Episode Transcript
Salt, sugar, and fat, what's not to like? Well, there is such a thing as too much of a good thing, and salt may be one of them.
We evolved as humans in a low-sodium environment, the inlands of Africa. We have taste buds specifically for salt, sodium chloride, and most of us like salty things. We may be the sweatiest animal on the planet, and we lose salt when we sweat from heat and vigorous exercise. So we do have dietary needs for a little bit of sodium chloride, the chemical we usually mean when we use the word "salt" in terms of food. But is there such a thing as too much salt?
We know that drinking seawater is remarkably unpleasant because it's too salty, and you can't survive by getting your water needs from seawater. You'll die.
And when we eat a lot of salt in our food, potato chips followed by boxed macaroni and cheese for lunch and a store-bought pizza with cheese and pepperoni for dinner, we get thirsty. We drink a lot of water, and we wake up all puffy. And who wants to wake up puffy? And all that puff shows up on the bathroom scales. Well, being puffy means that your body has held on to water to help dilute all the salt in your blood that you ate yesterday, and holding on to extra water means that your blood pressure can go up. And when your blood pressure goes up, it puts you at risk for heart disease and strokes and kidney failure.
America's high-salt diet, on average 3,000 to 6,000 milligrams a day, has been linked to high blood pressure, a leading risk of heart attacks, strokes, and kidney failure. More than 4 in 10 American adults have high blood pressure, and among black adults the number is 6 in 10.
The issue of salt in food is a complicated one. Of course, some people are sensitive to increased amounts of salt in their diet. Research studies have defined this salt sensitivity as people for whom an increase of 1,000 milligrams of sodium, about half a teaspoon of table salt, increases their blood pressure by 5%. Now, that doesn't sound like very much, but it's a significant difference when it comes to health outcomes. Some people are genetically salt sensitive, and some people are salt sensitive because they already have a chronic medical condition that gets worse on a high-salt diet.
Of course, there are studies that suggest that people who eat sodium at the 3,000 to 6,000 milligrams per day and say they don't necessarily have bad health outcomes. An international study of more than 100,000 people suggests that while there's a relationship between salt intake and high blood pressure, if you don't already have high blood pressure and you're not over 60 or eating way too much salt, salt won't have much impact on your blood pressure. However, most research suggests that a lower sodium diet is good for people who are older, over 50, who are African American descent, who have high blood pressure or diabetes, or whose blood pressure is gradually creeping up.
The Institute of Medicine, the Dietary Guidelines for Americans, and the American Heart Association recommend limiting your sodium intake to no more than 2,300 milligrams a day. That's about a teaspoon. People with heart failure and kidney disease are advised to keep their sodium at about 1,200 milligrams a day or about half a teaspoon. And for the very significant percent of Americans who have kidney stones, including yours truly, excess salt in the diet contributes to the formation of the most common kinds of kidney stones. Ouch. I had to have that explained to me by my urologist.
Now, low-sodium diet, that's easy, you say. You wouldn't put half a teaspoon from your saltshaker on your food each day. It turns out that the major source of sodium in our diet comes from prepared foods from the store, that boxed macaroni and cheese, prepared soup, bread, prepared salad dressings. About 70% of the sodium people consume comes from premade or packaged foods according to the FDA.
With that in mind, the FDA recently issued voluntary guidelines for the food industry to lower the amount of sodium in prepared foods, manufacturers, restaurants, and food service operators. These guidelines are voluntary and temporary to seek to decrease average sodium intake from approximately 3,400 milligrams to 3,000 milligrams per day, about a 12% reduction over the next 2.5 years. Now, that isn't very much, but it can make a difference in a population of people.
A recent study published in "The New England Journal of Medicine," done in China in 600 rural villages, randomized households to using regular salt in their cooking to a salt substitute, which switched out about 25% of the sodium chloride in their saltshaker with potassium chloride. This isn't enough for most people to taste the difference. They were encouraged to use a little less salt in their cooking, but could use other sources of sodium, like soy sauce, in the usual way. This is a very small dietary change. The control villages did their regular cooking. There were about 21,000 people in the study, with an average follow-up of about 5 years. The average age of the participants was 65 years. Half of them were women. About 72% had a history of stroke, and 88% had hypertension. That's a pretty high risk group. There was about a 15% decrease in strokes and major cardiovascular events and deaths in the salt substitute group over this 5 years, which would be quite significant if you're talking about a billion people or talking about 10 years. So it was kind of a big deal.
Other studies have shown similar effects in the U.S. in people who adhere to the DASH diet, which stands for dietary approaches to stop hypertension, sort of a Mediterranean diet with lower sodium. They have lower blood pressures.
So how much sodium in your diet if you're mostly healthy? About 2,300 milligrams or one teaspoon of table salt. If you have genetic or medical conditions that predispose you to greater risks with salt, even less. If you're like the average American and get 70% of your sodium intake from prepared and packaged foods, read the label.
Americans consume a lot more salt in their diet today than they did 50 years ago. Largely this is a change in how we cook or rather how we don't cook. Many more meals are pre-prepared from the store, and many more meals are eaten out with a lot of salt. Women are often in charge of the food shopping and food prep in the house. Clearly this isn't always the case, and there are many days many people just don't cook. They eat out and they eat foods in restaurants that are often very high in sodium and few actually will give you the amount, but sometimes you can look it up online. Or they eat in prepared or prepackaged foods.
Sodium is important enough for your health that the FDA food labels on the back of the package let you know how much sodium there is per serving. Your local pizza place with high sodium crust, high sodium cheese, and high sodium pepperoni, yum, won't have the sodium content. You can make choices in the food you buy. Many prepared food companies, like Campbell Soup, have offered lower sodium soup options in their canned soups. Even the chip aisle in the grocery store has chips with lower sodium.
So what do the labels on the front of the box mean? Sodium free or salt free, each serving in this product contains less than five milligrams of sodium, very low sodium. Each serving contains 35 milligrams of sodium or less, low sodium. Each serving contains 140 milligrams of sodium or less, reduced or less sodium. The product contains at least 25% less sodium than the regular version, but in the case of some soups that may mean going from 700 milligrams of sodium per serving to 500 per serving, and that is still a lot. Unsalted or no salt added, no salt added during processing of food that normally contains salt. So this could still be salty.
So make a commitment to cook more food at home from scratch and more whole foods, whole grains, veggies and beans, and don't add salt when you cook. Let people add the salt at the table if they need. Adding spices, pepper, or lemon can increase the flavor in your home foods without adding extra sodium. Do you like sea salt on your chocolate chip cookies? Forget adding salt to the dough and sparingly grind a few flakes, a very few flakes on the top of the cookies.
Even though you and your family might not be salt sensitive or have risk factors that would make a low-sodium diet important, some of you will someday. Getting out of the salt habit, eating more food cooked at home by somebody is good for you and the people you love. Have everyone become involve in food shopping choices and cooking at least some of the time and guide these choices, and that will help everyone be more independent in their sodium, sugar, and calorie choices and maybe your face won't be so puffy after pizza night.