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Is Our Food Becoming Less Nutritious?

Is our food becoming less nutritious? Many people claim that the nutrient content in our food has been decreasing over the decades. But is this really true, and should we be worried? A study published in 2004 looked at 43 different common garden crops, and how their nutritional value had changed between 1950 and 1999. Now, what they found was that on average, the protein content of those plants decreased by about 6%, Vitamin C decreased 15%, and vitamin B2 by a whopping 38 percent. They also noticed declines and minerals like iron and calcium. Now, there is some debate around the numbers because, well, How well could we really have measured those nutrients back in 1950? But there is still this concern that the food we’re eating today might be less nutritious than, say, the same vegetables 50 years ago. Several other recent studies also suggest a pattern is emerging. So if we’re witnessing a nutrient collapse, what’s causing it? One factor that many people point to is depletion of the soils. Given plants to draw their nutrients up from the soil, intense farming practices were thought to be the cause of nutrient depletion. If you look at micronutrients, things like minerals, well, there are decreasing levels in plants. But, farmers have always put a lot of effort into maintaining their soils, and using fertilizers to ensure that the plants have all the nutrients they need, which makes that argument less convincing. We’re still getting big plants, and they wouldn’t grow that well if they didn’t have the nutrients they need in the soil. So why else might nutrients be declining? One possibility is that it’s selective breeding. If you look at crops like corn today, they’re barely recognizable when you compare them to their ancestors, the wild corn from which these were bred. Basically since the advent of agriculture, we have been breeding our food crops for higher yields, for resistance to pests and changes in the climate. And, by and large, we’ve been successful. Crops are now bigger and grow faster than ever before. But are they more nutritious? Maybe we’ve accidentally been breeding the nutrition out of our foods in pursuit of other objectives. It’s tough to really assess how big of a factor selective breeding is, because we can’t easily compare this produce to the same produce a hundred years ago or a thousand years ago. So we need something else to be able to determine whether it’s selective breeding causing this decrease or something else. What would be really helpful would be a plant that has never been selectively bred. Where would you find one like that? Well, this is where weeds come in handy. In North America, there is a wild flower called goldenrod. It’s an important source of protein for bees, but not humans. And so, it has remained wild, or untouched by selective breeding, but how would you know what goldenrod was like 100 or 200 years ago? The Smithsonian Institute have been keeping hundreds of samples of goldenrod dating all the way back to 1842. Using these samples and samples they collected in 2014, scientists were able to compare modern goldenrod with goldenrod from over a hundred years ago, and the results were astounding. They found that there was a 30% decrease in the amount of protein in the goldenrod pollen over that period. If it’s not selective breeding, what else has contributed to goldenrod becoming less nutritious over the last 150 years or so? One rather surprising idea was that carbon dioxide could play a vital role. [Old time video]: Here we see in cross-section air with its particles of carbon dioxide gas enters the plant and makes its way into every living cell. CO2 is like plant food in the air. It basically increases the growth of all plants. Over the last couple of centuries, the level of CO2 in the atmosphere has increased a lot, from about 280 parts per million to over 400 parts per million today. Now, that might not sound like a lot, but if you’re thinking of it as plant food, we’re talking about an increase by almost 50%, and we can see the impact from space. It’s called the greening of the planet. Scientists have been tracking the impact of CO2 on plants via experiments called FACE, which stands for Free Air Carbon dioxide Enrichment. Their experiments run by injecting more CO2 into the area where plant crops are grown, and they find that wheat, barley, rice and potatoes; they will grow faster if there’s more CO2 in the atmosphere. But here’s the thing. They don’t necessarily become more nutritious, they simply put on more carbs. In other studies conducted in Japan and China, scientists pumped carbon dioxide into rice crops to simulate the kind of CO2 concentrations expected in 50 years time. On average, protein levels fell by 10 percent iron by 8 percent and zinc by 5 percent, But a lower concentration of nutrients doesn’t necessarily correlate with a decline in the plant’s nutrient contents. It’s called the dilution effect. So what does all this mean for us? Well, by 2050 scientists estimate that up to a hundred and fifty million people in the developing world may be on the verge of protein deficiency, due to the decreasing levels of protein in their staple foods. So does that mean we should all be taking vitamins and supplements? Well, no. At least, not yet. Because the nutrient declines are small enough that you should still be able to get everything you need from a well balanced diet, Including plenty of fruits and veggies. But, the increasing levels of CO2 and the dilution effect may be exacerbating the obesity epidemic. The thinking goes like this: We feel full, or satiated, when we’ve consumed a certain amount of protein. So if the protein levels are going down We may have to eat more food, more carbohydrates, and more fats to achieve the same level of protein. And that may make us fatter. While this is still a contentious theory what is becoming increasingly clear is that the changing atmosphere, specifically the rising level of CO2, is changing the food we eat. Hey, I hope you enjoyed that. I made this video as kind of a companion piece to my new feature-length documentary called Vitamania, all about the sense and nonsense of vitamins and supplements. You can watch that documentary if you haven’t already by clicking right here. It’s available globally, except for France and Germany because it’ll be on your TV on September 25th. I’m really sorry about that, but I really appreciate you making it possible for me to make both YouTube videos and Big international TV documentaries. It’s been a lot of fun and really, I couldn’t have done it without you.


  1. Narretei Author

    the food you get there looks really good. also congrats on a documentary on ARTE (assuming from the germany/france block). will watch it there then.

  2. Giuseppe Zompatori Author

    it's not the proteins in vegs but their fiber content that makes you full. LOL
    The dairy and meat industry wants you to believe proteins are more important than they really are.
    Look at the protein content of human milk, it's only around 2% and it's supposed to allow a young human being to double in size in a very short time.
    You don't have protein receptors on your tongue, real carnivores like cats do….

  3. deepz513 Author

    Yes I think do absolutely..and the taste too..all vegetables ..fruits and even meat. cuz of chemical …the need and greed of us humans:(

  4. Matt Leonard Author

    So in short, food is NOT becoming less nutritious. But plant food is becoming less nutrient dense as they increase in size due to rising Co2 levels

  5. Xavier Dupont Author

    Hi Veritasium, great video. Would you know why there is still no perfect diet, such as measure my body metabolism, then infer my needs in all the various chemicals, then produce a menu providing the right chemicals in the right amount? I'm sure the answer is complex, but I would believe that actually no such menu really exists because healthy bodies regulate their nutrient content, while people suffering from diabetes or thyroid disfunction can't have a correct menu without medication. I'm not considering obesity an illnesd here because it's a catch all that miss the actual cause of the problem, which may be triggered by diet imbalances but results in body dysfunction which does not revery to a normal condition when switching back to a more balanced diet and exercise. It works only for some people, but others can't actually do exercise because of dysfunctional adrenal glands and such. So I believe there is a very interesting subject in there, i. e. Is there a petfect diet for healthy people? and no perfect diet for some people unless they use medications ? And what would these perfect diets look like?

  6. Mellie Author

    Ok. I am 4 mins in and already i question some of what he is saying. He says that farmers put effort into the soil so the plants will grow through fertalizer. However they are usuing mostly chemical fertilzer which contains no vitamins or minerals whereas the manure of ruminants contains vitamins, minerals, fertilzer like nitrogen, ammonia etc., and beneficial bacteria. So unless farmers are using healthy manure or adding minerals and vitamins into the soil, plants will have them in fewer quantities. And yes u can use chemical fertilzer to make plants grow big and pretty yet still be fragile and lacking in certain areas…

  7. Mellie Author

    I totally agree with him about the impact of global change on food but i feel like this is a multipronged issue. There may not be only one cause…

  8. Martin A Author

    Incorrect 7 mins into vid. They can grow big and look the part, green and pest free. They look good and sell in supermarkets. The artificial nitrates and pesticides keep troublesome pests away and the nitrogen added causes good green colour and growth. But it's not just about looking green and being pest free, is it? What about all the micro nutrients in the soil that get upset by the artifical nitrates and pesticides. We can't just say they should be OK because they look the part because that is not so. Well now I've ssen all the vid it's even more ridiculous trying to blame carbon for that which mass produced crops has brought up. Some tomatoes are not even grown in soil just feed nitrates with a distribution system into a water obsorbent materials need we really ask where the nutrients have gone and blame carbon stupid video

  9. Jon Barnes Author

    You missed something obvious. Maybe in the same way that increased atmospheric CO2 causes an unbalanced inflation of the spatial dimensions and the nutrient density, our selectively breeding larger plants has caused a similar imbalance for similar reasons?

  10. fenrirgg Author

    Some hydroponic tomatoes are grown with higher concentration of CO2. It also changes the flavor, those tomatoes has less flavor than tomatoes grown on open field.

  11. Ranch Barbie Author

    Funny. There was a lot more CO2 in the atmosphere in the Jurassic period, plants were huge, and evidently had enough nutrition to spit out some of the largest animals this earth has ever known.

  12. WizardNumberNext Author

    Protein may have correlation with feeling full stomach, but it rather would be inverse correlation
    Protein creates insulin response
    Insulin blocks leptin, which is hormone which tells your brain you have eaten enough
    You can eat too much protein, same as carbohydrates. You cannot eat too much fat and actually fat would very easily call for lepton and won't create insulin response.
    You should research this subject as you, as probably everybody on this planet know at least one overweight or even ones person. You can help by providing with factual knowledge. You should start with MD Lastig and MD Fung

  13. Franziskus Hielscher Author

    It seems like it's the same thing happening to people – more calory dense food leading to bigger energy storage (fat) without much more intake of micronutrients – is happening to plants too, but instead of more calories they have more Carbondioxide available and thus store more energy as carbs while not taking up more micronutrients either.

  14. infinateU Author

    1,000’s of bacteria in soil help breakdown biomass that plants need to feed on. Does synthetic concentrated liquid nutrients make food taste bad?? I think so. Smoking marijuana that’s been feed liquid nutrients makes the smoke bitter, “flavor” is non existent and pain even follows.

  15. infinateU Author

    “Clean” “Organic” food is SO much easier to digest & this properly grown marijuana is SO much smoother and flavorful even. No pain or allergic reactions.

  16. Dr. Guy Madison Author

    I should have seen this a mile away…. oh its got to be climate change, just for views? What's with the stupid GQ look with vegetables? This channel has gone off the rails.


  17. Martin Hatchuel Author


    This is a hugely important argument as to why we should be working to reduce the carbon in our atmosphere. And you know what that means: It's tree-planting time.

  18. danny obrian Author

    We're the test done on ground farmed and forest , what if pestacide and weedkillers affect the uptake of nutrients or the biome that helps to break them down for absorption ?

  19. Classic rock Lover Author

    If you want the healthiest plants possible, you have to create, maintain and support a healthy biome in the top soil. Constantly replenishing the nutrients in the soil that the plants consume – that's the purpose of natural fertilizers with organic matter, like compost, manure, etc. You can also use fish fertilizer and work it into the ground, or even molasses.

    Conversational farming practices of only applying NPK is like feeding ONLY fast food to a person. They might still be alive, but they are not healthy.

  20. Aris Nikolopoulos Author

    very condensed information and put in a very clear way. But it seems a little awkward to be telling terrifying facts with a smiling face! 🙂

  21. MrDefend0r Author

    So the reason is exclusively not because of the soil because they are big? There are many big individuals of organisms that are sickly.

    And then in the next scene he says its because we bred for size and not nutrient value.

    And he never said the chinese study decreased vitamin content.

    Obviously capitalism and the international trading has ruined our food.

  22. Maxence-Olivier Decloedt Author

    You skip the argument of the soil too fast. Fertilizer sure help the plant to grow but it mainly give nitrogen and not all the minerals that the plant need. The selection made on the plants made them grow way faster on a soil without the live suppose to bring all the nutriments they need. Basically you eat a deadly sick plant doped with chemicals and which wouldn't survive without pesticide. I put a shortcut from a scientific and a specialist (sorry it's in french :

  23. Tsubasa Genzo Author

    I don't think that selective breading isn't responsible for that. You say "there is no way no have breeds from 50 years ago so let's compare the exact same plant".
    But some breeds, like these israelian tomatoes, are known to resist to dry conditions but to be less tasty. I'm pretty sure it also affects the nutritious quality of the food.
    If your breeds are bigger and more resistants I'm pretty sure there is a side effect for that.

  24. Orbit Corkra Author

    Yes it's true there is no nutrients in anything from the grocery store just salt and sugar and fat. Just look at the nutrition chart on products.. 0% everything except fat and salt or sugar. If you have some property, grow some food at least you will get nutrients. If you grow them in fertile soil and plenty of water you will end up with a bounty of decent vegetables and fruit that you can get some nutrients at least. When it's not summer you need to take vitamins and supplements regularly because food in grocery stores have 0 nutrients. Ok some items might have some vitamin c but grocery store veggies are just bland watery nothingness.

  25. Marc De Gagné Author

    Hey great video!
    If we found that increasing CO2, is decreasing the nutrition part of crops, was there a reverse experiment done? The lowering CO2 increases nutrition level?
    Thanks for making us brighter, with good docs!

  26. T Est Author

    Fertilizers, is what I suspect are the issue. Who uses organic cow poo anymore, everyone uses synthetic fertilizers. And yes they have some of the most important nutrients, but I would guess they are far less complex. Furthermore they grow crops faster these days, why the crops have less time to get mature, making them less dense in nutrients. That is my 5 cents, after 1:45.

  27. Jim Troy . Tom Scotty . Author

    We must grow all our food in hydroponic indoors ??? For no radio active fall out will contaminate the hydroponic indoor grow …

  28. BBM Author

    No, it won't make us fatter. You're describing a slight or possibly total keto type diversion. Eating more fats will make you leaner. Burning fat is slower/more effective than sugars. They each play a role though.

  29. Lana Author

    Since I am an omnivore and have a high level of activity (hike 8 to more than 10 miles every day), I am not suffering. I drink plenty of water and eat a well balanced diet with high amounts of protein. I feel great and have no illnesses. I am not fat, I am very fit.

  30. Waskito Author

    I don't know about nutrition but in just my lifetime all fruits and vegetables have turned from delicious to tasting plain and dull. Safe to say I went from eating vegetables daily to once a month over the years.

  31. niunka1 Author

    BULL S…. ! soil depletion is the reason why crops are less nutritious! Fertilizers only contain three elements which happen to promote plant growth. Human body needs 90 different elements to stay healthy. Hey Veritasium! Happy money making on global warming b.s.!

  32. Warren D Smith Author

    I believe one problem is plant breeding to (1) make plants which produce more kg per season, (2) make them look better (e.g. redder tomatoes) for marketers. Plants that do that, produce more, but with less nutrition concentration. You can try to tell using seeds of old varieties rather than modern varieties.

  33. aksel Bakari Author

    He is lying or know nothing about the subject
    It is not co2 actually
    It is seeds standardisation, the growing need for prodictivity that makes food has less votamunes and minerals
    It is seed lobby..
    Watch cash investigation a french program talked about that

  34. System32 Author

    Not going to affect me much, My diet mostly contains meat and dairy, The natural human diet, You can live perfectly fine on meat alone and be perfectly healthy Plants are just there if no meat is available

  35. Mac Lovingurmom Author

    Possibly but here's the bigger problem. Pesticides. Namely Bayer/Monsantos Roundup Weed Killer. Wash your foods thoroughly before you eat them. If possible dont buy foods sprayed with these chemicals.

  36. Mike Skinner Author

    This might help someone. I noticed that certain vegetables round here looked a bit odd. I googled it and found that they had a boron deficiency. I ordered a pack of boron from Boron in the US. After a short while my teeth lost their sensitivity to cold and my muscles stopped aching and an injury to my ankle that I twisted 50 years ago has healed. I can run now and no pain. You have to take the right amount as I tried taking a bigger dose and I was paralyzed for a day as it sorts where the calcium and magnesium go in the body via the parathyroid.

  37. Dr. Liam A. Dye Author

    So what's the solution for the dilution effect? If we can't take carbon out of the atmosphere, maybe we should saturate our crops with nutrients. That way they will still be as nutritious despite their increased growth rate.


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