Diet Myths: Adding Salt to Water when Cooking Adds Too Much Sodium?

If you are watching your sodium intake for health or weight loss reasons, it's important to look at a popular myth. Often, you'll hear cooks say that adding salt to water that they are about to boil will help to reduce cooking time. While technically true, the cooking time saved is a matter of a few seconds at best, which could hardly interest cooks.

Salting While Cooking

The whole truth is actually quite complicated. Adding salt to boiling water increases the temperature at which it boils, making the water take longer before it reaches a boil, yet allowing foods cooked in that water to cook in a higher temperature bath, decreasing the total cooking time. Therefore, at first it would seem that it would be pointless to salt water before boiling. Yet, even here it is not quite correct; adding salt before cooking dried pasta, for example, is absolutely essential-not because of any effect on cooking time, but because it is the only way to salt the inside of the pasta.

Complicated Truth

If figuring out that part of adding salt to boiling water is complicated, then you'll hopefully understand how much more complex the issue of whether it adds sodium to your food is. The technical answer is very simple. Yes, if you add water to water you intend to boil, and then cook something in that water, you will be adding sodium to the food. Yet, the real truth is not quite as easy.

The amount of salt that transfers from the cooking pot to the food after draining is a miniscule percentage. For example, to make pasta just a little salty, you have to add a significant amount of salt to the water beforehand. The general rule for professional cooks is to make the water as salty as the ocean before cooking dried pasta, though some cooks obviously espouse different ideals. Depending on what you're cooking in the pot, you can expect only around 10% to 20% of the salt you add to the water to end up in the food. This percentage drops even further if you wash the food after cooking. However, it should be said that washing after cooking drastically changes the taste of most boiled foods.

So, although it is true that sodium is added to food you cook in salted boiling water, it is not as much as you may at first think. Yet the real truth goes even deeper than that.

Sodium as Your Diet Enemy or Ally

The underlying assumption behind the original question is that you should avoid eating to much sodium. While it is true that too much salt is bad for you, sometimes the addition of salt helps food in other ways, even if it increases your raw sodium intake.

When cooking vegetables in salted boiling water, you will add around 10% of the sodium in the water to the vegetables, meaning you are adding that much more sodium to your diet. Yet the presence of the salt in the water may have the effect of reducing the amount of nutrients that leak out of the vegetables during cooking, meaning that vegetables are on the whole more nutritious when cooked in salted water. The concept behind this theory is that pure water is more capable of dissolving parts of the cooked food because it has plenty of water molecules around to accomplish this. According to the theory, salt water is not as conducive to osmosis, since not as much pure water is touching the cooking food, and a corresponding lesser percentage of the food will dissolve into the water.

It should be noted that so far there are no legitimate scientific studies that support this idea, so it might not be correct. Then again, there are no studies against it, so it very well might be true. Without detailed studies, there's no real way to know whether or not cooking vegetables in salted boiling water is worth the drawback of adding a small amount of sodium to your diet.

Sources cited:

What's Cooking America (http://whatscookingamerica.net/Pasta_Rice_Main/pasta.htm)
Mayo Clinic (http://www.mayoclinic.com/health/sodium/AN00317)