Mediterranean Diet Reduces 24-Hour Ambulatory Blood Pressure, Blood Glucose, and Lipids

Abstract

H igh blood pressure (BP) is a major risk factor for coronary heart disease, congestive heart failure, stroke, and renal disease 1 and as such is the leading cause of preventable deaths worldwide. 2 In 2000, 26.4% of the adult world population (972 million) had hypertension, defined as BP ≥140/90 mm Hg or current use of antihypertensive medication, and 29.2% were projected to be hypertensive by 2025. 3 The prevalence of hypertension increases with age, with the estimated lifetime risk for elderly subjects reaching 90%. 4 The magnitude of this burden underscores the need for increased awareness, treatment, control, and, primarily, prevention.A healthful lifestyle is a critical component of hypertension reduction strategies, 5 and diet is the lifestyle factor with the strongest effects on BP. 6,7 Established dietary modifications that effectively lower BP are weight loss, reduced sodium and increased potassium intake, reduction in excessive alcohol consumption, and vegetarian and dietary approaches to stop hypertension (DASH)-type dietary patterns. 6,7 The original DASH diet combined increased intake of fruits, vegetables, and low-fat dairy products with a relatively low intake of total and saturated fat, 8 and a subsequent version incorporated sodium restriction to further enhance BP reduction. Abstract-The PREvención con DIeta MEDiterránea (PREDIMED) trial showed that Mediterranean diets (MedDiets) supplemented with either extravirgin olive oil or nuts reduced cardiovascular events, particularly stroke, compared with a control, lower fat diet. The mechanisms of cardiovascular protection remain unclear. We evaluated the 1-year effects of supplemented MedDiets on 24-hour ambulatory blood pressure (BP), blood glucose, and lipids. Randomized, parallel-design, controlled trial was conducted in 2 PREDIMED sites. Diets were ad libitum, and no advice on increasing physical activity or reducing sodium intake was given. Participants were 235 subjects (56.5% women; mean age, 66.5 years) at high cardiovascular risk (85.4% with hypertension). Adjusted changes from baseline in mean systolic BP were −2.3 (95% confidence interval [CI], −4.0 to −0.5) mm Hg and −2.6 (95% CI, −4.3 to −0.9) mm Hg in the MedDiets with olive oil and the MedDiets with nuts, respectively, and 1.7 (95% CI, −0.1 to 3.5) mm Hg in the control group (P<0.001). Respective changes in mean diastolic BP were −1.2 (95% CI, −2.2 to −0.2), −1.2 (95% CI, −2.2 to −0.2), and 0.7 (95% CI, −0.4 to 1.7) mm Hg (P=0.017). Daytime and nighttime BP followed similar patterns. Mean changes from baseline in fasting blood glucose were −6.1, −4.6, and 3.5 mg/dL (P=0.016) in the MedDiets with olive oil, MedDiets with nuts, and control diet, respectively; those of total cholesterol were −11.3, −13.6, and −4.4 mg/dL (P=0.043), respectively. In high-risk individuals, most with treated hypertension, MedDiets supplemented with extravirgin olive oil or nuts reduced 24-hour ambulatory BP, total cholesterol, and fasting glucose. Clinical Trial Registration-URL: http://www.clinical...

Associations between Dietary Patterns and Blood Pressure in a Clinical Sample of Overweight Adults

“…Ambulatory blood pressure has been shown to eliminate "white coat hypertension" and has increased precision over office BP [60]. Repeated measurements of ambulatory blood pressure provide an even more accurate indication of usual BP than a single 24hr measurement [61]. However, automated office BP measurement is recommended for use in primary care settings as it has been shown to be comparable with awake ambulatory BP [62], and was thus deemed appropriate in this research context.…”

The role of oxidative stress on the pathophysiology of metabolic syndrome

“…One of the arrangements set out for this improvement was the reduction of oxidative stress and inflammation. [53][54][55][56][57] Among these studies, Mitjavila et al 58 observed a decrease of some markers of oxidative stress after one year of dietary intervention. In this same study, subjects with MetS who consumed the Mediterranean diet were compared to a group that consumed a diet with only low levels of fat.…”

Recent Findings of Studies on the Mediterranean Diet

“…[42][43][44][45][46][47][48][49][50][51][52][53] Mediterranean Diet 975 lower total cholesterol/HDL-C ratios compared with the low(er)-fat group (À0.38 and À0.26, respectively). In addition, the Mediterranean diet with nuts reduced fasting glucose (À5.4 mg/dL), SBP (À7.1 mm Hg), DBP (À2.6 mm Hg), and TG concentrations (À13 mg/dL) relative to the low(er)-fat diet.…”

“…44 However, in a subsequent analysis of a larger nondiabetic population, only the Mediterranean diet supplemented with EVOO reduced the risk of new-onset type 2 diabetes. 45 Additional follow-up studies reported reductions in carotid intima-media thickness, 46,47 apolipoproteins, 48 very low-density lipoprotein (VLDL) cholesterol, 49 inflammatory biomarkers, 50 and improvements in DBP, 51 ambulatory blood pressure, 52 and heart failure biomarkers. 53 It is interesting that supplementation with nuts versus EVOO elicited beneficial effects on different CVD risk factors, without a clear trend indicating whether one dietary pattern was more effective.…”