Doctor's Note

Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out theother “HHH” videos (Harmful, Harmless, or Helpful?). Also, there are over a thousand subjects covered in the rest of my videos–please feel free to explore them as well!

For some context, please check out my associated blog posts: Soymilk: shake it up! and Eating To Extend Our Lifespan.

  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other “HHH” videos (Harmful, Harmless, or Helpful?). Also, there are over a thousand subjects covered in the rest of my videos–please feel free to explore them as well!

  • evanbrand

    The work of dr matthias rath and, possibly, other sources, would suggest that vitamin C offers significant benefits..

    Second, is frozen fruit and, specifcally, frozen acai limited or void of nutritional benefit? If so, what can US residents do to get optimal acai?

    • Laurie K.

      Hello Evanbrand, yes, indeed you (and the others) are correct, vitamin C does have healthful benefits…if it’s obtained by eating whole foods. When you get your vitamin C from sources such as mangos, papayas, cantaloupes and yams, for example, you get other nutrients and antioxidants that are also vital for optimal health, like the beta carotene that is also abundant in these foods. The video discusses vitamin C from supplements, which can not only be a waste of money, but can be potentially detrimental to your health, particularly in large doses like vitamin A, see:http://nutritionfacts.org/videos/herbalife®-supplement-liver-toxicity/ There is also evidence that rather than protecting from disease, multivitamins can actually increase the risk of breast cancer: http://nutritionfacts.org/videos/multivitamin-supplements-and-breast-cancer/ Also, I wouldn’t put so much emphasis on one particular “superfood”, because there are many others that contribute to longevity, like cocoa (but of course without the milk and sugar that many folks tend to add for palatability), see: http://nutritionfacts.org/videos/kuna-indian-secret/ and: http://nutritionfacts.org/videos/new-antioxidant-superstars-2/. If you want to include acai in your diet, no need to concern yourself with the freezing process, it has very little (if any) impact on the quality and/or amount of antioxidants it contains. You should make every effort to eat a widely varied, plant based diet to ensure that you get as many phytonutrients as possible. It’s also very economical to eat this way, see: http://nutritionfacts.org/videos/superfood-bargains-2/ Have a wonder, healthy holiday!

  • mjordana

    Hmm, I think Dr Greger is being entirely too dismissive of the powers of Vitamin C in convenient supplement form. Just note that in the antioxidant study he draws on for many of his videos, namely The total antioxidant content of more than 3100 foods, beverages, spices, herbs, and supplements used worldwide, Vitamin C (specifically, CVS Vitamin C (as ascorbic acid), 500 mg) has 1,019.69 mmol/100g of antioxidant content. Compare this with the paltry 261.53 mmol/100g of antioxidant content of powdered amla (Indian gooseberries) which he lauds so much. Almost 4 times more! I rest my case.

  • GC

    Hi Dr. Greger. I am currently taking D-Mannose for “IC-Like” symptoms (mainly urinary retention/trouble emptying). I was going to take Glucosamine in addition, but I was advised to take high doses of Vitamin C instead to help repair the bladder wall. What do you think?

    • DrDons

      As always it is important to get the diagnosis right. Many common problems with bladder function reflect difficulties with muscle, hormones, lifestyle and aging. Others seem to be inflammatory and involve the bladder itself. Bladder Pain Syndrome of which Interstitial Cystitis(IC) is a subcategory is a poorly understood group of conditions of unknown cause which are difficult to treat. As a primary care physician I have had several patients plus one relative with the diagnosis of IC. I think it is best to find a physician who is experienced with treating patients with IC and who uses evidence based therapies. From my experience foods seem to have a significant effect on many bladder conditions but it can be hard to figure out. I think keeping a food diary is important to see if you can relate certain foods to improvement or aggravation of symptoms. If the problem seems to be one of the inflammatory conditions such as IC it would seem reasonable to follow a plant based diet with an emphasis on foods that improve the immune function and emphasize antiinflammatory over inflammatory foods while avoiding substances such as caffeine and alcohol which can have a detrimental effect. I would view the videos under the appropriate links. These include videos on the importance of a variety of plant foods in decreasing inflammation see… http://nutritionfacts.org/video/garden-variety-anti-inflammation/ or the importance of avoiding meat to minimizing inflammation see http://nutritionfacts.org/video/inflammatory-remarks-about-arachidonic-acid/. Lifestyle issues such as sleep see… http://nutritionfacts.org/video/sleep-immunity/ and exercise seem to help. I would only try isolated nutrients or therapies that have been supported in the literature and would discontinue them if after a fair trial they don’t seem to help. It is very important to work with your physicians to help sort all this out. Good luck.

      • GC

        Thanks, DrDons! I’m 25 and I’ve been plant-based for almost a year now, getting plenty of leafy greens, superfoods, and avoiding processed foods. I avoid alcohol since I know all too well that it makes it worse. I had all those unpleasant tests performed when I was younger and they could not find anything, but sent me for biofeedback, anyway, and prescribed Detrol. The biofeedback didn’t do anything but the Detrol helped a tiny bit (not enough to keep taking it, and I also did not like the ingredients in the drug). I’ve tried many others things including naturopathic medicine, diet modifications, bodywork, rebirthing, energy healing, and acupuncture. The only thing that helps is holistic Chiropractic, but only if I get adjusted at least twice a week, and still it does not provide the relief I am looking for. Rebirthing/Breathwork also helped once, it was the only relief I’ve had in YEARS, but then it stopped. I have noticed that it is worse if I am angry, anxious, or emotionally irritated about something, so I try to stay calm. I read that “pockets” can form in the bladder wall and trap bacteria (but does not show up on tests), which can lead to IC-like and UTI-like symptoms including urinary retention, and women suffering from the same thing suggested D-Mannose. I’m going to try it for a few months and see if I notice a difference.

  • dfdf

    is it good to take vitamin c as pills

    • http://www.paid4shop.com John

      Better absorbtion has better result. If it can’t be absorbed it waste the money. Recommend you use the isotonix one. Check istonix here:http://betterresultnutrition.com/

  • Michael Dean

    Just because vitamin C didn’t prove beneficial for things like lifespan, cancer or heart attack risk? Its possible that it could assist with the flu, common cold, athletic performance, mood or a multitude of other factors that the study didn’t address. It might not be a waste of money after all.

    • Toxins

      “Vitamin C is used as a dietary supplement because of its antioxidant activity, although a high dose (500 mg) may act as a pro-oxidant in the body1, 2. Here we show that 100 g of fresh apples has an antioxidant activity equivalent to 1,500 mg of vitamin C, and that whole-apple extracts inhibit the growth of colon- and liver- cancer cells in vitro in a dose-dependent manner. Our results indicate that natural antioxidants from fresh fruit could be more effective than a dietary supplement.”
      http://www.ncbi.nlm.nih.gov/pubmed/10879522

      • Michael Dean

        “May act as a pro-oxidant”

  • katieorourke

    this is one of the most misleading statements I have ever heard…a waste of money….where’s the evidence….what studies….who else is in agreement with this one study ??????

  • katieorourke

    What about new research just published that found vitamin c warded off stroke ???

    • Toxins

      I have not seen the study, but vitamin c is may be a marker of how much fruits and vegetables consumed, not necessarily how much vitamin c you isolated then consumed.

      “Vitamin C is used as a dietary supplement because of its antioxidant activity, although a high dose (500 mg) may act as a pro-oxidant in the body1, 2. Here we show that 100 g of fresh apples has an antioxidant activity equivalent to 1,500 mg of vitamin C, and that whole-apple extracts inhibit the growth of colon- and liver- cancer cells in vitro in a dose-dependent manner. Our results indicate that natural antioxidants from fresh fruit could be more effective than a dietary supplement.”
      http://www.ncbi.nlm.nih.gov/pubmed/10879522

      • katieorourke

        vitamin c supplements do not contain pesticide which is found on fruits and vegetables, unless you can afford to buy organic…Also vitamin C leaves the body within 12 hours, and your body rids itself of any amount it does not need. That’s why unless you take a time released capsule it is recommended that you take it every 12 hours to ensure round the clock levels..it does not accumulate in your body and any excess is rid through urinating.

        • Toxins

          Taking a supplement does not replace a whole food, and it will never be the case. I know of no studies showing vitamin c to be more protective then regular fruit and vegetable consumption. Again, I shared with you the above study showing that the whole is greater then the sum of its parts. I know of no reason to supplement vitamin c when a plant based diet can supply mass quantities of this single nutrient. When studies show no benefit or worse, I tend to open my eyes and follow the trail of evidence.

  • Peter

    What do you think of Liposomal C? I have experienced great benefits myself from taking it. I didn’t experience any benefits of taking “normal” vitamin c pills (although I didn’t try mega doses). There is even some research indicating that liposomal c kills cancer (http://knowledgeofhealth.com/researchers-achieve-cancer-killing-effect-with-oral-dose-vitamin-c/). What do you think?