The Effect of a Mediterranean Diet Versus Low-Fat Diet on Inflammation and Adiposity: an Intermediate Analysis of the AUSMED Heart Trial for Secondary Prevention of Coronary Heart Disease

Research output: ThesisDoctoral ThesisResearch

Abstract

Inflammation, which is exacerbated by obesity, is a pathophysiological cause of coronary heart disease (CHD). The Mediterranean diet (MedDiet) is recognised to prevent CHD, in part, via anti-inflammatory properties, however, diet efficacy via this mechanism is unclear in patients who have developed CHD. This thesis reports intermediate outcomes in pilot study participants from the AUStralian MEDiterranean Diet (AUSMED) Heart Trial, a randomised controlled trial testing the cardiovascular health benefits of MedDiet versus low-fat diet after a coronary event. The main aims were to test the effect of 6-month ad libitum MedDiet intervention on markers of inflammation, adiposity, dietary inflammatory index (DII), and MedDiet adherence in a multi-ethnic CHD cohort.

Participants (62±9 years, 83% male, BMI 30.0±5.1kg/m2) were randomised to the MedDiet (n=34) or low-fat diet (n=31). Dietitian-led interviews were held at 0-, 3- and 6-months for dietary counselling, measurement of anthropometry and body composition and collection of blood samples for pathology analyses. Dietary intake was assessed via validated MedDiet adherence questionnaire and 7-day food diaries, with DII subsequently determined.

Participants adhered well to the MedDiet and this led to improved diet quality and a significantly more anti-inflammatory DII score compared with low-fat diet participants after 6-months. Despite dietary changes, the MedDiet did not significantly improve inflammatory markers (C-reactive protein, interleukin-6, tumour necrosis factor-α or adiponectin), anthropometry, body composition or visceral fat compared with the low-fat diet. This lack of effect likely relates to small sample size in a medically-treated cohort. A clinically significant impact on inflammation in CHD patients may require a larger sample, adjunct exercise intervention and/or caloric restriction. This is the first demonstration in Australia that dietetic promotion of MedDiet principles would lead to greater improvements in diet quality compared to current low-fat diet recommendations in cardiac patients, which in turn could more effectively impact CHD risk markers.
Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • La Trobe University
Award date26 Sep 2018
Publication statusPublished - 21 Jun 2018
Externally publishedYes

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Mediterranean Diet
Fat-Restricted Diet
Adiposity
Secondary Prevention
Coronary Disease
Inflammation
Anthropometry
Diet
Body Composition
Anti-Inflammatory Agents
Diet Records
Caloric Restriction
Dietetics
Nutritionists
Intra-Abdominal Fat
Adiponectin
Insurance Benefits
C-Reactive Protein
Sample Size
Counseling

Cite this

@phdthesis{22feafeeff8e4f37b7fb01a931905401,
title = "The Effect of a Mediterranean Diet Versus Low-Fat Diet on Inflammation and Adiposity: an Intermediate Analysis of the AUSMED Heart Trial for Secondary Prevention of Coronary Heart Disease",
abstract = "Inflammation, which is exacerbated by obesity, is a pathophysiological cause of coronary heart disease (CHD). The Mediterranean diet (MedDiet) is recognised to prevent CHD, in part, via anti-inflammatory properties, however, diet efficacy via this mechanism is unclear in patients who have developed CHD. This thesis reports intermediate outcomes in pilot study participants from the AUStralian MEDiterranean Diet (AUSMED) Heart Trial, a randomised controlled trial testing the cardiovascular health benefits of MedDiet versus low-fat diet after a coronary event. The main aims were to test the effect of 6-month ad libitum MedDiet intervention on markers of inflammation, adiposity, dietary inflammatory index (DII), and MedDiet adherence in a multi-ethnic CHD cohort. Participants (62±9 years, 83{\%} male, BMI 30.0±5.1kg/m2) were randomised to the MedDiet (n=34) or low-fat diet (n=31). Dietitian-led interviews were held at 0-, 3- and 6-months for dietary counselling, measurement of anthropometry and body composition and collection of blood samples for pathology analyses. Dietary intake was assessed via validated MedDiet adherence questionnaire and 7-day food diaries, with DII subsequently determined.Participants adhered well to the MedDiet and this led to improved diet quality and a significantly more anti-inflammatory DII score compared with low-fat diet participants after 6-months. Despite dietary changes, the MedDiet did not significantly improve inflammatory markers (C-reactive protein, interleukin-6, tumour necrosis factor-α or adiponectin), anthropometry, body composition or visceral fat compared with the low-fat diet. This lack of effect likely relates to small sample size in a medically-treated cohort. A clinically significant impact on inflammation in CHD patients may require a larger sample, adjunct exercise intervention and/or caloric restriction. This is the first demonstration in Australia that dietetic promotion of MedDiet principles would lead to greater improvements in diet quality compared to current low-fat diet recommendations in cardiac patients, which in turn could more effectively impact CHD risk markers.",
author = "Hannah Mayr",
year = "2018",
month = "6",
day = "21",
language = "English",
school = "La Trobe University",

}

TY - THES

T1 - The Effect of a Mediterranean Diet Versus Low-Fat Diet on Inflammation and Adiposity: an Intermediate Analysis of the AUSMED Heart Trial for Secondary Prevention of Coronary Heart Disease

AU - Mayr, Hannah

PY - 2018/6/21

Y1 - 2018/6/21

N2 - Inflammation, which is exacerbated by obesity, is a pathophysiological cause of coronary heart disease (CHD). The Mediterranean diet (MedDiet) is recognised to prevent CHD, in part, via anti-inflammatory properties, however, diet efficacy via this mechanism is unclear in patients who have developed CHD. This thesis reports intermediate outcomes in pilot study participants from the AUStralian MEDiterranean Diet (AUSMED) Heart Trial, a randomised controlled trial testing the cardiovascular health benefits of MedDiet versus low-fat diet after a coronary event. The main aims were to test the effect of 6-month ad libitum MedDiet intervention on markers of inflammation, adiposity, dietary inflammatory index (DII), and MedDiet adherence in a multi-ethnic CHD cohort. Participants (62±9 years, 83% male, BMI 30.0±5.1kg/m2) were randomised to the MedDiet (n=34) or low-fat diet (n=31). Dietitian-led interviews were held at 0-, 3- and 6-months for dietary counselling, measurement of anthropometry and body composition and collection of blood samples for pathology analyses. Dietary intake was assessed via validated MedDiet adherence questionnaire and 7-day food diaries, with DII subsequently determined.Participants adhered well to the MedDiet and this led to improved diet quality and a significantly more anti-inflammatory DII score compared with low-fat diet participants after 6-months. Despite dietary changes, the MedDiet did not significantly improve inflammatory markers (C-reactive protein, interleukin-6, tumour necrosis factor-α or adiponectin), anthropometry, body composition or visceral fat compared with the low-fat diet. This lack of effect likely relates to small sample size in a medically-treated cohort. A clinically significant impact on inflammation in CHD patients may require a larger sample, adjunct exercise intervention and/or caloric restriction. This is the first demonstration in Australia that dietetic promotion of MedDiet principles would lead to greater improvements in diet quality compared to current low-fat diet recommendations in cardiac patients, which in turn could more effectively impact CHD risk markers.

AB - Inflammation, which is exacerbated by obesity, is a pathophysiological cause of coronary heart disease (CHD). The Mediterranean diet (MedDiet) is recognised to prevent CHD, in part, via anti-inflammatory properties, however, diet efficacy via this mechanism is unclear in patients who have developed CHD. This thesis reports intermediate outcomes in pilot study participants from the AUStralian MEDiterranean Diet (AUSMED) Heart Trial, a randomised controlled trial testing the cardiovascular health benefits of MedDiet versus low-fat diet after a coronary event. The main aims were to test the effect of 6-month ad libitum MedDiet intervention on markers of inflammation, adiposity, dietary inflammatory index (DII), and MedDiet adherence in a multi-ethnic CHD cohort. Participants (62±9 years, 83% male, BMI 30.0±5.1kg/m2) were randomised to the MedDiet (n=34) or low-fat diet (n=31). Dietitian-led interviews were held at 0-, 3- and 6-months for dietary counselling, measurement of anthropometry and body composition and collection of blood samples for pathology analyses. Dietary intake was assessed via validated MedDiet adherence questionnaire and 7-day food diaries, with DII subsequently determined.Participants adhered well to the MedDiet and this led to improved diet quality and a significantly more anti-inflammatory DII score compared with low-fat diet participants after 6-months. Despite dietary changes, the MedDiet did not significantly improve inflammatory markers (C-reactive protein, interleukin-6, tumour necrosis factor-α or adiponectin), anthropometry, body composition or visceral fat compared with the low-fat diet. This lack of effect likely relates to small sample size in a medically-treated cohort. A clinically significant impact on inflammation in CHD patients may require a larger sample, adjunct exercise intervention and/or caloric restriction. This is the first demonstration in Australia that dietetic promotion of MedDiet principles would lead to greater improvements in diet quality compared to current low-fat diet recommendations in cardiac patients, which in turn could more effectively impact CHD risk markers.

M3 - Doctoral Thesis

ER -