Aldosterone II
Newspapers today reported on work being carried out at Glasgow University on the relationship of aldosterone to blood pressure . The research was presented at the annual Society for Endocrinology BES meeting in Harrogate , UK. The initial research indicates that in older people, higher levels of aldosterone in the bloodstream are associated with high blood pressure .
In a paper entitled, "Aldosterone and cardiovascular function: a lifetime of damage ," Dr. John Connell , who is Professor of Endocrinology at the University of Glasgow and Head of the of the Medical Research Council's Blood Pressure Group, based in the British Heart Foundation's Cardiovascular Research Centre in Glasgow described how an excess of aldosterone greatly increases the risk of stroke and heart failure, thus explaining the results of several previous research studies that revealed more cardiovascular patients dying on low salt diets than on regular diets.
Professor Connell said:
"Aldosterone is a key cardiovascular hormone. The higher the level of aldosterone in your blood, the more likely it is that you will suffer from high blood pressure, which will increase your risk of suffering a heart attack or a stroke."
The research revealed that in older people, higher levels of aldosterone in the extracellular fluid are associated with high blood pressure. In young adults, high aldosterone levels predict that they will be more likely to develop hypertension later in their lives. There are a number of factors that determine elevated aldosterone levels in humans, including low birth weights, genetics and diet. More specifically, insufficient salt intakes will stimulate the renin-angiotensin-aldosterone system (RAAS) to produce more aldosterone in order to conserve the body's cache of sodium in order to retain osmotic balance.
Elevated aldosterone levels mean that throughout life, certain individuals will be more prone to developing high blood pressure, arterial stiffness and cardiovascular disease. Connell's previous research indicated that aldosterone may be a causal factor in 10% of UK patients with high blood pressure*.
It is difficult to understand why the UK Food Standards Agency, the EU Commission and the Health Canada are all deliberately ignoring this research in their drive to reduce the levels of salt consumed. The mechanistic research work on the malignant role of elevated aldosterone levels upon the cardiovascular system brings far more weight to the salt and health outcomes question than the highly promoted, yet scientifically flawed epidemiological studies on salt and blood pressure.
The human body is an organism governed by biological mechanisms and no amount of bias, hype or imprudent policies will change this. ______ *Connell, J.M.C., Davies, E. 2005. Journal of Endocrinology, 186, 1-20.
