Doctor's Note

I should do more videos on watercress! The only other one I think I have is Sometimes the Enzyme Myth Is True.

This video is the third of a 3-part series on enhancing athletic recovery times. Check out the first two if you're interested: Reducing Muscle Fatigue with Citrus and Reducing Muscle Soreness with Berries.

For more on the free radical theory of disease, see Mitochondrial Theory of Aging.

The 64 times more video is Antioxidant Power of Plant Foods Versus Animal Foods.

Why else is it important to eat antioxidant rich diets? See, for example, The Power of NO and Anti-Inflammatory Antioxidants. And why else is it important to eat broccoli family (cruciferous) vegetables? Check out:


Check out my associated blog post for more context:  Which Common Fruit Fights Cancer Better? and Preloading with Watercress Before Exercise.

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  • Brian Humphrey

    Awesome! Love the graph depicting how eating just a “singe” serving of watercress a day can blunt the oxidative stress produce by exercise. Love your message at the end “Eat More Plants”!

  • Steve Mayer

    Bless our vegetables. Every one.

    Whenever a video or article says one serving, I am left wondering what is a serving size? I weigh and measure my food because it helps me set useful boundaries. For me, a serving of broccoli is 8 ounces. That’s more than many people eat in a month (not us, on here of course)! My dinner salad (now with home grown broccoli sprouts, thank-you!) is 12 ounces.

    So what is a serving size or watercress? Is there a generally accepted serving size for vegetables, say, 4 ounces?

    • Dale

      I also wonder about serving sizes. I’m inclined to say that this is something very individualistic and highly variable according to the amount of exercise/activity one does, the type and quality of the food being ingested, the person’s age and probably a few other factors that I haven’t considered. However, when it comes to eating fruits and veggies, especially leafy greens — my serving size is unlimited :).

      • Darryl

        A USDA serving is 1/2 cup of cooked or chopped vegetables or 1 cup leafy raw vegetables. It’s not much, my typical dinner salad (covering a 12 inch plate) must count as a half-dozen servings.

  • Gregg Stern

    What are your thoughts on which is more nutritious: Veggie juice made in a masticating juicer or made in a vitamix?

    • Vitamix! Then you’re not throwing away the fiber.

      • Gregg Stern

        fiber aside, what about nutrients and enzymes? Also, related to today’s video – I am a little confused. If I am juicing greens everyday – do I come out better related to the DNA damage or does the consumption need to be just before exercise to come out ahead? P.S. – now with my 2 types of kale, spinach, romaine, cilantro, parsley, carrot, red pepper and celery I will add in the watercress.

        • Gregg Stern

          have not heard back, any thoughts on above

          • Veganrunner

            First you can’t put fiber aside–it is very important and Dr Greger has always stated juicing is not as good as drinking the entire fruit and vegetable in a smoothy.

            Next the video states that in the study conducted the participants were on the watercress for months. Read abstract in Sources cited above.

          • Gregg Stern

            not sure who you are but don’t really like the tone of your response nor was I asking you. I am well aware of the abstract and what the video state. I am also a doctor and well aware of the benefits of fiber and I discourage people from juicing fruit due to the glycemic impact but in this case you can put fiber aside because my question is about denaturing enzymes and vitamin content (since according to the Vitamix company, their product “rips through the cell walls”). Next time please let the good Dr. answer his own questions.

          • Veganrunner

            Hi Gregg,

            My apologies–no tone intended in my response. That’s what I get for trying to be concise on an iPad.

            Your question is answered in the cited studies and around 4:00 of the video. Here is a quote from the paper. .

            “These findings suggest that short- and long-term watercress ingestion has potential antioxidant effects against exercise-induced DNA damage and lipid peroxidation.” Looks like the addition of watercress to my morning smoothy will be benefitial.

      • cyndishisara

        The cell wall needs to be broken for nutrients to be realist so the VitaMix has to be the best way to make a smoothy by add water or a salad.

  • Plantstrongdoc M.D.

    Plants power the human body and heal it.
    No wonder that there are so many high performance vegan athletes, Rich Roll, Carl Lewis, Mac Danzig, Brendan Brazier, Rip Esselstyn etc.
    Are there any Atkins-diet eating high performance athletes………………?

    • Thea

      Plantsrongdoc: Great entry. I thought you might be interested in this article from the Meatout Monday people. It’s so cool!

      Vegan Bodybuilders Dominate Texas Competition

      The Plant Built ( team rolled into this year’s drug-free, steroid-free Naturally Fit Super Show competition in Austin, TX, and walked away with more trophies than even they could carry.

      The Plant Built team of 15 vegan bodybuilders competed in seven divisions, taking first place in all but two. They also took several 2nd and 3rd place wins.

      Plant Built was started in 2012 with the goal of promoting a plant-based diet in a sport where eating animal products is often believed to be the only way to achieve success. Their first time out as a team, they’ve destroyed that myth and are recreating the sport. Look forward to more proof positive from the Plant Built team that vegan food choices can power even the strongest athletes.

      … visit and for more inspiration.

      • Plantstrongdoc M.D.

        They don`t look protein deficient ! ;-)

      • Synergy

        I guess that kind of addresses my comment I just made a second ago before I read through the other responses.

        That is inspiring news. However, why is it that so many studies find decreased muscle mass in those following vegetarian diets? Have we isolated the responsible variables? (Calories, excess complete protein, taurine, carnitine, creatine/water retention, CLA, etc.)

        I can’t find any studies on the cause and what variables might reverse the disparity.

        • Thea

          Synergy: I’m not aware of those studies you are talking about which put people with vegetarian diets at a disadvantage for muscle mass.

          I have some off-the-wall thoughts for you though: If the studies simply looked at vegetarians and not whole-plant-food based eaters, then they could have been including a whole bunch of junk food eaters for the vegetarians. Many vegetarians are vegetarians for ethical reasons and eat both non-flesh animal products and other junk food. If health is not their thing, then maybe they don’t exercise much either. I would think that for a study to be valid, you would have to compare a healthy vegan diet to a (relatively) healthy non-vegan diet (i.e., as healthy as one can get while still taking on the health risk of eating animals). They would also have to adjust for exercise levels. I would think that it might be hard to find be sure one is comparing apples to apples.

          Of course, since I don’t know anything about those studies, I have no idea if they were careful in choosing subject groups or not. I also wonder how big the subject groups were and how long term the studies were. For example, if someone just switched to a whole plant food based diet, it is not the same as someone who has been on it for years or decades.

          As I said, I don’t know the answer, but I hope these ideas give you something to follow up on if you choose to pursue it. (Maybe someone more knowledgeable than me will jump in – especially if you can point us to some specific studies.)

        • Thea

          Synergy: Since you found the above link to vegan bodybuilders helpful, you may also find this link helpful:

          The above link features information on all sorts of vegan athletes, not just body builders. Are you a coach or athlete yourself? Maybe these sites will help inspire the people you talk to.

          One more thought: I’m sure you have already used this analogy for people: But tell them to take a look at the muscles on gorillas. Oh dear. And no meat? No dairy after weening? Wow. That analogy won’t work for some people (who won’t be able to get their minds past the thought that gorillas aren’t humans), but it will help others.

          Hope that helps!

      • Southbaysteve

        Congratuations! That is inspiring! I will visit your site soon!


        • Thea

          Steve: I agree that it is inspiring, but to be clear, that’s not my team or website. I’m just sharing.

          Since I’m out sharing, here’s part of this week’s story from Meatout Monday, another inspiring vegan athlete:


          Vegan Hiker Shatters Record

          “Josh Garrett, a dedicated vegan and avid hiker, crushed the previous world record for hiking the grueling Pacific Crest Trail, a 2,655-mile trek from Mexico to Canada. His official time was 59 days, 8 hours, 14 minutes — averaging 45 miles per day!

          Josh teaches exercise physiology and knows that plants are the way to fuel a champion’s body. He fueled his journey on ProBars and vegan mostly raw foods (raw so he wouldn’t have to pack cooking gear).”

  • Emootje

    I think hormesis explains why plants work and isolated vitamins don’t:
    I would love to see a future video about hormesis.

    • Darryl

      Recommend this article and blog which references the Dr. Rountree talk for an introduction to hormesis. This blog also has some great research links, though some entries could use a editor.

  • Eli

    Not entirely unrelated, but what do you think about the Ketogenic diet? Particularly as described here:

    Does the ketogenic diet also produce the same oxidative stress if the energy source is not from glucose?

  • lancemateas

    Cool video. Is there something special about watercress, or would a similar effect come from other cruciferous or green leafies? As to the serving size question, one serving of veggies equals 1 cup raw, or 1/2 cup cooked. Correct?

  • Darryl

    Watercress is, like broccoli and kale, a cruciferous vegetable, and its major pest-deterring and health promoting glucosinolate is converted by the action of chewing insects and humans to phenethyl isothiocyanate (PEITC). PEITC shares the same -N=C=S reactive bit as sulforaphane from broccoli, and the much the same cellular mechanism (induction 100s of genes with the Antioxidant Response Element promoter, mediated by Keap1-Nrf2).

    So, can we expect similar reductions in exercise induced oxidative stess with broccoli? So far, I’ve only found animal studies, but it seems likely.

    Other cruciferous sources of glucosinolates include mustard, horseradish, and real wasabi. You can guess my favorite condiments.

    • ted

      Thanks for posting those links Darryl! I add a lot of exercised-induced oxidative stress to my body almost every day, but now I wonder if the “super antioxidant” smoothie that I nurse on throughout the day works indirectly (productive) or directly (counter-productive). For the antioxidant power I’m using kale, blueberries, mango, and amla powder.

      • Darryl

        There’s no way I could do justice to the complex mixture of phytochemicals in those plants, but various glucosinolates (really, their isothiocyanate products) and quercetin from kale; the anthocyanins from blueberries; mangiferin from mangos; and gallic acid, ellagic acid, quercetin, kaempferol from amla all induce the “adaptive stress response” as described above. These foods contain many other structurally similar polyphenols that simply haven’t been investigated at this level yet.

        • ted

          Thanks for the in-depth info! Sounds like I’m ingesting the right stuff.

        • VegAtHeart

          Interesting arguments. Based on your absorption kinetics argument, I am speculating that a saturation effect may limit how much we benefit we get. If so, wouldn’t this suggest that it is better to have fairly steady intake of antioxidants (such as obtainable by sipping away all day at antioxidant rich beverages like green tea) rather than infrequent consumption of large doses of antioxidants (such as big meals rich in kale)? On the other hand, is it possible that there is also an adaptation effect that may come from maintaining steady levels of antioxidants (perhaps more relevant if hormesis is the fundamental explanation for the health benefits)?

          • Darryl

            In vivo, xenobiotic phenols and isothiocyanates and their conjugates remain elevated for 6+ hours (eg see kinetics for quercitin and sulforaphane), while In vitro, Nrf2 inducers elevate Nrf2 levels and translocation to the nucleus hours (depending on how long they remain stable in the cell. The cytoprotective enzymes, however, remain elevated for days, one can rub green tea or broccoli sprout extracts on nude mice and their skin is still protected from UVB carcinogenesis several days after being washed.

            So, unlike direct/stoichiometric antioxidants, where short timing and washout from the body is a problem, with the indirect “antioxidants”, it seems the main issue is getting dosage into the hormetic range (but not beyond, a lot of these xenobiotics are mutagens or hepatotoxins at high doses), and throughout the body (some penetrate the blood-brain barrier better than others).

            I nurse green tea throughout the day, but I also just make a point of preferring foods with known hormetins at meals:

            allyl isothiocyanate (AITC) – wasabi, horseradish, mustard, kale, cauliflower, cabbage, Brussels sprouts
            capsaicin – chili peppers
            carnosol (aka carnosic acid) – rosemary
            cafestol – coffee
            3-O-caffeoyl-1-methylquinic acid – bamboo leaves
            cinnamaldehyde – cinnamon
            chlorophyllin – plant leaves, esp spinach
            curcumin – turmeric
            diallyl sulfide – garlic & other Allium
            diallyl disulfide – garlic & other Allium
            diallyl trisulfide – garlic & other Allium
            epigallocatechin-3-gallate (EGCG) – green tea
            ethyl ferulate – solanaceae family
            ferulic acid – tomatoes, sweet corn, rice
            fisetin – strawberries, apples, grapes, onions
            genistein – soybeans
            indole-3-carbinol – broccoli, cabbage, cauliflower, brussels sprouts, collard greens, kale
            isorhamnetin – parsley, dill, kale, mustard greens, fennel leaves, chives, asparagus
            kaempferol – capers, saffron, kale, mustard greens, arugula, watercress, chinese cabbage
            kahweol – coffee
            alpha-lipoic acid – spinach, broccoli, yeast extract
            luteolin – widespread flavonoid
            lycopene – tomatoes, red bell peppers, watermelons, papayas
            myricetin – fennel, parsley, carob, goji berry, cranberries, black currants
            naringenin – oregano, grapefruit, oranges, tangerines
            naringin – grapefruit
            phenethyl isothiocyanate (PEITC) – chinese cabbage, turnips, rutabagas, watercress and radishes
            piperine – black pepper
            plumbagin – black walnuts
            purpurogallin carboxylates – black tea
            quercetin – capers, lovage, fennel leaves, red onions, watercress, kale, onions
            resveratrol – grapes, red wine, japanese knotweed
            S-allylcysteine – garlic
            sulforaphane – broccoli sprouts, broccoli, cabbage, Brussels sprouts
            xanthohumol – hops
            zerumbone – Thai ginger (Zingiber cassumunar)

          • VegAtHeart

            Thank you so much Darryl for an excellent response to my question. Over the past weeks, I have been reading your posts with great interest and really appreciate your generosity in sharing your knowledge.
            It is exciting to live at a time when the knowledge is becoming available to allow those informed to conceivably design diets that provide optimum stimulation of health-promoting biochemical pathways.
            As far as implementation is concerned, it would seem that making soups and stews by mixing a wide variety of whole plant products would be the best bet, although interactions effects may be an issue. If you come across any credible sources that provide rules for combining fruits and vegetables to maximize antioxidant benefits, please do share. Many thanks.

  • casp

    How does Astaxanthin work under the same conditions??
    any studies

  • KyleJeffreyKranz

    Yes, but is not stress THE POINT of this exercise, to stimulate adaptation?

  • Martha Helene Jones

    Living out here in the sticks I am blessed with a nearby artesian spring and fresh watercress growing in the cold runoff water. Are you aware of any studies of the potentially B12 producing micro-organisms that could be present in fresh spring water? Couldn’t B12 producing micro-organisms possibly still be on the surface of fresh watercress?

    • Thea

      Martha: How wonderful to be able to walk out your front door and gather fresh, healthy greens.

      I don’t authoritatively know the answer to your B12 questions, but I have a thought for you: It’s very possible that there is some B12 on your fresh watercress. Very possible indeed. However, given how very severe the consequences are if you don’t get enough B12, I would want to have the insurance that a supplement gives me. I would not want to rely on the on-going existence of microorganisms in fresh water. Even if you had your watercress tested today, what would guarantee that some dufus dumping chemicals/pesticide runoff upstream would not kill off those lovely micros in the future, meaning no more production of B12?

      One other thought for you: I don’t know how old you are. I just want to point out that everyone I know recommends that everyone, regardless of diet, take a B12 supplement after the age of 50. I would think that would apply even if you were getting some B12 from fresh, wild greens.

      Good luck to you!

      • Martha Helene Jones

        Hi Thea Thank you for your input. I am (nearly) vegan (half raw) so I take 500mg B12 3-5 times a week just to be safe. I drink the spring water and use it for cooking as well – it is tested regularly – since our tiny town uses the artesian spring for the town’s water supply. It would be nice to know the stats on any remotely located springs for B!2 content though – just to get some idea what might be there.
        I am 60yrs old and have been vegetarian since 20yrs old (apparently the anti-wrinkle, anti-oxidant properties are working because people often say I don’t look it!) In addition to a small garden, I pick lots of wild greens like, dandelion (the king of greens), purslane (for dha), henbit, sorrel, lamb’s quarters, chickweed, wild garlic, winter cress, dock, etc. for salads and cooking. In addition to other wild foods I make lemony staghorn sumac and pine needle tea for extra vit C.

        Stay safe and healthy, Martha

        • Thea

          Martha: Your diet sounds great and you sound great! So cool.

          • Veganrunner

            And it sounds like she lives in paradise.

          • Thea

            Aye! Sounds perfect to me.

    • Any natural source of water might well contain bacteria that produce Vitamin B-12. Without testing it would be hard to know. Even with testing the amount may vary from time to time. I would recommend you view Dr. Greger’s video’s posted from 2/3/12 to 2/9/13 concerning Vitamin B12. Taking a supplement is definitely recommended. Congrats on your excellent health.

      • Martha Helene Jones

        Thanks Don I have heard that anywhere from 2 quarts to 2 liters of unprocessed spring water could have a day’s supply of B12 but I always like to see the research for myself. Having worked in health foods I know there are lots of unfounded rumors, as well as misleading, if not outright harmful misinformation circulating around.

  • Stephen Lucker Kelly

    What about rocket lettuce (Arugula)? Or Dandelions? Would this have the same effect as watercress?

  • Synergy

    I am loving these exercise-related nutrition facts videos! Keep it up!

    The most common complaint I get while discussing vegetarian diets is that they are poor for athletic performance — nullifying any other benefits in the minds of my gym rat buddies.

    I wonder if there has been any further study as to why muscle mass is consistently found to be lower in vegetarian vs. omnivore athletes. Is it the reduced caloric intake? The IGF-1 promoting complete protein sources? Increased taurine, carnitine, creatine (increased water retention increasing “muscle” size)? Could it be related to CLA somehow? I’ve always wondered this, but I haven’t been able to find any data really looking for the causes of this disparity.

    • Plantstrongdoc M.D.

      Hi Synergy,
      Do you have references to “muscle mass is consistently found to be lower in vegetarian vs. omnivore athletes” because this is new to me. I know of no vegans or WFPD complaining of reduced athletic performance or musclemass, but “know” is of course not science.

      • Synergy

        There are a few on pubmed if you do some digging. Here is one example:

        “Relationship between animal protein intake and muscle mass index in healthy women.” via The British Journal of Nutrition, 2009.

        Finding: “a vegetarian diet is associated with a lower muscle mass index than is an omnivorous diet at the same protein intake. A good indicator of muscle mass index in women seems to be animal protein intake.”

        It doesn’t make sense to me that there would be anything special with regard to omnivorous diets. Unless it has to do with the variables I listed, all theoretically correctable on a vegan diet.

        • fruitbat

          I’m not going to look at the study right now, but bear in mind that many studies are flawed. One minor flaw immediately visible is that the researchers do not know the correct meaning of omnivorous. A vegetarian diet is omnivorous since it involves the eating of animal products. I suspect that they have not been able to measure true muscle mass correctly without discounting fat and water.

          Meat-based and other unhealthy diets may cause muscle mass to apparently increase by causing the cells to swell with water retention. Increased consumption of toxins (or producing toxins as by-products, eg urea from too much protein) causes increased water retention to dilute them. Their muscle weighs more but they don’t actually have more muscle cells. Think of a chimpanzee: they are “skinny” looking but are 5-7 times stronger than humans. Another study though, found that vegetarians eating an average of 75 grams of protein a day built muscle at the same rate as meat-eaters eating, IIRC, 125 grams of protein. So the studies are hardly “consistent” like you keep saying.

    • lancemateas

      I know what you mean. Is it because of some factors inherent to a veg diet, or is it perhaps that there are so few veg strength and power athletes? After all, there are plenty of omni “hard gainers.” As for the diet, Jeff Novick RD hints that there may be some short term benefit to “over nutrition” that might aid in hypertrophy. It is probably a combination of all the factors you mention, but my money is on IGF-1. I remember bodybuilders being enthusiastic about whey protein in part for its ability to raise IGF-1.

      • nc54

        Which then begs the question, could vegan athletes benefit by raising their IGF-1? Could they get the good aspects of IGF-1 elevation and negate the bad (increased cancer risk) with a huge consumption of fruits and vegetables?

  • VegAtHeart

    I would like to increase my watercress consumption.
    Can you suggest a good recipe that includes watercress?

  • 91rpm

    Hi Dr.

    Doess the Watercress works in the above manner better than Amla ?

  • Patrice

    What do you suggest for patients who have blood-clotting problems? I have been on Coumadin since 2005 following a massive PE which occurred after knee surgery. The ER doctor felt I would have been dead had the ambulance arrived 15 minutes later (not sure how he calculated the time), so I take the problem seriously and have continued on Coumadin since that time. My INR is followed closely, and we have not been able to get me to the point that I can even try 2 cups of green tea daily and have a control to work against – the INR has bounced around for unknown reasons. I am followed by Coumadin specialists at a major medical institution as well as well as the chairman of the Dept. of Vascular Medicine of another major medical institution and no one can figure out the problem. The Coumadin MUST be continued due to my resumption of using estrogen (controversial, but continuation is necessary due to rather severe uro-gyn problems and I use transdermal). How can I get the anti-oxidant benefits of so many important vegetables when I can’t handle high or medium Vitamin K foods?

  • Sebastian Tristan

    I have a gut feeling that arugula works even better than watercress.

  • Jeffrey Roy Vss

    Ok, Watercress and all those goodies mentioned AND your Hibiscus/pepper tea throughout the day with 300mg Ubiquinol and 20 mg PQQ. WooHoo!

  • tammy5f

    love this video! Does something like fresh basil leaves work as well as watercress did in the video? That i can grow a lot of basil and can eat everyday, however i have a difficult time finding good watercress :(

  • Martin Miller Poynter

    Hmm, I wonder how arugula stacks up against watercress. I eat 5oz of arugula 2 hours prior to exercise to boost performance. I wonder if the arugula has exercise induced oxidative stress reduction benefits, also?

    • dogulas

      Certainly. All dark green leafy vegetables are excellent sources of antioxidants.

  • green23

    I exercise a lot and want to reduce the free radicals. Watercress at the market can become expensive.

    Do watercress supplements work? What is the safe amount (mg) of watercress can I take before I exercise and will the supplements be effective?

  • Grant Peacock

    I find this to be one of the most amazing videos on ‘nutrition discovery’ that I have seen. I am persuaded to find a way to grow an ongoing supply of watercress at home (research required), but in the meantime, I’m curious to know if there are any other low-calorie pre-exercise foods that have been identified as approximately effective in reducing oxidative damage for pending workouts.

    Are any known, by chance?