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.

Mark Patrick Taylor, Macquarie University and Scott P. Wilson, Macquarie University

A recent study published in the prestigious New England Journal of Medicine has linked microplastics with risk to human health.

The study involved patients in Italy who had a condition called carotid artery plaque, where plaque builds up in arteries, potentially blocking blood flow. The researchers analysed plaque specimens from these patients.

They found those with carotid artery plaque who had microplastics and nanoplastics in their plaque had a higher risk of heart attack, stroke, or death (compared with carotid artery plaque patients who didn’t have any micro- or nanoplastics detected in their plaque specimens).

Importantly, the researchers didn’t find the micro- and nanoplastics caused the higher risk, only that it was correlated with it.

So, what are we to make of the new findings? And how does it fit with the broader evidence about microplastics in our environment and our bodies?

What are microplastics?

Microplastics are plastic particles less than five millimetres across. Nanoplastics are less than one micron in size (1,000 microns is equal to one millimetre). The precise size classifications are still a matter of debate.

Microplastics and nanoplastics are created when everyday products – including clothes, food and beverage packaging, home furnishings, plastic bags, toys and toiletries – degrade. Many personal care products contain microsplastics in the form of microbeads.

Plastic is also used widely in agriculture, and can degrade over time into microplastics and nanoplastics.

These particles are made up of common polymers such as polyethylene, polypropylene, polystyrene and polyvinyl chloride. The constituent chemical of polyvinyl chloride, vinyl chloride, is considered carcinogenic by the US Environmental Protection Agency.

Of course, the actual risk of harm depends on your level of exposure. As toxicologists are fond of saying, it’s the dose that makes the poison, so we need to be careful to not over-interpret emerging research.

A closer look at the study

This new study in the New England Journal of Medicine was a small cohort, initially comprising 304 patients. But only 257 completed the follow-up part of the study 34 months later.

The study had a number of limitations. The first is the findings related only to asymptomatic patients undergoing carotid endarterectomy (a procedure to remove carotid artery plaque). This means the findings might not be applicable to the wider population.

The authors also point out that while exposure to microplastics and nanoplastics has been likely increasing in recent decades, heart disease rates have been falling.

That said, the fact so many people in the study had detectable levels of microplastics in their body is notable. The researchers found detectable levels of polyethylene and polyvinyl chloride (two types of plastic) in excised carotid plaque from 58% and 12% of patients, respectively.

These patients were more likely to be younger men with diabetes or heart disease and a history of smoking. There was no substantive difference in where the patients lived.

Inflammation markers in plaque samples were more elevated in patients with detectable levels of microplastics and nanoplastics versus those without.

And, then there’s the headline finding: patients with microplastics and nanoplastics in their plaque had a higher risk of having what doctors call “a primary end point event” (non-fatal heart attack, non-fatal stroke, or death from any cause) than those who did not present with microplastics and nanoplastics in their plaque.

The authors of the study note their results “do not prove causality”.

However, it would be remiss not to be cautious. The history of environmental health is replete with examples of what were initially considered suspect chemicals that avoided proper regulation because of what the US National Research Council refers to as the “untested-chemical assumption”. This assumption arises where there is an absence of research demonstrating adverse effects, which obviates the requirement for regulatory action.

In general, more research is required to find out whether or not microplastics cause harm to human health. Until this evidence exists, we should adopt the precautionary principle; absence of evidence should not be taken as evidence of absence.

Global and local action

Exposure to microplastics in our home, work and outdoor environments is inevitable. Governments across the globe have started to acknowledge we must intervene.

The Global Plastics Treaty will be enacted by 175 nations from 2025. The treaty is designed, among other things, to limit microplastic exposure globally. Burdens are greatest especially in children and especially those in low-middle income nations.

In Australia, legislation ending single use plastics will help. So too will the increased rollout of container deposit schemes that include plastic bottles.

Microplastics pollution is an area that requires a collaborative approach between researchers, civil societies, industry and government. We believe the formation of a “microplastics national council” would help formulate and co-ordinate strategies to tackle this issue.

Little things matter. Small actions by individuals can also translate to significant overall environmental and human health benefits.

Choosing natural materials, fabrics, and utensils not made of plastic and disposing of waste thoughtfully and appropriately – including recycling wherever possible – is helpful.

Mark Patrick Taylor, Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie University and Scott P. Wilson, Research Director, Australian Microplastic Assessment Project (AUSMAP); Honorary Senior Research Fellow, School of Natural Sciences, Macquarie University

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