Abstract
Background The present study aimed to investigate levels of nutrient intakes, including dietary antioxidant quality (DAQ) score, among Saudi females with and without knee osteoarthritis (OA). We also aimed to examine the relationship between nutrient intakes and knee OA severity. Methods One hundred female participants with symptomatic primary knee OA were matched for age with 100 apparently healthy females and were sequentially recruited from the Orthopaedics Department, Faculty of Medicine, King Abdulaziz University Hospital, Saudi Arabia, in a case-control study design. Radiographic disease severity of OA was assessed by the Kellgren-Lawrence grading system. Symptomatic severity was evaluated according to the Western Ontario McMaster University Osteoarthritis scores. Dietary intake was assessed using a prevalidated food frequency questionnaire. The DAQ score was calculated considering the risk of an inadequate intake (<2/3 reference nutrient intake) for selenium, zinc, vitamins A, C and E. Results A higher intake of saturated fatty acids [15.4 (0.3) as a mean (SD) percentage of energy supplied] and monounsaturated fatty acids [16.6 (0.2) as a percentage of energy supplied] than the recommendations was evident among the study population. OA patients consume less antioxidants than non-OA subjects as determined by their DAQ score [8.41 (0.1) versus 9.17 (0.1), P < 0.0001]. After adjusting for potential confounders, DAQ score, and monounsaturated and polyunsaturated fatty acids, most of the micronutrient intakes were found to be negatively associated with the prevalence of radiographic knee OA. Conclusions Dietary antioxidants could be implicated in the development and progression of knee OA. Modifying dietary fatty acids may be one way of reducing the development and subsequent burden of knee OA.