Microplastics and nanoplastics are everywhere in our environment – including in our oceans and lakes, farmland, and even Arctic ice algae.

Microplastics have also been found inside of us – with studies detecting them in various tissues including in the lungs, blood, heart and placenta. Understandably, concern is rising about the potential risks of microplastics on our health.

However, while a growing body of research has focused on microplastics and nanoplastics, there’s still a lack of direct evidence that their presence in human tissues is harmful to our health – and it’s uncertain if they are related to particular diseases.

A new study has uncovered a correlation between microplastics and heart health, though. The researchers found that people who had detectable microplastics and nanoplastics in the plaque in their arteries had a higher risk of heart attack, stroke and death.

Heart health

The researchers looked at 257 people altogether. All of the patients were already undergoing preventative surgery to remove plaque from their carotid arteries (the main arteries that supply the brain with blood). This allowed the researchers to collect plaque samples and perform a chemical analysis. They then followed up with participants 34 months later.

Of the 257 participants, 150 were found to have the presence of microplastics and nanoplastics in their arterial plaque – mainly fragments of two of the most commonly used plastics in the world, polyethylene (used in grocery bags, bottles and food packaging) and polyvinyl chloride (used in flooring, cladding and pipes).

A statistical analysis of this data found that patients with microplastics and nanoplastics in their plaque had a higher risk of suffering a heart attack, stroke or death from any cause, compared with those who had no microplastics or nanoplastics in their plaque.

The researchers also analysed the macrophages (a type of immune cell that helps remove pathogens from the body) in the patients’ arteries. They found that participants who’d had microplastics and nanoplastics in their plaque also had evidence of plastic fragments in their macrophages.

They also looked at whether certain genes associated with inflammation (which can be a sign of disease) were switched on in the participants. They found that the participants who’d had microplastics and nanoplastics in their plaque also had signs of inflammation in their genes.

These results may suggest an accumulation of nanoplastics and microplastics in carotid plaque could partly trigger inflammation. This inflammation may subsequently change the way plaque behaves in the body, making it less stable and triggering it to form a blood clot – which can eventually block blood flow, leading to heart attacks and strokes.

Interestingly, the researchers also found the presence of nanoplastics and microplastics was more common in participants who had diabetes and cardiovascular disease. This raises a lot of questions which have yet to be answered – such as why microplastics were more common in these participants, and if there may be a correlation between other diseases and the presence of microplastics in the body.

Other health risks

This study only focused on patients who had carotid artery disease and were already having surgery to remove the build-up of plaque. As such, it’s unclear whether the findings of this study can be applied to a larger population of people.

However, it isn’t the first study to show a link between microplastics and nanoplastics with poor health. Research suggests some of this harm may be due to the way microplastics and nanoplastics interact with proteins in the body.

For example, some human proteins adhere to the surface of polystyrene nanoplastics, forming a layer surrounding the nanoparticle. The formation of this layer may influence the activity and transfer of nanoplastics in human organs.

Another study suggested that nanoplastics can interact with a protein called alpha-synuclein, which in mouse studies has been shown to play a crucial role in facilitating communication between nerve cells. These clumps of nanoplastics and protein may increase the risk of Parkinson’s disease.

My published PhD research in chicken embryos found that nanoplastics may cause congenital malformations due to the way they interact with a protein called cadherin6B. Based on the interactions myself and fellow researchers saw, these malformations may affect the embryo’s eyes and neural tube, as well as the heart’s development and function.

Given the fact that nanoplastics and microplastics are found in carotid plaque, we now need to investigate how these plastics got into such tissues.

In mice, it has been demonstrated that gut macrophages (a type of white blood cell) can absorb microplastics and nanoplastics into their cell membrane. Perhaps a similar mechanism is taking place in the arteries, since nanoplastics have been identified in samples of carotid plaque macrophages.

The findings from this latest study add to a growing body of evidence showing a link between plastic products and our health. It is important now for researchers to investigate the specific mechanisms by which microplastics and nanoplastics cause harm in the body.

Meiru Wang, Postdoctoral Researcher, Molecular Biology and Nanotoxicology, Leiden University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Whether you enjoy chocolate milk regularly, as a weekend treat, or as an occasional dose of childhood nostalgia, it probably wouldn’t be the first option you think of for post-workout recovery.

Unless you’re on TikTok, perhaps. According to many people on the social media platform, chocolate milk is not only delicious, but it offers benefits comparable to sports drinks after a workout.

So is there any evidence to support this? Let’s take a look.

Rehydrating after a workout is important

Water accounts for somewhere between 50% and 60% of our body weight. Water has many important functions in the body, including helping to keep our body at the right temperature through sweating.

We lose water naturally from our bodies when we sweat, as well as through our breathing and when we go to the toilet. So it’s important to stay hydrated to replenish the water we lose.

When we don’t, we become dehydrated, which can put a strain on our bodies. Signs and symptoms of dehydration can range from thirst and dizziness to low blood pressure and confusion.

Athletes, because of their higher levels of exertion, lose more water through sweating and from respiration (when their breathing rate gets faster). If they’re training or competing in hot or humid environments they will sweat even more.

Dehydration impacts athletes’ performance and like for all of us, can affect their health.

So finding ways to ensure athletes rehydrate quickly during and after they train or compete is important. Fortunately, sports scientists and dietitians have done research looking at the composition of different fluids to understand which ones rehydrate athletes most effectively.

The beverage hydration index

The best hydrating drinks are those the body retains the most of once they’ve been consumed. By doing studies where they give people different drinks in standardised conditions, scientists have been able to determine how various options stack up.

To this end, they’ve developed something called the beverage hydration index, which measures to what degree different fluids hydrate a person compared to still water.

According to this index beverages with similar fluid retention to still water include sparkling water, sports drinks, cola, diet cola, tea, coffee, and beer below 4% alcohol. That said, alcohol is probably best avoided when recovering from exercise.

Beverages with superior fluid retention to still water include milk (both full-fat and skim), soy milk, orange juice and oral rehydration solutions.

This body of research indicates that when it comes to rehydration after exercise, unflavoured milk (full fat, skim or soy) is better than sports drinks.

But what about chocolate milk?

A small study looked at the effects of chocolate milk compared to plain milk on rehydration and exercise performance in futsal players (futsal is similar to soccer but played on a court indoors). The researchers found no difference in rehydration between the two. There’s no other published research to my knowledge looking at how chocolate milk compares to regular milk for rehydration during or after exercise.

But rehydration isn’t the only thing athletes look for in sports drinks. In the same study, drinking chocolate milk after play (referred to as the recovery period) increased the time it took for the futsal players to become exhausted in further exercise (a shuttle run test) four hours later.

This was also shown in a review of several clinical trials. The analysis found that, compared to different placebos (such as water) or other drinks containing fat, protein and carbohydrates, chocolate milk lengthened the time to exhaustion during exercise.

What’s in chocolate milk?

Milk contains protein, carbohydrates and electrolytes, each of which can affect hydration, performance, or both.

Protein is important for building muscle, which is beneficial for performance. The electrolytes in milk (including sodium and potassium) help to replace electrolytes lost through sweating, so can also be good for performance, and aid hydration.

Compared to regular milk, chocolate milk contains added sugar. This provides extra carbohydrates, which are likewise beneficial for performance. Carbohydrates provide an immediate source of energy for athletes’ working muscles, where they’re stored as glycogen. This might contribute to the edge chocolate milk appears to have over plain milk in terms of athletic endurance.

Coffee-flavoured milk has an additional advantage. It contains caffeine, which can improve athletic performance by reducing the perceived effort that goes into exercise.

One study showed that a frappe-type drink prepared with filtered coffee, skim milk and sugar led to better muscle glycogen levels after exercise compared to plain milk with an equivalent amount of sugar added.

So what’s the verdict?

Evidence shows chocolate milk can rehydrate better than water or sports drinks after exercise. But there isn’t evidence to suggest it can rehydrate better than plain milk. Chocolate milk does appear to improve athletic endurance compared to plain milk though.

Ultimately, the best drink for athletes to consume to rehydrate is the one they’re most likely to drink.

While many TikTok trends are not based on evidence, it seems chocolate milk could actually be a good option for recovery from exercise. And it will be cheaper than specialised sports nutrition products. You can buy different brands from the supermarket or make your own at home with a drinking chocolate powder.

This doesn’t mean everyone should look to chocolate milk when they’re feeling thirsty. Chocolate milk does have more calories than plain milk and many other drinks because of the added sugar. For most of us, chocolate milk may be best enjoyed as an occasional treat.

Evangeline Mantzioris, Program Director of Nutrition and Food Sciences, Accredited Practising Dietitian, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.