“Don’t eat that! It’s not washed,” I remember being told as I munched on unwashed fruit as a kid.
From a very early age, I was taught to wash any produce before eating. You’ve probably heard the same, whether from the media or from family members.
We tend to think washing produce will somehow make it safer to eat, but does it really?
If you’ve ever had a garden, you’ll know that some vegetables absolutely require some washing simply to remove dirt (unwashed potatoes, anyone?). But most of the produce we encounter at the grocery store has already been washed.
So why are we re-washing it?
Some experts will argue that washing produce will remove pesticide residues, but I’ve always been a bit skeptical that a quick rinse under the faucet would have any meaningful effect on pesticide residues.
Some even suggest that the choice between organic or conventional produce based solely on the argument against pesticide residues is misguided because you can simply “wash off” pesticide residues.
That’s why I decided to look into the research and find my answers.
Here’s what I found.
Does Washing Produce Remove Pesticides?
Short answer: It depends.
Long answer: See below.
I’ve always had an interest in the effect of growing conditions on the nutrition of our food – everything from the soil quality, plant variety, choice of fertilizer (such as compost vs. synthetic), use of pesticides (including type of pesticide), and more.
I even took an elective class in college called “Pesticides, Public Policy, and the Environment” for fun (yes, you can call me a nerrrrrrrd!).
And after reviewing the science, I still can’t give a super simple answer to the “pesticides & produce” question.
That’s because there are thousands (yes, thousands) of different pesticides used commercially and not all of them behave the same.
The effects of food processing on pesticide residue levels may be influenced by the physical location of the pesticide residue as well as the physico-chemical properties of the pesticide such as solubility, volatility, hydrolytic rate constants, water–octanol partition coefficient and thermal degradation.” (Food Research International, 2009)
In addition, not all pesticide residues can simply be washed off. Some pesticides, called systemic pesticides, are absorbed into the plant.
For produce treated with systemic pesticides, no amount of washing will significantly reduce residues. It’s IN the food, not ON it.
For non-systemic pesticides (of which there are many sub-classes), washing is effective at reducing pesticide residues. Peeling may further reduce pesticide residues that have been absorbed by the fruit or vegetable.
Washing has been found to reduce pesticides that are loosely attached to the surface while peeling removes even those that have penetrated the cuticles of the fruits or vegetables.” (Food Chemistry, 1999).
The challenge is that it’s hard to predict which pesticides can simply be washed off (or even know what pesticides – or what combinations of pesticides – were used on your produce).
In one study, twelve pesticides were measured on washed and un-washed produce (the fungicides captan, chlorothalonil, iprodione, and vinclozolin; and the insecticides endosulfan, permethrin, methoxychlor, malathion, diazinon, chlorpyrifos, bifenthrin, and DDE (a soil metabolite of DDT). Washing produce reduced residues of nine out of the twelve pesticides. (Journal of Agricultural and Food Chemistry, 2000)
But what I found most surprising:
The rinsability of a pesticide is not correlated with its water solubility.” (Journal of Agricultural and Food Chemistry, 2000)
Adding to the confusion, the type of vegetable may also play a role in whether or not washing will make much of a difference.
A study out of India looked at pesticide residues left on eggplant, cauliflower, and okra after washing. Residues of organophosphates (a type of insecticide) were reduced by 77% for eggplant, 74% for cauliflower, and 50% for okra when washed. (Journal of Agricultural and Biological Science, 2008)
And finally, a meta-analysis (read: legit review) of 33 studies that quantified the effects of food processing techniques on pesticide residues in produce echoed the above findings. Washing, among other food processing (such as cooking and peeling), reduced pesticide residues anywhere from 10-82%. (Food and Chemical Toxicology, 2010)
So what’s the verdict?
Does washing produce remove pesticides?
Short answer: kind of.
Long answer: see above.
My take?
I’ll continue to wash my produce, particularly any that are not organic.
Although the media seems to bash organic produce on the regular, a 2014 study that systematically reviewed 343 studies found that conventionally grown crops were 4x more likely to be contaminated with pesticide residues compared to organically-grown crops. Plus, organic foods were significantly higher in antioxidants. (British Journal of Nutrition, 2014)
[I understand that buying organic is not always possible. Believe me, I get it. When I lived in remote Alaska, it was not possible for me to get only organic produce, no matter how much I wanted to.]
At the very least, washing produce can reduce pesticide residues by 10%. At best, maybe 82%.
But at least you’ll know you tried!
In addition (again, if you can’t buy organic or buy from a local farmer who doesn’t use pesticides), you can always peel fruits and veggies. That means removing the outer leaves of cabbage, peeling apples & pears, and root veggies, like sweet potatoes.
It’s also worth noting that cooking veggies can also reduce the pesticide residues, particularly blanching and boiling. (Food and Chemical Toxicology, 2010)
The next time someone asks you about washing produce to remove pesticides, I hope you can give them an informed answer.
Now I’d love to hear from you!
- Do you wash your produce? Why or why not?
- If so, is reducing pesticide exposure the main reason? Or is it something else?
Tell me about it in the comments below.
Until next week,
Lily
PS – If you’re still struggling to eat enough produce because you simply “don’t like the taste” of veggies, grab a copy of my FREE veggie ebook below and get ready for a steamy love affair with produce.
Hey there!
But by peeling apples, pears, potatoes… don’t you think you are loosing so much of the fiber and nutrients that are in the skin?
It’s certainly a trade off, Gabriela. The skin tends to be high in fiber and antioxidants.
And also skins are full of the plant’s own pesticides that discourage being eaten. Perhaps peeling is therefore a good thing particularly for those who are sensitive to these phytotoxins!
Fibre causes IBS in any case.
I eat almost exclusively organic produce and I always wash it. You don’t know how many people have handled the produce and what they had on their hands.
I do the same, Joan for the same reasons. I’ve seen people actually cough on the produce at my grocery store.. there is also the soil bacteria (which might even be higher on the organic produce) and risk of cross contamination from other foods at the food depot/grocery store. I’m reminded of the issues with “washed” salad greens : http://www.consumerreports.org/cro/magazine-archive/2010/march/recalls-and-safety-alerts/bagged-salad/index.htm
In particular, I was taught from a very young age to wash bananas the moment you get them home from the store. My mum explained that this is due to a residue of chemicals sprayed on the exterior of the bananas to protect them during transport and reduce their aging. It’s a waxy residue wouldn’t have put much thought to until you realize how often your hands touch not just the exterior of the fruit when peeling, but then you touch the delicious fruit you’re placing in your mouth transferring some of that residue right to you. I’m not sure how much of that is still a relevant practice, but this post helped reassert my commitment to at least a rinse right when I get home from the store.
Hi Lily,
Very nicely written article (like all your articles that I’ve read, still need to read a lot of them).
Also nice that you mention what research you found.
I just asked the washing question a couple of day’s ago to an agricultural engineer and she said:
peeling does remove lots of nutrients, so better not peeling, let them soak in a water/vinegar solution for like half an hour is a better option.
Until now I washed everything, now I’ll start using the vinegar option when I have the time to do it (else wash with vinegar solution). I still have to look up the water/vinegar ratio.
Do you have any idea/research on the vinegar thing?
Thanks!
I haven’t seen research comparing vinegar wash vs plain water in regards to pesticide residues.
I did find one in regards to bacterial contamination (not the focus of my above article) and there was no difference in bacteria levels from washing in plain water, water + vinegar, or water + lemon juice. Pre-soaking for 2 min in fresh water followed by rubbing/brushing produce while rinsing under the tap was the most effective method. (Journal of Food Protection, 2006)
yes lili i do wash my veggies and fruits my mum would always tel me since i was a little girl cause u nevr know where they came from
Thanks for looking into the research.
For my garden veggies, I might pick them right off and eat them, but whatever I bring home I wash, as my carrying basket isn’t always so clean 🙂
One thing I wonder about is the fruit and vegetable washes that are sold in stores. They seem effective on removing waxes, but how do we determine pesticides? There doesn’t seem to be much information about it. I wonder if it gives people a false sense of security.
What I also have found is that the “cleaner” foods listed from EWG (such as citrus) might only be so because the preparation for the foods is similar to typical consumption. Since we typically don’t eat the peel, then we usually don’t have to worry about the pesticides that could be on it. To be on the safe side, I will buy organic when I want to zest my citrus, but sometimes a sale of $1 for a bag of conventional lemons is hard to resist. Do any of the studies you looked at address this at all?
Hi Renata,
See my response to Ugo (above). To my knowledge, there are no studies on commercial “veggie washes” and their effect on pesticide residues.
Depending on the type of pesticide used (systemic or non-systemic), peeling could make a huge difference on pesticide residues or not much. :/
How timely, Lily, I’ve been thinking this recently when I run produce under the tap water for a second. There are things that I generally don’t rinse because they are essentially rinsed at the grocery story, and I don’t see much point. Things like berries, cilantro, greens.
I’m a super nerd when it comes to water, as in I don’t drink anything but spring water, and won’t touch the tap. So my thinking when I rinse my produce is, am I doing MORE harm by rinsing it with chlorine, flouride and who knows what else? It’s a conundrum, but I’m really glad you took the time to dig in and do the science!
Thank you so much for your insight!
By spring water, do you mean bottled water? I ask because bottled water is regulated by the FDA and has much less stringent regulations than tap water; therefore, tap water is typically (if the water supply is in compliance) actually “cleaner” than bottled water.
Nice article Lily — Nutrition is always so difficult eh? And then there is the school of thought that excessive washing and not eating enough dirt is causing our food alleries/intolorences. We can’t win. Any thoughts on too much washing?
I tend to rinse, but I don’t scrub every last piece of dirt. And stuff I grow myself, I only wash if it looks dirty, or has residue from creatures sharing my bounty. Of course, the rain washes stuff too…..
Wow. Very sobering article. (And such a lovely website!)
I used to buy those specially formulated fruit/veggie washes – even when I purchased all organic – but I don’t really know how much they helped. I also see tips about using vinegar baths to remove residues, but I can’t bring myself to eat vinegar-scented fruits and veggies. 😛 Now I resort to washing and gently scrubbing with water or sometimes a little dish soap, but it’s scary to think how much pesticide we’re all consuming.
Very insightful post! I’m looking into agricultural science and these are great facts!
Thank u for your article. I’ve only recently contemplated switching to organic and noticed you can’t always get organic. It is reassuring that you can get rid of pesticides by washing fruit and veg. I am Italian and I have always washed them and also peeled them as I have been taught. In Italy many wash them with bicarbonate of soda. I don’t go as far as that but I will wash them more thoroughly after reading your article. Do you know which fruit and veg are likely to be treated with systemic pesticides?
Thanks for doing all that homework. How frustrating that there is no clear answer!
My husband loves bananas and I have been cheerfully composting the peels. I thought I was being so persnickety about keeping bad stuff out of my compost bin; just recently I learned that banana peels have pesticide on them. Don’t know how I happened to miss that….
So, do you happen to know, if I wash and brush-scrub the bananas as soon as we bring them home, will that suffice, or are the pesticides on bananas the type that soak into the peel? I should think that if it’s the latter, they’re soaking into the flesh of the banana as well and I need to (a) buy organic only, (b) persuade my husband to get his potassium elsewhere, (c) build a greenhouse.
I would definitely buy organic bananas. Not just for pesticide concerns, but because the chemicals are highly toxic to the environment and farm workers.
And yes, you can find potassium in many other places. Avocados, which test very low for pesticides, are an excellent source.
I wash everything in vinegar and water, sometimes natural dish soap and rinse well. I buy most organic fruit and veggies that are on the dirty dozen list.
Very good article
The leafy greens are washed and soaked to help combat dehydration, prolonging the life of the produce and also for aesthetic appeal to increase sales.
Beets and radishes come covered in a thick sandy soil that requires soaking and rinsing.
Many chain stores have high standards regarding visual appearance. If cut and stored properly the celery you buy off the shelf could be up to a month past it’s harvest day. Store employees generally soak and tend to the produce carefully before you see it to help boost sales. Most produce arrives at your store quite dirty and has come quite far in many cases. A newly opened box of organic bell peppers gives off a horrific noxious odor that could be the shipping box or the produce itself. Checking country of origin helps quite a bit as not all countries use the same chemicals. Many use wax coated boxes as well as reusable plastic crates they return to the distribution center to be “washed” and reused.
Also knowing the conditions of the store( is it generally clean, does it pay/treat employees well? How was the product stored while in processing? How stressed for time was the person who processed it) makes a difference in how clean it will be.
Lily,
I appreciate you diving into the research on this. I love that you made “dry material” interesting!
Digging into the nitty gritty research is oddly fun for me. 😉
wash your fruit and veggies in vinegar and water
so what is the vinegar to water ratio?
Thanks for common sense review of washing produce, pesticides and organic. Totally agree with your assessment.
I can’t imagine most pesticide residues come off easily by just rinsing my fruit w/water. I use a vegetable cleaner(inexpensive). The main reason I wash is because too many people “man handle “ the fruit, especially children who are left unattended by their clueless parents!
The best and only known solution to date which is proven scientifically, is bicarbonate of soda you soak 1 litre of water 1 tablespoon soda soak veg for 15 minutes kills most but still leaves some nasties which are then impossible as are in the middle of veg or fruits. Then soak in mother apple cider vinegar few minutes last rinse.https://www.consumerreports.org/pesticides-herbicides/easy-way-to-remove-pesticides/
YES!! I rinse, I even soak, because if there is any chance at all it could help to remove even just 10% Then Why Not rinse!!?? It’s easy! Great article; Thanks!
I buy organic and do not soak, but I do wash off. My question is – how can we use all this great energy to change the industry and get rid of these nasty chemicals?
Thank you for your due diligence and sharing your knowledge. I’ve always wondered if I were wasting money on buying organic but still buy it when possible. I’ve always washed fruits and vegetables since we don’t know how it has been handled, And since I figure it’s got to help with reducing pesticides. I figure the least amount you can get, the better, so I will continue to wash. Thank you again!
I’m having a bit of an issue as i want to make grapefruit tea, which requires the peel. I just bought two bags thinking they were organic as they were in the organic section, but i don’t’ see it labelled on the bag or the fruit as being organic. Since it’s the peel i need for the tea, even if i wash it, i’m worried that i’ll poison myself rather than empower my immune system. What can i do in regards to cleaning the peel so it’s reasonably safe to make a tea with it?
Thank you so much for this very enlightening and thorough (investigative?)article, most interesting! I usually wash all of our fruits, veggies, but not some like bsnanas or melons & cantaloups although when very young(until I came to Canada at 22) I wondered why my Aunt would include cantaloupes +other melons to be washed as we don’t really know ‘where they’ve been grown’ she’d say! I will be trying the ‘solution!’ washing from now on, also educate anyone who might care to listen & learn, especially the parents of my young grandchildren! Thanks sgsin Lily! PS I wish i could have your veggie book in Print form?
Is it possible for one to order your booklet on veggies? How? at Amazon perhaps? please let me know. Thanks again Lily, Grace S.
First of all I would like to thank you Lily, for taking all the time and trouble for write this article. We have ALWAYS washed fruit and veg really well but I admit we hardly ever peel fruit unless the skins are really tough (apples, pears, not mangoes and such like). I think we are doing as much as we can, but the whole thing does bother me. There is no wonder more and more people are getting the “big C”. We have lived in France for 20 years and for the last few years weed-killer has been banned, so our gardens are just a mass of weeds, hardly any grass. My argument though is that “they” still spray produce with pesticides and we have no say in the matter. I wouldn’t think you can say any more to help us, as you have done your very best already, but unless we all buy organic, and trust that the produce IS organic, we will only continue to take harmful pesticides into our bodies. We buy “Bio” products in France but I have never as such, seen any simply labelled ORGANIC. The only way to avoid them as I see it is to stop eating fruit and veg. What a muddle!
Any thoughts on things like Therasage ozone machine that claims to reduce pesticides when used to clean produce?