Wednesday, May 19, 2010
Salt: How Much Or How Little?
The US government recently lowered its recommendation for sodium consumption, which has led to a lot of questions on our Beachbody diets. Salt, which is made up of sodium and chloride, is one of the least well understood nutrients we consume. It’s absolutely essential for life, so much so that wars have been fought over it. Yet over consumption of this prized mineral is one of the greatest health risks our society faces. The problem is that most of us haven’t a clue on how much we need and the government, which hands out a blanket standard for an entire population, isn’t helping. Fortunately it’s not all that complicated. So let’s take a look at how much salt we need daily, and how to avoid getting too much.
The above is a sneak peek of an article I’m writing on salt consumption. Today’s blog is primarily to reference a great article by Dr. Bill Misner, who unknowingly has been one of my mentors. Misner, now retired, is an outstanding age group athlete and formerly the nutrition expert at Hammer Nutrition. Many of his theories were once at odds with the nutritional musings of the national “experts”. Over time most of those experts were proven wrong. Misner’s once maverick ideas on nutrition, especially for endurance athletes, is now the standard most adhere to.
DOES A HIGH SODIUM DIET INHIBIT ENDURANCE PERFORMANCE AND HEALTH?
BY WILLIAM MISNER, PH.D.
As you’ll see Dr. Bill, as we call him, likes to throw numbers and science around. In the article I’ll interpret and deconstruct his commentary, along with a few others, but for this blog I’m going to over simplify.
Essentially, this problem with salt is this:
We don’t need very much of it at all to function daily if we’re sedentary, maybe 500mg a day at most. In fact, a recent study concluded that 70% of Americans were sedentary so even though we’ve chopped around a thousand milligrams off of the RDA we’re still high at 1,500mg/day.
Exercise, however, is a massive variable. The more we exercise the more salt we need. In fact, we can burn off 2,000mg of it in one hour of intense exercise in hot weather. So simple math shows us that the RDA should be between 500mg/day and perhaps 10,000 or more mg/day for someone doing an Ironman in July. Of course you only need that 10,000mg on the event day. Each day’s consumption should reflect activity to some degree.
As a society we eat far too much salt. In fact, the average sedentary person eats over 2,000mg/day and the average endurance athlete over 6,000mg/day to account for how much they sweat. Restaurants and convenience foods are the culprit as they are loaded with salt. Now here’s the rub:
“Limiting sodium is recommended since research supports that chronic consumption of more than 2300 milligrams per day may contribute to Congestive Heart Failure (CHF), Hypertension, Muscle Stiffness, Edema, Irritability, Osteoarthritis, Osteoporosis, Pre-Menstrual Syndrome (PMS), Liver disorders, Ulcers, and Cataracts.”
But athletes need to worry about hyponatremia, a life-threatening situation where sodium levels are diluted due to sweating and excessive water consumption. However, randomly consuming more sodium along with more water does not seem to be the best course of action. Instead, athletes who lessened both water and sodium intake to 24-28 ounces of water and 300-600mg of sodium/chloride, along with other electrolytes (calcium, magnesium, potassium) per hour while training and racing, along with lowering their overall daily sodium consumption, performed best. The bottom line was that athletes who lowered their overall salt intake and only increased it based on the needs of their daily training performed best.
The article doesn’t go into this but lowering your salt intake is easy if you eat natural foods, which contain almost no sodium. This is why wars were fought over salt before there was a processed food industry; we were always looking for more. But 500mg is only about a quarter teaspoon. If you’re someone who eats out a lot, or buys packaged foods, you should pay attention to the sodium content on the label. It is then vital that salt is added to your diet to account for exercise. 300-600mg/hr should be added in normal condition, and more in hot weather.