The impact of dietary constituents on inflammation and cognitive function in healthy older Irish adults: A pilot study

<b>Background:</b> Ageing is frequently associated with systemic inflammation and cognitive decline, yet the impact of diet and lifestyle factors on these age-related processes remains unexplored. Nutrient deficiencies, particularly in essential vitamins and minerals, may accelerate cognitive decline and heighten inflammation in older adults. <b>Aim:</b> This pilot study aimed to examine how dietary intake, body mass index (BMI) and physical activity affect plasma cytokine levels and cognitive performance in older adults. <b>Methods:</b> Twenty-nine healthy Irish adults, aged 65-85 years participated in the study. Physical examination, cognitive testing using the Cambridge Neuropsychological Test Automated Battery and plasma cytokine analysis (tumor necrosis factor-alpha [TNF-α], interleukin [IL]-6, IL-10, IL-8, IL-4, IL-1β) were conducted. Dietary intake was assessed using a validated Food Frequency Questionnaire, and physical activity was evaluated using the International Physical Activity Questionnaire. <b>Summary:</b> Participants with higher BMI and lower physical activity levels exhibited increased plasma concentrations of TNF-α, indicating elevated systemic inflammation and altered IL-10 levels, reflecting changes in anti-inflammatory regulation. Cognitive performance was poorer in participants who consumed excessive carbohydrates and polyunsaturated fatty acids and also in those whose total caloric intake fell below European Food Safety Authority dietary reference values. In contrast, participants with higher intake of saturated and monounsaturated fatty acids demonstrated better cognitive function. Deficiencies in vitamin B12, magnesium, manganese and copper were linked to elevated inflammatory markers and poorer cognitive outcomes. <b>Conclusion:</b> This study highlights the importance of nutrition and lifestyle in managing inflammation and cognitive decline in ageing. Targeted dietary interventions which address nutrient deficiencies may help preserve cognitive health and reduce inflammation in older adults.