 How does the food you eat contribute to your health? Do supplements help prevent disease? For the past 25 years, the Linus Polling Institute has served as a world-renowned research center at Oregon State University. Our mission is to promote optimal health through cutting-edge nutrition research and trusted public outreach. We use a synergistic strategy connecting several scientific fields to bring a better understanding to dietary components and the role that they play in obtaining optimal health. We provide that information to the world, allowing people everywhere to live longer, better lives. Welcome to the Linus Polling Institute's webinar series. Everyone, I'm sorry if that intro of music did not play correctly, but welcome to the Linus Polling Institute's webinar series. This is Galvanizing Your Health Why You Need Zinc webinar by our own resident expert on the subject, Dr. Emily Ho. Also known as the director of the Linus Polling Institute. I am Alexander Michaels. I'm your moderator for this webinar this afternoon, or morning slash afternoon, depending on where you are in the world. And I'm also the communications officer for the institute. And I will be handling the Q&A session later today. It's my great pleasure to be here and bring you this final webinar of the Linus Polling Institute's 2022 webinar series. We're already working on our webinar series for next year, so don't worry, we'll be back. And we'll probably start again in February with our Linus Polling Day webinar, which we will be announcing soon. But today I'd like to focus on the webinar on zinc and this is just going to go like many other webinars in our series. Dr. Ho will be coming on shortly and she will talk for about, you know, 25 minutes, 30 minutes in a presentation. And then we're going to switch to a Q&A session, which will take up the remainder of the hour. We hope to finish around noon Pacific time. And any questions that we don't get to during that time, we'll just address in future publications like our research newsletter. I wanted to quickly, before I start bringing Dr. Ho on and, you know, because the Q&A will come up relatively soon. If at any point during Dr. Ho's presentation, you do have a question, certainly put it into the Q&A button down at the bottom of your screen and we'll try to get to as many questions as we possibly can. I'll let you know that there are 850 people registered for today's webinar and I think we received over 400 questions in advance. So that will limit the number of questions that we can get to today. Okay, so Emily, would you like to turn your camera on? As I already said, our speaker today is Dr. Emily Ho. Dr. Ho presented at the end of our webinar series last year and the year before. And so I don't think I need to go into a complete biography of her career and, you know, her history with the Institute. But I'll sum up a little bit. As you recall, Dr. Ho's research falls into two big buckets. One of them is the cruciferous vegetables bucket and the other one is the galvanized metal bucket, the zinc bucket. And so today we're going to focus on her zinc work. Her interest in zinc started with Dr. Tammy Bray at the Ohio State University. If I remember that correctly, it was working in diabetes. Type 1 diabetes, is that right? She then went to UC Berkeley as a post-doctoral trainee. At UC Berkeley, she trained under the legendary Dr. Bruce Ames at Corey, the Children's Hospital Oakland Research Institute. And it was in Dr. Ames' lab where she started to investigate zinc more carefully. And it's looking at its role in cancer. And I'm sure she looked at its role in DNA damage, because that's what Dr. Ames loved to do. And she continued to work on cancer and immune function. And she joined the Linus Pauling Institute in 2003. I remember actually sitting in her job talk in 2003 as a graduate student and being interested in the zinc angle, especially. Almost 20 years later, Dr. Ho is one of the nation's leaders in zinc research. She's received an outstanding researcher in vitamins and minerals award from the American Society of Nutrition and has published over 100 peer-reviewed articles in this area and continues to publish, as I was just looking at some of her articles from earlier this year. And in our latest newsletter, there will be an article from the Ho Lab on zinc. So thank you, Emily, for agreeing to talk to us today about zinc. And without further introduction, the floor is all yours. Oh, she can't unmute. There we go. All right. Now we can hear you now. You hear me now? Yep. And see me now as well. Yep. You ready to go. Okay, perfect. Well, thank you all for being here. Good morning. Good afternoon. Good evening, depending on where you are. I'm really excited to share this time with you and talk to you a little bit about some of the research that we're doing, not only at the Lions Polling Institute, but specifically in my lab as well. We see if I can get this to advance. So as, as you all know, you know, at the Institute, all of our researchers include myself, really strive to help discover and enable individuals and communities to tip the balance towards optimal health. I'm going to talk to you about some of my research. Specifically. And as Alex had mentioned, kind of the joke of my lab with my students is whether or not they're team broccoli or team zinc. Last year, I talked to you about some of the team broccoli work that we do. And today I'm going to talk to you about team zinc. A bit more. So before we get kind of into things, let's talk about what is zinc. So zinc is, you know, an essential mineral or a metal. So it's an inorganic compound that you'll find on the periodic table. If you remember this from your chemistry, high school classes. It's most similar to nutrients like copper shown here. And hence there's some interactions with copper that I'll talk about. You'll also notice it's in this middle section of the periodic table. This is a group of metals that are called transition elements. A lot of these transition elements like iron, which is another essential nutrient transition in that they have, they give up or gain electrons. And think it's a little bit unique in that it is a transition element in terms of where it fits on the periodic chart. But it is a transition element. It's a transition element in terms of where it fits on the periodic chart. But it doesn't transition. So zinc state does not gain or accept electrons. It stays in a plus two state all the time, unlike copper and iron that transition between a, either a plus one or plus two or plus two plus three states. And this unique chemistry of zinc really affords it some unique properties in terms of our human health. And in particular, the lack of transiting, it really acts as a strong, a stabilizing factor within our bodies and within ourselves. And the stability works in a bunch of different ways. So one of the stabilizing things. So again, the title of this talk is galvanizing your health. And this is exactly what zinc does. It happens to again, because of the stability, it's able to act as a pretty potent antioxidant. And the way that they, and the way that they it does this is because of that lack of redox activity so it's able to stabilize and help prevent things from getting oxidized and that's exactly what this photo is showing in terms of galvanized steel basically by layering zinc over iron you prevent that iron from being oxidized so in very simple terms that's what zinc is also doing within our bodies helping prevent our cellular macromolecules and ourselves from oxidizing and rusting and ultimately losing function. The reach that zinc has in terms of function is multifactorial. Zinc is a part of over 300 different enzymes within the body it's associated with an additional thousand different proteins and especially transcription factors and zinc helps them do their job so zinc is important in a whole host of systems within our bodies and within the cells so at the cellular level any cell that needs to divide or metabolize needs zinc for cells to talk to each other they need zinc. At the functional level the systems that tend to need rapid growth or rapid cell metabolism tend to be the systems that rely more heavily on zinc so things like our reproductive systems in our brain and our nervous system and in our wound healing is another process that zinc is very important in and I'm going to focus a little bit on and if you were at my webinar I guess two years ago I focused quite a bit on the immune system and I'm going to re-talk about that and in particular another system that zinc is very important is in terms of our cellular protection and our cellular repair mechanisms as well so I'm going to go over that but there's lots of reasons why we need zinc but I'm going to focus a lot on these these bottom two areas in particular for for today so first question is you know how much zinc do we need so currently the recommended dietary allowances are the RDA for zinc for an adult if you're a male it's about 11 milligrams if you're female it's a little bit less at eight milligrams per day where do we get our zinc we can get it from a lot of different foods and we are going to test out Alex I don't know if you can help share a poll just you hopefully can see this poll is up people are answering so which foods have the most zinc just curious if what we know we got about 40 of the people answering so far still answers streaming in just a quick test of your knowledge all right look at the last few moments and I don't know Alex are you able to yeah we're doing pretty good actually or almost 75 percent of everybody has responded great okay we're gonna call it in five four three two one hey they got it Emily all right you guys are on it so foods that oh okay great so yes of this list crab it was was the highest a lot of seafoods do have high amounts of zinc the bottom line I don't know I'm gonna can you close that yes all right so it's moving again let me see my slides are moving so good sources of zinc so one kind of general rule when it comes to zinc is that it tends to follow protein so there's very little free zinc in in our bodies and that includes in our food sources as well and where zinc often resides in cells are as part of these enzymes or protein so protein rich foods do tend to have more more zinc things like lean meats seafoods but also vegetarian sources so from vegetarian sources or plant-based sources the the the foods that tend to be more protein rich tend to have have more more zinc one caution that you have though in terms of if for example you're a vegetarian most of the plant-based sources plant-based sources that have quite a bit of zinc also tend to have another compound called phytate this phytate long chemical name is an acetyltol triphosphate it's a very negatively charged compound so it tends to bind two plus things like zinc so it's estimated that so even though these whole grain for example nuts and legumes contain quite a bit of zinc you will only absorb about 50 a portion of it so it's estimated that you need to increase your zinc intake by close to 50 to be able to absorb the same net amount because of that phytate so if you're aiming if you're a woman for example if you're aiming to get a lot sorry eight milligrams of zinc that you would actually need to consume 12 milligrams to get the net eight if you're a vegetarian in terms of highest amount of zinc pictured here are oysters oysters almost have a log full higher amount of zinc than some other so for example beef a serving of beef has about six milligrams of zinc whereas a serving a three ounce serving of oysters has close to 30 milligrams of zinc so you get quite a bit just from a single serving of oysters if you're worried about your zinc so why are we talking about zinc I feel like zinc sometimes flies under the radar in terms of a nutrient that you should be thinking about but you should be thinking about it the world health organization estimates a zinc deficiency it affects about one-third of the population developing countries are often the hardest hit but even in developed countries like the U.S. zinc deficiency is an issue it's estimated about 12% of the population does not consume the EAR for zinc so that's the lower amount not the RDA not the 11 or 10 milligrams so a significant portion of the population is not getting enough zinc if you're over the age of 55 that number goes up to close to 40% that aren't consuming enough zinc so I'll talk a little bit about older adults in a moment and one of the bane of our existence and one of the reasons why zinc often does kind of fly under the radar is that we don't have a great test or marker that's either sensitive or reliable for human zinc deficiency and I'll talk a little bit more about that as well but the bottom line is that the prevalence of zinc deficiencies is likely very much under reported because of this lack of of a biomarker it also causes a lot of confusion in terms of supplementation trials so in a lot of the supplementation trials there are a lot of yes no maybe answers and a lot of that is because we don't have a good biomarker and we don't know if you take a zinc supplement if you're actually repleting someone back to what they should be or if they're already okay and supplementing that has a very different response and we literally don't know necessarily where we're starting with in a lot of these supplementation trials so I'll talk about that later so why do you need zinc let's talk a little bit about what happens when you become zinc deficient so I mentioned that zinc is a potent antioxidant and it is for many different reasons and this is work that I actually started in Dr. Ayn's lab is just ask the question when you take away zinc what happens and the bottom line is when you take away zinc lots of things start to go wrong this is an assay for oxidants and when we this is in a culture system when we fed the cells a low zinc diet through their media we immediately saw that the zinc deficient cells had a lot more reactive oxygen species this also results in increased damage to the cell so what this assay is it's it's nicknamed the comet assay because the comets show DNA damage basically you're assessing strand breaks and when you're when you have lots of strand breaks the the cells start to look like this this comet and you can see here that the cells that are zinc deficient not only have lots of oxygen stress but have lots of damage so our cells get damaged all the time but we also have repair mechanisms that help coordinate the response to to deal with oxygen stress and damage as well and one of those proteins that does this is this protein called p53 p53 is a transcription factor you can see here that this is a western blot and the bigger blobs means that there's more of the protein and that's the normal response in response to damage for example p53 up regulates and it coordinates a whole host of responses to help deal with that damage and it does that through transcription so this is an example of p53 the the red dot is the zinc in it and how p53 works it needs to be able to bind to DNA and then tells the DNA to turn on and and then turn on all the transcription and the proteins that are important and things like like DNA repair and what we found is despite seeing increased protein levels so there's more of the protein the p53 there that it's not functioning properly and that the the p53 oh looks like my gel is not there uh isn't binding to the DNA so it's it's being produced in response to DNA but it's not functioning properly so this ends up being quite the double whammy in terms of DNA damage which is one of the important factors in terms of cancer progression increased DNA damage is is going to increase your cancer risk so when your cells don't get enough zinc again what happens as you have increased oxygen stress increases in and DNA damage that DNA damage should signal a whole host of other systems to help repair and deal with that damage but in the context of this deficiency those systems are also impaired so you're creating conditions where not only are you creating more damage but also the ability to deal and repair with that damage so the net effect is a decrease in DNA repair and the net effect is way more damage again this is going to potentially increase your risk for for cancer down the road so again we are susceptible to stresses all the time so we want to ask the question um when does this happen in vivo in terms of susceptibility to increased DNA damage and what also happens if you add on additional oxidative stress so we did a study in animals um we have here at OSU a very strong kinesiology department as well and what we decided to do is look at the interaction between diet and exercise so we took animals and we fed them either a zinc adequate or a marginally zinc deficient diet which is the mzd as well and then we also looked at the impact of exercise so in this model what we did was voluntary wheel running in terms of our potential or ox potential oxidant source oxidative stress source using exercise I do want to note though so in this model again it's voluntary wheel running where we put a wheel into the the the cages of of the animals similar to people in terms of rodents there are couch potato couch potato rodents and also ultramarathon loving animals as well and these sprag dolly rats happen to be running lover animals so I know you know many of you at home may have your voluntary treadmill in your homes that you may or may not use these animals love to run under treadmills so on average so these wheels have a wheel counts these guys are running close to 5k each night so you know think little legs 5k they're running a lot so this is a model of high intense pretty vigorous exercise the amount of oxidant stress that they are exposed to is fairly high the other thing I want to mention is that my lab has done historically a lot of work in prostate cancer as well and zinc does have a unique interaction in terms of the prostate the prostate is actually one of the tissues that contains the highest amount of zinc at least of the soft tissues bone is a tissue that contains more zinc but of all the soft tissues the prostate contains the highest amount the prostate also has several different areas in it and the area called the peripheral zone is the zinc accumulating region of the prostate and not all the other regions of the prostate accumulate zinc what's interesting is that the zinc accumulating section of the prostate is also typically where prostate cancer happens as well and the last fact is we also know that as cancer develops there seems to be a dose dependent decrease in zinc levels in that region of the prostate so the nastier the tumor the lower the the zinc level is so this is just an example of the prostate so again there's several zones and this peripheral zone is again the zone that tends to develop prostate cancer and on the chart here you can see you know our blood plasma has about 15 nanoliskogram other soft tissues are about 200 and you can see that peripheral zone has over 10 times the concentration of zinc in that again this is the zone that prostate cancer tends to develop and you can see it drops pretty significantly as the as the as cancer develops so getting back to our study what we found kind of really interestingly is this was not a prostate cancer study at all we simply were looking at the interaction between exercise and zinc status and one of the first things that we noticed is that the prostate was highly sensitive to loss of zinc when you are not when you're not consuming enough zinc so these are zinc levels so here's the plasma on the left are the zinc adequate on the right are the animals that receive the low zinc diet and you can see in their plasma levels start to decrease but what's interesting of all the tissues again just feeding a low zinc diet the prostate saw a significant loss in particular in this dorsal lateral lobe so the in rats the names of the zones are a little bit different but that this dorsal lateral lobe is equivalent to that peripheral zone so again that area that tends to accumulate zinc and it also seems to lose zinc very specifically when you're fed when you're not eating enough and here is another zone the zinc and you can see that the the ventral lobe does not lose it think you can also see there's quite a bit more zinc in the in the that peripheral zone as well so what is happening functionally so we assessed oxidative damage in these animals as well so here again is looking at that dorsal lateral lobe that again is the prostate cancer susceptible lobe and the bottom line is so when I look at zinc adequate to zinc deficient at least in the animals that are not exercising there actually was not much change in DNA damage similarly if I compare a zinc adequate animal sedentary versus exercise there isn't much change however if I combine the two we now start to see a pretty significant increase in that in DNA damage saying that you know normally in just exercise you're able to not have damage even with the stress of zinc deficiency by itself you're able to potentially repair and deal with that damage however if you have both simultaneously you override the system or you overwhelm the system and now you're increasing DNA damage possibly by limiting those DNA repair mechanisms what's interesting if I look at the ventral lobe which again is the lobe that isn't losing the zinc in response to the low diet but also is not the lobe that is susceptible to cancer that we see no changes across the board so deficiency or exercise alone and did not change DNA damage but however a combination did as well which ultimately says maintaining adequate zinc status especially if you're exposed or stressed due to exercise or potentially any other stress that causes oxidation that you really need to make sure that you are maintaining adequate zinc status and this could have an impact on cancer risk and I'll talk next about the other system that also has high susceptibility to damage our immune cells so what populations are going to be most susceptible to zinc deficiency so I mentioned before in the US and in many other countries if you're over the age of 55 you tend to consume less zinc so 40% of both men and women do not get enough to think older adults do not get enough zinc in their diets another unique thing that we see is as you age your ability to utilize zinc is not as efficient as a young person so you tend to have lower zinc status even if you are consuming potentially enough zinc due to changes potentially in absorption and or distribution so you have very much again a double whammy in terms of susceptibility to zinc deficiency as you age and what are the consequences so we know that aging is associated with a compromised immune system and it's possible that that compromised immune system could be related to compromised zinc status as well if I superimpose impact of zinc deficiency on the immune system with age-related dysfunction with the immune system they're very very very similar in that you see things like increased susceptibility to infectious disease reduced vaccine efficacy so you have a blunting of some arms of the immune system but we also have overactivity with both aging and zinc deficiency in terms of our inflammatory state and you have increased chronic inflammation as well both with zinc deficiency and age we know that the immune system is highly complex in terms of multiple parts there's our barrier function our native immunity which is things like our neutrophils and our macrophages that help invade engulf and destroy and then we also have a required system which are things like our T cells and our B cells that help produce systems to target foreign viruses and bacteria and the bottom line is zinc is really needed for for all of these functions so we've done some studies in older animals as well so this is a study where we took young which are about two months old animals which are considered to be a young adult versus almost two-year-old mice which is more like over 65-year-old and we found that the first thing is despite giving these animals what we think is a zinc adequate diet so this is the AIN93M diet that these animals still kind of look like they're zinc deficient so their plasma zinc levels are falling and they look like they're just deficient even though we think we're giving them enough we also see a market increase in inflammation so this is a marker called interleukin 6 that's a pro-inflammatory marker and the older animals have significantly higher amounts of inflammation what's interesting is that if we supplement zinc that we're able to you know restore zinc levels and the older animals close to that of the young animals but importantly restoring the zinc levels also mitigated the inflammation so we saw a really big change in terms of inflammatory status a result of correcting the zinc levels so the correcting the zinc levels also corrected the immune dysfunction and helped prevent inflammation so hopefully by now I've convinced you that getting enough zinc is important and as I talked about before you would think that this would be a standard thing that our physicians would look for in terms of of your status since it's such a critical part of your immune function, cancer susceptibility and many other systems unfortunately we do not have a great biomarker for zinc deficiency currently the test that your doctor will order if they are interested in zinc is a fasting plasma zinc level and I'm going to show you some data from from my lab where we did a human study where we looked at modulating zinc status in in this case adult men so the men came in there was a kind of acclimation period for almost two weeks where we put them on a zinc adequate diet containing that 11 milligrams and then we put them on a low zinc diet about four milligrams of zinc per day for about six weeks and then after that time we also did a repletion where they we fed them back a little bit of a zinc supplement and also gave them an adequate amount of zinc and looked at the effects and the first thing I want to show you is this is the plasma zinc levels and what do you notice they're pretty well all the same so these are people for over a month are eating a low zinc diet so we know they are at risk for zinc deficiency yet the biomarker that is currently used in the clinic doesn't change so clearly this is not a sensitive marker for for zinc deficiency and likely misses if you're using this as a test it's going to it's going to miss a lot of potential cases of potential zinc deficiency and the reason why that missing is a problem is when we look at functional changes so even though the the test that's using the clinic says you're not zinc deficient you are and there are some things are starting to go wrong so in this case we use that same common assay and you can see starting in the grain this is the beginning of the depletion period there is a steady increase in DNA damage throughout the study period good news once we replete the individuals we are able to reverse the so the problem isn't is absolutely reversible and can be easily rectified just by giving back enough zinc the other thing that I want to point out though is this is the other thing that we saw at this baseline period a significant drop in in DNA damage and the reason why I bring this up is we attempted to recruit people that were not zinc deficient unfortunately what did we probably use what would we use as our screener is plasma zinc levels so what we think is happening in this baseline period of study is that we likely had a lot of individuals that that were at least marginally zinc deficient and basically during that two-week acclimation period we were able to replete them and help fix some of their DNA damage so there's a lot of new research in terms of trying to including in my lab trying to identify better biomarkers but the bottom line is getting enough zinc is going to be highly important again because there isn't a great test it's really up to to you to to make sure that you're consuming enough zinc so again currently there are recommendations the RDA if you're a man 11 milligrams if you're a woman 8 milligrams this is important for your immune system but many other functions within in your body you may especially if you're an old adult old or adult want to consider taking a zinc supplement but there is a bit of a caution and you can get too much of a good thing so zinc by itself is actually fairly non-toxic however if you consume too much zinc it can interfere with other minerals especially that copper that I told you was similar in terms of properties and if you take too much zinc you will limit your body's ability to absorb copper and copper deficiency also has impacts on your immune system oxen stress and that type of thing as well so the current upper limit for zinc per day is is 40 milligrams per day so you may want to consider if you do consider a zinc supplement to make sure that you're not consuming over 40 milligrams per day to limit the the interactions especially with copper and and with iron so the bottom line is you need to make sure that you're getting adequate zinc daily that's both through foods and with supplements you can again take extra zinc as a supplement but be careful in terms of of your levels that you again can get too much of a good thing and have problems with excess zinc as well and to to be mindful of that as well the bottom line is you know what we do at the institute is to help you live better longer and zinc is certainly one of the things that that you should consider and take note of in terms of helping your overall health and healthy aging before I open up for questions I do want to point out at the institute we have this fabulous resort the micronutrient information center we have articles on zinc itself we also talk about zinc and some other immune fighting or boosting or achieving nutrients in these two articles here and then we also have a more recent article in terms of other nutritional strategies to help your immune system if you're interested in that again last time when I talked about zinc I talked a little bit more in depth in terms of immunity as well so if you want to check out that webinar it's also on the website so again just encourage you to in this time I'm only able to kind of really do a brief overview if you want to dig in check out the micronutrient information center we also have newsletters there will be a zinc article in the next newsletter as well and there's lots of other resources on our website for for you to check out so with that we'll open up for Q&A hey um okay um yeah so uh thank you Emily for for giving that presentation I uh every time I hear you talk about zinc I immediately want to run out and get some oysters somewhere I know some people are probably thinking but uh I love oysters so uh that's one of my favorite ways to get zinc um so in a moment we're going to move on to the Q&A section I see that people are typing questions in and have been doing so since the beginning of the talk um and as I'm speaking you know go ahead and add more questions to that Q&A section we'll try to get to as many as we can um I wanted to mention though at this point that uh the Linus Pauling Institute uh complements some of these webinars with additional information that we put into our newsletter uh the research newsletter that's our recent edition of the news newsletter is going to be coming out sometime this month it's it's kind of on its way to printing at the moment so you'll be getting it in your inboxes fairly uh fairly soon in the next couple weeks but we usually take the extra questions that you didn't get answered in these webinars and and get Emily's answers and put them into our newsletter and sometimes we create extra materials related to the uh webinars so look there for follow-ups things that you didn't get answered today um and and in our our most recent newsletter the one that's coming out soon uh we actually have some Q&A from our previous webinar on Vitamin E with Dr. Mara Traver so you can check that out uh when it comes out in uh in your inbox or mailbox depending on what you signed up for if you haven't signed up for the newsletter you can do so on our website and we'll be sending out links for that as a follow-up to this webinar um if you appreciate the webinars newsletters or other information that we provide to the institute we ask that you please consider a donation to our research and outreach programs these programs are primarily funded through donations or generous giving from our followers so without your support we wouldn't be able to bring you these programs that we do on a regular basis and we'll continue to do uh in the coming year um so you'll lend us your support in any way that you can um and i'm going to put that link to giving uh just so everybody has it into the chat right now but uh obviously i will send it to you otherwise as well as well as some of the links that Emily uh put in some of her slides including uh directions to get to the micronutrient information center where we have a lot of our information on zinc and the immune system okay switching gears it's time uh through the q and a um so some quick ground rules the the lines Pauling Institute is not a medical institution so we don't answer questions on per personal medical health conditions uh so we try to get very general uh with um in terms of the medical conditions general information on health and nutrition uh but we will obviously dig into some of the specifics around zinc um and if i like i said a couple times already if um we don't get your question today we'll try to get to in future installments of our newsletter so um with that i think the first question i want to ask you Emily is about um um i mean we you talked about food sources of zinc um is there any consideration about like different food sources and whether or not it's it's going to be an adequate source i mean uh meat tends to be a decent source but uh what about let's let's start with the vegetarian diets you know who if you're a vegetarian or a vegan where is the the best place for you to get your sink yeah that's a great question as i've mentioned um the vegetarian sources of zinc like things like lentils seeds um they have two to three milligrams of zinc per per serving so that's usually a tablespoon a couple tablespoons of those but the issue is those foods also have what are called anti-nutrients in them things like phytates there's another compound oxalates that that bind up the zinc so what happens there is when you consume those foods a complex forms in in your stomach and in your your gi tract that limits that makes it bigger so now you can't absorb the zinc as as well and it's not a total block but i think i mentioned um it's estimated that you would need to increase your zinc total zinc intake by about 50 percent to account for that block and that's not something that you see for example on a food label in terms of your your daily value so if you're exclusively vegetarian um that you might want to consume that one you need to consume more zinc but two that again for insurance you might want to consider taking a multivitam multimineral um that has zinc the other thing that i want to point out um if you're looking at a multivitam multimineral um zinc is one that is often left off the table on in terms of some multivitam multivitam it does have a adverse taste uh sometimes to some people so um definitely look at your your supplement label um in terms of zinc content just because it says it's a multimineral doesn't necessarily meet me uh that doesn't necessarily have zinc or it could be a very low amount of zinc i definitely want to ask you some questions about the the supplements and there's a few that are are in the chat and in our list right now but staying with food so um the phytates or the other anti nutrients that like oxalate can you think of that as more like a almost like a imperfect coating around the zinc that that prevents some of it from getting absorbed and just passing through or um there's there's there's ways to handle those though in terms of food prep if i remember correctly yeah so um if the phytate or oxalate binds with the zinc um it's that's a covalent bond so you can okay um but there are strategies to help minimize the phytate um so there are enzymes um that phytase enzymes but cooking um some cooking preparations will help limit uh so fermentation uh for example i think that will help break down the phytate so the phytate content basically will the phytate won't bind to the zinc um as as efficiently but none of even if you cook it um you'll decrease it but you won't totally get rid of it okay so eliminate some you know limit limit the problem you know um but still there's probably an increased need for additional sources of zinc uh based on just numbers yeah yeah getting the getting the right numbers um so um i guess i'll transition there into the zinc biomarkers actually um you know a lot of people have asked about like how do i know if i'm getting enough zinc um because obviously the combination of the food sources you eat there's some uncertainty of how much you're getting there you've got as you mentioned the um variation absorption and so obviously people would turn to blood for from for measuring this but that as you said isn't the best place to go is there any other indicators i mean um we had a question in the in the chat that about like white streaks on nails is that an indicator of zinc deficiency or are there other ways that you can tell so um for a lot of nutrients the biomarker that you're going to try to use is measuring the the nutrient in different things yeah people looked at plasma red blood cells um you've looked people have tried to look at hair and nail zinc as well um all of them seem to be not terribly sensitive um hair and uh and nail zinc so the if you become just uh zinc deficient the your collagen synthesis and uh your just cell synthesis is is depleted so you get brittle nails you can get those like uh it was mentioned those white streaks you have to be you're fairly deficient though um once those symptoms show so it's not a that that is not an early ultimately we want a biomarker to find things early before problems really start to happen and if you see those defects in your nails or changes in your hair and and nails because those are not rapidly turning over systems that largely means that you've probably been deficient or look for for a while sure um there's been a lot of work on the research side in terms of identifying better blood based biomarkers um so uh metallophenene which is a small molecular protein that sensitive to zinc has been postulated to be used um there's a a paper uh like one of my collaborators Janet King that has been looking at metabolites um especially fatty acid metabolites that may be a better biomarker the issue with those biomarkers is one there isn't standardization yet so there isn't a number um you can see compared to someone who isn't getting who is getting zinc that the levels are different but it's not like we have a value a target value right right yeah and that's kind of where where the research needs to go in terms of something that people can do now though um is you know getting a dietary assessment in terms of looking at uh their food intake um in terms of uh what they're normally eating and getting an estimate of how much that is and then adding on to that supplements perhaps is is is one way it's kind of rude but yeah the and I was going to mention when you we talked about hair and nails obviously that's a very nonspecific uh deficiency symptom so you know you can get white streaks and your nails for a variety of reasons and you know strange things happening with your hair for multiple vitamin and mineral deficiencies so obviously don't use that as a great indicator um when it comes to uh getting the rda though I mean um is is there some indication that maybe more than the rda would be I mean especially you know you we've mentioned a couple times already about the anti-nutrients or the little fight date you know it could argue that and then with aging um as you get older is it could argue that maybe you want to get a little bit higher than the rda but we do we have any idea of how much more um or is it just kind of a little bit of a hand waving there's definitely a little bit of hand waving I'm certainly an advocate in terms of trying to increase the the rda especially for for older adults yeah certainly the rda for zinc is the same if you're 18 or if you're 90 and given the the research that that's out there it suggests that as you age especially getting in the last decades of your life that you might need more because you're not going to be able to utilize as as much I think certainly I mean right now there's calcium and vitamin d are really the only nutrients that have age specific rda's and I think there's other ones that including zinc that need to be considered um I still do think though that that you have to be mindful even if you want to increase um I mean I uh I do tell my mom to take 20 to 25 uh level of zinc um but you can get you know 50 100 milligrams zinc supplements out there as well and I would still advocate for staying below uh the 40 to 50 milligrams uh per day for the the other nutrient interactions okay that's that's a great segue into supplements because there's there's definitely a lot of questions about supplements and and zinc supplements um let's start with uh well let's talk about like when's the best time to take your zinc supplement because I know that or or what you should do if you have problems taking zinc for example I I get stomach aches whenever I take a zinc supplement and uh and I've noticed that um there there are certain times I get stomach aches certain times I don't certain supplements uh I don't know if it's the forms but we can talk about forms in just a moment but you know is there any tips in terms of like if you get some reaction to taking zinc or is there a best time to take your zinc yeah no that's a great question um so a lot of the mineral supplements do have um stomach gi issues as a bit of a potential side effect um zinc uh is one of those supplements that you do want to make sure you take with food um that you take it with food um and that will sometimes help um I often recommend people to try to take their zinc supplement later in the day so even if you take it with food first thing in the morning you're still kind of have an empty stomach so if you do it you know more at your lunch time or or at your dinner time um you'll likely have something post-pranial in in your stomach you know if it's that first meal of the day just takes a while for everything to get down there um even though you're you are taking it with food so um you know taking it with food then then that brings up the question and then not just the food itself but um other supplements uh so is there any issues with mixing zinc with other mineral supplements I think a lot of people ask about zinc and calcium zinc and magnesium cal-max zinc is obviously a supplement that you see on the marketplace um you do you have to worry about mixing it with other minerals is there an issue there so um in terms of their chemistry there is potential competition um the way that zinc you know gets into our our bodies uh are multiple transporters uh so there are zinc specific transporters and then there's these divalent metal transporters um and also amino acid transporters that zinc will get in so uh if you are taking a lot of calcium or magnesium or other metals there's a chance that the um you might have competition uh for that divalent metal transporter to get um so it might limit it but to be honest it's pretty minimal in terms of those those interactions because there are alternative transporters that are zinc specific that magnesium or calcium will not look at um that like I said based on the chemistry there's going to be some competition but in terms of reality uh if you're taking a calcium supplement um you'll limit zinc to a small degree um but if it's inconvenient or if your supplement is just one that's formulated with calcium and zinc in it you don't need to necessarily worry about it I see okay so um you know one thing that I did find worked good for me was a cal-max zinc supplement I didn't get the stomach problems that I did with a uh with a zinc alone supplement um the um so so it's basically you know maybe less than perfect but no not clinically relevant differences uh when it comes to that mix yeah especially when you're taking it at a supplemental level gotcha um uh so let's talk about the the forms of zinc supplementation there's obviously different products out there on the market do you have any idea of which ones are better which ones are maybe I think bioavailability tends to be the goal but minimizing side effects is another one um so do you uh you have a not necessarily a recommendation but just some guidelines so in general at least in people the evidence that the different forms of zinc even food based differences in bioavailability is questionable I guess but with that said so getting back to the food so most of the zinc that's in food is complex there's very little free zinc as free zinc you know anywhere in in our biology so in our food and our supplements zinc is always stuck to some something um how it's stuck to something may change um both uh side effects and bioavailability um again it's a little bit up for debate how big of a difference it is I mean the studies that I've seen it may be a five percent change and so the ones um so they're so I guess stepping back um to supplemental forms the most common forms you're going to see zinc complex to our salts um sulfate zinc acetates or other organic acids zinc gluconate um and then there are the um chelated forms that tend to be stuck to things like amino acids uh small proteins um and that type of thing um in animal studies so again one way that zinc can get in is through piggybacking on amino acid transporters as well okay so uh there is an animals at least some evidence that the amino acid chelates um may have increased bioavailability but just because they they're able to piggyback on another transport mechanism uh evidence in people is a little bit more questionable um in terms of and I think also um some of the stomach side effects as well because it's it's basically kind of piggybacking on regular protein and metabolism um maybe less as well um but the bottom line is um you are going to take a zinc supplement form rather than amount matters more than than four gotcha okay um obviously if you have any reaction to any particular form you could try a different form to see if that deals with you better but maybe taking it with food is the better uh the better approach as you said um copper then copper then comes up very commonly when we're talking about zinc supplementation and so you did mention that you know taking uh high amounts of zinc does help uh or sorry does limit copper uh can you elaborate that a little bit more I mean should we be taking copper with with zinc if we're supplementing at least or at what level do you start worrying about copper? Yeah let me um step back and turn to telling you kind of how that interaction happens um and it is at high levels so at normal levels or RDA for example um you won't have that same competition when you start to get above that 40 to 50 milligrams of zinc what happens is high amounts of zinc um will induce or cause a a protein called metallothionine to be upregulated in your GI tract um the metallothionine uh similar to the phytates binds up copper and in zinc um so when you have lots of zinc you'll make more of the protein but you've got lots of zinc around so it'll only bind up some but if you don't have uh but metallothionine will also bind copper so if you have a little bit of copper around it'll also suck up the copper and similar to the phytates it forms a new complex um that uh will limit the ability of the copper to get absorbed so if you're taking like a multivitamin that has not terribly high levels of of zinc you're not going to have this induction of this new protein that sucks up the copper it's only when you get up to these higher levels of of zinc that you'll cause this protein to be made in the gut and it'll start to suck up the copper and make it uh less bioavailable um so there is some strategies uh some supplements some high dose zinc supplements um do put copper in the formulation as well to kind of override this again it's all in numbers game if you increase the protein it'll suck up x amount of copper but if you have excess amount of it around it won't suck it all up so some will still get through and and that in that regard there's really no optimal ratio of zinc to copper um it's just getting some extra copper to make sure that you don't yeah so i know um in some uh formulations so copper you mean so the zinc level that we need is just about like around 10 milligrams our copper needs are less than a milligram so uh you don't need to have 11 milligrams of copper you'd probably only need like one to two milligrams of copper uh to overcome that to have enough to still get through if you have that excess so even eating some foods that are you know provide extra copper it would be or being aware of the copper that you're taking otherwise you don't necessarily have to take another supplement on top of that right um and we're almost at or actually we are over time unfortunately so uh i wanted to mention though before i finish up um that there have been a lot of questions about zinc and and covid um zinc and long covid and i will mention that you know a lot of studies have not been done there have been a lot of clinical trials on zinc and covid uh we we still follow those with interest um dr ho touched on some of these in her think zinc webinar that we will of course send to everybody if they want some more information uh but uh emily do you want to finish up with maybe uh uh a comment about zinc and and say that means cold and flu season right now you know should we think about possibly getting some more zinc during this uh this time of the year um yeah i mean i always advocate for making sure that you are getting enough zinc um and a lot of people aren't getting enough zinc in their the regular diet so taking again a multi-vitamin multi-mineral with zinc or a zinc supplement but again trying to make sure you don't get too too much uh per per day is is is going to be important but um definitely to think about zinc especially in the cold and flu season is is something to to consider including maybe taking a supplement just as extra insurance given uh the uh getting enough in your diet maybe sometimes problematic so you know nutritional support as we we've said several times but not necessarily hammering that zinc in there uh to necessarily cause other problems that could erupt yeah a lot of the supplementation trials that have been ongoing for covid for flu for cold you know show some promise but again a lot of times we don't know if that supplement is is restoring a deficiency um or if it's actually supplemental above and beyond and so far the evidence is preventing a deficiency definitely has at effects getting super amounts of zinc may do more harm so i think i'm going to have to close up there i know there's some great questions still in the q&a and we're going to have to i think take this into our newsletter for for follow-ups so um i mean obviously if you have a question that didn't get addressed and you you want to see it addressed you can still email it email us lpi at organ state at edu and we'll get emily's answers together and get into our next edition of the newsletter which will be coming out in this uh later the winter slash spring uh edition so um i'd like to thank everyone for their attention and the great questions uh this is one of the reasons we do things like this to help you find the answers uh to to nutrition nutrition questions and questions about vitamins minerals and other parts of our diet um and i'd like to give emily one more chance to to to address everybody and and uh just bring us to a close great well thank you everyone for joining us i'm i literally could talk about zinc like for days and days and days um so if you have more questions feel free to reach on to reach out to us uh we're also working on our schedule for 2023 um mark on your calendar's line is pauling day it will be coming in february and we'll likely have a a webinar focused on vitamin c again as well so um take a note of that um and uh we'll have some communication at the start of the year um alice mentioned our newsletter is also almost out the door as well so be on the look out for that um again if you like uh events like this and what we do at the institute uh alice will pop up the link for in the qr code for uh giving to the institute as well we really uh value the support of our of all of our followers to help us uh support the research and support events like this um lastly again if you have any comments or questions again email us at lpi at organstate.edu um we will be we'll do our best to uh to answer all your questions um and then lastly be sure to visit our website um in our social media page stay healthy um and stay well