title: Partial substitution of carbohydrate intake with protein intake from lean red meat lowers blood pressure in hypertensive persons.
abstract: BACKGROUND
  Compared with carbohydrate intake, dietary intake of plant protein can lower blood pressure in humans, but the effects of animal protein intake on blood pressure have yet to be investigated.
  
  
  OBJECTIVE
  We aimed to determine whether partial substitution of carbohydrate intake with animal protein intake from lean red meat changes blood pressure and other markers of cardiovascular disease risk in hypertensive persons.
  
  
  METHODS
  Hypertensive persons (n = 60) were recruited to an 8-wk parallel-design study. The participants were randomly assigned either to maintain their usual diet (control group) or to partially replace energy intake from carbohydrate-rich foods with protein from lean red meat (protein group). Measurements were performed at baseline and at the end of the intervention.
  
  
  RESULTS
  Compared with the control group, the protein group had a significantly higher protein intake [x (95% CI) percent of energy: 5.3% (3.7%, 6.9%), P < 0.001] and a corresponding lower carbohydrate intake [-5.3% of energy (-7.9%, -2.7%), P < 0.001]. Body weight and intakes of fat, alcohol, and fiber were not significantly different between the groups. Compared with the control group, the clinic, 24-h, awake, and asleep systolic blood pressures were lower [-5.2 (-10.3, -0.1), -4.0 (-7.4, -0.6), -4.7 (-8.9, -0.5), and -4.7 (-10.3, -0.1) mm Hg, respectively, P < 0.05] and fasting plasma glucose concentrations were higher [0.33 mmol/L (0.09, 0.58 mmol/L), P = 0.008] in the protein group. These differences were independent of age, sex, and changes in weight, alcohol intake, or urinary sodium and potassium excretion. Diastolic blood pressure and heart rate, arterial compliance, blood lipids, and serum insulin were not significantly different between the groups.
  
  
  CONCLUSIONS
  Within the context of other studies, these results suggest that modest substitution of carbohydrate-rich foods with protein-rich foods may lower blood pressure in hypertensive persons.
authors.affiliation: University of Western Australia, School of Medicine and Pharmacology at Royal Perth Hospital, GPO Box X2213, Perth, WA 6001, Australia. jonathan@cyllene.uwa.edu.au
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Hodgson
authors.forename: Valerie
authors.initials: V
authors.lastname: Burke
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Beilin
authors.forename: Ian B
authors.initials: IB
authors.lastname: Puddey
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D001835:Body Weight / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism; D005260:Female; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D008460:Meat; D008875:Middle Aged; D011188:Potassium / Q000652:urine; D012964:Sodium / Q000652:urine
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D008055:Lipids; D012964:Sodium; D011188:Potassium