If you are experiencing blood pressure issues, you may have heard that reducing your salt intake is one of the best dietary changes you can make to help get your blood pressure under control.
For years, the prevailing wisdom touted by major medical organizations is that significantly reducing sodium intake will improve blood pressure and reduce the risk of stroke or heart attack. Your doctor may have told you to keep your sodium intake under 1800 mg/d if you have a history or are dealing with cardiovascular disease. But that recommendation may be misguided, and low-sodium diets may actually do more harm than good.
Why Does Salt Get Such a Bad Rap? Over a century ago, French scientists found a correlation between a high salt diet and high blood pressure in six of their patients. The findings were debunked just a short three years later, but the belief that salt was bad lingered. A half-century later and Dr. Lewis Dahl conducted a study on rats that were bred to have differing susceptibility to developing hypertension. Dahl induced hypertension in the rats by feeding them a high salt diet – 500 grams of sodium per day! The rats – unsurprisingly – developed hypertension, quickly. By reducing their sodium intake, Dahl was able to demonstrate that there was a link between hypertension and salt intake and that by decreasing sodium in the diet, hypertensive symptoms were abated. But we must remember, correlation findings do not necessarily equal causal relationships. While there is no dispute that Dr. Dahl’s research was well-intended, it was significantly flawed. For instance, the average American’s salt intake is roughly 8.5 grams of salt per day (compared to the 500 g given to the rats in the study). Furthermore, hundreds of studies conducted since Dahl’s work have demonstrably shown that reducing sodium intake alone does not significantly relieve hypertension. In May 2011, research published in the Journal of the American Medical Association reported that “the less sodium that the study subjects excreted in their urine – an excellent measure of prior consumption – the greater their risk was of dying from heart disease.”1, 2 Therefore the desired out, in this case preventing heart disease, is not successfully achieved by the intervention, which in this case is sodium restriction. Dahl’s study only marginally touched on the genetic component that may lead to developing high blood pressure. Certain segments of the general population are predisposed to being hypersensitive to salt; however, genetics is only one factor. Hypertension is a symptom -- not a disease itself – and is generally a symptom of a much larger health problem. Obesity, diabetes, and high cholesterol are all factors that contribute to high blood pressure. The Problem with Sodium Restriction Salt is our main supply of sodium – a mineral that our bodies need for everything from maintaining a healthy balance between intracellular and extracellular fluid to supporting electrical currents across cell membranes. Reducing our salt intake isn’t necessarily a bad idea, except when it is. Simply cutting salt out of your diet completely can actually cause more harm than not cutting it out at all. When salt intake is reduced, your body responds by releasing aldosterone and renin which increase blood pressure. If the sodium levels in your blood are too low, you could develop hyponatremia – a condition that causes the water levels in your blood to rise and the cells to swell. Being Heart Healthy is a Multi-Pronged Approach Elevated blood pressure is a problem that requires a holistic treatment solution. Simply reducing your salt intake is not enough, and arguably ineffective at preventing the real problem: a heart attack. A low-carb, low-sugar diet, along with regular exercise, will reduce blood pressure and improve your overall health significantly. Exercise and diet are important components in getting you back to health. If you are worried about your blood pressure or looking for ways to improve your cardiovascular health, please feel free to contact Toronto Naturopathic Doctor, Dr. Courtney Holmberg at 647-351-7282 to schedule a consultation today! Sources: 1. https://www.scientificamerican.com/article/its-time-to-end-the-war-on-salt/ 2. https://jamanetwork.com/journals/jama/fullarticle/899663