Partial substitution of carbohydrate intake with protein intake from lean red meat lowers blood pressure in hypertensive persons.
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.
Hodgson
Jonathan M
JM
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
Burke
Valerie
V
Beilin
Lawrence J
LJ
Puddey
Ian B
IB
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
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D008055:Lipids; D012964:Sodium; D011188:Potassium