Guess what? Organic really is better | Chris Kresser
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Guess what? Organic really is better.

by Chris Kresser

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For some reason that isn’t clear to me, the mainstream media and medical establishment seem very attached to the idea that organic produce is no healthier or safer than conventional produce. 

They often point to a study performed at Stanford in 2012 as proof of this claim, as if it were the final word. After all, it’s Stanford! 

New study confirms that organic produce is higher in antioxidants and lower in pesticide residues.

But it turns out the Stanford study wasn’t nearly as conclusive as the media made it out to be. I wrote an article critiquing it shortly after it was published, and Mark Sisson also weighed in. In short, the Stanford researchers inexplicably omitted or undervalued certain nutrients from the comparison that have already been shown to be more concentrated in organic foods, such as vitamin C, polyphenols, and flavonoids. What’s more, according to the researchers own conclusion, “consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.” (1

New analysis of 343 studies finds that organic really is better

A new study published in the British Journal of Nutrition is the latest addition to the debate. It’s the largest meta-analysis (i.e. review of studies) that has been published on this topic to date, covering 343 individual studies looking at the composition of crops and food. (2)

The study found that organic crops had higher levels of certain antioxidants—such as phenolic acids, flavonols and anthocyanins—and that eating organic foods could boost a person’s antioxidant intake by up to 40% (the equivalent of two portions of fruits or vegetables a day). 

Some “experts” have claimed these results are meaningless because “antioxidants are not essential nutrients.” But while antioxidants in plants may not be essential, in the sense that we cannot live without them, a growing body of evidence suggests that they are crucial for optimal health. 

In fact, recent research has revealed that what we call “antioxidants” in plants are actually “pro-oxidants” that gently stress our bodies. Rather than killing us or making us sick, however, these compounds promote adaptations that make us healthier and stronger and may extend our lifespan. The science writer Moises Velasquez-Manoff describes this phenomenon in a recent article called “Fruits and Vegetables Are Trying To Kill You:

…these plant “biopesticides” work on us like hormetic stressors. Our bodies recognize them as slightly toxic, and we respond with an ancient detoxification process aimed at breaking them down and flushing them out.

Consider fresh broccoli sprouts. Like other cruciferous vegetables, they contain an antifeedant called sulforaphane. Because sulforaphane is a mild oxidant, we should, according to old ideas about the dangers of oxidants, avoid its consumption. Yet studies have shown that eating vegetables with sulforaphane reduces oxidative stress.

When sulforaphane enters your blood stream, it triggers release in your cells of a protein called Nrf2. This protein, called by some the “master regulator” of aging, then activates over 200 genes. They include genes that produce antioxidants, enzymes to metabolize toxins, proteins to flush out heavy metals, and factors that enhance tumor suppression, among other important health-promoting functions.

Some scientists have even gone as far as suggesting that antioxidants (or more accurately, “pro-oxidants”) are primarily responsible for the health benefit we get from eating plants. Thus, the finding that we may get 40% more antioxidants from eating organic produce is not insignificant. 

Pesticide residues and toxic metals are not harmless

In addition to finding higher levels of antioxidants in organic produce, the study authors also found lower levels of cadmium—a toxic, heavy metal—and lower levels of pesticide  residues. On average, cadmium and pesticide levels were 48% and 400% lower, respectively, in organic produce than in conventional varieties.

Cadmium (Cd) is a highly toxic metal that accumulates in the human body. It is classified as a category I carcinogen—which means it contributes to cancer development—and has been linked to an increased risk of everything from Alzheimer’s disease, to thyroid problems, to cardiovascular disease, to hormone imbalance. (3, 4, 5, 6) It’s fairly obvious, therefore, that we should do everything we can to minimize our exposure to cadmium.

The question of how exposure to pesticide residue in foods impacts human health is still controversial. That said, there is more than enough evidence to warrant caution—and that is especially true for children and pregnant women. Reports over the past few years have linked pesticide exposure in children to ADHD, intelligence/IQ, and numerous other problems. Researchers have also begun to identify mechanisms through which pesticides can disrupt the development of children even at very low exposures. (7)

Why local trumps organic when it comes to nutrient content

As I’ve argued before, the most significant factor in determining the nutrient content of fruits and vegetables is not whether they are grown organically or conventionally, but how long they have been out of the ground before they are consumed. 

Most of the produce sold at large supermarket chains is grown hundreds – if not thousands – of miles away, in places like California, Florida and Mexico. This is especially true when you’re eating foods that are out of season in your local area (like a banana in mid-winter in New York).

The problem with this is that food starts to change as soon as it’s harvested and its nutrient content begins to deteriorate. Total vitamin C content of red peppers, tomatoes, apricots, peaches and papayas has been shown to be higher when these crops are picked ripe from the plant. (8) This study compared the Vitamin C content of supermarket broccoli in May (in season) and supermarket broccoli in the Fall (shipped from another country). The result? The out-of-season broccoli had only half the vitamin C of the seasonal broccoli. (9)

Jo Robinson goes into great detail on this topic in her excellent book, Eat On The Wild Side. In fact, she argues that the fruits and vegetables we eat today are almost unrecognizable to what our ancestors ate in terms of nutrient content, in part because of the effects of industrial food production.

So while it certainly makes sense to eat organic, if you’re interested in maximizing the nutrient density of your food, eating foods that are grown locally and consuming them as close to harvest as possible is even more important. This means shopping for produce at farmer’s markets or using a CSA, or even better, growing your own backyard fruits and veggies. 

Final thoughts and recommendations

Before I share recommendations, it’s worth pointing out that this new study was funded by the European Union and the Sheepdrove Trust, an organic farming charity. One might argue that the involvement of the Sheepdrove Trust constitutes a conflict of interest.

Unfortunately, such conflicts are the rule rather than the exception in most nutritional and medical research. Critics of the Stanford study have pointed out that the Freeman Spogli Institute, which supported the research, has received millions of dollars in funding from Cargill (the world’s largest agricultural business) and the Bill & Melinda Gates Foundation, which has deep ties to agricultural and biochemical companies like Monsanto. In addition, one of the co-authors of the study, Dr. Ingram Olkin, has accepted money from the tobacco industry’s Council for Tobacco Research, which is a fraudulent front organization for Big Tobacco. 

When a study is funded by an organization with a vested interest in the result, we should certainly be cautious when interpreting those results. However, such a funding source does not by definition make the study worthless. We can still evaluate it on its own merits. 

With that in mind, I think the findings of this new, large study are sound and consistent with the majority of the previously published evidence—especially as it relates to higher levels of pesticide residue and heavy metals in conventional produce. 

Here’s what I’d suggest given what we know:

  • Buy organic, locally grown produce as much as possible. This typically means shopping at farmer’s markets and/or joining a local community supported agriculture (CSA) program.
  • It’s particularly important for young children and women who are trying to conceive, pregnant, or breastfeeding to eat organic, because they are more susceptible to being harmed by pesticide residue and heavy metals.
  • If you have limited access to organic produce, due to financial or geographical reasons, try to at least buy organic varieties of the fruits and vegetables that are grown with the highest amount of pesticide when grown conventionally. The Environmental Working Group maintains a list of these, which it calls the “Dirty Dozen”. It also maintains a list of the “Clean Fifteen”, which are the fifteen varieties of fruits and vegetables that are relatively safe to buy conventionally. You can see both lists here.

Now I’d like to hear from you. Do you buy organic and/or local? Why or why not? Do you notice a difference in how you feel when you eat local/organic produce? Do you notice a difference in how it tastes? Let us know in the comments section. 

55 Comments

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  1. I don’t live in the States but in Africa. Where I am, we have no idea of the conditions under which our veggies are grown. I suspect that most are heavily sprayed. Much in our local supermarket looks tired and wilted. We rejoice when our fresh produce is indeed fresh. Best we can do!

  2. It would be extremely helpful to have the actual citations at the end of each of your articles. I am finding with some of the older articles that the links are broken or invalid and I am unable to locate the research article. Thank you!

  3. Just a word on growing your own; absent living in a forest, growing a reasonable amount of food is relatively easy; the problem is finding out what grows best in your climate. Here in San Jose, I mainly grow tomatoes and Zucchini in buckets of home-made compost during the hot summer, but I also have some cucumbers and bell peppers. During the spring, salads are in. These are the easy ones. Peas are easy but also cheap in the supermarket and generally fine. Fava beans used to be good with me once I worked out that I needed to sow them earlier to avoid heat during the flowering period, but now they all get taken by the birds. Cabbages get infested by aphids.
    The real simple one is fruit -although diabetics here might not want so much. We have apricots, lemons, grapes, apples, pomegranates peaches and persimmons, and neighbors have figs and plums. All without much effort at all. Trees pretty much look after themselves.
    You might live in cooler climates, but you will hopefully have far more rain than we have here, and cool weather solves a lot of my pollination issues. So your radishes, summer lettuce, green beans, and so on might all do better than mine.
    So give it a try – and grow some easy herbs, like Oregano and mint.

  4. Being a Foodie I’ve always let my nose and taste buds do the walking in the grocery store. There’s no comparison in my mind because organic and freshly picked produce always, ALWAYS, smells and tastes better. I never put much stock in what the naysayer ‘scientific experts’ said because the smell and taste always told me there was a difference. I thank my grandmother for teaching me to always smell my produce in the store before buying it. To me, there is no comparison.

  5. This article does not represent an accurate report of the meta-analysis. The researchers primary conclusion is that the existing data out there is hard to homogenize (which presents a serious problem for any meta-analysis). And while the means for many compounds may have leaned organic, the error bars encompassed 0% difference between conventional/organic for most of those. The review also found that conventional produce is a better source of protein that organic, but I don’t see that mentioned here. And the cadmium link is so very very weak, that it’s not even included in their weighted meta analysis because the handful of data points they had were so few and weak that they didn’t even include basic statistics like SD/SE. While 343 studies sounds really impressive, it’s important to note that they excluded 17,000 studies from their analysis – so there’s a lot they didn’t look at. And, for each individual piece of information, there are far fewer studies than that – for example the researchers note “it should be pointed out that (1) there are only eleven studies in which the frequencies of occurence of pesticide residues were compared, (2) eight of these studies focused on only 1 crop species, (3) no comparative studies for cereals, oilseeds, and pulses were identified in the literature review, and (4) the data available did not allow scientifically robust comparisons of the concentrations of pesticides.”

    This is certainly an interesting paper, but the big story here is that we need better, more tightly controlled, experimental research protocols and studies done with specific and narrow focus in order to properly evaluate the differences between organic (which they point out is hard to pin down WHAT that means in each individual study examined) and conventional.

  6. While it is certainly true that organically raised produce has many advantages over conventionally raised produce, it is still not the “top of the mountain” when it comes to plant foods. Numerous studies demonstrate that wild plants have higher nutrition, greater amounts of beneficial phytochemicals (e.g., antioxidants), better fatty acid ratios, and more fiber. I am surprised this is still not finding its way into recommendations for plant foods. Certainly, not everyone has access to them (but this is also true of organic produce for various reasons). And because many cannot identify wild plants is no reason not to share this information–it would provide incentive to learn about the real foods that have not been manipulated by humans. Thank you for your article.

  7. I do buy local/organic and have for many years. In fact, this is the first year in 35 that I have not had my own garden due to other challenges in life. I miss it so much!! Thank goodness for locally grown organic farmers! We discovered even into winter that there are abundant crops, and I would like to put in a plug for fermented foods, which go a long way adding to nutrient profiles and in fact may reduce some harmful substances in foods according to info published in Mercola’s newsletter. Bacteria are our friends! (there are more of them than us!)

  8. “For some reason that isn’t clear to me, the mainstream media and medical establishment seem very attached to the idea that organic produce is no healthier or safer than conventional produce.”
    Let’s see if I can clear it up for you: SCIENCE!!

    Oh, and one more thing: It might not be good to tout higher antioxidants in anything. Seems like they might aggravate cancer: http://www.sciencedaily.com/releases/2014/07/140710094434.htm

    • While you’re busy shouting science in all capital letters, it’s important to remember that any scientific experiment, study, or meta-analysis is done by humans that will bring their own beliefs and biases into the work, and these beliefs and biases don’t disappear just because you ignore them, or because scientific results are written in the passive voice (eg, “It was discovered…”). So that’s why you can have one study, funded by companies that use and make pesticides, that finds organic produce isn’t better, while a meta-analysis, funded by a charity that supports organic practices, finds that it is.

  9. I live in Germany and a couple of months per Year in Italy.
    In those countries conventionally or organically grown produce do not differ in taste, but they do in terms of pesticide residuals and at times of appearance. That is it.
    Organic and conventional potatoes taste the same in Germany, as well as Onions, carrots, broccoli, lettuce, etc.
    From a comment above, citing salads in Greece, and the article, I take that the quality of (South) European produce differs significantly from the US one.

    • Think so?
      I most definitely taste a difference between a cucumber bought in the supermarket and the cucumber sold in my local Demeter farmer’s shop (the latter being way better!).

      And I taste a difference in their locally grown carrots – not as crunchy as the organic carrots from the supermarket. I have to admit, I stopped buying their carrots.

  10. One thing we all seem to be forgetting is that:

    1. This study was conducted in Britain
    2. The soils are different from ours
    3. The varieties of produce grown are different from ours

    If we look at our history (or rather, theirs), we will see that pastoral farming practices are in large part still intact, and that “approved” types of fertilizer, pesticides, and even laws governing the use of the term “organic” are different than ours–theirs being more strict. Also, they have a vast history of death and disease which contributed to the formation of the soil they farm in today–plagues, wars, raw sewage, compost, dead animals, etc. We do not have so much a historical layering of occurrences, because the wars, plagues, and raw sewage were minimal (comparatively speaking).

    We also bury our dead in lead-lined coffins, which don’t allow for the blending of decomposition matter and soil to interact, as well as keep Grandma’s ashes on the fireplace mantel in a decorative urn, instead of returning them to the ground.

    This difference in soil replenishment is a big part of what makes organic produce much better than conventional…FOR BRITAIN. This doesn’t necessarily mean the same will and does happen over here.

    Testing over here is apt to be more exact for our situation.

  11. I want to point out that food from “Farmers Market” might be local grown foods, etc. Certain vendors have been know to pick up consumable goods at a warehouse just like your local grocery store. You will have to make sure you know what you are looking at before you buy. I had vendors post “grown in Michigan” but it not from their farm or even local farm.

    • Definitely. Charlatans are a serious menace and the barriers to prevent the selling commercial produce as “organic” are minimal. I’ve long suspected that farmer’s markets and similar venues unwittingly play host to a few charlatans. State consumer protection agencies are toothless tigers (I used to work for one so I know) leaving buyers with the onerous task of tracing to the source. The Paleo sphere desperately needs resources to vet the legitimate growers and sellers.

  12. “On average, cadmium and pesticide levels were 48% and 400% lower, respectively, in organic produce than in conventional varieties.”…

    400% lower? What could that possibly mean? Chris, please tell me you didn’t mean to say that!

  13. The most recent analysis is not much different than the 2012 meta-analysis nor the one before that (http://www.ncbi.nlm.nih.gov/pubmed/19640946). All have showed that some organic foods have microscopically more nutrients and some have fewer. Some have microscopically fewer pesticide traces than conventional. (It is important to note that the USDA NOP does not require field testing of organic produce so, commercially, it is difficult to know what we’re buying.) No long-term studies have been done to determine whether that translates to better health outcomes.

    The other thing is, there are so many variables in region, weather, and native soil that nutrients can vary within same types of crops from harvest to harvest.

    The California Dept of Ag is one of the most transparent agencies when it comes to food. It’s interesting to read their pesticide data reports and to see that many conventional crops have been sprayed with the pesticides used in organic farming, with sulfur being one of the most commonly used pesticides in both conventional and organic (sulfur is allowed in organic).

    As far as the EWG “dirty dozen”, it uses some fuzzy math to come up with its numbers, by combining what has been used over multiple years. For instance, if broccoli was sprayed with atrazine in 2001, and then with glyphosate in 2008, and then Spinosad in 2013, EWG will state broccoli was found to have three residues, and put it on the dirty dozen list.

  14. I’d be interested in hearing your views about this episode of The Checkout, a consumer advice program on Australia’s public broadcaster (ABC). It does a thorough hatchet job on organic food, and concludes that “If you’re gonna pay a lot more for a little ‘feel good’ factor, you should at least make sure it feels real”.
    http://youtu.be/jlqk8oV1FVI

  15. I live in SC and farmers markets are not the best in the country. But I did my due diligence and found local farmers who, even though they don’t have the organic certification, grow organically. I even bought soil from my farmer and I’m now growing my own veggies.

  16. Just want to point out – “If you have limited access to organic produce, due to financial or geographical reasons, try to at least buy organic varieties of the fruits and vegetables that are grown with the highest amount of pesticide. ” I think you meant least amount of pesticides. 🙂 And you don’t have to put this up on the comment board.

    • A few people seem confused, but he means that you should figure out which vegetables are conventionally grown with the most pesticides, then try to buy those particular fruit/veg from organic producers.

  17. I am interested in learning more about the heavy metal residues, such as cadmium, mentioned in the article. we all know about the “dirty dozen” for pesticide residue- does that go hand in hand with heavy metal residue? if not, which crops are the ones to stingily avoid, not just for pesticides, but for the heavy metal exposure? ? ? i think i read somewhere that iceberg lettuce was a bad one for cadmium, but what else to avoid….?

  18. Love that you cited Eat on The Wild Side, but I don’t believe you meant to say modern fruits and veggies are indistinguishable from their ancestors — the book argues exactly the opposite.

  19. My home-grown organic fruits and vegetables taste so incredibly good that I now hate to eat most store-bought produce.

    It’s quite possible to grow most of the vegetables that you eat on a Paleo diet (well over half) in less than 200 square feet of garden beds. It’s also possible to harvest fresh vegetables 12 months a year – even in cold climates! And you don’t need a fancy greenhouse to do it, either.

    • I don’t mean to sound rude, but honestly, I’m tired of people saying this. If you can do this then I’m glad you can, but while I have a rather large yard, almost none of it gets much direct sunlight thanks to large trees all around us. If you mean that you can grow all the sorrel you want for your paleo diet in your yard, then I’d agree with you, but otherwise, nope. Most of the vegetables we want to grow require more sun than we can give them. And I wouldn’t even consider life without these big trees around me even though they shade out my garden areas.

      • If you really want to have a vegetable garden, no one is saying that you have to have the garden in your own yard. If you live in an apartment, or have a shady yard, it’s often possible to arrange to have a sunny garden patch with a friend or neighbor, or in a community garden. You can even ask for space through Craigslist or a sign at a local food coop. There are people that would love a share of fresh vegetables in exchange for someone gardening in their yard.

      • Debra is just trying to encourage people into creating a better life for themselves. If you really wish to give yourself the benefit and pleasure of home grown organic food, stop wasting time by focusing on what’s in your way, But instead, taking all that energy into clearing away the trees blocking your light.

    • Perhaps the best way to find out if organic is better is to do as Debra suggest and grow your own. My sister and I have always been at odd with each other. No matter what I get into, she would oppose it. When I started eating organic, she would mock my decision and say I don’t believe that there is any different.

      Then one day a group of organic farmers approached her to ask whether she would allow them to grow organic vegetables in her garden to sell at the farmer’s market in exchange for all the vegetables she could eat. My sister, but the deal didn’t work out, because the vegetables were not the type that my sister liked and she finally told them that this deal was not going to work out. Meanwhile, the farmers had already transformed her garden to organic. Rather than letting it go to waste, my sister just planted vegetables that she liked, but organic ones.

      As I said, no matter what I tell my sister, if I’m for it, she will absolutely oppose it. That and the fact that we live about 8 hours drive apart, I seldom see her. When I finally saw her about a year or so later, I was totally blown away by how good she looked. Her skin was so much softer and much younger looking.

      So, I don’t need an article to tell me organic is better, here is a person, who absolutely does not think there is a difference, never even bought organic, but when an organic garden was placed in her home and she ate from it, she became younger. I don’t think any article and tests, mainly funded by organizations with agendas are going to be half as effective as getting your own garden and trying it yourselves.

    • yeah, i agree. i grew some savoy cabbage a few years ago just for kicks and it was so delicious to make a coleslaw from it and some fresh lemons picked right from the tree. The cabbage in the supermkt is so bland, has no taste at all.

  20. Helpful analysis of the scientific literature (as always). I follow your recommendations of buying local and organic as much as possible and think eating organic is really important. One thing I’ve ran into is the argument that antioxidants don’t matter – specifically Melinda Wenner Moyer’s “The Myth of Antioxidants” in Scientific American about a year ago. Can you comment on this?

  21. Good article, it is so important not to feed pesticide laced food to our nursing mothers and little children. Thank you for bringing it to our attention.

    Organic produce might be a bit more expensive, but what is your good health worth?

  22. Great article, but I think you mean “the fruits and vegetables we eat today are almost UNRECOGNIZABLE when compared to what our ancestors ate” . . . The book “Eating on the Wild Side” argues that the produce we eat now is much LESS nutritious than what our ancestors ate.

  23. Great article! Love how you break things down. FYI there’s a typo in the last bullet point…it says to buy fruits and veg with the “highest” amount of pesticide and I know you meant to say “least.”

    • There is no typo. If you read the _entire_ sentence you see that the use of “highest” is intended and correct.

    • Yes, it’s not a typo… Just worded slightly awkwardly. Chris is saying to buy produce grown organically, especially when the conventional variety has higher concentrations of pesticides (such as those on the dirty dozen).

  24. I love to shop at farmer’s markets. Both for the amazing local/organic produce as well as it being a very relaxing ritual. I have not quite noticed a difference in the way I feel with organic vs not, but I definitely notice a difference in taste. The early girl tomatoes in season now as well as the berries are so amazingly tasty!

  25. The beauty of living in SoCal is the abundance of farmers markets. It might be a tad pricier but it is well worth it in my opinion.

  26. In our hazelnut orchard we are in the transition from a more conventional approach to organic (and beyond). There is so much to be learned about soil biology and as an orchard grower – it just makes plan sense to invest in this change. We have some hurdles like replacing commercial fertilizer on a grand scale (for 225 acres) and rethinking how we work with hazelnuts trees (they grow more like a bush than a tree). There are so many that can benefit and not just us humans – how about earthworms and fungi? Thank you for continuing to educate us on making better choices for ourselves and the planet.

    • Thank you for making the commitment to organic farming. It is no small undertaking but well worth the effort. And congratulations for discovering the amazing world of soil microbes and fauna! May you continue to be in awe of the incredible world we live in!

  27. Hi Chris,

    Great article! The importance of fresh and local produce is certainly very important. The differences between it and conventional are just too significant to be ignored, especially in the long term.

    How does organic frozen produce stack up against local produce in terms of nutrition?

  28. I more or less stopped eating vegetables for a while because they were making me sick. I had subconsciously started making what appeared to be very poor food choices e.g. fried foods vs. a salad. Then I went on a trip to Greece–where I was more or less forced to eat salad at every meal since most restaurants charge you extra for the salad whether or not you eat it. I rediscovered joy in eating vegetables and remembered that I used to love salads.
    Then I returned to America. I tried eating salads in restaurants and buying conventional vegetables. I found that I would get welts on my tongue after consuming small quantities of lettuce and other vegetables. My tongue would get tingly and numb and soon get welts. I tried organic produce and low and behold–no welts or tingly tongue!
    Probably fairly obviously there is a whole lot more to my health story than just the organic vs. conventional vegetables issue, but my experience has been fairly dramatic, so people may be interested.

      • Don’t be such a coward. If you want to give a negative comment, explain what you mean. Don’t just put a damper on it.

      • Emmett, Apparently you missed the place that I said, “Probably fairly obviously there is a whole lot more to my health story…” Of course there is something missing–a whole lot of some things! However, I thought that this part of the story was relevant to this article and might be interesting and useful to some readers.
        It was in fact this problem with many conventional vegetables that helped me get on the right track with my health.
        I have not yet met anyone else who actually consistently got welts on their tongue from eating fruits and vegetables, but I HAVE met a LOT of people who get some mouth tingling/mild numbness but hadn’t really thought about it. Perhaps my abbreviated story will help them become more aware and figure out what is causing the problem(s) for them.

        If you have a specific question and legitimate interest, I would be willing to share more information.

  29. The paleo/primal community tends to shun beans because of phytopesticides which may or may not be broken down with proper preparation. Please explain the difference here from consuming pro-oxidants in plants.

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