Friday, March 15, 2013

Washing Produce - The Dirty Truth

The “five second rule” is a cute thing we reference when someone drops something on the ground, but the reality is that almost all plants live (or spend some time) on the ground before they end up in stores for us to buy and eat. To say that some plants are “dirty” belies the truth that plants quite literally grow in the dirt. Between pesticides, bacteria, viruses, and just plain dirt, the food you buy in stores often carries more than just nutrients into your body.

The brightly colored produce you see in the market might look cosmetically “clean”, but what you can’t see are the residues of pesticides and microscopic bacteria or viruses that can make you sick. Even though it is time consuming, it is really important to clean your produce thoroughly to protect yourself from these hidden dangers.

Is water alone enough to do the job? What about products made to wash off pesticides from produce? What is the best way to clean fruits and vegetables to remove dangerous chemicals and pathogens?

The Dirty Truth About Produce

When you walk into the produce section of a supermarket or store, the fruits and vegetables look vibrant and clean, but there’s more than meets the eye. Markets only rinse off produce so that it looks clean and appealing to you, but their quick  rinsing doesn’t do much to protect you from pesticides or microorganisms that can cause illness.

The truth of the matter is that growing food is dirty business; you can’t get away from the fact that plants grow in dirt. We often forget what actually goes into getting food from the fields to our plates. To grow food, farmers have to fertilize their crops (that can mean animal poop) and prevent infestation (pesticides and herbicides). To get that food to your table, it needs to be picked (clean hands?) and transported using machines and trucks to markets.

Even if the head of lettuce you buy grew from seed without getting exposed to anything bad, it rubs up against hundreds of others that might have, and that’s just in the truck that takes it to the store.

There’s just no way to know what (or who) has touched your produce before it’s in your shopping cart. As they say, “one bad apple spoils the bunch”. It’s very important to remember that it only takes a very small number of bacteria or viruses to make you sick. The threat of these illnesses lurks on the skin of every apple and in the crevice of every lettuce head that you see in the supermarket.

You might think that buying only organic produce would avoid this issue, but is that really the case?

Organic Foods May Still Be Dirty

Obviously, buying organic food and avoiding synthetic pesticides is the best choice. However, even
organic food can still contain some pesticide residues or become exposed to bacteria or viruses. Contamination can happen from the person picking it, in the truck on its way to the store, or when it’s being stocked in the store where you buy it; it takes a lot of hands to get food to stores, and not all those hands are guaranteed to be clean. For these reasons, it's always a good idea to wash any produce in case it is somehow contaminated either in transport or in the store.

What About Those Fruit And Vegetable Washing Products?

Over the last few years, a number of products marketed specifically for removing pesticides from fruit and vegetables have come to markets. They make all kinds of claims about how well they remove pesticides from fruits of vegetables, and they seem like something that would be a good idea to use to protect yourself from those hidden dangers. Unfortunately, when tested independently, they are simply no better at removing pesticides than tap water alone.

Water Wins

Since there was no difference between water and the other products, it appears that it is the act of rubbing and washing with your hands that is what actually removes most of the residues. You should wash and rinse your produce for at least 30 seconds and make sure to rub it down with your hands very thoroughly. You could also use a soft brush (like a toothbrush) to get some extra scrubbing power.

Unless the temperature of the water reaches the boiling point (called blanching) it doesn’t appear to affect the results, just as long as the water is present to wash away any contaminants. However, blanching does remove pesticide residues more effectively than washing alone.

Produce might look clean on the shelves, but it's what
you can't see that could harm you.

Adding vinegar to the water appears to have mixed results when it comes to pesticides; sometimes it is slightly better at removing pesticides than water alone, and sometimes it is the same. It isn’t very clear or intuitive as to which types of fruits or vegetables benefit from adding vinegar to the water, so it is probably best just to add a little to the water you use to wash any produce. Vinegar is inexpensive, you use very little of it each time, and washing produce with it will actually help to keep your fruits and veggies fresher longer.

Vinegar also helps to remove bacteria and viruses from produce when you use it as part of the washing. It doesn’t necessarily kill any of these microorganisms, it just makes it harder for them to stick around on the surface, so they wash away easier in the water. Washing strawberries in vinegar, for instance,
removes over 90-95% of viruses and bacteria.

Since vinegar can sometimes leave an unpleasant flavor, it’s a good idea to rinse your produce with plain water once you’re done washing. That should get rid of any of the leftover vinegar flavor.

How To Wash Produce

So it appears that washing produce in water ( I recommend filtered water) is the best option, especially when combined with a little vinegar. Just make sure to rub the surface of the produce with your hands or a soft brush to scrub or “mechanically” remove any pesticides or pathogens.

For leafy vegetables and softer fruit, wash them for at least 30 seconds in a bowl with a small amount of vinegar diluted in water; the ratio should be about 1 capful (about 1-2 tablespoons) per gallon of water. After washing them thoroughly, rinse them off with plain water for another 30 seconds.

For waxy vegetables and waxy fruits (think bell peppers and apples) the best option appears to be to wash them for at least 30 seconds in the vinegar mixture above (1-2 tablespoons vinegar per gallon of water) with about 3-4 tablespoons of salt added to it. The added salt helps to “scrub” the waxy surface of the produce. After washing thoroughly, rinse them off with plain water for another 30 seconds.

Even if you don’t eat the outside part of the produce (think oranges, cantaloupe, pumpkin, etc.), even the sharp edge of a knife can carry bacteria or viruses into the inside. So it is still very important to wash the outside thoroughly in the same way as the other items above. You should also use a soft brush to really get into the crevices and scrub the skin. The reason for washing the outside is that you still peel, cut through, or simply handle the outside to get at the delicious fleshy stuff inside.

Cooking Helps Too

As mentioned above, blanching is effective at removing pesticide residues. If you blanch and then fry most vegetables, it actually removes almost 100% of pesticides and kills virtually all bacteria or viruses that could make you sick. The blanching process is basically like re-washing produce in water (the heat of the water acts like your hands rubbing). Frying removes most of the leftover water and kills microorganisms that may not have been killed from boiling water alone. Nonetheless, it is still important to wash things first, as it ensures the best chance of removing any and all possible contaminants.

The Bottom Line

To safely remove pesticides and microorganisms, wash produce in a mild water (filtered if possible) and vinegar solution, then rinse with filtered tap water for at least 30 seconds for each step. Washing, blanching, and then frying vegetables removes virtually anything that could cause a problem.

To avoid the toxins of pesticides and the risks of food borne illness, washing produce properly is essential. Remember, even if you only buy organic (or even grow your own food), it is still important is to thoroughly wash your fruits and veggies to protect the health of you and your family.

Researched and written by Dr. Rebecca Malamed, M.D. with assistance from Mr. Malcolm Potter.

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