Hosted by Ryan O’Shea, this episode of Lifespan News is on how plastic nanoparticles might lead to at least one hallmark of aging being accelerated.
Studies show that everyday objects such as baby bottles and tea bags can release plastic particles into the environment and into our bodies. Now, new research shows the scale of this problem. Items such as single-use coffee cups can release trillions of microscopic plastic particles into hot liquid. Separately, scientists have found that exposure to plastic nanoparticles can drive cellular senescence and dysfunction. What does this mean for us? Let’s explore what we know and what we don’t in this episode of Lifespan News!
Plastic has changed the face of civilization, but the convenience of plastic comes at a price – often in terms of environmental pollution from its manufacturing and waste. There has also been a growing understanding that plastic could harm us as well. Plastic can disintegrate into nanoparticles that can be suspended in the atmosphere for prolonged periods of time, and can enter the body through breathing. Exposure can also occur by ingestion or even absorption by the skin.
Researchers at the US government’s National Institute of Standards and Technology have now published some alarming data in the journal Environmental Science and Technology which showed that common consumer products can release trillions of nanoparticles into hot water when they are used.
The researchers analyzed two types of products – food-grade nylon bags like those used for slow cooking, and hot beverage cups lined with low-density polyethylene. They exposed the products to hot water and then analyzed the released particles. They found that most of the released particles were between 30-80 nanometers in size, and that the nylon bags released seven times more particles than the beverage cups.
According to researcher Christopher Zangmeister, “The main takeaway here is that there are plastic particles wherever we look. There are a lot of them. Trillions per liter.” “In the last decade scientists have found plastics wherever we looked in the environment. People have looked at snow in Antarctica, the bottom of glacial lakes, and found microplastics.” “Our study is different because these nanoparticles are really small and a big deal because they could get inside of a cell, possibly disrupting its function.”
Zangmeister clarified that they do not know the full effects of these nanoparticles on cells. He’s right, and that’s part of the problem.
The research into the effects of plastic nanoparticles on human health is still in its infancy. There have been indications that particles in the blood can lead to ailments such as pulmonary hypertension, but much remains unclear.
Now in a new study, scientists in Korea investigated the effect of plastic nanoparticles on cellular senescence, a major driver of aging. In particular, senescence in vascular endothelial cells, which compose the inner layer of blood vessels, is known to promote cardiovascular dysfunction.
The researchers used endothelial cells taken from a pig’s coronary artery, subjecting them to various concentrations of 25-nanometer particles of polystyrene, one of the most ubiquitous types of plastic. In the first experiment, the nanoparticle solution induced senescence in the cells in a concentration-dependent manner.
Exposing specimens of arterial tissue to nanoparticles for 24 hours significantly hampered their reactivity – a measure of how well an artery responds to stimuli by contracting and relaxing.
Senescent vascular cells are characterized by reduced production of nitric oxide, a vasodilator crucial for vascular health. Sure enough, nanoparticle-exposed cells had much lower levels of a nitric oxide-producing enzyme.
Nanoparticles also significantly increased the levels of oxidative stress, even in the lowest concentration. Several pathways can contribute to oxidative stress, but experiments showed that nanoparticle exposure significantly affected one that includes downregulation of the Sirt1 protein.
A major question is whether the concentrations that were used in this study bear any resemblance to real-life concentrations of plastic nanoparticles in our blood? Unfortunately, they do.
This is one of the first studies to directly analyze the effects of plastic particles on the cardiovascular system, and there’s so much more to know. As was stated, these plastics are everywhere we look – from the deepest parts of the ocean to the world’s highest mountains, as well as inside our bodies.
But there are a lot of different types of plastics, and not all of these studies are focused on the same kinds. Perhaps different types of nanoparticles impact us differently, but we don’t know that yet.
So, am I ready to eliminate plastics from my life? No. But I will be closely watching this research, and we need a lot more of it. When there’s more to share, we’ll have it for you here, so be sure to subscribe. I’m Ryan O’Shea and we’ll see you next time on Lifespan News!