ARTICLE IN PRESS Evidence-based Cardiovascular Medicine (2005) 9, 261
Evidence-based
CARDIOVASCULAR MEDICINE www.elsevier.com/locate/ebcm
HYPERTENSION
Soy protein may lower blood pressure$ Background
Intervention
Observational studies suggest that increasing vegetable protein intake may reduce blood pressure.
Participants received cookies containing 40 g soybean protein supplements per day or complex carbohydrate control for 12 weeks.
Objective He and colleagues assessed the effect of soybean protein supplements on blood pressure in people with high-normal or mildly elevated blood pressure. The primary endpoint was change in blood pressure at six and twelve weeks.
Method This randomised double-blind trial took place in three centres in China. The authors did not report when the study was conducted.
Participants Participants were 302 people aged 35 to 64 years with untreated systolic blood pressure of 130 to 159 mm Hg, diastolic blood pressure of 80 to 99 mm Hg, or both. Average age 51 years; 53% were women. Exclusion criteria were self-reported use of antihypertensive medications within two months; history of cardiovascular disease; diabetes; cancer; plans to become pregnant; chronic obstructive pulmonary disease; psychiatric disease, or any other serious life-threatening illness that required regular medical treatment. DOI of assoiated commentry: 10.1016/j.ebcm.2005.09.008 Abstracted from He J, Gu D, Wu X et al. Effect of soybean protein on blood pressure: a randomized, controlled trial. Ann Intern Med 2005; 143(1): 1–9. $
doi:10.1016/j.ebcm.2005.09.007
Main results Compared with controls, the soy protein group had a net reduction in systolic blood pressure of 4.31 mm Hg (95% CI 2.11 to 6.51 mm Hg reduction, po0:001) and a net reduction in diastolic blood pressure of 2.76 mm Hg (95% CI 1.35 to 4.16 mm Hg reduction, po0:001). People with hypertension had greater reductions than those without hypertension.
Authors’ conclusions The authors concluded that increasing soybean protein intake may help prevent and treat hypertension. They noted that the trial did not examine whether blood pressure reductions were due to the protein or isoflavones in soybean.
Overall quality topic importance method quality practical use Poor
Fair
Good
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Study sponsored by US National Institutes of Health and Ministry of Science and Technology of the People’s Republic of China Enquiries to
[email protected] Results abstracted by Debbie Singh