the harm to health caused by cleaning products

The home environment may be contaminated with chemicals that are potentially harmful to the brain, warns a study from Case Western Reserve University in the United States. Published in the journal Nature Neuroscience, the article highlights that molecules found in extremely common products, such as disinfectants, furniture and even hair creams, attack a specialized brain cell called oligodendrocyte, responsible for protecting neurons.

Researchers claim there is insufficient data on the impacts of everyday chemicals on brain health; Therefore, they investigated more than 1,800 substances to which human beings are exposed. They looked, in particular, for compounds that damage oligodendrocytes — it is already known that dysfunctions in these cells of the central nervous system are associated with bipolar disorder, schizophrenia and multiple sclerosis, among other neurological disorders.

Scientists have found that two classes of chemicals damage these cells: organophosphate flame retardants and quaternary ammonium compounds. The first are substances applied to various surfaces, such as furniture and appliances, to reduce the rate at which the fire spreads in the event of fires. The second are based on household disinfectants, the use of which, according to researchers, has increased since the Covid-19 pandemic.

Neurodevelopment

To study the potential of chemicals in destroying oligodendrocytes, the team from the Institute of Glial Sciences at the Case Western School of Medicine used cellular systems and organoids — three-dimensional structures composed of tissues from certain organs, which recreate their functionality. The biological material was exposed to organophosphate flame retardants and quaternary ammonium compounds, which caused, respectively, damage to cell maturation and death.

The researchers also demonstrated in the laboratory that these products damage oligodendrocytes in the developing brain of mice. For them, exposure to chemicals could help explain the spread of neurological diseases in children in the United States. Recently, the World Health Organization released a report indicating that diseases associated with the central nervous system are already the most common in the world, surpassing cardiovascular diseases.

According to Paul Tesar, director of the Institute of Glial Sciences at the Faculty of Medicine and main researcher of the study, a small proportion of cases of neurological problems can be attributed solely to genetics, indicating that there are unknown environmental factors that also contribute to the pathologies.

“Loss of oligodendrocytes underlies multiple sclerosis and other neurological diseases,” highlights Tesar. “We have now shown that specific chemicals in consumer products can directly damage oligodendrocytes, representing a previously unrecognized risk factor for neurological diseases.”

Erin Cohn, lead author of the article and postgraduate student in the Medical Scientist Training Program at the Faculty of Medicine, said, in a note, that the chemicals studied affected, in the research, only oligodendrocytes. “Understanding human exposure to these chemicals may help explain a missing link in how some neurological diseases arise,” she believes.

Caution

For Oliver Jones, professor of chemistry at the Royal Institute of Technology in Melbourne, Australia, interpreting the study requires caution. “When we evaluate the risks of a chemical, we need to consider things like dose (how much of the compound we are exposed to), route (how we are exposed), and duration (how long we are exposed). It is not a question of knowing whether something is toxic or not, but rather whether it is toxic in the conditions to which we are likely to be exposed,” explains Jones, who was not involved in the study.

In the case of the paper published in Nature Neuroscience, Jones points out, the authors exposed cells in a Petri dish to a relatively high amount of these compounds, which is not the same dosage route or duration of exposure that humans would typically encounter. “So while the work reveals some potentially interesting and useful data, it should be treated as preliminary,” he says.

Paul Tesar agrees with the need for more studies to verify whether the association found in the laboratory is repeated in the real world. “Our findings suggest the need for a more comprehensive examination of the impacts of these common household chemicals on brain health,” he says. “We hope our work will contribute to decisions about regulatory measures or behavioral interventions aimed at minimizing chemical exposure and protecting human health.”

Kitchen oil

Reusing cooking oil is a common practice around the world, but a study shows that consuming foods that have undergone this preparation method can lead to the degeneration of brain cells in the offspring. The research, carried out with mice, will be presented at the annual congress of the American Society of Biochemistry and Molecular Biology, which begins today in San Antonio, California.

The researchers discovered that the increase in neurodegeneration in rats that consumed the reused oil is associated with the substance’s effects on the communication network between the liver, intestine and brain.

“The liver-gut-brain axis plays a crucial role in regulating several physiological functions, and its dysregulation has been linked to neurological disorders,” explains Kathiresan Shanmugam, professor at the Central University of Tamil Nadu, in India, and leader of the study.

According to Shanmugam, frying at high temperatures has been linked to several metabolic disorders, but until now, there has been no long-term research into the influence of consuming reused oil and other harm to the body. “To our knowledge, we are the first to report that long-term fried oil supplementation increases neurodegeneration in first-generation offspring.”

Harmful

Reusing frying oil removes natural antioxidants and can produce harmful compounds such as acrylamide, trans fat and peroxides, the study says. In the experiment, the researchers found that rats fed reheated sesame or sunflower oil showed increased oxidative stress and inflammation in the liver, compared to those that received only the food or a mixture of it with unreused fat.

The animals also showed significant damage to the colon that caused changes in endotoxins and lipopolysaccharides — toxins released by some bacteria. “As a result, liver lipid metabolism was significantly altered and transport of the brain’s important omega-3 fatty acid, DHA, was decreased. This, in turn, resulted in neurodegeneration, which was observed in the brain histology of the rats that consumed the reheated oil, as well as its descendants”, says Kathiresan Shanmugam.

Although more studies are needed, the researcher says that supplementing with omega-3 fatty acids and nutraceuticals, such as curcumin and oryzanol, may be useful in reducing liver inflammation and neurodegeneration.

“But clinical studies in humans are needed to evaluate the adverse effects of eating fried foods, especially those made with repeatedly used oil,” highlights Shanmugam.

Bad for the brain

Harmful

“But clinical studies in humans are needed to evaluate the adverse effects of eating fried foods, especially those made with repeatedly used oil,” highlights Shanmugam. (DUST)