Image Credit: Wojciech Kulicki / Flickr. This image has been modified.

Cancer-Causing Caramel Color

Caramel coloring may be the most widely consumed food coloring in the world.  Unfortunately, its manufacture can sometimes lead to the formation of a carcinogen called methylimidazole, which was identified as a cancer-causing chemical in 2007. For the purposes of its Proposition 65 labeling law, California set a daily limit at 29 micrograms a day. So, how much cancer might caramel-colored soft drinks be causing? We didn’t know…until now… My video Which has more Caramel Coloring Carcinogens: Coke or Pepsi? explores these questions and more.

Researchers tested 110 soft drink samples off store shelves in California and around the New York metropolitan area, including Connecticut and New Jersey. None of the carcinogen was found in Sprite, which is what you’d expect since Sprite isn’t caramel-colored brown. Among sodas that are, the highest levels were found in a Goya brand soda, while the lowest levels were in Coke products, which were about 20 times less than Pepsi products. Interestingly, California Pepsi was significantly less carcinogenic than New York Pepsi. “This supports the notion that [labeling laws like] Proposition 65…can incentivize manufacturers to reduce foodborne chemical risks…” To protect consumers around the rest of the country, federal regulations could be a valuable approach to reducing excess cancer risk—but how much cancer are we talking about?

Johns Hopkins researchers calculated the cancer burden, an estimate of the number of lifetime excess cancer cases associated with the consumption of the various beverages. So, at the average U.S. soda intake, with the average levels of carcinogens found, Pepsi may be causing thousands of cancer cases, especially non-California Pepsi products, which appear to be causing 20 times more cancer than Coke. Of course, there’s no need for any of them to have any these carcinogens at all “as caramel colorings serve only a cosmetic purpose [and] could be omitted from foods and beverages…” But we don’t have to wait for government regulation or corporate social responsibility; we can exercise personal responsibility and just stop drinking soda altogether.

Cutting out soda may reduce our risk of becoming obese and getting diabetes, getting fatty liver disease, suffering hip fractures, developing rheumatoid arthritis, developing chronic kidney disease, and maybe developing gout, as well.

In children, daily soda consumption may increase the odds of asthma five-fold and increase the risk of premature puberty in girls, raising the likelihood they start getting their periods before age 11 by as much as 47 percent.

If we look at the back of people’s eyes, we can measure the caliber of the arteries in their retina, and the narrower they are, the higher the risk of high blood pressure, diabetes, and heart disease. Researchers performed these kinds of measurements on thousands of 12-year-olds and asked them about their soda drinking habits. Their findings? Children who consume soft drinks daily have significantly narrower arteries. “The message to patients can no longer remain the simplistic mantra ‘eat less, exercise more.’” It matters what you eat. “[S]pecific dietary advice should be to significantly reduce the consumption of processed food and added sugar and to eat more whole foods.”

Prop 65 is lambasted by vested interests, but, as I mentioned, it may push manufacturers to make their products less carcinogenic. Other Prop 65 videos include:

For more background on caramel coloring, see my video Is Caramel Color Carcinogenic?.

There are other soda additives that are potentially toxic, too. See my three-part series on phosphates:

Other coloring agents are less than healthy. For more on this, see Artificial Food Colors and ADHD and Seeing Red No. 3: Coloring to Dye For.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

71 responses to “Cancer-Causing Caramel Color

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  1. In the 1950’s we kids got one soda per week, on Saturday. The rest of the time we drank water when we were thirsty. Nobody has ever suffered from lack of soda pop.

  2. From one of the links in the post and then a link to another study, it appears that adverse retinal artery diameter was associated with lower amounts of lutein and zeaxanthin. Kale and dark greens are good sources as well red algae. See below on study abstract.
    Association of serum lutein and zeaxanthin with quantitative measures of retinal vascular parameters.
    Kumari N1,2, Cher J1, Chua E2, Hamzah H2, Wong TY2,3, Cheung CY2,4.
    Author information
    To evaluate the association between serum carotenoids and quantitative measures of retinal vasculature in elderly Singapore Chinese subjects. decreased serum lutein…. None of the other carotenoids demonstrated meaningful relationship with quantitative measures of retinal vasculature. Lower levels of lutein and zeaxanthin demonstrated significant relationship with adverse quantitative measures of retinal vasculature in elderly healthy subjects.

    PMID: 30260964 PMCID: PMC6160008 DOI: 10.1371/journal.pone.0203868

    1. I love Balsamic vinegar, but it’s difficult to find one that doesn’t have caramel coloring added to it. When I can’t, I don’t buy.

  3. This like 99% of all reporting on cancer causing food stuffs in the media this is totally meaningless and possibly misleading until two questions are answered: 1.) What is the effect size when applied to the population size of the consumer base? 2.) What is the dosage dependency curve like? The answer to the first question tells us if coke vs pepsi is a difference of 0.01 cases/year to 0.2 cases/year or 100 cases a year vs 2000 cases a year (both are 20x, but in the former case, there a lot more important things out there to worry about). The second issue is more subtle, but many chemicals are harmless or even beneficial below certain levels… comon examples: Acetaminophen, which is liver-toxic above recommended dosage and very very safe at or below the recommended dosage. Another is Vitamin D, which you must have some of to live but will kill you if you eat too much of it.

    1. Gus,

      You may have a point but it causing obesity and Diabetes, kidney diseases, fatty liver, hip fractures, asthma, arthritis and being a carcinogen, plus being highly acidic, and highly addictive, and a significant source of sugar or artificial sweeteners and wrecking the gut microbiome, that becomes something to look at.

      I drank liters plural of soda per day for years and my relatives still do. A few of the people got kidney cancer. That is anecdotal but i was wondering which carcinogen causes kidney cancer and 2 liters of Diet Pepsi per day might?

      1. I gave it up 2 years ago, but had tried several times and it was hard to give up.

        It made water taste bad.

        Now, water tastes good and soda tastes toxic.

        1. Everyone who I know who drinks it tells me how much they hate water.

          It wrecks teeth and mouth microbiome, too, for good measure and diet soda gives you a sweet tooth which is proven scientifically.

          People eat junk food and drink soda. I think it wrecks the taste of fruit, too, but pairs well with pizza and candy.

          Artificial flavors war against natural flavors.

          The pleasure trap of the brain is another thing.

          1. In the 1970s, I was addicted to Joe’s Pizza in Harvard Square, especially when coupled with Fanta orange soda. Could eat it once a day. I was skinny then, running 40 miles a week, and could handle the calories but…. The pizza didn’t taste nearly as good without the soda, and we all suspected Joe of doing some fancy chemistry in his back room.

            Then I was addicted to Diet Pepsi for decades. Gave it all up when I went vegetarian in 1989, but I can still see the effects.

    2. Gus-This is exactly what I would say if I were a troll for Big Corporations trying to shirk responsibility for increasing cancer. It’s too complicated so it’s impossible to know. Keep drinking our product. Anyone questioning it is confused or insane. We now return to our regularly scheduled carcinogens.

    3. I agree. I believe that one can easily overdose on Vitamin D3. I read that testosterone levels may increase. Which could be bad or good depending on how much one can handle. I believe it is less possible to overdose from Vitamin D2 (not from Bovine) that would not have added casine or elevate testosterone. D1 (the sunshine vitamin) is the chose Vitamin D but sunshine is not always available.

    4. Is there anything that will not kill you if you consume too much of it? I imagine that a truck load of kale. would kill you, if consumed too quickly.

        1. M C

          Yes, perhaps, but Dr Lisle in The Pleasure Trap and Dr Barnard in The Cheese Trap both differentiate between how people don’t tend to binge when they eat Whole Foods and they most certainly do binge on the foods which corporations paid millions learning how to impact the pleasure centers of the brain with.

          I drank so much soda and now I drink water and tea, but neither of those have compulsion involved at all, where soda did.

        1. There is an App for how much you need to eat of foods for them to kill you.

          Nine 2 liter bottles of Coke in a short period of time would kill you.

          There was a time in my life when I drank a few Double Gulps per day and 3 of those would be 5.67 liters. I would drink one for breakfast, one with lunch and one with supper. Two more would have been a lethal dose.

          1. I think McDonald’s supersizing everything probably started the high quantities, but 7-11 was so inexpensive that it was cheaper than most of the drinks I could buy other than water, which hadn’t been sold the way it is now back then and I genuinely hated water so much that I didn’t drink it at all except for taking pills and mostly I would take those with soda, too.

    5. Heh, now that a bunch of folks who want a bandwagon not science have accused me of being associated with or working for soda companies, I’ll say NOPE. Just a private individual, and I have maybe drunk a dozen cans of soda in the last 10 years. Gave it up a long time ago. There are other good reasons to quit soda, but I absolutely HATE WITH A PASSION inept use of study results. What’s really criminal is this could very well be a critical result that might save thousands of folks from cancer, but THERE IS NO WAY TO KNOW based on the content of this article. It’s like someone saying go get me one size larger… without telling you the original size.

      1. Gus,

        You don’t drink it and never really did and that might affect your view on it.

        I find the information very valuable because everybody around me drinks it all day long.

        You are suggesting moderation as the answer but you have used a type of moderation, which America is not known for at all and that has gotten worse with each generation.

        Researchers are calling it a carcinogen and that may be what people who drink it all day long have the right to hear.

        Every few weeks people around me are getting diagnosed with cancer and it could be the animal products, instead of the soda, but if people who have lumps appear suddenly want to change their diets, they need to know what to change to get the carcinogens out of their lives.

        I stopped drinking soda when I had a lump on my breast and horizontal nail ridges on my fingers, plus brain and eye issues.

        It wasn’t the only thing I changed but there was a short list and it was on there.

        I don’t miss it at all and I don’t miss being like an addict about that and cheese, which was my other “hard to give up” things.

        I am not lecturing my brothers for drinking it, but one has chronic gout and diabetes and one has kidney cancer and just had surgery and the doctor said that he has a 50% chance of getting it back i within 5 years.

        I said to him, “Unless you get the carcinogens out of your diet and environment.”

        He said, “The doctor didn’t mention diet.”

        And went and drank a soda.

        Anecdotal, yes.

        1. I had a few puffs on a few cigarettes in my life and a few beers, which tasted and looked as close to what I imagine pee would taste like and I might not see those as problems and genuinely didn’t see them as things people even could stand using long enough to get addicted no less overuse or develop health problems from them.

          My parents had alcohol around for holidays but bottles of beer could last years in our fridge and bottles of wine and rum were disposed of when that house was sold.

          Once every few years, I used a tiny bit from a tiny bottle of wine for cooking and still had most of the tiny bottle left over.

          I say it because my intake was never what drinkers intakes were and when that topic comes up, I am not as concerned.

    6. I think the point is that the resulting thousands of unnecessary deaths annually are a public health issue even if the risk is tiny at the individual level. After all, there are far fewer deaths annually from aviation accidents in the USA (and the risk for an individual passenger is tiny) but aviation safety is still stricty regulated.

      Also, as far as I can understand it, there is no benefit whatsoever to the individual consumer from this stuff. All the benefits (financial or otherwise) accrue to the producer and all the risks are borne by the consumer.

    1. I don’t understand what there is to consider. Soda, pop, whatever you want to call it is garbage. It is not a food that actually does some good for you. The videos that Dr Greger did on the effects of artificial sweeteners on the brain etc are also frightening. Why anyone would actually pay money for it is beyond me.

        1. Rueka, re: “If you read labels, you’ll find Carmel colors, dyes and pigments in many other things besides pop.”

          The foods I eat don’t have labels … whole fruits, whole berries, whole nuts, whole seeds, whole grains, whole beans, etc., etc. ;-)

          1. “The foods I eat don’t have labels”
            – – – – –

            Good thinking, Hal. You don’t have to worry about those labels ending up in your toilet bowl. :-)

            1. WFPB-Hal,

              “The foods I eat don’t have labels … whole fruits, whole berries, whole nuts, whole seeds, whole grains, whole beans, etc., etc. ;-)”

              Ding…ding…ding…we have a winner…!

              1. I guess I’m a “loser,” then. :-( The Ezekiel bread wrapper –on which is a label– lists the ingredients of the bread.

                Ezekiel bread has shot up to over 6 bucks in my area. Boo! Hiss! Maybe it’s time to look for a substitute.

        2. Not in my food cupboards or refrigerator there isn’t! Any food that comes in a bag/package/tin can in my house is a single whole food commodity like dried beans, canned tomatoes, or grains like barley or oatmeal. Like WFPB-Hal, the greater bulk of what I eat is fresh produce.

          1. This company makes food colourings…… both the ‘bad kind’ and some of the natural ones. I enclose tne link here only for interest. They describe some of the natural colourings and the food stuffs they are made from.

            Rueka, I didn’t mean to sound ‘holier than thou, ‘ above , and if it sounded like that, I apologize. I do not assume anything about what others prefer to eat, and indeed, it is their own business. I have seen people in my neighbourhood with visible health issues buying pop by the shopping cart load frequently. I understand the need to enjoy our food, and to include some treats too. Chocolate for example, or home baking, which have actual food on the ingredient list would for me have greater appeal. And yes, label reading is so important, I agree.

            1. Not hearing negative things from you, Barb. Comments could be getting mixed up. For now, I’m off the conversation, but Dr. Gregor is my first choice web doctor!

              1. Good for you Barb and Hal!

                My beans and rice and tomato products still have labels.

                Someday, I will buy bulk. I would like to cut out the packages, but I don’t trust the food bins.

                I want bins where people’s hands aren’t going in all day long after they pick up chicken etc.

                Rueka, my cell phone gets so confused typing your name in. I agree with you, Dr Greger is a treasured part on my days.

          2. Congratulations on having the means, preferences, and will power to apply WFPB so completely!

            Proposition: “When all else has been eliminated, that which remains, no matter how improbable, must be true” -Sherlock Holmes’ father, attr.” Solve for the value of “all”.

    2. I agree, but the degree of risk will be related to the degree of consumption at some level.

      For instance, T.Colin Campbell figures out that Casein increased the size of tumors. If you only use a little bit of milk in your coffee, you might be okay, but if you are a milk mustache person who already has cancer, you can make decisions without all of the details because those human studies may take decades to Dot every i.

      The logic that everything could kill you under values that SAD diet is what we got using that logic and WFPB is proof enough to me that kale doesn’t kill very many people at all. People get healed from cancer going WFPB. They get cancer on the SAD diet. Countries pre-SAD didn’t have much of it and post adopting a SAZd diet got cancer and soda is part of what we pumped to the nations.

      1. The logic, water can kill you, so just drink soda sucks.

        Kale can kill you so just eat bacon.

        Look up kale and you will find how many people were killed by it.

        Same for water and I would challenge you that if 10 people died from drinking too much water and millions die from carcinogens, then your logic is a way to deceive yourself.

  4. Things I’ve known all along about dyes and pigments because I clearly react to them. Having you verify is so important to the health of others. These dyes as a culprit of ADHD could be construed with vaccines being a cause of it? There are no dyes in a vaccine, I hope, but vaccines are being blamed for cause of ADHD and it could be the ingestion of dyes before and after vaccine all along?

    1. Hi Rueka,
      Fortunately, vaccines do not cause ADHD or have any other ill effects (other than a stinging sensation!), but they do save many thousands of lives from life-threatening diseases.

  5. Why do soft drinks have to be that particular color or shade? Is it because we expect it to be that color? Were we raised with that color? Is it embedded in our mind—- I know the other ingredient is sugar that is bad, so can someone mix the dark pigments of say blueberries and black beans together and come up with an acceptable looking more healthy color ingredient if possible. I see these cases of fizzy non-colored water in cans and have even noted their price is cheaper then the real stuff. For me, I’ll sip my good clear non-carbonated colorless water and know my body appreciates it. Be well my friends. Wish you the best of health.

    1. I agree with your suggestions. I don’t drink soda pop either but for those that do, those color suggestions I thing are good.

      1. YR, That’s a fascinating article. I think I may have a little piece of that gene mutation myself. Many years ago when I would go to the dentist for a filling, the pain drug injected into the gum wouldn’t take effect for about an hour, and after the drilling was finished! And when it did take effect, it would leave my jaw numb for another couple of hours. So I finally asked the dentist to skip the pain killer. It turned out that the drilling really didn’t hurt that much at all even with no pain killer.

      2. Nope.

        It is a trend online though.

        My coworker found it when he arrived this morning. It was before my family members and I am glad that none of them are following internet trends.

  6. I haven’t been sleeping through the night the past 2 nights and I haven’t been using my gadget.

    But I got so much done today…. oops, yesterday.

    I think my brain is already performing better.

    I don’t count “to do list” lack of sleep because even with the “to do list” I slept some every hour from midnight on versus falling asleep at 4 in the morning.

    I would fall asleep for a half hour, get up and do something and I succeeded at all of it and that is my brain functioning better. I am more emotional tonight after 2 nights of not sleeping as much but I got so much done that I fully expect to be back to sleeping this weekend.

    I won’t have to tell you if my brain gets worse because it gets so obvious, and maybe I won’t have to tell you if my brain gets better because hopefully that will become obvious, too, but I will mention that I was able to organize projects and I was able to implement them quickly with no emotion and no brain fog. Sleep? Gadget causing brain plasticity and increasing circulation to my brain? Or both?

    1. My brother is now being offered to be part of a checkpoint inhibitor study hoping to prevent cancer from coming back.

      They don’t know if they truly got it all is what they said.

      I told him that everybody has cancer cells.

      It sucks that it works better than other things with fewer adverse effects but a portion of people will have the adverse reaction of tumors growing faster.

      I am not in the decision-making process for him.

      He has to make his own decisions but he won’t change his diet and that breaks my heart.

    2. ‘Cancer therapy selects for cancer cells resistant to treatment, a process that is fundamentally evolutionary’

      Some people have advocated providing drug therapy only intermittently to allow non-adapted cancer cells to outcompete the adapted cancer cells so that when the drug treatment is given again the caner remains vulnerable to the drug. This contrasts with the full nuclear strike treatment approach. Others suggest using a startegy that employs complementary drugs to address the evolution of cancer cells to resist treatment

      People who don’t believe in evolution though would opresumably ignore such ‘alternative’ approaches to treatment.

  7. Weirdsville…there’s a whole lot of shuffling going on! It’s the second time this thread was exchanged for a “what to eat for chest pain” blog.

    “Chest pain” showed up a few days ago, got three responses, disappeared, returned yesterday, and now it’s gone again.

    Does somebody have brain fog around here? :-/

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