Monitoring and implementation of salt reduction initiatives in Africa: A systematic review

This systematic review aims to document salt consumption patterns and the implementation status and potential impact of salt reduction initiatives in Africa, from studies published between January 2009 and November 2019. Studies were sourced using MEDLINE, Embase, Cochrane Library electronic databases, and gray literature. Of the 887 records retrieved, 38 studies conducted in 18 African countries were included. Twelve studies measured population salt intake, 11 examined salt level in foods, 11 assessed consumer knowledge, attitudes, and behaviors, 1 study evaluated a behavior change intervention, and 3 studies modeled potential health gains and cost savings of salt reduction interventions. The population salt intake studies determined by 24-hour urine collections showed that the mean (SD) salt intake in African adults ranged from 6.8 (2.2) g to 11.3 (5.4) g/d. Salt levels in foods were generally high, and consumer knowledge was fairly high but did not seem to translate into salt lowering behaviors. Modeling studies showed that interventions for reducing dietary sodium would generate large health gains and cost savings for the health system. Despite this evidence, adoption of population salt reduction strategies in Africa has been slow, and dietary consumption of sodium remains high. Only South Africa adopted legislation in 2016 to reduce population salt intake, but success of this intervention has not yet been fully evaluated. Thus, rigorous evaluation of the salt reduction legislation in South Africa and initiation of salt reduction programs in other African countries will be vital to achieving the targeted 30% reduction in salt intake by 2025

Projected effects on salt purchases following implementation of a national salt reduction policy in South Africa.

OBJECTIVE: To assess the contribution of different food groups to total salt purchases and to evaluate the estimated reduction in salt purchases if mandatory maximum salt limits in South African legislation were being complied with. DESIGN: This study conducted a cross-sectional analysis of purchasing data from Discovery Vitality members. Data were linked to the South African FoodSwitch database to determine the salt content of each food product purchased. Food category and total annual salt purchases were determined by summing salt content (kg) per each unit purchased across a whole year. Reductions in annual salt purchases were estimated by applying legislated maximum limits to product salt content. SETTING: South Africa. PARTICIPANTS: The study utilised purchasing data from 344 161 households, members of Discovery Vitality, collected for a whole year between January and December 2018. RESULTS: Vitality members purchased R12·8 billion worth of food products in 2018, representing 9562 products from which 264 583 kg of salt was purchased. The main contributors to salt purchases were bread and bakery products (23·3 %); meat and meat products (19 %); dairy (12·2 %); sauces, dressings, spreads and dips (11·8 %); and convenience foods (8·7 %). The projected total quantity of salt that would be purchased after implementation of the salt legislation was 250 346 kg, a reduction of 5·4 % from 2018 levels. CONCLUSIONS: A projected reduction in salt purchases of 5·4 % from 2018 levels suggests that meeting the mandatory maximum salt limits in South Africa will make a meaningful contribution to reducing salt purchases

Effects of a Mediterranean diet on blood pressure: A systematic review and meta-analysis of randomised controlled trials and observational studies

Objective: To conduct a systematic review and meta-analysis investigating effects of MedDiet on blood pressure in randomised controlled trials (RCTs) and associations of MedDiet with risk of hypertension in observational studies. Methods: PubMed, The Cochrane Library and EBSCOhost were searched from inception until January 2020 for studies that met the following criteria: 1) participants aged ≥18 years, 2) RCTs investigating effects of a MedDiet versus control on BP, 3) Observational studies exploring associations between MedDiet adherence and risk of hypertension. Random-effects meta-analyses were conducted. Meta-regression and subgroup analyses were performed for RCTs to identify potential effect moderators. Results: Nineteen RCTs reporting data on 4137 participants and 16 observational studies reporting data on 59,001 participants were included in the meta-analysis. MedDiet interventions reduced systolic and diastolic BP by a mean -1.4 mmHg (95% CI: -2.40 to -0.39 mmHg, p=0.007, I2=53.5%, Q=44.7, τ2=1.65, df=19) and -1.5 mmHg (95% CI: -2.74 to -0.32 mmHg, p=0.013, I2=71.5%, Q=51.6, τ2=4.72, df=19) versus control, respectively. Meta-regression revealed that longer study duration and higher baseline systolic BP was associated with a greater decrease in BP, in response to a MedDiet (p<0.05). In observational studies, odds of developing hypertension were 13% lower with higher versus lower MedDiet adherence (95% CI: 0.78 to 0.98, p=0.017, I2=69.6%, Q=41.1, τ2=0.03, df=17). Conclusions: Data suggest that MedDiet is an effective dietary strategy to aid BP control, which may contribute towards the lower risk of CVD reported with this dietary pattern. This study was registered with PROSPERO: CRD42019125073. KEY WORDS: Mediterranean diet, blood pressure, hypertension, cardiovascular diseas

The effect of dietary patterns on blood pressure: insights for clinical practice

Hypertension or high blood pressure has been identified as a major risk factor for developing cardiovascular disease, stroke and kidney disease. To lower blood pressure, lifestyle changes such as following a healthy diet, weight loss and exercise have been recommended. This thesis draws on dietary data from a weight loss trial in which blood pressure was a secondary outcome. Previous studies investigating the effect of diet on blood pressure have mainly focussed on single nutrients such as sodium and potassium. Whilst this has been informative, food is not consumed as single nutrients but as whole foods, in different combinations which make up dietary patterns. An understanding of the interdependence between nutrients, foods and dietary patterns would help in translating dietary advice in clinical practice especially in food-based recommendations for blood pressure reduction. The central hypothesis of this thesis is that dietary patterns, characterised in terms of nutrients and foods, significantly influence blood pressure in adults. To assess the current level of evidence on the effect of dietary patterns on blood pressure, a systematic review and meta-analysis of randomised controlled trials was conducted. A dietary pattern characterised by high consumption of fruit, vegetables, whole grains, legumes, seeds, nuts, fish and low-fat dairy and low consumption of meat, sweets and alcohol resulted in significant reductions in systolic (SBP) and diastolic (DBP) blood pressure by 4.26 mm Hg and 2.38 mm Hg, respectively. Whether this would still relate to a clinical sample of overweight adults is an important question for practice

Changes in sodium levels of processed foods among the International Food and Beverage Association member companies in Australia: 2013-2017

Excess dietary sodium is a modifiable cause of high blood pressure. The World Health Organization has targeted a 30 % reduction in mean population sodium consumption by 2025. In 2008, members of the International Food and Beverage Alliance (IFBA) made commitments to lower sodium content in their products. The aim of this study was to determine recent changes in sodium levels between 2013 and 2017 in foods and beverages produced by companies that are IFBA members (n = 10) and non-IFBA members (n = 6) that were included in the 2018 Global Access to Nutrition Index operating in Australia. Independent Samples t-tests and Mann Whitney U tests were used to test the differences in sodium levels. There was no clear difference in sodium content between 2013 and 2017 detectable for the IFBA members (mean difference 17 mg/100 g, 95 % confidence interval (CI), –82 to +48; p = 0.612; median difference 27 mg/100 g, p = 0.582). For the non-IFBA companies there was a decrease in median sodium content (−30 mg/100 g; P = 0.002) but not mean sodium content (−52 mg/100 g, 95 % CI −106 to +3; p = 0.064). Sodium reduction in IFBA companies appear to have had slow progress in Australia. Stronger implementation and monitoring programs are needed to drive industry action