Associations between dietary consumption and cardiometabolic disorders among community-dwelling Australian adults

Abstract

Background: Cardiometabolic disorders including atherosclerosis, diabetes, and metabolic syndrome (MetS) are major causes of mortality and morbidity. Nutrition is a lifestyle factor that plays an important role in the development of cardiometabolic disorders.

Objective: The research project aimed to examine the association of omega-3 fatty acid intake and dietary quality with abdominal aortic calcification (AAC) among community-dwelling adults from a subset of the Melbourne Collaborative Cohort Study (MCCS) and whether protein intakes from different sources are differently associated with the incident diabetes and MetS in the whole population of the MCCS.

Methods: Analyses regarding association of omega-3 fatty acid intakes and dietary quality with AAC were based on a subset (n=312) of the MCCS with diet assessed at baseline (1990-1994) and follow-up (2010-2011) and AAC measured using radiography and dual-energy x-ray absorptiometry (DXA) at follow-up (2010-2011). Analyses regarding protein intakes, diabetes and MetS were conducted using data from the MCCS of 41,514 participants. Dietary intakes, diabetes, and MetS were assessed at both baseline (1990-1994) and follow-up (2003-2007). A meta-analysis of the association between protein intakes and incident diabetes was also conducted.

Results: Baseline energy-adjusted alpha linolenic acid (ALA) intake showed inverse associations with AAC severity by both radiography (odds ratio (OR) (95% CI) for tertiles 3 vs 1: 0.49 (0.23, 1.02)) and DXA (0.37 (0.16, 0.83)) in women. Women in the third tertile of total omega-3 fatty acid intake had lower AAC severity by radiography with OR (95% CI) 0.33 (0.16, 0.71) and DXA with OR (95% CI) 0.27 (0.12, 0.62) compared with those in the first tertile. Omega-3 fatty acid intake was not associated with AAC severity in men. Higher baseline dietary quality assessed by Alternate Healthy Eating Index-2010 was associated with lower AAC severity by both radiography (OR (95% CI) for tertiles 3 vs 1: 0.53 (0.29, 0.99)) and DXA (0.38 (0.20, 0.70)).

Multivariate-adjusted ORs (95% CIs) of incident MetS for the highest compared with lowest quartile of percentage energy intake from total, animal and plant protein were 1.46 (1.01, 2.10), 1.67 (1.13, 2.48) and 0.60 (0.37, 0.97), respectively. The multivariate-adjusted OR (95% CI) for incident type 2 diabetes in the highest compared with the lowest quintile of animal protein intake as % energy was 1.29 (0.99, 1.67). In the meta-analysis of 11 prospective cohort studies, the pooled relative risks for type 2 diabetes comparing the highest with the lowest category of total, animal, and plant protein intakes were 1.09 (1.06, 1.13), 1.19 (1.11, 1.28), and 0.95 (0.89, 1.02), respectively.

Conclusion: Higher intakes of ALA and total omega-3 fatty acids and high quality diets were associated with lower risk of AAC in adults. Higher plant protein and lower animal protein consumption, and substitution of animal protein, were associated with lower incidence of MetS and diabetes. This research provides novel evidence regarding the potential benefits of adherence to dietary guidelines especially high intakes of plant foods and low intakes animal foods in the prevention of cardiometabolic disorders.