Oral Presentation 49th Nutrition Society of Australia Annual Scientific Meeting 2025

Do markers of oxidative stress change following consumption of energy-restricted diets containing almonds compared with carbohydrate-rich snack foods? (130013)

Alison M Coates 1 2 , Sharayah Carter 1 2 3 , Catherine Yandell 1 2 , Kevin Croft 4 , Jonathan Buckley 1 2 , Sze-Yen Tan 5 , Geraint Rogers 6 7 , Alison Hill 1 8
  1. Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, Adelaide, SA, Australia
  2. Aliied Health and Human Performance, University of South Australia, Adelaide, SA, Australia
  3. School of Health and Biomedical Sciences, Royal Melbourne Institute of Technology (RMIT University), Melbourne, VIC, Australia
  4. School of Biomedical Sciences, Pharmacology and Toxicology, University of Western Australia, Perth, WA, Australia
  5. School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), , Deakin University, Melbourne, VIC, Australia
  6. Microbiome Research, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
  7. College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
  8. Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia

Markers of oxidative stress have previously been found to be elevated in people with obesity (1) due to the generation of reactive oxidant species from multiple pathways and impairment of antioxidant defences (2). Weight loss, through dietary change and behaviour modification, is recommended to reduce the risk of health complications associated with obesity. Consumption of almonds, as a food rich in Vitamin E with antioxidant properties, may also reduce oxidative stress (3). This study aimed to determine whether biomarkers of oxidative stress change following consumption of energy-restricted diets containing almonds or carbohydrate rich snacks for 9 months.  Adults  with overweight or obesity (n = 140,  BMI 30.7 ± 2.3 kg/m2, 47.5 ± 10.8 years) were randomly assigned to consume 15% of total daily energy from either almonds (n = 68, AED) or isocaloric carbohydrate-rich snacks (n = 72, CRD) in a dietary intervention that comprised 3 months (3M) weight loss (30% energy restriction) followed by 6 months (6M) of weight maintenance.  At baseline (BL), 3M and 9M, dietary intake of vitamin E was captured from weighed 4-day food records (FoodWorks Nutritional Analysis Software) and biomarkers of oxidative stress (oxidized low-density lipoprotein (ox-LDL), the ratio of ox-LDL to LDL and F2-isoprostanes) were measured from blood and urine samples collected following an overnight fast. Intention to treat analyses were conducted using mixed effects modelling (fixed effects: group and time and participant ID as the random effect) with body mass index at BL as a covariate. Significance was set at P<0.05 and data are presented as estimated marginal means and standard errors. Significantly greater increases in Vitamin E consumption occurred for AED compared to CRD (3M: 3.98 ± 0.72 mg/d vs -4.10 ± 0.71 mg/d, 9M: 3.55 ± 0.75 mg/d vs -0.52 ± 0.78 mg/d, p < 0.001 interaction effect). There was a significant difference in ox-LDL between groups (AED: 65.49 ± 2.10 U/L vs CRD: 72.36 ± 2.09 U/L, p = 0.02, group effect) and significant reductions over time in all participants (3M: -5.79 ± 1.83 U/L, 9M: -4.36 ± 2.05 U/L, p = 0.005, time effect), but no group by time interaction. There were no significant changes in the ratio of ox-LDL to LDL, or plasma or urinary F2-isoprostane levels over time or differences between groups. Reduced energy consumption over 9 months reduced some markers of oxidative stress but the inclusion of almonds did not modify these effects despite increasing dietary intake of Vitamin E. The decrease in ox-LDL over time is likely due to a decrease in LDL cholesterol (previously reported) 4, rather than a reduction in LDL oxidation. Future studies should explore precision health approaches to manage oxidative stress and improve health outcomes.

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  2. 2. Perez-Torres I et al. (2021) Int J Mol Sci 22(4), 1786
  3. 3. Chen CYO, Blumberg JB (2008) Asia Pac J Clin Nutr 17(Suppl 1), 329–332
  4. 4. Carter S et al. (2023) Obesity 10, 2467-2481