ABSTRACT
BACKGROUND: Studies examining the association between dairy consumption and metabolic health have shown mixed results. This may be due, in part, to the use of different definitions of dairy, and to single types of dairy foods examined in isolation. OBJECTIVE: The objective of the study was to examine associations between dairy food intake and metabolic health, identify patterns of dairy food consumption and determine whether dairy dietary patterns are associated with outcomes of metabolic health, in a cross-sectional survey. DESIGN: A 4-day food diary was used to assess food and beverage consumption, including dairy (defined as milk, cheese, yogurt, cream and butter) in free-living, healthy Irish adults aged 18-90 years (n=1500). Fasting blood samples (n=897) were collected, and anthropometric measurements taken. Differences in metabolic health markers across patterns and tertiles of dairy consumption were tested via analysis of covariance. Patterns of dairy food consumption, of different fat contents, were identified using cluster analysis. RESULTS: Higher (total) dairy was associated with lower body mass index, %body fat, waist circumference and waist-to-hip ratio (P<0.001), and lower systolic (P=0.02) and diastolic (P<0.001) blood pressure. Similar trends were observed when milk and yogurt intakes were considered separately. Higher cheese consumption was associated with higher C-peptide (P<0.001). Dietary pattern analysis identified three patterns (clusters) of dairy consumption; 'Whole milk', 'Reduced fat milks and yogurt' and 'Butter and cream'. The 'Reduced fat milks and yogurt' cluster had the highest scores on a Healthy Eating Index, and lower-fat and saturated fat intakes, but greater triglyceride levels (P=0.028) and total cholesterol (P=0.015). CONCLUSION: Overall, these results suggest that while milk and yogurt consumption is associated with a favourable body phenotype, the blood lipid profiles are less favourable when eaten as part of a low-fat high-carbohydrate dietary pattern. More research is needed to better understand this association. CONCLUSION: Overall, these results suggest that although milk and yogurt consumption is associated with a favourable body phenotype, the blood lipid profiles are less favourable when eaten as part of a low-fat high-carbohydrate dietary pattern. More research is needed to better understand this association.
Subject(s)
Body Composition/physiology , Dairy Products , Diet , Dietary Fats , Lipids/blood , Adolescent , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Diet Records , Feeding Behavior , Female , Humans , Ireland , Male , Middle Aged , Nutrition Surveys , Nutritional Status , Waist Circumference/physiology , Waist-Hip Ratio , Young AdultSubject(s)
Adaptor Proteins, Signal Transducing , Carrier Proteins/metabolism , Helminth Proteins/metabolism , Protein Serine-Threonine Kinases/physiology , Receptors, Cell Surface/physiology , Schistosoma mansoni/physiology , Amino Acid Sequence , Animals , Base Sequence , Carrier Proteins/chemistry , Carrier Proteins/genetics , Cloning, Molecular , Helminth Proteins/chemistry , Helminth Proteins/genetics , Molecular Sequence Data , Protein Serine-Threonine Kinases/chemistry , Receptors, Cell Surface/chemistry , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Schistosoma mansoni/enzymology , Schistosoma mansoni/genetics , Signal Transduction , src Homology DomainsABSTRACT
Schistosoma mansoni receptor kinase-1 (SmRK1) is a divergent type I transforming growth factor beta (TGFbeta) receptor on the surface of adult parasites. Using the intracellular domain of SmRK1 as bait in a yeast two-hybrid screen we identified an interaction with S. mansoni 14-3-3epsilon. The interaction which is phosphorylation-dependent is not specific to schistosomes since 14-3-3epsilon also binds to TbetaRI, the human type I TGFbeta receptor. 14-3-3epsilon enhances TGFbeta-mediated signaling by TbetaRI and is the first TbetaRI-interacting non-Smad protein identified that positively regulates this receptor. The interaction of 14-3-3epsilon with schistosome and human TbetaRI suggests a conserved, but previously unappreciated, role for this protein in TGFbeta signaling pathways.
