Plastic is in our clothes, cars, mobile phones, water bottles and food containers. But recent research adds to growing concerns about the impact of tiny plastic fragments on our health.

A study from the United States has, for the first time, found microplastics in human brains. The study, which has yet to be independently verified by other scientists, has been described in the media as scary, shocking and alarming.

But what exactly are microplastics? What do they mean for our health? Should we be concerned?

What are microplastics? Can you see them?

We often consider plastic items to be indestructible. But plastic breaks down into smaller particles. Definitions vary but generally microplastics are smaller than five millimetres.

This makes some too small to be seen with the naked eye. So, many of the images the media uses to illustrate articles about microplastics are misleading, as some show much larger, clearly visible pieces.

Microplastics have been reported in many sources of drinking water and everyday food items. This means we are constantly exposed to them in our diet.

Such widespread, chronic (long-term) exposure makes this a serious concern for human health. While research investigating the potential risk microplastics pose to our health is limited, it is growing.

How about this latest study?

The study looked at concentrations of microplastics in 51 samples from men and women set aside from routine autopsies in Albuquerque, New Mexico. Samples were from the liver, kidney and brain.

These tiny particles are difficult to study due to their size, even with a high-powered microscope. So rather than trying to see them, researchers are beginning to use complex instruments that identify the chemical composition of microplastics in a sample. This is the technique used in this study.

The researchers were surprised to find up to 30 times more microplastics in brain samples than in the liver and kidney.

They hypothesised this could be due to high blood flow to the brain (carrying plastic particles with it). Alternatively, the liver and kidneys might be better suited to dealing with external toxins and particles. We also know the brain does not undergo the same amount of cellular renewal as other organs in the body, which could make the plastics linger here.

The researchers also found the amount of plastics in brain samples increased by about 50% between 2016 and 2024. This may reflect the rise in environmental plastic pollution and increased human exposure.

The microplastics found in this study were mostly composed of polyethylene. This is the most commonly produced plastic in the world and is used for many everyday products, such as bottle caps and plastic bags.

This is the first time microplastics have been found in human brains, which is important. However, this study is a “pre-print”, so other independent microplastics researchers haven’t yet reviewed or validated the study.

How do microplastics end up in the brain?

Microplastics typically enter the body through contaminated food and water. This can disrupt the gut microbiome (the community of microbes in your gut) and cause inflammation. This leads to effects in the whole body via the immune system and the complex, two-way communication system between the gut and the brain. This so-called gut-brain axis is implicated in many aspects of health and disease.

We can also breathe in airborne microplastics. Once these particles are in the gut or lungs, they can move into the bloodstream and then travel around the body into various organs.

Studies have found microplastics in human faeces, joints, livers, reproductive organs, blood, vessels and hearts.

Microplastics also migrate to the brains of wild fish. In mouse studies, ingested microplastics are absorbed from the gut into the blood and can enter the brain, becoming lodged in other organs along the way.

To get into brain tissue, microplastics must cross the blood-brain-barrier, an intricate layer of cells that is supposed to keep things in the blood from entering the brain.

Although concerning, this is not surprising, as microplastics must cross similar cell barriers to enter the urine, testes and placenta, where they have already been found in humans.

Is this a health concern?

We don’t yet know the effects of microplastics in the human brain. Some laboratory experiments suggest microplastics increase brain inflammation and cell damage, alter gene expression and change brain structure.

Aside from the effects of the microplastic particles themselves, microplastics might also pose risks if they carry environmental toxins or bacteria into and around the body.

Various plastic chemicals could also leach out of the microplastics into the body. These include the famous hormone-disrupting chemicals known as BPAs.

But microplastics and their effects are difficult to study. In addition to their small size, there are so many different types of plastics in the environment. More than 13,000 different chemicals have been identified in plastic products, with more being developed every year.

Microplastics are also weathered by the environment and digestive processes, and this is hard to reproduce in the lab.

A goal of our research is to understand how these factors change the way microplastics behave in the body. We plan to investigate if improving the integrity of the gut barrier through diet or probiotics can prevent the uptake of microplastics from the gut into the bloodstream. This may effectively stop the particles from circulating around the body and lodging into organs.

How do I minimise my exposure?

Microplastics are widespread in the environment, and it’s difficult to avoid exposure. We are just beginning to understand how microplastics can affect our health.

Until we have more scientific evidence, the best thing we can do is reduce our exposure to plastics where we can and produce less plastic waste, so less ends up in the environment.

An easy place to start is to avoid foods and drinks packaged in single-use plastic or reheated in plastic containers. We can also minimise exposure to synthetic fibres in our home and clothing.

Sarah Hellewell, Senior Research Fellow, The Perron Institute for Neurological and Translational Science, and Research Fellow, Faculty of Health Sciences, Curtin University; Anastazja Gorecki, Teaching & Research Scholar, School of Health Sciences, University of Notre Dame Australia, and Charlotte Sofield, PhD Candidate, studying microplastics and gut/brain health, University of Notre Dame Australia

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

Made from fermented apples and naturally high in acetic acid, apple cider vinegar has been popular in recent years for its purported health benefits – from antibacterial properties to antioxidant effects and potential for helping manage blood sugars.

Its origins as a health tonic stretch much further back. Hippocrates used it to treat wounds, fever and skin sores.

An experimental study, released today, looks into whether apple cider vinegar could be effective for weight loss, reduce blood glucose levels and reduce blood lipids (cholesterol and triglycerides).

The results suggest it could reduce all three – but it might not be as simple as downing an apple cider vinegar drink a day.

What did they do?

A group of scientists in Lebanon did a double-blinded, randomised, clinical trial in a group of overweight and obese young people aged from 12–25 years.

Researchers randomly placed 30 participants in one of four groups. The participants were instructed to consume either 5, 10 or 15ml of apple cider vinegar diluted into 250ml of water each morning before they ate anything for 12 weeks. A control group consumed an inactive drink (a placebo) made (from lactic acid added to water) to look and taste the same.

Typically this sort of study provides high quality evidence as it can show cause and effect – that is the intervention (apple cider vinegar in this case) leads to a certain outcome. The study was also double-blinded, which means neither the participants or the scientists involved with collecting the data knew who was in which group.

So, what did they find?

After a period of three months apple cider vinegar consumption was linked with significant falls in body weight and body mass index (BMI). On average, those who drank apple cider vinegar during that period lost 6–8kg in weight and reduced their BMI by 2.7–3 points, depending on the dose. They also showed significant decreases in the waist and hip circumference.

The authors also report significant decreases in levels of blood glucose, triglycerides, and cholesterol in the apple cider groups. This finding echoes previous studies. The placebo group, who were given water with lactic acid, had much smaller decreases in weight and BMI. There were also no significant decreases in blood glucose and blood lipids.

From animal studies, it is thought the acetic acid in apple cider vinegar may affect the expression of genes involved in burning fats for energy. The new study did not explore whether this mechanism was involved in any weight loss.

Is this good news?

While the study appears promising, there are also reasons for caution.

Firstly, study participants were aged from 12 to 25, so we can’t say whether the results could apply to everyone.

The statistical methods used in the study don’t allow us to confidently say the same amount of weight loss would occur again if the study was done again.

And while the researchers kept records of the participants’ diet and exercise during the study, these were not published in the paper. This makes it difficult to determine if diet or exercise may have had an impact. We don’t know whether participants changed the amount they ate or the types of food they ate, or whether they changed their exercise levels.

The study used a placebo which they tried to make identical in appearance and taste to the active treatment. But people may still be able to determine differences. Researchers may ask participants at the end of a study to guess which group they were in to test the integrity of the placebo. Unfortunately this was not done in this study, so we can’t be certain if the participants knew or not.

Finally, the authors do not report whether anyone dropped out of the study. This could be important and influence results if people who did not lose weight quit due to lack of motivation.

Any other concerns?

Apple cider vinegar is acidic and there are concerns it may erode tooth enamel. This can be a problem with any acidic beverages, including fizzy drinks, lemon water and orange juice.

To minimise the risk of acid erosion some dentists recommend the following after drinking acidic drinks:

• rinsing out your mouth with tap water afterwards
• chewing sugar-free gum afterwards to stimulate saliva production
• avoiding brushing your teeth immediately after drinking because it might damage the teeth’s softened top layer
• drink with a straw to minimise contact with the teeth.

Down the hatch?

This study provides us with some evidence of a link between apple cider vinegar and weight loss. But before health professionals can recommend this as a weight loss strategy we need bigger and better conducted studies across a wider age range.

Such research would need to be done alongside a controlled background diet and exercise across all the participants. This would provide more robust evidence that apple cider vinegar could be a useful aid for weight loss.

Still, if you don’t mind the taste of apple cider vinegar then you could try drinking some for weight loss, alongside a healthy balanced and varied dietary intake. This study does not suggest people can eat whatever they like and drink apple cider vinegar as a way to control weight.

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.