Dietary Aluminum Exposure Is More Closely Linked to Antioxidant Dynamics than to Body Mass Index

The association between aluminum exposure and obesity remains uncertain. This study investigated whether aluminum exposure (dietary, serum, and urinary) is linked to obesity and whether dietary antioxidant capacity moderates this relationship. A total of 54 adult women (26 obese, 28 normal weight) were recruited from a private weight loss clinic in Türkiye. Dietary aluminum exposure was estimated using 24 h dietary recalls and literature values, and antioxidant capacity was calculated through a food frequency questionnaire. Serum and spot urine samples were collected, and aluminum levels were measured using inductively coupled plasma optical emission spectrometry. No significant differences were observed between normal weight and obese groups in serum aluminum (127.7 ± 102.42 vs. 122.9 ± 88.37 µg/L, p > 0.05), urinary aluminum (28.1 ± 12.73 vs. 14.1 ± 10.77 µg/L, p > 0.05), or weekly dietary aluminum exposure (0.61 ± 0.45 vs. 0.45 ± 0.24 mg/kg bw/week, p > 0.05). Dietary aluminum exposure correlated positively with total antioxidant capacity (r = 0.665, p < 0.001). Regression analysis revealed that dietary aluminum exposure was inversely associated with body mass index (β = -0.27, p < 0.05), while antioxidant capacity did not moderate this relationship, nor did the age difference. These results suggest dietary aluminum exposure reflects diet quality and/or food preparation methods, etc., rather than directly influencing obesity.