Dietary Modification - Mediterranean Diet

BACKGROUND: A Mediterranean-style diet (MedSD) is associated with positive health outcomes, particularly reduced risk of cardiovascular disease. It is of interest to assess the feasibility of adherence to a MedSD in a subset of older adults in the United States.

OBJECTIVE: To assess the efficacy of implementing a MedSD intervention in a subset of postmenopausal women living in the United States, and to detect the influence of this dietary pattern on blood lipid levels.

DESIGN: A partial feeding, nutrition counseling, pilot study with a one-group longitudinal design.

PARTICIPANTS: Sixteen healthy, postmenopausal, American women living in suburban communities in Farmington, CT, with a mean±standard deviation age of 77±6.8 years and a body mass index of 26.1±3.1.

INTERVENTION: Participants were counseled by a registered dietitian nutritionist on how to follow a MedSD, which included increased sources of n-3 polyunsaturated fatty acids, fruits, and vegetables, and decreased saturated fat, n-6 polyunsaturated fatty acids, and simple sugars for 12 weeks. To maintain isocaloric conditions, participants were asked to substitute sources of saturated fat and refined carbohydrates for extra virgin olive oil (3 T/day), walnuts (1.5 oz/day), and fatty fish (3 to 5 servings/wk), which were provided at 3-week intervals.

MAIN OUTCOME MEASURES: Dietary adherence measures included the Mediterranean Diet Score, 3-day diet records, and serum fatty acid and lipid profiles.

STATISTICAL ANALYSES: Mixed model longitudinal analyses were conducted to assess changes over time (Weeks 0, 12, and 24) in the outcome variables.

RESULTS: Mediterranean Diet Score increased by 8.9 points (P<0.001) after the MedSD phase. Dietary sugar decreased by 10.8 g (P<0.05), total dietary n-3 increased by 1.6 g (P<0.01), total dietary n-6 increased by 5.5 g (P<0.01), and dietary n-6:n3 ratio decreased by 3.6 units (P<0.01). In serum, 22:6 (n-3), 20:5 (n-3), and 18:3 (n-3) increased (P<0.001, P<0.01, and P<0.001, respectively), and 14:0, 16:0, 17:0, 20:4 (n-6), 22:4 (n-6) declined after the intervention (P<0.01, P<0.001, P<0.01, P<0.01, and P<0.001, respectively), which support a change in dietary intake toward a MedSD. Serum high-density lipoprotein cholesterol levels increased by 3.8 mg/dL (0.098 mmol/L) (P<0.05) and serum triglyceride levels decreased by 11.6 mg/dL (0.131 mmol/L) (P<0.10).

CONCLUSIONS: A pilot study of a 12-week MedSD intervention with counseling from a registered dietitian nutritionist can favorably influence the dietary pattern and lipid profile of postmenopausal women living in the United States.