Indication: Total & Cause-Specific Mortality
Source: Annals of Internal Medicine, Apr. 2, 2013; 158 (7): 515-525
Research: Long-chain omega 3 polyunsaturated fatty acids (PUFAs), including EPA, DPA and DHA have been shown to reduce cardiovascular risk, but effects on cause-specific and total mortality and potential dose-responses remain controversial. Researchers investigated associations of plasma phospholipid EPA, DPA, DHA and total PUFA levels with total and cause-specific mortality among healthy older adults not receiving supplements. This prospective cohort study funded by the National Institutes of Health involved 2,692 U.S. adults aged 74 years ([+ or -]5 years) without prevalent coronary heart disease (CHD), stroke or heart failure at baseline. Phospholipid fatty acid levels and cardiovascular risk factors were measured in 1992. Relationships with total and cause-specific mortality and incident fatal or non-fatal CH'D and stroke through 2008 were assessed.
Results: During 30,829 person-years, 1,625 deaths (including 570 cardiovascular deaths), 359 fatal and 371 non-fatal CHD events, and 130 fatal and 276 non-fatal strokes occurred. After adjustment, higher plasma levels of omega 3 PUFA biomarkers were associated with lower total mortality, with extreme-quintile hazard ratios of 0.83 for EPA (95% CI, 0.71 to 0.98; P for trend = 0.005), 0.77 for DPA (Cl, 0.66 to 0.90; P for trend = 0.008), 0.80 for DHA (C1, 0.67 to 0.94; P for trend = 0.006), and 0.73 for total omega 3 PUFAs (CI, 0.61 to 0.86; P for trend < 0.001). Lower risk was largely attributable to fewer cardiovascular than non-cardiovascular deaths. Individuals in the highest quintile of phospholipid PUFA level lived an average of 2.22 more years (CI, 015 to 3.1.3 years) after age 65 years than those in the lowest quintile.
Researchers noted that temporal changes in fatty acid levels and misclassification of causes of death may have resulted in underestimated associations, and unmeasured or imperfectly measured covariates may have caused residual confounding. Overall, researchers concluded that higher circulating individual and total omega 3 PUFA levels are associated with lower total mortality, especially CHD death, in older adults.
Indication: Stroke Risk
Source: Stroke (American Heart Association), Mar. 28, 2013 (Epub ahead of print)
Research: Fiber intake is associated with reduced stroke risk in prospective studies, but no meta-analysis had been published to date. Multiple electronic databases were searched for healthy participant studies reporting fiber intake and incidence of first hemorrhagic or ischemic stroke, published between January 1990 and May 2012. Eight cohort studies from the U.S., northern Europe, Australia and Japan met inclusion criteria.
Results: Total dietary fiber intake was inversely associated with risk of hemorrhagic plus ischemic stroke, with some evidence of heterogeneity between studies (12; relative risk per 7 g/day, 0.93; 95% confidence interval, 0.88-0.98; 12=59%). Soluble fiber intake, per 4 g/day, was not associated with stroke risk reduction with evidence of low heterogeneity between studies, relative risk 0.94 (95% confidence interval, 0.88-1.01; 12=21%). There were few studies reporting stroke risk in relation to insoluble fiber or fiber from cereals, fruit or vegetables.
Researchers concluded that greater dietary fiber intake is significantly associated with lower risk of first stroke. Overall, findings support dietary recommendations to increase intake of total dietary fiber. However, a paucity of data on fiber from different foods precludes conclusions regarding the association between fiber type and stroke. There is a need for future studies to focus on fiber type and to examine risk for ischemic and hemorrhagic strokes separately.
Nutraceutical: Mediterranean Diet
Indication: Cardiovascular Disease Risk
Source: New England Journal of Medicine, Feb. 25, 2013, (E-pub ahead of print)
Research: The PREDIMED trial (Prevencion con Dieta Mediterranea) was a parallel-group, multicenter, randomized trial conducted in Spain. Eligible were men (55 to 80 years of age) and women (60 to 80 years of age) with no cardiovascular disease at enrollment, who had either type 2 diabetes mellitus or at least three of the following major risk factors: smoking, hypertension, elevated low-density lipoprotein cholesterol levels, low high-density lipoprotein cholesterol levels, overweight or obesity or a family history of premature coronary heart disease.
Researchers randomly assigned participants to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts or a control diet (advice to reduce dietary fat). Participants in the two Mediterranean-diet groups received either extra-virgin olive oil (approximately 1 liter per week) or 30 grams of mixed nuts per day (15 grams of walnuts, 7.5 grams of hazelnuts and 7.5 grams of almonds). A general medical questionnaire, a validated food-frequency questionnaire and the Minnesota Leisure-Time Physical Activity Questionnaire were administered on a yearly basis, information from the food-frequency questionnaire was used to calculate intake of energy and nutrients. Weight, height and waist circumference were directly measured. Biomarkers of compliance, including urinary hydroxytyrosol levels (to confirm compliance in the group receiving extra-virgin olive oil) and plasma alpha-linolenic acid levels (to confirm compliance in the group receiving mixed nuts), were measured in random subsamples of participants at 1, 3 and 5 years. The primary end point was a composite of myocardial infarction, stroke and death from cardiovascular causes. Secondary end points were stroke, myocardial in farction, death from cardiovascular causes and death from any cause.
Results: The median follow-up period was 4.8 years. A total of 288 primary-outcome events occurred: 96 in the group assigned to a Mediterranean diet with extra-virgin olive oil (3.8%), 83 in the group assigned to a Mediterranean diet with nuts (3.4%) and 109 in the control group (4.4%). Taking into account the small differences in the accrual of person-years among the three groups, the respective rates of the primary end point were 8.1, 8.0 and 11.2 per 1,000 person-'cars. The unadjusted hazard ration were 0.70 (95% confidence interval [CI], 0.53 to 0.9-1) for a Mediterranean diet with extra-virgin olive oil and 0.70 (95% CI, 0.53 to 0.94) for a Mediterranean diet with nuts as compared with the control diet (P = 0.015, by the likelihood ratio test, for the overall effect of the intervention).
The results of multivariate analyses showed a similar protective effect of the two Mediterranean diets versus the control diet with respect to the primary end point. Regarding components of the primary end point, only the comparisons of stroke risk reached statistical significance. Researchers concluded that in this trial, an energy-unrestricted Mediterranean diet supplemented with either extra-virgin olive oil or nuts resulted in an absolute risk reduction of approximately three major cardiovascular events per 1,000 person-years, for a relative risk reduction of approximately 30%, among high-risk persons who were initially free of cardiovascular disease. These results support the benefits of the Mediterranean diet for cardiovascular risk reduction. They are particularly relevant given the challenges of achieving and maintaining weight loss.
Nutraceutical: Total Antioxidant Capacity
Indication: Risk of Heart Failure Source: American Journal of Medicine, Apr. 3, 2013; doi:10.1016
Research: Few studies have investigated the association between individual antioxidants and risk of heart failure. No previous study has investigated the role of all antioxidants present in diet in relation to heart failure, according to researchers. The aim of this study was to assess the association between total antioxidant capacity of diet, which reflects all of the antioxidant compounds in food and the interactions between them, and the incidence of heart failure among middle-aged and elderly women. In September 1997, 33,713 women (aged 49-83 years) from the Swedish Mammography Cohort completed a food-frequency questionnaire. Estimates of dietary total antioxidant capacity were based on the Oxygen Radical Absorbance Capacity assay measurements of foods. Women were followed for incident heart failure (hospitalization or mortality of heart failure as the primary cause) through December 2009 using administrative health registries. Cox proportional hazard models were used to calculate relative risks and 95% confidence intervals.
Results: During 11.3 years of follow-up (394,059 person-years), researcgers identified 894 incident cases of heart failure. Total antioxidant capacity of diet was inversely associated with heart failure (the multivariable-adjusted relative risk in the highest quintile compared with the lowest was 0.58 [95% confidence interval, 0.47-0.72; P for trend < .001]). The crude incidence rate was 18/10,000 person-years in the highest quintile versus 34/10,000 person-years in the lowest quintile.
Researchers concluded the total antioxidant capacity of diet, an estimate reflecting all antioxidants in the diet, was associated with lower risk of heart failure. These results indicate that a healthful diet high in antioxidants may help prevent heart failure.
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|Article Type:||Clinical report|
|Date:||May 1, 2013|
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