These common foods could be linked to microplastics in human brain

MICROPLASTICS IN HUMAN BRAIN HAVE BEEN LINKED TO DEPRESSION, ANXIETY, AND DEMENTIA IN SHOCK RESEARCH 18:02, 21 May 2025 Tiny plastic particles hidden in food, water and the air we breathe

have even been found inside human brains. Microplastics are plastic pieces less than five millimetres long that are produced as a result of the breakdown of larger plastic items. They are

produced by single-use food packaging, plastic water bottles, vehicle tires, fibres from our carpets and even our clothing – and they're even lurking in the food we eat. A

groundbreaking collection of four papers has revealed mounting evidence that 'a spoon's worth' of microplastics may be accumulating in human brains, potentially contributing

to the rising global rates of depression, dementia, and other mental health disorders. Previous research has found approximately a spoonful of microplastics inside the brain, with

significantly more microplastics found in post-mortem samples from 2024 than in those from 2016 – and higher levels in the brains of people diagnosed with dementia. Article continues below

While it is not yet known whether microplastics are harmful or toxic to humans, the latest research suggests that they could be linked to problems in the brain – and that the foods we eat

may be to blame. "We're seeing converging evidence that should concern us all," explains study author Dr Fabiano from the University of Ottawa. "Ultra-processed foods now

comprise more than 50 per cent of energy intake in countries like the US, and these foods contain significantly higher concentrations of microplastics than whole foods. Recent findings show

these particles can cross the blood-brain barrier and accumulate in alarming quantities." The modern diet relies heavily on fast food, snacks, and sugary treats. In fact, studies have

shown that these ultra-processed foods (UPFs) make up more than half of people's energy intake in the UK – among the highest levels in Europe. There is no strict definition of UPFs but

examples include sweets, sugary drinks, biscuits, ice cream, and crisps. Common household items such as breakfast cereals and mass-produced bread are also considered to be ultra-processed.

They often contain high levels of saturated fat, salt, sugar and additives like preservatives, emulsifiers and artificial colours and flavours, which experts warn are not used when people

cook from scratch and leave less room in diets for more nutritious foods. A review published found that people who consumed UPFs had a 22 per cent higher risk of depression, 48 per cent

higher risk of anxiety, and 41 per cent higher risk of poor sleep. The authors of the latest papers believe microplastics may be a missing link in this relationship. "This hypothesis is

particularly compelling because we see remarkable overlap in biological mechanisms," says Dr Wolfgang Marx from Deakin University's Food & Mood Centre. "Ultra-processed

foods have been linked to adverse mental health through inflammation, oxidative stress, epigenetics, mitochondrial dysfunction, and disruptions to neurotransmitter systems. Microplastics

appear to operate through remarkably similar pathways." The researchers hope the findings will trigger a 'paradigm shift' in how experts treat environmental contaminants and

brain health. "What emerges from this work is not a warning. It is a reckoning," writes Dr Ma-Li Wong, author of one of the studies. "The boundary between internal and

external has failed. If microplastics cross the blood-brain barrier, what else do we think remains sacred?" Dr Fabiano added: "As the levels of ultra-processed foods,

microplastics, and adverse mental health outcomes simultaneously rise, it is imperative that we further investigate this potential association. Article continues below "After all, you

are what you eat." The papers on microplastics and brain health are published in the May 2025 issue of _Brain Medicine_.