to package salad dressings, cooking oil, peanut butter, etc. A certain amount of particles from these plastic containers leeches into the foods or beverages packaged within them, so they are consumed along with the contents of the package. There are three things that enhance the amount of plastic material that leeches into the food or beverages inside: heat, acid and fat.

When plastic containers are exposed to heat, the material breaks down more readily. Water and beverage bottles may not directly be heated, but they are likely exposed to heat at some point during shipping or sitting in your hot vehicle. Rotisserie chickens from the grocery store can serve up a double dose of plastic, because not only are they packaged in plastics and sit under heat lamps, but the fat and oil in the chicken increases absorption, as well. Likewise, oils packaged in plastic bottles readily accumulate these particles, too. Acidic contents, like sodas and other carbonated beverages, will enhance the breakdown of their plastic containers. Adding a squeeze of lemon to your bottled water can have the same effect.

The science isn’t clear on what kind of harm the accumulation of these plastics exert on the human body, but recent studies have noted the presence of micro- and nanoplastics in carotid atheromas (fatty deposits, known as plaques, in the carotid artery) with increased inflammation and a higher risk of future adverse cardiovascular events. In controlled exposure studies, these plastics clearly enhance or drive toxic outcomes. There is also mounting evidence that plastics are endocrine disrupting chemicals, or EDCs, that act on the body’s hormonal system in possibly dangerous ways.

Because plastics are lipophilic (drawn to and readily absorbed by fatty substances), they accumulate in fatty tissues of the body. The human brain is composed of about 60% fat, which is likely why the majority of plastics were found in brain tissue in the previously mentioned study. Studies have shown that the accumulation of plastic in the liver and kidneys boosts the growth and accumulation of fat cells and disrupts metabolism. These plastics are known as obesogens because of their negative impact on the hormonal system, metabolism, and potential for driving obesity.

Half of the plastic produced is used only once and then discarded, while our bodies (and the environment) bear the brunt of its permanent existence. Plastic water bottles are likely the most problematic for a variety of reasons. The average American uses 160 water bottles annually and recycles only about 38 of them. The reason most people purchase bottled water is likely because they believe it’s cleaner than tap water, but this isn’t necessarily true. Bottled water labeled “purified water” simply means it’s tap water, filtered to remove the unpleasant taste of chlorine and some minerals, like iron; not to remove hazardous chemicals. Bottled spring water is a much cleaner choice, but regardless of how pure the water started off, the longer it stays in that plastic bottle, the higher the concentration of chemicals leeched from the bottles it will contain.

Much cleaner choices for drinking water are spring water in glass bottles, or using a water filter on your tap at home that effectively removes hazardous chemicals and metals. A reverse osmosis filter is a good solution, but note that refrigerator filters and most water pitcher filters don’t do anything beyond removing unpleasant taste.

Using a glass or stainless steel water bottle to fill and carry with you is a far better solution than water (or other beverages) in individual plastic bottles. Even if it is the only change you make to decreasing your plastic use, giving up all beverages in plastic bottles will go a long way to diminishing your exposure.

Other simple ways to greatly diminish your plastic exposure:
• Use glass, ceramic, or stainless steel to store food at home. Foods frozen in plastic will leech fewer contaminants that those stored at room temperature or in the refrigerator.
• Never heat foods in plastic. Frozen packaged foods often instruct you to heat the whole container in the microwave, but that’s not a good idea! At least move the food to a glass dish before heating.
• Avoid purchasing oils, salad dressings and nut butters in plastic bottles. Choose those packaged in glass when possible.
• Avoid single use plastics as much as possible. Bring reusable shopping bags to use in place of the plastic sacs provided in the grocery store, and choose reusable storage containers over plastic ziplock bags at home.
• Avoid microplastics in many personal care products by avoiding those that have “polypropylene” or “polyethylene” in the ingredient list.
• Bring your own thermos to the coffee shop when you can, or at least remove the plastic drinking lid when you purchase coffee on the go. Hot coffee and plastic are not a good combo.

Clearly, exposure to plastics can’t be entirely avoided, but decreasing our use of them where possible can go a long way to decreasing our accumulation. With the significant increase of micro- and nanoplastics found in the organ tissue of bodies in only the past 8 years, it seems like a wise move for us all to decrease our use of it as much as possible, at least to slow the exponential growth of plastic particles in the environment for our children future generations.