====== Salt and hypertension ======

It's been known for several thousand years that an excess intake of common salt can have adverse effects on the cardiovascular system. ([[https://www.sciencedirect.com/science/article/pii/S1875213613000302?via%3Dihub|ref.]])

Recent research has shown unequivocally that long-term high intakes of salt can cause a range of problems in otherwise healthy individuals. Dietary specialists worldwide have now come to an agreement that salt intake for adults should be no more than 5g. per day.

>A large number of epidemiologic, evolutionary, and clinical studies have confirmed that salt intake is an important factor in elevating the BP <sup>[ Blood Pressure ] </sup>in humans. The first double-blind controlled study of moderate salt restriction was performed in the early 1980’s by MacGregor et al."\\ \\ Source : [[https://synapse.koreamed.org/pdf/10.5049/ebp.2014.12.1.7|Electrolyte Blood Press 12:7-18, 2014]]{{:oa_padlock_grn.png?16}}

It's now thought that the ways in which salt affects blood pressure is considerably more complicated than was first suggested, and the exact mechanisms which lead to salt-induced persistent high blood pressure and cardiovascular damage are still not fully understood.

>“Salt” and “sodium” are used synonymously. In fact, salt is only 40% sodium; 1 g of salt has 400 mg sodium. The remaining 60% of salt— chloride—is an often forgotten but likely important part of the link between salt and blood pressure. Replacing sodium chloride with sodium citrate abolished the increase in plasma volume and blood pressure induced by sodium chloride. Similar effects have been observed when sodium chloride was replaced by sodium phosphate or sodium bicarbonate."\\ \\ Source :  [[https://www.sciencedirect.com/science/article/abs/pii/S0002934311009491|The American Journal of Medicine 125, 433-439]]{{:oa_padlock_grn.png?16}}

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//Notes //:

1) The biological processes which regulate blood pressure in general are also poorly understood - see : [[content:medicine:diseases:g-l:hypertension]]

2) It's not clear why humans (and some other mammals) are so keen on consuming high levels of salt, see : [[content:life_sciences:human_body:salt_preferences]]

3) The 5g. per day recommendation is for the //total// salt intake - and generally there is poor public awareness that many highly-processed foods are manufactured and marketed with extremely high intrinsic salt levels.

4) Some individuals have very acute reactions to higher salt levels - being so-called 'salt intolerant' - again implying that the underlying bio-mechanisms are far more complex than textbook explanations sometimes suggest.