Watch out: High-fat diet to cause damage in the human body, and even in the brain!

A diet rich in fat, sugar and ultra-processed foods may do far more harm than previously thought, with new research suggesting it can cause long-term damage to the pancreas and even impair memory after only a short period of indulgence.

New research shows worrysome results

According to researchers from Sweden’s Karolinska Institute, obesity caused by a so-called Western diet can lead to structural changes in the pancreas that may not be fully reversible. Foods typically associated with this diet include fast food, deep-fried and breaded meals, and other popular dishes high in fat, salt and sugar. While their negative impact on general health is well known, the new findings highlight a more specific and worrying mechanism, as reported by Haszon.hu.

The scientists focused on the tiny blood vessels supplying the pancreatic islets, also known as the islets of Langerhans. These cell clusters produce vital hormones such as insulin, which regulates blood sugar levels. The study found that obesity disrupts these blood vessels, thickening their walls and reducing blood flow. As a result, insulin struggles to enter the bloodstream efficiently, contributing to elevated blood sugar levels.

• Hungarian chimney cake: the sweet street food that became a global sensation

There are other risks as well, and the damage is permanent

Professor Per-Olof Berggren, the study’s lead author, explained that these hidden vascular changes play a key role in the development of glucose intolerance – a condition where blood sugar levels are higher than normal but not yet in the diabetic range. If left unchecked, this state significantly increases the risk of developing type 2 diabetes.

In experiments, male mice fed a high-fat Western diet for 12 weeks became obese and glucose intolerant. Even more concerning, after switching back to a healthy diet for nearly six months, most of the damage remained. The pancreatic blood vessels continued to function poorly and failed to respond to VEGF-A, a protein essential for blood vessel growth and survival.

The researchers also identified a molecule, known as atypical protein kinase C (aPKC), which becomes overactive in response to fatty, sugary diets. This molecule blocks normal blood vessel signalling, preventing recovery even after dietary improvement. While the findings are based on animal models and may not translate fully to humans, the authors say they raise serious concerns.

Meanwhile, a separate study from the University of North Carolina suggests that fast food can affect the brain just as quickly. Researchers found that even a few days of high-fat meals disrupted specific memory-related neurons in the brain’s hippocampus. The good news is that this effect appeared to be reversible after returning to normal eating or practising intermittent fasting.

• Hungarian New Year’s Eve: What do we eat and why?