Mediterranean diet is worldwide promoted as one of the healthiest and most sustainable dietary patterns. One of the main pillars of Mediterranean diet is the abundant consumption of plant-based ingredients typically consumed as raw or minimally processed. However, even in the Mediterranean countries, these fresh foods are increasingly replaced by ultra-processed foods (UPF). Epidemiological evidence suggests that consumption of UPF may be detrimental to human health, but there is only one clinical trial on this topic which is largely debated in the scientific community due to limitations related to the short duration of the trial and the composition of dietary interventions. The present study aims at exploring whether the inclusion of UPF within a Mediterranean-based dietary pattern can impact on cardiometabolic markers, gut microbiota and other health markers in a dietary intervention performed in Italian subjects. For this purpose, 50 clinically healthy subjects will be recruited for a 7-month randomized, open, cross-over dietary trial. Eligible participants will be randomly assigned to consume a 3-month Mediterranean diet high in UPF (intervention group) or a low-UPF Mediterranean diet (control group), spaced by a 1-month wash-out period. The two diets will have the same composition in terms of food groups. However, in the high-UPF Mediterranean diet group, 5 servings/day of UPF, as defined by the NOVA system, will be consumed (e.g., flavored yogurt, breakfast cereals with added sugar, processed meat). In the control group, these foods will be replaced by products from the same food group, but not UPF (e.g., plain yogurt, breakfast cereals with no added sugar, unprocessed meat). The inflammatory potential of pairs of food products, both UPF and non UPF, will be evaluated using an in vitro cell model testing the modulation of inflammatory markers. Before and after each intervention blood, urine and fecal samples will be collected. The primary endpoint is change in low-density lipoprotein (LDL) cholesterol levels from baseline. Among the other markers, blood pressure and anthropometric parameters will be measured; biochemical parameters, adipokines, inflammatory and oxidative stress markers, fecal microbiota composition and short chain fatty acids (SCFAs) will be analyzed. Adherence to the study, dietary intake and food waste production will be evaluated through specific food diaries, useful also for estimating the metabolic food waste.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
50
A 3-month dietary intervention with a Mediterranean diet with 5 servings/day of UPF, as defined by the NOVA system (e.g., flavored yogurt, breakfast cereals with added sugar, processed meat).
A 3-month dietary intervention with a Mediterranean diet with 5 servings/day of products from the same food group, but non-UPF (e.g., plain yogurt, breakfast cereals with no added sugar, unprocessed meat)
University of Florence
Florence, Italy
University of Milan
Milan, Italy
Low-density lipoprotein (LDL) cholesterol levels
Measurement of LDL-cholesterol levels change from the beginning to the end of each of the two intervention phases in mg/dL
Time frame: 7 months
Total cholesterol levels
Measurement of total cholesterol levels change from the beginning to the end of each of the two intervention phases in mg/dL
Time frame: 7 months
High-density lipoprotein (HDL) cholesterol levels
Measurement of HDL cholesterol levels change from the beginning to the end of each of the two intervention phases in mg/dL
Time frame: 7 months
Triglycerides levels
Measurement of triglyceride levels change from the beginning to the end of each of the two intervention phases in mg/dL
Time frame: 7 months
Fasting blood glucose levels
Measurement of fasting blood glucose levels change from the beginning to the end of each of the two intervention phases in mg/dL
Time frame: 7 months
Insulin levels
Measurement of insulin levels change from the beginning to the end of each of the two intervention phases in U/I
Time frame: 7 months
Aspartate aminotransferase (AST) levels
Measurement of AST levels change from the beginning to the end of each of the two intervention phases in U/I
Time frame: 7 months
Alanine aminotransferase (ALT) levels
Measurement of ALT levels change from the beginning to the end of each of the two intervention phases in U/I
Time frame: 7 months
Gamma-glutamyl transferase (GGT) levels
Measurement of GGT levels change from the beginning to the end of each of the two intervention phases in U/I
Time frame: 7 months
Folates levels
Measurement of folate levels change from the beginning to the end of each of the two intervention phases in ng/mL
Time frame: 7 months
Vitamin B12 levels
Measurement of vitamin B12 levels change from the beginning to the end of each of the two intervention phases in pg/mL
Time frame: 7 months
Urea levels
Measurement of urea levels change from the beginning to the end of each of the two intervention phases in mg/dL
Time frame: 7 months
Creatinine levels
Measurement of creatinine levels change from the beginning to the end of each of the two intervention phases in mg/dL
Time frame: 7 months
Body weight
Measurement of body weight change from the beginning to the end of each of the two intervention phases in kg
Time frame: 7 months
Body mass index (BMI)
Measurement of BMI change from the beginning to the end of each of the two intervention phases. Weight and height will be combined to report BMI in kg/m\^2
Time frame: 7 months
Fat mass
Measurement of fat mass change from the beginning to the end of each of the two intervention phases. Percentage of fat mass will be assessed using the Akern bioelectrical impedance analyser (model SE 101).
Time frame: 7 months
Concentration of ghrelin in plasma
Measurement of ghrelin change from the beginning to the end of each of the two intervention phases in pg/mL
Time frame: 7 months
Concentration of leptin in plasma
Measurement of leptin change from the beginning to the end of each of the two intervention phases in ng/mL
Time frame: 7 months
Concentration of adiponectin in plasma
Measurement of adiponectin change from the beginning to the end of each of the two intervention phases in microg/mL
Time frame: 7 months
Concentration of resistin in plasma
Measurement of resistin change from the beginning to the end of each of the two intervention phases in ng/mL
Time frame: 7 months
Concentration of visfatin in plasma
Measurement of visfatin change from the beginning to the end of each of the two intervention phases in ng/mL
Time frame: 7 months
Concentration of interleukin (IL)-4 in plasma
Measurement of IL-4 change from the beginning to the end of each of the two intervention phases in pg/mL
Time frame: 7 months
Concentration of interleukin (IL)-6 in plasma
Measurement of IL-6 change from the beginning to the end of each of the two intervention phases in pg/mL
Time frame: 7 months
Concentration of interleukin (IL)-10 in plasma
Measurement of IL-10 change from the beginning to the end of each of the two intervention phases in pg/mL
Time frame: 7 months
Concentration of Protein C-reactive (PCR) in plasma
Measurement of protein C-reactive (PCR) change from the beginning to the end of each of the two intervention phases in mg/L
Time frame: 7 months
Concentration of interferon gamma (IFN-γ) in plasma
Measurement of IFN-γ change from the beginning to the end of each of the two intervention phases in pg/mL
Time frame: 7 months
Concentration of tumor necrosis factor -alpha (TNF-α) in plasma
Measurement of TNF-α change from the beginning to the end of each of the two intervention phases in pg/mL
Time frame: 7 months
DNA damage expressed as number of DNA strand breaks induced by hydrogen peroxide (H2O2)
Measurement of H2O2-induced DNA strand breaks change from the beginning to the end of each of the two intervention phases in percentage (%)
Time frame: 7 months
Concentration of F2-isoprostanes in urine
Measurement of F2-isoprostanes change from the beginning to the end of each of the two intervention phases in pg/mosm
Time frame: 7 months
Gut microbiota composition and function changes
Measurement of gut microbiota composition change from the beginning to the end of each of the two intervention phases. Each subject will be asked for a stool sample at the beginning and at the end of each intervention phases in order to analyse the composition of the gut microbiota and short-chain fatty acids production.
Time frame: 7 months
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