Older Australians Can Achieve High Adherence to the Mediterranean Diet during a 6 Month Randomised Intervention; Results from the Medley Study

Abstract

Adherence to a Mediterranean diet (MedDiet) is thought to be achievable in non-Mediterranean regions, but this has yet to be investigated. We aimed to determine if an older Australian population could adhere to a MedDiet for six months. We conducted a randomised, parallel dietary intervention trial with two dietary arms: the Mediterranean diet (MedDiet) group and the habitual diet (HabDiet) control group. A 15-point Mediterranean diet adherence score and food and nutrient intakes were estimated from three-day weighed food records collected at baseline, two and four months. Erythrocyte fatty acids, serum carotenoids and urinary metabolites were assessed at baseline, three and six months. We enrolled 166 participants; 152 commenced and 137 completed the study (70 in the MedDiet group, 67 in the HabDiet group). Adherence scores were significantly higher in the MedDiet group at two months (between group difference 2.2, 95% CI 1.3, 2.9) and four months (between group difference 2.6, 95% CI 1.9, 3.3). Consumption of vegetables, fruits, fish, legumes, nuts and olive oil significantly increased in the MedDiet group compared to the control, and discretionary food intake decreased (p < 0.01). Measures of compliance including serum β-carotene, lycopene and erythrocyte monounsaturated fatty acids were significantly higher in the MedDiet group at three and six months (p < 0.05). Our results indicate that a population of older Australians can adopt a Mediterranean diet over a six month period.

Keywords: Australia; Mediterranean diet; adherence; elderly; food intake; nutrients.

Figure 1

Mean adherence score at each time point by diet group. Mean (error bars depict SEM) MedDiet adherence scores of Australian men and women (age ≥ 65) at baseline, and two and four months after following a MedDiet (n = 80) or their HabDiet (n = 70). MedDiet adherence score based on intakes of 15 food groups calculated from 3-d WFRs, range 0–15 where 15 represents highest possible adherence level. Mean scores at each time point presented. Linear mixed effects model with score as the dependent variable, diet and visit as factors, and unstructured covariance used to compare groups. Analyses were intention to treat. MedDiet, Mediterranean diet; HabDiet, habitual diet; WFR, weighed food record.

Figure 2

Changes in food intakes from baseline to four months, by four diet group. MedDiet (n = 80), HabDiet (n = 70): (A) changes between 10 and 50 g; (B) changes >50 g/day; and (C) changes <10 g per day. All changes based on the MedDiet group, with the exception of red wine for which the change was based on the HabDiet group. Miscellaneous foods included small goods, cakes, muffins, high fat crackers, pastries, sweet biscuits, high-sugar breakfast cereals, muesli bars, take away foods, chips, chocolate, confectionary <50% sugar, ice cream, beer, port, spirits, white wine. Sugar products included all foods comprising >50% sugars. MedDiet, Mediterraenan diet; HabDiet, Habitual diet.

Figure 3

Self-reported enjoyment of requirements of the Mediterranean diet. Australian men’s and women’s (n = 68, age ≥ 65) answers to how well Mediterranean dietary recommendation were enjoyed/managed over a 6 month dietary intervention. Thus, an “all of the time” response indicates the dietary recommendation was enjoyed and/or well managed for the entire study duration. Yoghurt was recommended six times per week, legumes three times per week, tuna one time per week, olive oil (extra virgin) daily, nuts 4–6 times per week, red meat < 1/week, extras three serves or fewer per week and milk (skim) < 1 cup per day. Serving sizes were 170 g, 75 g, 95 g, 1 table spoon, 35 g, 100 g, 600 kJ and 250 mL for yoghurt, legumes, tuna, olive oil, nuts, red meat, extras and skim milk, respectively.