Doctor's Note

This video is a good reason to subscribe (for free of course) to my videos. One never knows when new science will change my dietary recommendations.

Lemon can actually boost the antioxidant content of green and white tea. See Green Tea vs. White. And for a comparison of their cancer-fighting effects in vitro, Antimutagenic Activity of Green Versus White Tea.

What about the aluminum content in regular tea? That was the subject of my last video Is There Too Much Aluminum in Tea? Before that I covered another potential downside of sour tea consumption in Protecting Teeth From Hibiscus Tea but then before that a reason we should all consider drinking it in: Hibiscus Tea vs. Plant-Based Diets for Hypertension.

For more on the iron absorption effect, see my video Risks Associated with Iron Supplements.

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  • Jane’s Addiction

    I’m really proud of Dr. G for making this video and for stating so clearly and unequivocally that he’s changed his mind and changed his recommendations. A mark of a true scientist is being willing and able to admit that one is wrong when exposed to new and better data and theories. We need more people in the world with this kind of integrity. Thanks, Dr. G.

    • Arjan den Hollander.

      No pride or prejudice here Jane ^^

    • James Wald

      This is why it’s so important to eat a *diverse* whole food, plant-based diet. Mix it up with green/white, hibiscus, and chai.

    • Sean MacLeod

      Dr. G even stated on a podcast that he follows the science and when the science indicates that lamb-stuffed foigras prevents death, he’ll recommend that. Until then… “plants are preferred…”

  • Joevegan

    Before I started visiting this website, I drank 8 to 10 cups of black coffee per day. Now I drink 3 to 6 cups of white tea, with lemon, in the morning and afternoon; and 3 or 4 cups of hibiscus tea in the afternoon and evening. I think I’m okay in light of this new research. My thinking in developing this routine was to decrease my caffeine consumption later in the day so it wouldn’t effect my sleep.

    • sf_jeff

      Same here. My cups are probably double-cups, but I drink 1 coffee, 2-3 cups of a variety of caffeinated tea, 1 glass 1/2 hibiscus, 1/2 concord grape juice, and 2-3 cups decaffeinated tea, with white, green, mint, chamomile most common in the rotation. (The chamomile is an accident; it seems that all the prettiest boxes seem to have it…)

  • Steve

    Dr. Greger mentioned “blending in” hibiscus tea. Is there any reason not to add tea leaves (green, black or hibiscus) into a smoothie, for example, rather than drinking it as a tea. I don’t like the taste but would like its benefits, so burying it in a beverage whose taste I like would be a solution, if it were safe and effective. Approve or disapprove?

    • drew4021

      Steve, I’m pretty sure in the video on his morning smoothie he mentions blending in tea leaves along with the other ingredients. It’s the same idea as a matcha tea smoothie. Take a look for it

    • Thea

      Steve: Here’s how I interpreted the video: By consuming the actual leaf (rather than a filtered brewed tea), you significantly increase the amount of aluminum and manganese in your diet. Because we have so many unknowns concerning those two substances in regards to hibiscus tea leaves, Dr. Greger now thinks it is prudent to not consume the tea leaves themselves – at least that is how he changed eating practices for his family.

      That’s all we can say on the matter at this time. It is up to you to decide if blending X amount of the hibiscus leaves themselves in your tea makes sense.

      But note that the discussion seems to give a pass on green and black tea/tea leaves (see the previous video too). The question in this video is mainly about the hibiscus tea/leaves.

      Sometimes I think it helps to read the video transcript after watching the video. You might want to do that to see if you agree with what I wrote in terms of understand what Dr. Greger is saying.

      • sf_jeff

        Good points, also, I would be a bit cautious of combining tea and hibiscus, at least in large quantities, because we don’t really know if adding hibiscus would increase the absorption profile of tea.

  • April

    You state the kids with kidney failure shouldn’t drink hibiscus tea. What about adults who are at risk of kidney failure and are working hard to avoid it?

    • guest

      Drink water. Eat fruit.

    • sf_jeff

      Good question. By the way, is there a simple test to determine if you are at risk or not?

  • SaraVC

    Does iodine warm you up? Ever since adding nori sheets – 3 day – I no longer feel so darn cold being a vegan.
    My thyroid is fine and I eat large amounts of steamed cruciferous veggies. Never iodized salt, just iodine from
    greens and other plants. But the nori upped my iodine up a lot.

    • ReluctantVegan

      If the nori is prepared with oil, then you are increasing your calories and your fat. In my experience, increasing fat has helped me stay warmer as a vegan (and also when I was vegetarian).

      • Gar Zuzik

        From a endocrinology perspective, the upregulation of thyroidal production can increase one’s body temperature, the sensation of body temperature, and also insoluble fibers can allow for removal of estrogen by the body, thus altering the whole hormonal homeostatic state.

    • Sean MacLeod

      Eating five thousand calories a day keeps me on fire as a vegan. Fruits and veggies only.

  • Kitsy Hahn

    Don’t like it. Won’t drink it.

    • Sean MacLeod

      Let us remember that Big Macs are popular for a reason. Tasty. Beer tastes like piss but people get quite used to it after a while. Eat according to science and health and your taste buds will fall right in line :)

  • Lars

    I received the results of my annual blood test and for the first time my iron level shot up to a little above high normal. This would coincide in time with my starting to use hibiscus tea (usually a large mug in the evening)? Could this be the cause?

    • ReluctantVegan

      Glad you are checking your iron levels annually. Dr. Gregor mentions in his nutritional recommendations to have your iron checked before trying to eat foods to increase iron (men especially). Both my and my husband’s iron stores (as measured in a medical lab) shot up once we switched from vegetarian to vegan. Mine went from low to high normal. His went from high normal to WAY too high (dangerously high). We did not consume hibiscus tea at that time, but we HAD switched from a stainless steel pan to a cast iron pan for ALL our meals. Due to the high iron, we have now switched back to stainless steel cooking pans, but have not had iron retested yet.

      • Lars

        Good Advice. I have been using Stainless for a long time – so don’t think that is doing it. Maybe too much kale.

      • jengi

        Do you think it was the cast iron cookware that did it? My husband and I have low iron levels (we are both vegan) and have been taking supplements. I’d love to get off the supplements, but have tried before without success. If I cooked with cast iron cookware occasionally, would it be effective in raising iron levels without taking them too high? Any advice on this would be much appreciated.

        • ReluctantVegan

          My personal experience, and the scientific literature, support the use of cast iron cookware to increase iron levels. I had just found and typed in a list of articles for you, and when I clicked post, the whole 5 paragraph answer disappeared. I don’t have the heart to re-find and re-type. BUT, you can go to and search:
          Iron content of Cambodian foods when prepared in cooking pots containing an iron ingot.
          Open that article and go to the bottom where it lists its references. There you will find a wealth of studies on getting iron from iron cookware.

          Here’s one more:
          Mineral migration and influence of meal preparation in iron cookware on the iron nutritional status of vegetarian students.

          Personal experience: as a vegetarian for over a year, I had planned to switch to vegan, so I had some baseline labs done. My iron was low (40), my % Saturation (back-up supply in blood) was low (11%), and my ferritin (long-term back up supply stored in organs) was low (23). I switched to vegan AND I starting cooking 95% of our meals in cast-iron skillet (no iron supplementation). Nine-10 months later, my iron was normal (154), and I had more than enough in back-up supply in the blood (44%). The long-term storage in the organs is still low, but I presume it will gradually replenish as the back-up supply in the blood is slowly deposited into the long-term storage in the organs. Because two things changed at once (veg to vegan, AND stainless steel to cast iron), I cannot definitively say it was the skillet. Perhaps I inadvertently started eating more iron-rich plants when the diet changed, or increased absorption by serving them with acidic sauces. Who knows for sure?

          You are both starting out with low iron, so my opinion is that you could safely cook ALL your meals in a cast iron skillet and not fear iron overload. Women lose iron each month; men do not – so you will have different responses. So you should BOTH get your iron studies re-done in, say, 6-10 months after switching to cast iron – just to see what’s going on.

          You will want to do your research and bring it with you to your doctor to discuss your plan. I am not in a position to actually guide your practice here – just trying to give you info and direction to help with your discussion with your doctor.

          I found to be very helpful. I wish you the best of luck!

    • Sean MacLeod

      Another variable at work: America’s poor health. Let us remember that people in the “optimal” ranges for cholesterol drop dead of heart attacks. The ranges for many health factors are derived from the average population. They may be skewed.

  • Dhej

    Very nice! I have been drinking it like water too!

  • t091582

    There is one thing in this informative video that does not make sense to me.. Dr. G says that adding lemon to tea does not increase aluminum absorption… 2 things about that.

    1. I could not find that in the links to the studies that were provided.

    2. here is a quote from one of the studies:

    “The estimated absorption of aluminium was 8 and 50 times
    higher when antacids were taken with orange juice or with citric acid,
    respectively, than when taken with water. Thus, measurable quantities of
    aluminium are absorbed from single oral doses of antacids. The absorption is
    substantially enhanced by concomitant ingestion of citric acid.”
    so I ask… if citric acid increases aluminum 8 to 50 times when ingesting antacids, why would it not increase the aluminum absorption when adding lemon to tea?
    And one more question about this.. even if it has been shown to not increase aluminum in the blood, what about increasing aluminum in the brain? Can we assume if aluminum is not in the blood that it is not getting absorbed in the brain?
    I’m still not adding lemon to my tea!

    • Mike Fessler

      “Elemental Analysis of Aluminum Accumulations in the Livers, Kidneys and Brains of Mice Observed by HAADF-STEM-EDX”, Kiyokazu Kametani and Tetsuji Nagata. Annals of Microscopy, Vol. 8, April 2008. ThIs is a great study feeding mice aluminum, adding aluminum plus citrate. Please review this study as the citrate plus aluminum added to the Mice water increase the bioability of nine times more aluminum to the liver then the brain. Also, at the 10 Keele Conference on aluminum toxicity, a study showed that Hibicus tea leaves are used as the base for most fruit teas and this plant is grown in highly acidic soils laden with aluminum. The discussion by the Aluminum Scientist was to use milk instead of a citrate. Citrate will bind the aluminum, I have lemon and warm water separately in the morning to create less acidosis, as view by OligoScan for acidosis.

      • mark

        Thank you Mike!

  • t091582

    oops, I did find the link… which was from 1993. would like to know if there are any more studies about lemon with tea (green, black, white) and aluminum absorption..

  • Lee

    Dr. Greger – just wondering if there have been any studies on Hibiscus Tea/acidic drinks affecting Mercury leaching from amalgam fillings?

  • Priscila

    Since Hibiscus enhances alumin absorption, can I conclude it will also enhance iron absorption?

  • John

    Dr. Greger, can you let us know approximately how much hibiscus per cup would approximate the concentrations considered in these studies? Obviously, you can add a little or a lot of hibiscus to a cup of tea, and it would be helpful to have an idea of how much we are talking about for these recommendations regarding consumption limits. Thanks!

  • Luis

    So, the obvious question stands for bulk hibiscus drinkers: How much dried hibiscus do you put per cup of water? I seem to like a little less than 1/4 tsp hibiscus per 8oz water cup, but that might be too much! I also tried 1/8 tsp per 8oz water cup, but it is too diluted for my taste.

  • Chahna

    I forgot to ask how much hibiscus leaf is needed to make that quart of tea for daily use? Thank you.

  • JM

    One possible solution to the aluminum in the hibiscus conundrum is to add a bit of horsetail to the tea. It is full of silica which binds to and removes aluminum – big time! But do your own research because some sources say some or all people should not take horsetail because of possible side effects. Mike Adams seems to like it though, as do many other health practitioners – here’s Adam’s article –
    If you are concerned with having ingested aluminum then Adams and others claim taking horsetail is one way to remove it from your body. But you don’t want to take too much of this either — research it first and talk with a health practitioner.

  • noe

    Sorry but at the end of the video, I didnt understund how much Ibiscus tea is to much? a quarter of liter?
    at the moment we drink at least 1 liter a day..

  • NYC

    I started drinking hibiscus tea daily after watching the previous video on here. Unfortunately, I think it did more harm than good for me, I believe it created a deficiency of iron because of the high manganese content which competes with iron. I was on the lower end of iron already, but I believe this lowered it even further. Not good. I am going to get a blood test soon.

  • Em Crone

    Drink lots of different kinds of teas!

  • Lauren Bateman

    I just read through all the comments and questions, and have some partial answers I hope will help: Dr. Greger says in this 1 quart per day; that’s 1.1 liter = 2 pints = 32 oz. = 4 cups. I cut and measured contents of a teabag: 1 teaspoon; so, 4 teaspoons in that much water — then to cold steep — then filter out — is good.
    Anyone with compromised kidneys, to be safe, should avoid it.

    • Emmi

      If you heat it up loses antioxidant properties?

  • Sean MacLeod

    A quick note: I’m watching every single video. There are thousands of chunks of gold here. Watching all of these videos puts me in a better position health wise than going to dietitian school or med school – especially considering that doctors, nurses and dietitians are taught what the pharmaceutical industry wants them to “know.” Death and doubt are America’s two most commonly-bought commodities. That is, if you think early death is a commodity. Dr. Michael Greger, you deserve the Nobel Peace Prize, the Pullitzer, Oscar and Grammy. I love you.

  • Sean MacLeod

    Every time I watch a video, I shoot right over to

  • Sean MacLeod

    Amazon, I’ll take US dollars, thank you.

  • sf_jeff

    Manganese in grains?

    I was concerned because it turns out there seems to be a large number of different vegetarian sources of manganese. For example, 1/3 cup of barley has 60% of daily rdi, and there is a similar story with other grains and vegetables.

    Doing a little math, though, 60% really means 1.2 mg, so if you get three such sources per day, it seems well within the buffering capability indicated in this video. So, I am deciding not to worry. Agree?

    Example source:

    Manganese 1.19mg in .33 cups barley.

  • Cida

    As a breast cancer survivor, I am very careful about what I eat especially considering the estrogen activities of some foods. Hibiscus is one of them… On the other hand, I am wondering if the hibiscus tea is beneficial to breast cancer survivors ( for those whose tumor was estrogen +) or if it is at least safe to drink for these survivors.

    • Joseph Gonzales R.D.

      HI Cida. I do not see any human clinical trials on hibiscus tea and breast cancer. In vitro it’s been found to promote apoptosis in breast cancer cells. I think a cup or two is fine, but any more (Dr. Greger mentions drinking under 4 cups) could be problematic. Always good idea to check with your oncologist. Let me know if you’d like any more information about diet and survivorship. Thanks for commenting!

      Kind regards,

      • Emmi

        If you heat it up loses antioxidant properties? In Argentina we drink every tea hot. I wonder if heat changes the antioxidant levels.

        • Joseph Gonzales R.D.

          Good point, but I would think steeping tea brings out the potency. So boiling water and pouring over tea leaves or hibiscus petals is just fine. No need to sun brew or cold brew tea to my knowledge.

  • Youcef

    Long-term drinking of hisbiscus tea should be avoided, unless you have a very high intake of magnesium. Why is that?
    Having a poor magnesium status, a high intake of competing ions (like
    manganese), or both leads to a higher amount of dysplasic (abnormal)
    cells, and therefore a higher chance of cancer having cancer later in
    life [1]. Unfortunately, according to WHO, most populations, including the US are magnesium deficient [2]. How does it work?
    Very simple: All cell divisions need magnesium (Mg) in almost every step. When other ions, like manganese (Mn) are in high concentration, they serve as substitute ions instead of magnesium (the orthoplasic ion). [1]

    [1] CARCINOGENESIS – Mechanism and prevention (LA CARCINOGÉNÈSE Mécanisme et prévention) . p.133 -143 (only available in French for now)
    [2] Calcium and magnesium in drinking-water, Public health significance

  • S Slavin

    Not sure if anyone is checking these but would love if Joseph or some other NF staff can take a look.

    I started drinking Hibiscus lately (1000mg – tea bag has an amount on it – in 10-20oz of water) and I feel like I really feel the diuretic effect.

    How much is normal? I feel like within an hour of finishing a 10oz cup it just all comes right out, as if I haven’t used the bathroom all the day. How does Dr. Gregor work if he drinks HIbiscus all day?

  • S Slavin

    @Joseph Gonzales R.D.

    Not sure if anyone is checking these but would love if Joseph or some other NF staff can take a look.

    I started drinking Hibiscus lately (1000mg – tea bag has an amount on it – in 10-20oz of water) and I feel like I really feel the diuretic effect.

    How much is normal? I feel like within an hour of finishing a 10oz cup it just all comes right out, as if I haven’t used the bathroom all the day. How does Dr. Gregor work if he drinks HIbiscus all day?

  • noexitlovenow

    It may be important to realize that Hibiscus Tea is not your only source of Manganese. I am finding it difficult to stay below the recommended maximum just eating normal food. Brown rice has lots of manganese. Pumpkin seeds have lots of manganese. Oatmeal, my vegetable stew, great northern beans, and V8 vegetable juice also contribute among other sources in my diet. It all adds up. I’m seriously looking for an alternative to brown rice with less manganese, but all the whole grains and even sweet potatoes have a lot of manganese.

    • dafox

      Manganese toxicity resulting from foods alone has not been reported in humans, even though certain vegetarian diets could provide up to 20 mg/day of manganese.

      Food and Nutrition Board, Institute of Medicine. Manganese. Dietary reference intakes for vitamin A, vitamin K, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. Washington, D.C.: National Academy Press; 2001:394-419.
      Keen CL, Zidenberg-Cherr S. Manganese toxicity in humans and experimental animals. In: Klimis-Tavantzis DL, ed. Manganese in health and disease. Boca Raton: CRC Press, Inc; 1994:193-205.

    • Alan

      I personally think that we as a people looking for good health get a little carried away about things sometimes. If we eat a variety of fruits, veggies, nuts, seeds and grains – all in moderation with less of the nuts and seeds as the fruits, veggies and grain, i firmly believe we can stop worrying about how much manganese or aluminum or any other vitamin, mineral or what have you are in them. We need to eat in a quite environment without worry and with thankfulness.

  • Nice scientific reviews of tea and aluminum. Nice and hard work.

  • GG

    Is hibiscus tea safe during pregnancy? I’ve read some studies showing that it could possibly have some anti-fertility/abortive affects. Are there any studies done in humans regarding the safety of hibiscus tea during pregnancy? I know chamomile is probably not safe.

    Doctor Greger, have you ever considered making a series on pregnancy health? After all, the diseases of western civilization start in the womb, and pregnant women have special nutritional needs. For example, there are many healthy foods that should not be consumed during pregnancy, such as flax seed and chamomile. It would be excellent to have a convenient list of foods to avoid, and foods to include during pregnancy. Thank you.

  • NoExitLoveNow .

    Of course, we don’t only drink tea. Whole wheat and brown rice have a lot of manganese. Chia seeds and wild blueberries have a lot of manganese. My vegetable stew has a lot of manganese. It all adds up pretty quickly.

  • Steve

    I add rooibos with honeybush, chamomile, and artichoke teas to my evening habiscus tea.

  • Susie

    Just came across this and thought I would share it with other hibiscus fans…
    Hibiscus Flower Quesadillas

  • Priscila

    Dr. G, manganese competes with iron for its transport with transferrin in the blood. Won’t it compete with iron for its absorption in the gut as well?

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  • Kent Lang

    I get a lot of Manganese through Diet (Oatmeal, wheat germs, wholegrain bread and pasta, green tea)
    It’s around 20 mg/day.
    How bad is that? How do you reach you caloric needs without these products?