Salt and hypertension: a phylogenetic perspective


  • Arye Lev-Ran,

    1. Maccabi Health Services, Petah-Tikva, Israel
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    • Arye Lev-Ran sadly passed away in September 2002, having drafted much of this article. This final version is dedicated to his memory.

  • Massimo Porta

    Corresponding author
    1. Department of Internal Medicine, University of Turin, Italy
    • Department of Internal Medicine, University of Turin, Corso AM Dogliotti 14, I-10126 Torino, Italy.
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Our hunter–gatherer ancestors appeared to survive on little salt. When today's rural dwellers move to urban environments, they increase their salt intake and the salt-sensitive among them become prone to age-related increase in blood pressure and hypertension. This paper reviews our knowledge of the mechanisms of salt disposal and plasma volume regulation, salt consumption in human evolution, salt intake and prevalence of hypertension, and the results of interventions aimed at modulating both. Finally, it discusses current hypotheses on the mechanisms of selective pressure that may have favored the emergence of a salt-sensitive, hypertensive genotype. Similar to ‘thrifty’ genes, which supported energy savers in times of scarcity, but may now be causing obesity and type 2 diabetes, ‘thirsty’ genes, by acting on salt and water retention, might have helped individuals survive the challenge of volume-depleting illnesses, especially when combined with stress-inducing situations, but may now cause high BP and related damage in the post-reproductive age. Copyright © 2005 John Wiley & Sons, Ltd.