Too much salt is bad for your heart. Research has proven this statement to be true. High levels of sodium in the body can contribute to high blood pressure, setting the stage for more serious heart events. However, scientists from the University of Glasgow have recently discovered that a compound found in salt, chloride, could have equally adverse effects when it is too low.
The Scottish researchers report that low chloride could lead to a higher risk for cardiovascular disease and even death in those who already have hypertension. The scientists collected data on 12,968 patients with hypertension. They followed up on this data for 35 years and discovered that sodium and chloride exert different effects on the body, despite the fact that they are usually consumed together.
Sodium chloride is what is commonly known as table salt. It contains equal portions of sodium and chloride. This salt is responsible for giving the world’s oceans their salinity. It’s also a major component of extracellular fluid in the body. As far as your diet goes, you’ll see sodium chloride not only in your salt shaker, but heavily used in foods such as condiments, cheese, and dried meats and fish.
Studies have focused on the negative effects of sodium in the body but have largely ignored chloride. Chloride has been seen as the non-important part of the salt equation. That might all change based on the findings of the Glasgow University researchers. When they isolated chloride, they found that study participants with the lowest levels of serum chloride had a 20% increased risk of death compared to those with the highest levels of the compound.
What accounts for this beneficial effect of chloride? Chloride plays a role in balancing fluids in the body and behaves much like an electrolyte. Normally, the balance of chloride is carefully regulated by your body. However, changes in levels of the chemical can happen and this can usher in some pretty serious health consequences. Too much chloride (called hyperchloremia) can lead to diarrhea, kidney problems, and over-activity of the parathyroid glands (four glands responsible for regulating the amount of calcium in your blood and bones). When you have too little chloride (called hypochloremia), often the result of heavy sweating, you can experience muscle weakness, twitching, and bouts of sweating.
There’s already a standard blood test that measures chloride levels in the body. This test is usually performed along with tests for sodium, potassium, and bicarbonate. When you eat salt, chloride is absorbed by your intestines. Excess chloride is excreted through your urine. For this reason, your doctor may order a 24-hour urine sample to find out how much chloride is leaving your body. The normal range for chloride is 96-106 mEq/L (milliequivalents per liter).
The researchers noted that their study findings suggest that more attention needs to be paid to chloride when it is part of the salt equation. Discovering that high levels of chloride have opposite benefits to high levels of sodium suggests that current recommendations about salt intake are now part of a murky area in terms of overall health.
Source(s) for Today’s Article:
“Could low salt intake increase mortality risk?” Medical News Today web site, Sep. 9, 2013; http://www.medicalnewstoday.com/articles/265814.php, last accessed Sep. 9, 2013.
McCallum, L., et al., “Serum Chloride Is an Independent Predictor of Mortality in Hypertensive Patients,” Hypertension. August 26, 2013.
Osanai, T., et al., “Relationship between salt intake, nitric oxide and asymmetric dimethylarginine and its relevance to patients with end-stage renal disease,” Blood Purif 2009; 20(5): 466–8.