Change in Salt Intake Affects Blood Pressure of Chimpanzees

Department of Epidemiology and Public Health, Imperial College London, Faculty of Medicine, St. Mary's Campus, Norfolk Place, London W2 1PG, UK.
Circulation (Impact Factor: 14.43). 10/2007; 116(14):1563-8. DOI: 10.1161/CIRCULATIONAHA.106.675579
Source: PubMed


Addition of up to 15.0 g/d salt to the diet of chimpanzees caused large rises in blood pressure, which reversed when the added salt was removed. Effects of more modest alterations to sodium intakes in chimpanzees, akin to current efforts to lower sodium intakes in the human population, are unknown.
Sodium intakes were altered among 17 chimpanzees in Franceville, Gabon, and 110 chimpanzees in Bastrop, Tex. In Gabon, chimpanzees had a biscuit diet of constant nutrient composition except that the sodium content was changed episodically over 3 years from 75 to 35 to 120 mmol/d. In Bastrop, animals were divided into 2 groups; 1 group continued on the standard diet of 250 mmol/d sodium for 2 years, and sodium intake was halved for the other group. Lower sodium intake was associated with lower systolic, diastolic, and mean arterial blood pressures in Gabon (2-tailed P<0.001, unadjusted and adjusted for age, sex, and baseline weight) and Bastrop (P<0.01, unadjusted; P=0.08 to 0.10, adjusted), with no threshold down to 35 mmol/d sodium. For systolic pressure, estimates were -12.7 mm Hg (95% confidence interval, -16.9 to -8.5, adjusted) per 100 mmol/d lower sodium in Gabon and -10.9 mm Hg (95% confidence interval, -18.9 to -2.9, unadjusted) and -5.7 mm Hg (95% confidence interval, -12.2 to 0.7, adjusted) for sodium intake lower by 122 mmol/d in Bastrop. Baseline systolic pressures higher by 10 mm Hg were associated with larger falls in systolic pressure by 4.3/2.9 mm Hg in Gabon/Bastrop per 100 mmol/d lower sodium.
These findings from an essentially single-variable experiment in the species closest to Homo sapiens with high intakes of calcium and potassium support intensified public health efforts to lower sodium intake in the human population.

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Available from: Mark P Little, Oct 10, 2015
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    • "Conversely, a reduction in salt intake has been shown to result in a significant decrease in blood pressure among both normotensive and hypertensive individuals [5] [6] [7] [8] [9] [10]. "
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    ABSTRACT: This experimental study was aimed at assessing the potential effect of a theory-driven intervention-implementation intentions-on reducing salt intake among hypertensive Brazilian women. Ninety-eight participants were randomly assigned to participate in an implementation intentions intervention aimed at promoting lower salt intake through decreased addition of salt and salty spices to meals (intervention group, n = 49; group, n = 49). Endpoints were assessed at baseline and at the 2-month follow-up. Primary endpoints were a self-reporting measure of salt intake given by salt addition to meals (discretionary salt + salty spices = total added salt) and the 24 h urinary-sodium excretion. Secondary endpoints included intention, self-efficacy, and habit related to adding salt to meals. Patients in the intervention group showed a significant reduction in salt intake as assessed by 24 h urinary-sodium excretion. A significant reduction in the measure of habit was observed for both groups. No differences were observed for intention and self-efficacy. The results of this pilot study suggest the efficacy of planning strategies to help hypertensive women reduce their salt intake.
    08/2014; 2014:196410. DOI:10.1155/2014/196410
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    • "A body of evidence suggested that salt or sodium intake reduction can regulate BP and decreases the future risk of cardiovascular diseases [32]. An experimental study with chimpanzees found that the lower sodium intake predicted lower BP and arterial BP at the end of a 2-year intervention [33]. A metaanalysis of 10 controlled trials confirmed that a modest reduction of salt intake initiated drops in BP in adolescents [34]. "
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    ABSTRACT: Purpose: To evaluate the effectiveness of the HEROES (Healthy, Energetic, Ready, Outstanding, Enthusiastic Schools) initiative, a multicomponent school-based obesity prevention intervention based on the Centers for Disease Control and Prevention's coordinated school health approach, on the improvement of blood pressure (BP) and to determine long-term predictors of systolic and diastolic BP changes among high school students who were exposed to the intervention. Methods: Biometric and behavioral data from high school students were analyzed at baseline, 6, 12, and 18 months (N = 847, three schools). The attrition rate at 18 months was 26.1%. Sequential generalized estimating equation models were fit to the data using SAS 9.3, taking into account clustering effects within the same school and correlations within repeated measures. Results: A significant downward trend was observed in systolic BP (p = .0006) and diastolic BP (p < .0001) among the students who were exposed to the HEROES initiative. The prevalence of hypertension decreased from 17.1% at baseline to 12.8% at 6 months (p < .0001), 12.0% at 12 months (p < .0001), and 15.0% (p = .0024) at 18 months. Baseline body mass index, increases in body mass index percentiles, and increases of television-viewing hours were associated with BP increases. Increases in frequencies of eating french fries or chips, skipping breakfast, and consuming supersize meals when eating fast food were predictive of systolic BP changes, not of diastolic BP changes. Conclusions: An 18-month multicomponent school-based obesity intervention program may be effectively used to decrease rates of high BP among adolescents.
    Journal of Adolescent Health 06/2014; 55(4). DOI:10.1016/j.jadohealth.2014.04.011 · 3.61 Impact Factor
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    • "For the past five decades various studies have been conducted on the comparative sodium intake levels in different countries [75, 76]. Animal experiments, epidemiological studies, and clinical trials have provided convincing evidence for the detrimental effect of sodium intake on blood pressure (BP), coronary heart disease, and stroke, as well as noncardiovascular diseases [77–81]. These comparative studies have shown that generally the simpler and less modernized a society and culture are, the lower the sodium intake is, with a concomitant lessening of the associated disorders. "
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    ABSTRACT: Autoimmune diseases have registered an alarming rise worldwide in recent years. Accumulated evidence indicates that the immune system's ability to distinguish self from nonself is negatively impacted by genetic factors and environmental triggers. Genetics is certainly a factor, but since it normally takes a very long time for the human genetic pattern to change enough to register on a worldwide scale, increasingly the attention of studies has been focused on the environmental factors of a rapidly changing and evolving civilization. New technology, new industries, new inventions, new chemicals and drugs, and new foods and diets are constantly and rapidly being introduced in this fast-paced ever-changing world. Toxicants, infections, epitope spreading, dysfunctions of immune homeostasis, and dietary components can all have an impact on the body's delicate immune recognition system. Although the precise etiology and pathogenesis of many autoimmune diseases are still unknown, it would appear from the collated studies that there are common mechanisms in the immunopathogenesis of multiple autoimmune reactivities. Of particular interest is the citrullination of host proteins and their conversion to autoantigens by the aforementioned environmental triggers. The identification of these specific triggers of autoimmune reactivity is essential then for the development of new therapies for autoimmune diseases.
    02/2014; 2014:437231. DOI:10.1155/2014/437231
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