The Antioxidant Potential of the Mediterranean Diet in Patients at High Cardiovascular Risk: An In-Depth Review of the PREDIMED

Cardiovascular disease (CVD) is the leading global cause of death. Diet is known to be important in the prevention of CVD. The PREDIMED trial tested a relatively low-fat diet versus a high-fat Mediterranean diet (MedDiet) for the primary prevention of CVD. The resulting reduction of the CV composite outcome resulted in a paradigm shift in CV nutrition. Though many dietary factors likely contributed to this effect, this review focuses on the influence of the MedDiet on endogenous antioxidant systems and the effect of dietary polyphenols. Subgroup analysis of the PREDIMED trial revealed increased endogenous antioxidant and decreased pro-oxidant activity in the MedDiet groups. Moreover, higher polyphenol intake was associated with lower incidence of the primary outcome, overall mortality, blood pressure, inflammatory biomarkers, onset of new-onset type 2 diabetes mellitus (T2DM), and obesity. This suggests that polyphenols likely contributed to the lower incidence of the primary event in the MedDiet groups. In this article, we summarize the potential benefits of polyphenols found in the MedDiet, specifically the PREDIMED cohort. We also discuss the need for further research to confirm and expand the findings of the PREDIMED in a non-Mediterranean population and to determine the exact mechanisms of action of polyphenols

Time Course of Change in Blood Pressure from Sodium Reduction and the DASH Diet

Both sodium reduction and the Dietary Approaches to Stop Hypertension (DASH) diet lower blood pressure (BP); however, the patterns of their effects on BP over time are unknown. In the DASH-Sodium trial, adults with pre-/stage 1 hypertension, not using antihypertensive medications, were randomly assigned to either a typical American diet (control) or DASH. Within their assigned diet, participants randomly ate each of 3 sodium levels (50, 100, and 150 mmol/d, at 2100 kcal) over 4-week periods. BP was measured weekly for 12 weeks; 412 participants enrolled (57% women; 57% black; mean age, 48 years; mean systolic BP [SBP]/diastolic BP [DBP], 135/86 mm Hg). For those assigned control, there was no change in SBP/DBP between weeks 1 and 4 on the high-sodium diet (weekly change, -0.04/0.06 mm Hg/week) versus a progressive decline in BP on the low-sodium diet (-0.94/-0.70 mm Hg/week; P interactions between time and sodium <0.001 for SBP and DBP). For those assigned DASH, SBP/DBP changed -0.60/-0.16 mm Hg/week on the high- versus -0.42/-0.54 mm Hg/week on the low-sodium diet (P interactions between time and sodium=0.56 for SBP and 0.10 for DBP). When comparing DASH to control, DASH changed SBP/DBP by -4.36/-1.07 mm Hg after 1 week, which accounted for most of the effect observed, with no significant difference in weekly rates of change for either SBP (P interaction=0.97) or DBP (P interaction=0.70). In the context of a typical American diet, a low-sodium diet reduced BP without plateau, suggesting that the full effects of sodium reduction are not completely achieved by 4 weeks. In contrast, compared with control, DASH lowers BP within a week without further effect thereafter. Clinical Trial Registration - URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000608

Effect of the Mediterranean diet on blood pressure in the PREDIMED trial: results from a randomized controlled trial

BackgroundHypertension can be prevented by adopting healthy dietary patterns. Our aim was to assess the 4-year effect on blood pressure (BP) control of a randomized feeding trial promoting the traditional Mediterranean dietary pattern.MethodsThe PREDIMED primary prevention trial is a randomized, single-blinded, controlled trial conducted in Spanish primary healthcare centers. We recruited 7,447 men (aged 55 to 80 years) and women (aged 60 to 80 years) who had high risk for cardiovascular disease. Participants were assigned to a control group or to one of two Mediterranean diets. The control group received education on following a low-fat diet, while the groups on Mediterranean diets received nutritional education and also free foods; either extra virgin olive oil, or nuts. Trained personnel measured participants’ BP at baseline and once yearly during a 4-year follow-up. We used generalized estimating equations to assess the differences between groups during the follow-up.ResultsThe percentage of participants with controlled BP increased in all three intervention groups (P-value for within-group changes: P<0.001). Participants allocated to either of the two Mediterranean diet groups had significantly lower diastolic BP than the participants in the control group (−1.53 mmHg (95% confidence interval (CI) −2.01 to −1.04) for the Mediterranean diet supplemented with extra virgin olive oil, and −0.65 mmHg (95% CI -1.15 to −0.15) mmHg for the Mediterranean diet supplemented with nuts). No between-group differences in changes of systolic BP were seen.ConclusionsBoth the traditional Mediterranean diet and a low-fat diet exerted beneficial effects on BP and could be part of advice to patients for controlling BP. However, we found lower values of diastolic BP in the two groups promoting the Mediterranean diet with extra virgin olive oil or with nuts than in the control group.Trial registrationCurrent Controlled Trials ISRCTN3573963

A systematic review of the sources of dietary salt around the world

Excess salt intake contributes to hypertension and increased cardiovascular disease risk. Efforts to implement effective salt-reduction strategies require accurate data on the sources of salt consumption. We therefore performed a systematic review to identify the sources of dietary salt around the world. We systematically searched peer-reviewed and gray literature databases for studies that quantified discretionary (salt added during cooking or at the table) and nondiscretionary sources of salt and those that provided information about the food groups contributing to dietary salt intake. Exploratory linear regression analysis was also conducted to assess whether the proportion of discretionary salt intake is related to the gross domestic product (GDP) per capita of a country. We identified 80 studies conducted in 34 countries between 1975 and 2018. The majority (n = 44, 55%) collected data on dietary salt sources within the past 10 y and were deemed to have a low or moderate risk of bias (n = 75, 94%). Thirty-two (40%) studies were judged to be nationally representative. Populations in Brazil, China, Costa Rica, Guatemala, India, Japan, Mozambique, and Romania received more than half of their daily salt intake from discretionary sources. A significant inverse correlation between discretionary salt intake and a country's per capita GDP was observed (P < 0.0001), such that for every $10,000 increase in per capita GDP, the amount of salt obtained from discretionary sources was lower by 8.7% (95% CI: 5.1%, 12%). Bread products, cereal and grains, meat products, and dairy products were the major contributors to dietary salt intake in most populations. There is marked variation in discretionary salt use around the world that is highly correlated with the level of economic development. Our findings have important implications for the type of salt-reduction strategy likely to be effective in a country

Potassium-Enriched Salt Substitutes: A Review of Recommendations in Clinical Management Guidelines.

Excess dietary sodium intake and insufficient dietary potassium intake are both well-established risk factors for hypertension. Despite some successful initiatives, efforts to control hypertension by improving dietary intake have largely failed because the changes required are mostly too hard to implement. Consistent recent data from randomized controlled trials show that potassium-enriched, sodium-reduced salt substitutes are an effective option for improving consumption levels and reducing blood pressure and the rates of cardiovascular events and deaths. Yet, salt substitutes are inconsistently recommended and rarely used. We sought to define the extent to which evidence about the likely benefits and harms of potassium-enriched salt substitutes has been incorporated into clinical management by systematically searching guidelines for the management of hypertension or chronic kidney disease. We found incomplete and inconsistent recommendations about the use of potassium-enriched salt substitutes in the 32 hypertension and 14 kidney guidelines that we reviewed. Discussion among the authors identified the possibility of updating clinical guidelines to provide consistent advice about the use of potassium-enriched salt for hypertension control. Draft wording was chosen to commence debate and progress consensus building: strong recommendation for patients with hypertension-potassium-enriched salt with a composition of 75% sodium chloride and 25% potassium chloride should be recommended to all patients with hypertension, unless they have advanced kidney disease, are using a potassium supplement, are using a potassium-sparing diuretic, or have another contraindication. We strongly encourage clinical guideline bodies to review their recommendations about the use of potassium-enriched salt substitutes at the earliest opportunity

Potassium-Enriched Salt Substitutes: A Review of Recommendations in Clinical Management Guidelines

Excess dietary sodium intake and insufficient dietary potassium intake are both well-established risk factors for hypertension. Despite some successful initiatives, efforts to control hypertension by improving dietary intake have largely failed because the changes required are mostly too hard to implement. Consistent recent data from randomized controlled trials show that potassium-enriched, sodium-reduced salt substitutes are an effective option for improving consumption levels and reducing blood pressure and the rates of cardiovascular events and deaths. Yet, salt substitutes are inconsistently recommended and rarely used. We sought to define the extent to which evidence about the likely benefits and harms of potassium-enriched salt substitutes has been incorporated into clinical management by systematically searching guidelines for the management of hypertension or chronic kidney disease. We found incomplete and inconsistent recommendations about the use of potassium-enriched salt substitutes in the 32 hypertension and 14 kidney guidelines that we reviewed. Discussion among the authors identified the possibility of updating clinical guidelines to provide consistent advice about the use of potassium-enriched salt for hypertension control. Draft wording was chosen to commence debate and progress consensus building: strong recommendation for patients with hypertension - potassium-enriched salt with a composition of 75% sodium chloride and 25% potassium chloride should be recommended to all patients with hypertension, unless they have advanced kidney disease, are using a potassium supplement, are using a potassium-sparing diuretic, or have another contraindication. We strongly encourage clinical guideline bodies to review their recommendations about the use of potassium-enriched salt substitutes at the earliest opportunity

The impact of a brief lifestyle intervention delivered by generalist community nurses (CN SNAP trial)

BackgroundThe risk factors for chronic disease, smoking, poor nutrition, hazardous alcohol consumption, physical inactivity and weight (SNAPW) are common in primary health care (PHC) affording opportunity for preventive interventions. Community nurses are an important component of PHC in Australia. However there has been little research evaluating the effectiveness of lifestyle interventions in routine community nursing practice. This study aimed to address this gap in our knowledge.MethodsThe study was a quasi-experimental trial involving four generalist community nursing (CN) services in New South Wales, Australia. Two services were randomly allocated to an &lsquo;early intervention&rsquo; and two to a &lsquo;late intervention&rsquo; group. Nurses in the early intervention group received training and support in identifying risk factors and offering brief lifestyle intervention for clients. Those in the late intervention group provided usual care for the first 6 months and then received training. Clients aged 30&ndash;80 years who were referred to the services between September 2009 and September 2010 were recruited prior to being seen by the nurse and baseline self-reported data collected. Data on their SNAPW risk factors, readiness to change these behaviours and advice and referral received about their risk factors in the previous 3 months were collected at baseline, 3 and 6 months. Analysis compared changes using univariate and multilevel regression techniques.Results804 participants were recruited from 2361 (34.1%) eligible clients. The proportion of clients who recalled receiving dietary or physical activity advice increased between baseline and 3 months in the early intervention group (from 12.9 to 23.3% and 12.3 to 19.1% respectively) as did the proportion who recalled being referred for dietary or physical activity interventions (from 9.5 to 15.6% and 5.8 to 21.0% respectively). There was no change in the late intervention group. There a shift towards greater readiness to change in those who were physically inactive in the early but not the comparison group. Clients in both groups reported being more physically active and eating more fruit and vegetables but there were no significant differences between groups at 6 months.ConclusionThe study demonstrated that although the intervention was associated with increases in advice and referral for diet or physical activity and readiness for change in physical activity, this did not translate into significant changes in lifestyle behaviours or weight. This suggests a need to facilitate referral to more intensive long-term interventions for clients with risk factors identified by primary health care nurses

Estimated Benefits and Risks of Using a Reduced-Sodium, Potassium-Enriched Salt Substitute in India: A Modeling Study

Background: Salt substitution (ie, replacement of table and cooking salt with potassium-enriched salt substitutes) is a promising strategy to reduce blood pressure and prevent cardiovascular disease, particularly in countries like India where there is high sodium intake, mainly from discretionary salt, and low potassium intake. Life-threatening hyperkalemia from increased potassium intake is a postulated concern for individuals with chronic kidney disease. methods: We used comparative risk assessment models to estimate the number of (1) cardiovascular deaths averted due to blood pressure reductions; (2) potential hyperkalemia-related deaths from increased potassium intake in individuals with advanced chronic kidney disease; and (3) net averted deaths from nationwide salt substitution in India. We evaluated a conservative scenario, based on a large, long-term pragmatic trial in rural China; and an optimistic scenario informed by our recent trial in India. Sensitivity analyses were conducted to assess the robustness of the findings. Results: In the conservative scenario, a nationwide salt substitution intervention was estimated to result in ≈214 000 (95% uncertainty interval, 92 764-353 054) averted deaths from blood pressure reduction in the total population and ≈52 000 (22 961-80 211) in 28 million individuals with advanced chronic kidney disease, while ≈22 000 (15 221-31 840) hyperkalemia-deaths might be caused by the intervention. The corresponding estimates for the optimistic scenario were ≈351 000 (130 470-546 255), ≈66 000 (24 925-105 851), and ≈9000 (4251-14 599). Net benefits were consistent across sensitivity analyses. Conclusions: Modeling nationwide salt substitution in India consistently estimated substantial net benefits, preventing around 8% to 14% of annual cardiovascular deaths. Even allowing for potential hyperkalemia risks there were net benefits estimated for individuals with chronic kidney disease

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012