The INTERSALT Study was a 1988 international observational study which investigated the link between dietary salt, as measured by urinary excretion, and blood pressure. The study was based on a sample of 10,079 men and women aged 20–59 sampled from 52 populations around the world. The authors of the study provided a widespread international investigation of the correlation between dietary salt intake and blood pressure in a systematic and standardized way with regards for relevant confounding variables, beyond just age and sex.[1]

Results

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The study found a significant direct relationship between dietary salt intake, the urinary sodium:potassium ratio and systolic blood pressure, and between salt intake and the slope of blood pressure with age – both for all 52 populations, and for 48 populations excluding four low-sodium populations (Yanomamo and Xingu Indians of Brazil, Papua New Guinea and rural Kenya).[1]

Reception

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The results were disputed by the Salt Institute (the salt producers' trade organisation, since disbanded), who demanded that the results be handed over for re-analysis.[2] A re-analysis was published in 1996 and the results were the same.[3] The results have since been confirmed by the TOHP I and TOHP II studies,[4]trials of salt reduction and blood pressure in chimpanzees[5][6], meta-analyses of the human clinical trial data[7] and the SSaSS trial of salt substitute and cardiovascular disease.[8]

References

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  1. ^ a b Intersalt Cooperative Research Group (1988). "Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion". Br Med J. 297 (6644): 319–28. doi:10.1136/bmj.297.6644.319. PMC 1834069. PMID 3416162.
  2. ^ Godlee F (2007). "Editor's choice: Time to talk salt". Br Med J. 334 (7599): 0. doi:10.1136/bmj.39196.679537.47. PMC 1858563.
  3. ^ Elliott P, Stamler J, Nichols R, et al. (1996). "Intersalt revisited: further analyses of 24 hour sodium excretion and blood pressure within and across populations. Intersalt Cooperative Research Group". Br Med J. 312 (7041): 1249–53. doi:10.1136/bmj.312.7041.1249. PMC 2351086. PMID 8634612.
  4. ^ Cook NR, Cutler JA, Obarzanek E, et al. (2007). "Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)". Br Med J. 334 (7599): 885–8. doi:10.1136/bmj.39147.604896.55. PMC 1857760. PMID 17449506.
  5. ^ Elliott, Paul; Walker, Lesley L.; Little, Mark P.; Blair-West, John R.; Shade, Robert E.; Lee, D. Rick; Rouquet, Pierre; Leroy, Eric; Jeunemaitre, Xavier; Ardaillou, Raymond; Paillard, Francoise; Meneton, Pierre; Denton, Derek A. (2 October 2007). "Change in Salt Intake Affects Blood Pressure of Chimpanzees: Implications for Human Populations". Circulation. 116 (14): 1563–1568. doi:10.1161/CIRCULATIONAHA.106.675579.
  6. ^ Denton, Derek; Weisinger, Richard; Mundy, Nicholas I.; Wickings, E. Jean; Dixson, Alan; Moisson, Pierre; Pingard, Anne Marie; Shade, Robert; Carey, D.; Ardaillou, Raymond; Paillard, Françhise; Chapman, John; Thillet, Joelle; Baptiste Michel, Jean (October 1995). "The effect of increased salt intake on blood pressure of chimpanzees". Nature Medicine. 1 (10): 1009–1016. doi:10.1038/nm1095-1009.
  7. ^ Aburto, N. J.; Ziolkovska, A.; Hooper, L.; Elliott, P.; Cappuccio, F. P.; Meerpohl, J. J. (3 April 2013). "Effect of lower sodium intake on health: systematic review and meta-analyses". BMJ. 346 (apr03 3): f1326–f1326. doi:10.1136/bmj.f1326. PMC 4816261.
  8. ^ Neal, Bruce; Wu, Yangfeng; Feng, Xiangxian; Zhang, Ruijuan; Zhang, Yuhong; Shi, Jingpu; Zhang, Jianxin; Tian, Maoyi; Huang, Liping; Li, Zhifang; Yu, Yan; Zhao, Yi; Zhou, Bo; Sun, Jixin; Liu, Yishu; Yin, Xuejun; Hao, Zhixin; Yu, Jie; Li, Ka-Chun; Zhang, Xinyi; Duan, Peifen; Wang, Faxuan; Ma, Bing; Shi, Weiwei; Di Tanna, Gian Luca; Stepien, Sandrine; Shan, Sana; Pearson, Sallie-Anne; Li, Nicole; Yan, Lijing L.; Labarthe, Darwin; Elliott, Paul (16 September 2021). "Effect of Salt Substitution on Cardiovascular Events and Death". New England Journal of Medicine. 385 (12): 1067–1077. doi:10.1056/NEJMoa2105675.