Salt: the forgotten foe in UK public health policy

Salt intake, blood pressure and cardiovascular disease mortality in England, 2003-2018

OBJECTIVES

The aim of this study was to assess the changes in salt intake and concomitant changes in blood pressure (BP) and cardiovascular disease (CVD) mortality in England from 2003 to 2018.

METHODS

National surveys and death registration data were used for the analysis of salt intake as measured by 24-h urinary sodium excretion (449-1069 participants per year), BP (2651-6738 participants per year) and CVD mortality.

RESULTS

A decline in salt intake from 9.38 (SD 4.64) to 7.58 (3.41) g/d was observed between 2003 and 2014 ( P  < 0.01), followed by an increase to 8.39 (4.13) g/d in 2018 ( P  < 0.01). Similar trends in BP and CVD mortality were also observed between 2003 and 2018. SBP/DBP decreased from 125.3 (15.92)/74.48 (11.33) mmHg to 122.57 (14.92)/73.33 (10.75) mmHg between 2003 and 2014 ( P  < 0.01), followed by a plateau up to 2018 [122.04 (14.64)/73.84 (10.54) mmHg, P  > 0.05]. Likewise, a fall in stroke and ischaemic heart disease mortality rates was observed between 2003 and 2014, from 12.24 and 43.44 cases per 100 000, to 8.19 and 27.23 cases per 100 000 ( P  < 0.01), respectively, followed by a plateau afterwards ( P  > 0.05).

CONCLUSION

The UK salt reduction programme was initially successful in reducing population salt intake by 19% (from 9.38 g/d in 2003 to 7.58 g/d in 2014). However, in recent years, the programme stalled and thus led to an interruption in the decline of salt intake. BP and CVD mortality reduction was also interrupted when salt reduction stalled. The changes in salt intake may have played an important role in the concomitant changes in BP and CVD mortality. Urgent action is needed to reinvigorate the UK's once world-leading salt reduction programme.

Changes in sodium levels in Australian packaged foods between 2014 and 2019: an interrupted time series analysis of the impact of the Victorian Salt Reduction Partnership's media advocacy strategy

BACKGROUND

The Victorian Salt Reduction Partnership (VSRP) implemented a media advocacy strategy (intervention) to stimulate food manufacturers to reduce sodium levels across targeted Australian packaged foods between 2017 and 2019. This study assessed changes in sodium levels of targeted and non-targeted packaged foods during the intervention (2017 to 2019) compared to before the intervention (2014 to 2016) in Australia.

METHODS

Annually collected branded-food composition data from 2014 to 2019 were used. Interrupted time series analyses was conducted to compare the trend in sodium levels in packaged foods during the intervention (2017-2019) to the trend in the pre-intervention period (2014-2016). The difference between these trends was derived to estimate the effect of the intervention.

RESULTS

A total of 90,807 products were included in the analysis, of which 14,743 were targeted by the intervention. The difference in before and during intervention trends between targeted and non-targeted food categories was 2.59 mg/100 g (95% CI: -13.88 to 19.06). There was a difference in the pre-intervention slope (2014, 2015, 2016) and intervention slope (2017, 2018, 2019) for four of 17 targeted food categories. There was a decrease in sodium levels (mg/100 g) in one food category: frozen ready meals (-13.47; 95% CI: -25.40 to -1.53), and an increase in three categories: flat bread (20.46; 95% CI: 9.11 to 31.81), plain dry biscuits (24.53; 95% CI: 5.87 to 43.19), and bacon (44.54; 95% CI: 6.36 to 82.72). For the other 13 targeted categories, the difference in slopes crossed the line of null effect.

CONCLUSIONS

The VSRP's media advocacy strategy did not result in a meaningful reduction in sodium levels of targeted packaged food products during the intervention years compared to trends in sodium levels before the intervention. Our study suggests media advocacy activities highlighting the differences in sodium levels in packaged food products and industry meetings alone are not sufficient to lower average sodium levels in packaged foods in the absence of government leadership and measurable sodium targets.

Treatment of hypertension and obstructive sleep apnea counteracts cognitive decline in common neurocognitive disorders in diagnosis-related patterns

The aim of this study was to investigate the effect of arterial hypertension (AH) and of obstructive sleep apnea (OSA) on cognitive course in the neurocognitive disorder (NCD) cohort RIFADE which enrolled patients with NCD due to Alzheimer's disease (AD), vascular NCD (vNCD), and mixed NCD (AD + vNCD = mNCD). Multiple risk factors (RF), including AH and OSA, that contribute to the development of various kinds of dementia have been identified in previous studies. Studies that observed AH lacked investigation of long-term effects and did not isolate it from other RF. Studies involving OSA as a risk factor did not include participants with all stages of NCD. 126 subjects were screened for AH and OSA. Repeated cognitive measurements were performed with the DemTect as primary outcome and the clock drawing test as secondary outcome measure. 90 patients had AH (71.4%) and 40 patients had OSA (31.7%). RF-status had a significant effect on cognitive outcome in models with RF as single factors (AH p = 0.027, OSA p < 0.001), a 2-factor analysis with AH × OSA (AH as main factor p = 0.027) as well as a model including the 3 factors AH × OSA × diagnosis (p = 0.038). Similarly, a 3-factor model was significant for the clock-drawing test, whereas single factor-models remained insignificant. AH and OSA appear to be risk factors in common NCD and cognitive decline can be mitigated by treatment of these RF.

Estimated Dietary and Health Impact of the World Health Organization's Global Sodium Benchmarks on Packaged Foods in Australia: a Modeling Study

BACKGROUND

In 2021, the World Health Organization (WHO) set sodium benchmarks for packaged foods to guide countries in setting feasible and effective sodium reformulation programs. We modeled the dietary and health impact of full compliance with the WHO's sodium benchmarks in Australia and compared it to the potential impact of Australia's 2020 sodium reformulation targets.

METHODS

We used nationally representative data on food and sodium intake, sodium levels in packaged foods, and food sales volume to estimate sodium intake pre- and post-implementation of the WHO and Australia's sodium benchmarks for 24 age-sex groups. Using comparative risk assessment models, we then estimated the potential deaths, incidence, and disability-adjusted life years averted from cardiovascular disease, chronic kidney disease, and stomach cancer based on the reductions in sodium intake.

RESULTS

Compliance with the WHO's sodium benchmarks for packaged foods in Australia could lower mean adult sodium intake by 404 mg/day, corresponding to a 12% reduction. This could prevent about 1770 deaths/year (95% uncertainty interval 1168-2587), corresponding to 3% of all cardiovascular disease, chronic kidney disease, and stomach cancer deaths in Australia, and prevent some 6900 (4603-9513) new cases, and 25 700 (17 655-35 796) disability-adjusted life years/year. Compared with Australian targets, the WHO benchmarks will avert around 3 and a half times more deaths each year (1770 versus 510).

CONCLUSIONS

Substantially greater health impact could be achieved if the Australian government strengthened its current sodium reformulation program by adopting WHO's more stringent and comprehensive sodium benchmarks.

The perspective of hypertension and salt intake in Chinese population

Salt intake is too high nowadays. It has been widely recognized that there is a close relationship between hypertension (HTN) and dietary salt intake. Investigations reveal that long-term high salt intake, mainly sodium intake, induces a relevant increase in blood pressure in hypertensive and normotensive individuals. According to most scientific evidence, a diet with high salt intake in public increases cardiovascular risk, salted-related HTN, and other HTN-associated outcomes. Given the clinical importance, this review aims to present the prevalence of HTN and trends in salt intake in the Chinese population and will comprehensively discuss the risk factors, causes, and mechanisms of the association between salt intake and HTN. The review also highlights the education of Chinese people regarding salt intake and the cost-effectiveness of salt reduction from a global perspective. Finally, the review will emphasize the need to customize the unique Chinese practices to reduce salt intake and how awareness changes people's eating lifestyle and helps adopt diet salt reduction strategies.