MEDiterranean ISlands - Australia Study: Greek Mediterranean Diet Pattern Adherence, Successful Aging and Associations in Greek Australian Island-Born Long-Term Migrants

Submission note: Thesis Submitted in Total Fulfilment of the Requirements for the Degree of Doctor of Philosophy (PhD) to the Department of Dietetics, Human Nutrition and Sport, School of Allied Health, Human Services and Sport, La Trobe University, Victoria, Australia.

Thesis with publications.

Greek-born Australians continue to demonstrate a lower standardised mortality rate than the Australian-born population. Past Australian Greek migrant studies identified resistance to dietary acculturation, but did not explore successful aging, cuisine and factors which facilitate adherence to a healthy traditional diet. Recently, the Greek MEDiterranean IslandS study [MEDIS] reported closer adherence to a traditional diet pattern and more successful aging among elderly Greek resident islanders compared to mainland counterparts. A diminishing window of opportunity exists to examine these and previously unexplored characteristics among Australia’s elderly long-term Greek Island-born migrants. This thesis examines associations between independent factors and adherence to the traditional Greek Mediterranean Dietary Pattern and successful aging among Greek Australian Island-born (GAI) migrants. It compares GAI migrants to MEDIS Greek Islanders (GI) and characterizes a Greek migrant cuisine using Principal Component Analysis (PCA). MEDIS-Australia is an observational study modelled on the MEDIS study for an Australian Greek setting. Clinical data were collected for GAI migrants aged 65 years or older, free from CVD, active cancer and cognitive decline (N equals 146). A detailed questionnaire was interviewer-administered. MEDIS researchers provided comparator data for resident GI (n equals 431). Primary outcome measures were the MedDietScore and Successful Aging Index score. GAI migrants have moderately high adherence to their traditional diet and are aging as successfully as their GI counterparts. They retain traditional sociocultural characteristics—religious fasting and home-grown food gardening. Dietary adherence is associated with male gender, financial well-being and church attendance. Successful aging is associated with male gender, not smoking, less frequently accessing health services and nut intake. Factors associated with successful aging in the combined cohorts are Australian residence, male gender and not being sedentary. Two dominant healthy Greek Med Diet plant-based dietary patterns characterised the cuisine of GAI migrants: 1) vegetable-based pattern [low meat]; 2) vegetarian pattern [no meat]. Subsequent studies may investigate cuisine-related meal and/or food combination patterns. Further research could examine cuisine as a predictor of successful aging.