New research has confirmed a connection between diets high in ultra-processed foods and an increased risk of developing dementia. The study, published in the American Journal of Public Health, reports that individuals who consume the most ultra-processed foods have a 58% higher likelihood of being diagnosed with dementia compared to those who eat the least.
The findings also relate to cognitive impairment, with a 46% greater risk observed among the highest consumers of these foods. Ultra-processed items commonly include packaged snacks like crisps, sugary drinks, and biscuits that are often high in refined sugars, unhealthy fats, salt, and artificial additives.
Dr Sabine Donnai, founder of the Viavi longevity clinic, explains that while this observational research does not prove a direct cause, the results align with existing knowledge about factors contributing to cognitive decline. These include inflammation, metabolic problems, cardiovascular disease, and poor gut health. She notes that even moderate consumption of ultra-processed foods may carry some risk, indicating brain health relies on consistent dietary choices over time rather than single meals or foods.
Understanding why ultra-processed foods may harm the brain is key. The brain requires steady nutrients, healthy blood flow, and balanced inflammatory signals to function properly. Diets heavy in processed foods may impair these conditions by promoting insulin resistance, obesity, high blood pressure, and damage to the gut microbiome, all of which can increase systemic inflammation. Such chronic inflammation can accelerate neurodegeneration and reduce the brain’s capacity to repair itself as people age.
For those concerned about their diet’s impact on brain health, Dr Donnai recommends focusing on an overall pattern of eating that supports cognitive function rather than searching for single “superfoods.” She identifies five food groups to prioritise:
- Oily fish: Salmon, sardines and mackerel are rich in omega-3 fatty acids, particularly DHA, a key component of brain cell membranes.
- Berries: Blueberries, blackberries and strawberries contain antioxidants and polyphenols that protect the brain from oxidative stress.
- Leafy greens: Foods like spinach, kale and rocket supply folate, vitamin K, magnesium and plant compounds linked to slower cognitive ageing.
- Extra virgin olive oil: This oil’s anti-inflammatory polyphenols have been associated with improved cognitive outcomes.
- Nuts and seeds: Varieties such as walnuts, flaxseeds and pumpkin seeds provide healthy fats and minerals that benefit both brain and vascular health.
One food drawing growing scientific interest is pomegranate. It contains polyphenols called ellagitannins that gut bacteria convert into urolithins, compounds potentially supportive of mitochondrial function and inflammation control. While evidence for pomegranate is still emerging, it may play a supplementary role in brain health.
Other foods under investigation for possible cognitive benefits include legumes, cocoa, fermented foods, and spices like turmeric.
Dr Donnai also highlights blood sugar control as a crucial but often overlooked factor for protecting brain health over the long term. She advises choosing minimally processed, fibre-rich foods such as vegetables and legumes while limiting ultra-processed products and added sugars.
Currently, these findings reinforce the importance of balanced, nutrient-dense diets as part of a broader approach to reducing dementia risk. Public health messages around diet and brain function continue to evolve as research deepens, but cutting down on ultra-processed foods and emphasising whole foods remains a practical strategy for many.
For individuals and families, making gradual changes towards including more oily fish, fresh berries, leafy greens, olive oil and nuts can contribute positively to brain health, alongside managing other risk factors like physical activity and smoking. Careful attention to long-term eating habits supports healthier ageing and cognitive resilience.
