Ultra-processed foods could damage your brain, Harvard study

Scientists link consumption of such foods with memory problems, stroke and dementia and suggest production methods are to blame, not just calorie content

The risk of suffering a stroke also increased as people ate more of the foods, with the research concluding that “food processing plays an important role in overall brain health”.

Eating lots of ultra-processed foods could harm brain health, according to a large trial linking the products to stroke and dementia.

Middle-aged adults were more likely to report memory problems if their diet was mainly composed of mass-produced items such as fizzy drinks, burgers, cakes and sweets.

The risk of suffering a stroke also increased as people ate more of the foods, with the research concluding that “food processing plays an important role in overall brain health”.

The study, published in the journal Neurology, argued that ultra-processed foods appeared to be inherently harmful due to the way they were manufactured, rather than simply damaging health because they were high in calories. Researchers warned that industrially produced foods, which are high in additives, can disrupt gut bacteria and lead to inflammation in the body linked to several chronic diseases.

Data from 30,000 people across 11 years

Scientists at Harvard Medical School looked at data from more than 30,000 adults aged 45 and over who were followed for 11 years. They filled out questionnaires about what food they ate and were divided into four groups ranging from those who ate the most processed foods to those who ate the least processed foods.

By the end of the study, 1,108 participants had had a stroke and 768 had been diagnosed with cognitive impairment - signs of early memory loss linked to dementia.

The risk of memory problems was 16 per cent higher in those who ate a greater proportion of ultra-processed foods compared with those who ate a largely unprocessed diet with lots of fresh fruit or vegetables. The risk of stroke increased by 8 per cent the more highly processed food people ate, regardless of how many calories they ate in total.

The study found that consumption of ultra-processed foods was associated with a higher risk of both stroke and cognitive impairment. Picture: Getty Images

The findings were adjusted to take into account other factors that influence dementia and stroke risk, such as age, sex and high blood pressure.

Dr William Taylor Kimberly, lead author of the study, said: “We found that increased consumption of ultra-processed foods was associated with a higher risk of both stroke and cognitive impairment.

“Our findings show that the degree of food processing plays an important role in overall brain health. More research is needed to confirm these results and to better understand which food or processing components contribute most to these effects.”

Growing body of evidence highlighting risks

In a linked editorial, Dr Zhendong Mei, from Harvard Medical School, said that the reasons why ultra-processed foods were associated with poorer brain health were not yet fully understood. He said that additives and emulsifiers had been “associated with disruptions in the gut microbial ecosystem and inflammation”, and the foods were also high in sugar and calories, which can damage blood vessels.

The findings add to a growing body of evidence linking ultra-processed food to heart disease, heart attacks, strokes, cancer, depression and diabetes, with campaigners calling for restrictions to be placed on their marketing.

Ultra-processed foods make up more than half of the typical daily diet and they are typically low in fibre and nutrients and high in calories. The food is typically sold ready made and in packages, and is subjected to a series of sophisticated industrial processes, including splitting whole foods into oils, fats and sugar and then recombining them.

The Times