Buffalo HealthCast
The official health equity podcast of the University at Buffalo’s School of Public Health and Health Professions.
Buffalo HealthCast
Dietary exposure on toxicants: Health impacts on vulnerable groups, especially on infants and children
Welcome to Buffalo HealthCast, the official podcast of the University at Buffalo's School of Public Health and Health Professions 🎙️
In this episode of Buffalo HealthCast, Dr. Gauri Desai, an expert in environmental epidemiology, explores the impact of environmental toxins on children's health and development. She delves into how diet can both mitigate and sometimes contribute to toxic exposures, shedding light on the surprising role dietary components play in our well-being.
With a focus on children's health, Dr. Desai discusses how what we eat can protect or expose us to harmful substances, offering valuable insights on the benefits and risks of diet in reducing toxic exposure. Don’t miss this eye-opening conversation!
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Welcome to Buffalo healthcast, the official podcast of the University of Buffalo School of Public Health and Health Professions. This is Vennela Damarla, the Podcast Producer for Buffalo healthcast, and an MPH student. Today we have Dr Gauri Desai environmental epidemiology with training in epidemiology and microbiology. Dr Desai, research focuses on impact of environmental toxins on children's growth and development, as well as the role of diet in mitigating this toxic exposures. She is also a dedicated educator, teaching undergraduate courses on global health, public health, epidemiology and maternal and child health. Welcome to the podcast, Dr Desai,
Dr. Gauri Desai:Thank you for having me.
Vennela Damarla:So let's begin with some of the questions. Dr Desai, before we get into the science, could you share a bit about your background, what sparked your interest in studying dietary toxicants and their impact on health, especially in young children.
Dr. Gauri Desai:So you were right about my background. My background is both in microbiology and epidemiology, particularly in the field of environmental and nutritional epidemiology. So I started out with an interest in environmental exposures and how they impact children's growth and development, and understanding whether and how changing the child's diet can help in reducing the toxicity of those environmental exposures. So as I continue to work in this domain, the experts in this field started pointing to the fact that dietary components are certainly beneficial to health, and they can also reduce the toxicity of environment mental exposures to some extent, but sometimes these dietary components themselves can be sources of toxicants. So I was it was through the reading of the upcoming literature and understanding where the field was going that I started developing an interest in this, in this topic.
Vennela Damarla:Well, thank you, Dr Desai, that was interesting to know. So let's start with the questions now, could you help us understand what dietary toxicants are. What does this term mean in the context of food?
Dr. Gauri Desai:Sure, so a dietary toxicants means the exposure to elements like in this case, like lead, arsenic, cadmium, mercury, other elements that we get through food. So in the context of food, it means that some foods might expose us to these toxic elements to different degrees.
Vennela Damarla:Well, that was very, really easy to understand. Thank you for simplifying it. So what are the common toxicant found in everyday foods, and how might they differ from food contaminants.
Dr. Gauri Desai:I think I'll start with the second part of the question. First, food toxicants are a subset of food contaminants. So food can be contaminated by multiple things. It could be chemicals, micro organisms, other organic matter, and also elements like lead, arsenic, cadmium, mercury, etc. And so toxic elements such as lead, arsenic, etc, are a type of contaminant. So it's really one is the subset of the other.
Vennela Damarla:Well, you have mentioned that lead, arsenic, cadmium and mercury are one of the most common toxicants. So how do these toxicants end up powering food supply?
Dr. Gauri Desai:So toxicants can become part of our foods, both naturally as well as through human activities. So let me start with the example of arsenic. Arsenic is a naturally occurring element in the Earth's crust and through human activities, like when we dig deep into the Earth's crust to get to water, when we are extracting this groundwater for use, sometimes that arsenic, which is naturally there in the Earth's crust, gets mobilized, and then it enters The groundwater in in the water system, in the water supply. Now, the food that is grown or is cooked using this contaminated water can retain some of that arsenic. Contaminated soil is another source that we need to consider. So this soil contamination could be a natural process, like in the case of arsenic, or it could be because we are looking at an urban garden that's right next to a highway and has really high amounts of lead from the dust, so sources like traffic, street dust or incineration tire, where these can contribute to soil contamination Particularly with lead in an urban environment. Another aspect of this is certain types of vegetables are more likely to accumulate high levels of harmful heavy metals than others. So in general, these heavy metals, elements in general, tend to accumulate in root, leaf and stem tissues. So vegetables like sweet potatoes, carrots, spinach, broccoli naturally will have higher amounts of these toxicants compared to vegetables that come from flowers, like cucumbers, tomatoes, peppers as well. And then finally, I want to stress that with lead, lead is an element that is used in glazed ceramics in a lot of cultures in a lot of countries. So the glass dishes and pots that are used to serve food, a lot of these contain really pretty design, colorful design, but that's made out of lead, and so eating right from these ceramic pots and dishes will expose people to lead, so overall, toxicants can come to our foods from different sources, and they have been found in both store bought as well as homemade foods.
Vennela Damarla:Thank you. Dr Desai, so basically, these toxicants are naturally occurring as well as they are introduced to human activities. Absolutely yes. So people keep in mind, when you see a very fancy stuff out there, don't just buy it because it might contain higher amounts of lead. So moving on to the next question, we often hear that infants and young children are more vulnerable to certain substances. Why is dietary exposure to this toxicants especially concerning for young children?
Dr. Gauri Desai:So that's a very important point. So infants and young children are particularly vulnerable to the effects of exposures to toxic elements, and there are a few reasons for that. So one is that children have high amounts of toxicant exposures because they their intake per unit body weight is higher than that of adults. So if food is the source of toxicants, these kids are their intake per body. Unit body weight is higher, and so that is going to end up, they are going to end up with a higher body burden of these toxicants. Another aspect is that as adults, our bodies have certain mechanisms by which we are able to detoxify these contaminants, to some extent, to different degrees. Infants and young children are still developing, and for the most part, their bodies have not yet developed these mechanisms fully. They're not ready in place, and so their ability to detoxify these toxicants when they are exposed to it is very limited. And then finally, we need to keep in mind that exposure that happens when the body is still growing and developing has long term and oftentimes irreversible effects. So exposure seen in that is seen in infancy and childhood can have consequences that we see in adulthood, and they persist throughout the life. So it really is a very critical and vulnerable stage, a vulnerable population. So we do need to pay special attention to infants and young children in the population.
Vennela Damarla:Okay, so how does exposure to toxic and in infancy and early childhood differ from exposure later in life?
Dr. Gauri Desai:So it really goes back to what makes infants and young children vulnerable. I mentioned a few of these things earlier, in terms of, you know, the exposure that happens in that phase of life that really has very severe and lifelong, oftentimes irreversible consequences. So let me take the example of lead. There have been, you know, a lot of several studies that have shown that early life lead exposure is linked with children's cognitive development. So it is inversely associated it hampers children's cognitive development. It's associated inversely with, again, children's academic achievement, which in turn impacts their employment, impacts their salaries as well in adulthood, so impacts their whole life trajectories. We've seen that early life lead exposure is associated with violent behavior, with jail time as well, so a lot of severe consequences with arsenic, we see cognitive deficits when early life exposure happens, several types of cancers, kidney damage, skin lesions, heart disease have also been seen in adulthood. So really, it is that early life stage that we want to focus on when exposure happens in this stage, there are several long term, sometimes even intergenerational consequences. So that's why it differs from you know, when exposure happens later in life.
Vennela Damarla:It's really awful to know that this toxicant can cause cognitive impairment, cancer, kidney diseases and a lot more. So moving on to the next question, what are some of the health risks associated with exposure to heavy metals and toxicants like arsenic or lead?
Dr. Gauri Desai:So some of the things I mentioned before different types of cancers, so it really depends on which element we are looking at, whether it's lead, arsenic, cadmium, what levels are we looking at and what specific population are we looking at? Is it infants? Is it toddlers? Is it school going? Children? Other factors that impact the outcomes are things like, are they sufficient or deficient in certain nutrients? What the What's the nutritional status of the population? What is the environment in which they are growing? So are these kids growing in a sort of a medium to rich household? What's the socio economic status? What are the other types of intellectual stimuli that they are getting from the household? So all of these things will play a role. But keeping this in mind, the generally seen adverse health outcomes associated with these heavy metals include cancers, cardiovascular diseases. So heart disease, diabetes, cholesterol levels, kidney disease, skin lesions, cognitive deficits, educational attainment, etc. So a wide, really wide range of outcomes,
Vennela Damarla:yes, yeah, there are really wide range of health risk associated with this, toxicants. Moving on to next question, how can chronic exposure to this elements impact a child's development or overall health?
Dr. Gauri Desai:That's a really good point. It's important to distinguish between one episode of acute exposure versus getting constantly exposed to it chronically for years and years, even though it is at a low level. So since your question focuses on the second part, I think it's important to state that even if you know an individual or a community is being exposed to low levels of toxicants, but it's chronic exposure, years and years worth of exposure, we do still see a lot of these adverse outcomes that I mentioned, including developmental deficits, including cancers and cardiovascular outcomes. So even at low levels, a lot of these toxicants are are seen to be harmful.
Vennela Damarla:Okay, so are there currently any regulations or guidelines in the US for acceptable levels of this toxicants in foods, especially in baby foods.
Dr. Gauri Desai:Yes,So we do have, we do have some regulations. We have something called as the interim reference level, IRL, it is a benchmark or a reference level that the FDA, the US Food and Drug Administration. FDA, the FDA uses these to determine if the amount of exposure to the contaminant in food is something to be concerned about in terms of health risks. So is it? Is it a health concern? So based on that, the interim reference level for dietary lead intake for children is 2.2 micrograms per day. So to give you an idea, one microgram is 1,000,000th of a gram. So the FDA says that 2.2 micrograms per day is the limit for lead exposure in children through diet. The European Food Safety Agency has a reference value of 0.36 micrograms per kilograms, body weight per day for cadmium. In Europe, they also have a reference value for arsenic. So yes, overall, globally, different countries have different levels of regulations. Since you are specifically asking about the US, there is an FDA set limit for lead in foods, but we do not have a set enforceable level for arsenic and cadmium generally for foods. The FDA has something called as the closer to zero action plan, and this is. A plan that aims to reduce dietary toxicant exposure, and as part of the plan, the FDA will release these reference levels for dietary arsenic and other toxicants as well. So right now we have a level for lead, but levels for lead and cadmium, probably mercury as well, are coming up, so it's in the works. Another aspect of this is FDA does have a guideline for how much arsenic or how much lead is permissible in specific types of baby foods, like in cereal or in fruit juices. But note that these currently are guidelines. They are not enforceable, so we do have an idea of what's permissible. It's not all of that is enforceable, but some of it is coming up.
Vennela Damarla:Irrl is something that that is something new that I've learned today. So hopefully we'll wait for the all the guidelines of the toxicants related to arsenic and many other toxicants soon. So how do us regulations compare to those in other countries, such as the European Union, which is often seen as more restrictive.
Dr. Gauri Desai:sure, So like I mentioned, the European Food Safety Agency currently does have reference values for arsenic and cadmium as well. In the US, we don't, we only have one set up for lead, but we are slowly catching up. Soon, the FDA will release these reference values for arsenic and cadmium. So it will it it's coming up.
Vennela Damarla:In recent studies, certain foods showed higher toxicant levels. What does current research tells us about the level of toxicants in popular baby food plants.
Dr. Gauri Desai:So yes, toxicants have been found in several baby foods manufactured by several brands, generally speaking, from all of those, the gist is that there are some baby foods that are likely to have or more likely to have toxicants than other baby foods. So rice puffs, juices, teething biscuits, rice cereal, carrots and sweet potatoes are the most common ones that babies consume, but they are also the common wants to have toxicants, so rice is a well known source of arsenic, and so rice based baby foods do have some some levels of arsenic, and then carrots and sweet potatoes as well. So we have been able to identify some of these as sort of high risk foods. So that's that's some progress on that front.
Vennela Damarla:It seems like everything around us, including food, has a some amount of toxicant levels. So could you share any surprising findings from recent studies on toxicants in food?
Dr. Gauri Desai:Sure. So, it's not entirely surprising if you know how toxicants might get in in the foods, but still, a lot of people find it very surprising that not just store bought but even homemade baby foods also do contain a lot of toxicants. So it's a myth that all homemade foods are free of toxicants. Unfortunately, they're not if a food naturally contains lead or arsenic, rice, sweet potatoes, carrots are example, even if you cook it at home, it will have some degree of these toxicants.
Vennela Damarla:Yeah, it is really surprising to know even the homemade food also has toxicant levels. So what steps can parents or caregivers take to reduce their children's exposure to this toxicants in food?
Dr. Gauri Desai:So one main point here is to ensure that the child has a varied and diverse diet, so completely avoiding one food because it's likely to have heavy metals or toxic elements. It's a bad idea, because foods are also sources of nutrients, so we don't want to eliminate foods from the diet out of the fear of getting exposed to toxicants. Having a varied and diverse diet ensures that the child is not getting concentrated exposure from the same two foods that they're eating, but they're also getting nutrition from multiple foods. So a varied, diverse diet is clearly the way to go, overall, promoting the intake of water over juice, not only focusing on the intake of rice, the reason I'm stressing that here is one, rice is a well known source of arsenic, so to different degrees, it will likely contain some arsenic. And two, generally, we see that parents tend to have a rice heavy diet for their kids. And it makes sense, because rice is easily available. Available. It's easy to cook, it's easy to eat, it's easy to digest. Yes, it makes sense, but from this perspective, focusing only on rice might not be a great idea. Focusing on multiple grains would be the way to go, in addition eating a wide variety of fruits and vegetables, while ensuring safe cooking and eating practices is what parents could focus on.
Vennela Damarla:So you mentioned that safe cooking methods might help reduce what cooking methods or what particular foods that might help reduce or limit the exposure?
Dr. Gauri Desai:Yeah. So in terms of cooking methods, if the tap water that's available in the household is safe, then washing fruits and vegetables well is recommended. Peeling root vegetables like sweet potatoes, peeling sweet potatoes, peeling carrots, is recommended if we are talking about rice and arsenic, if the tap water is safe. Washing rice with excess water, so washing it multiple times, throwing away that water, using a lot of water to wash the rice is recommended. In addition, if you are growing your own fruits and vegetables, a lot of people do safe gardening techniques is also essential. So using raised beds in an urban environment, urban garden is another recommended way to at least reduce the amount of amount of exposure, and then when it comes to the other side, serving and eating, avoiding these ceramic glazes that might have led is another recommendation.
Vennela Damarla:Well, thank you so much. So Dr Desai, I'm curious to know if the organic foods that we get outside, which is very expensive, say that they're very safe, pure, and then they're free from pesticides. So do you think it's the organic foods are any different from the normal foods with pesticides.
Dr. Gauri Desai:So, that's a good point in terms of pesticide application. They probably don't use the same types and the same amounts of pesticides. Since they are organic, they would be free from those, but they wouldn't necessarily be free from toxicants like arsenic, lead and cadmium, because organic foods are grown without the use of pesticides, but if they are grown in soil that has lead in it, or irrigated using water that has arsenic in it, just being organic is not going to help us get rid of these toxicants. So yes, they are expensive, and probably it's worth the money because you are not getting exposed to those kinds of pesticides. But you can't say the same for these toxic elements.
Vennela Damarla:Turns out to be organic foods are not really safe, as they are portray. So moving on to the next question, What responsibility do you believe food manufacturers should have in managing toxicant levels, especially in products that are aimed at children?
Dr. Gauri Desai:Yeah. So if you are a manufacturer, or producer of food, there are some things that are discussed in the literature found to be effective to different degrees. So alternating irrigation practices, avoiding the use of contaminated water while growing those crops. Again, if we are talking about an urban environment, avoiding urban gardens with no raised beds. So if there's no other option, of course, an urban garden is useful because it's a source of food, but then using a raised bed, using safe soil, safe water, is something that's that's recommended.
Vennela Damarla:Okay, so are there industry practices that could help reduce toxicant level in the foods we eat?
Dr. Gauri Desai:Sure, so this goes back to how toxicants get into the foods. So some ways in which the industry can be a little bit more responsible towards this issue is thinking about where they're sourcing the foods from. So sourcing foods from areas that are not well known sources of contaminants, geographically speaking, is important. So for example, let's go with rice. Rice is a well known source of arsenic. We also generally have a good idea of which geographic areas have high levels of arsenic in the groundwater. So if we know this, avoiding sourcing rice from those areas would be an example of responsible sort of technique or behavior from the industry Point.
Vennela Damarla:what are some critical areas for future research in dietary toxicants?
Dr. Gauri Desai:So understanding how the overall diet, and not just individual foods, contribute to toxicant exposure, is one thing that's really needed. We also need to understand how much disease burden in the population is because of dietary toxicants. So we know that toxicants are bad. We know that diet is a source, but we don't clearly know how much disease that we see in the population can be linked back to the toxicant exposure that's happening exclusively through diet. So understanding that link understanding those numbers, is essential. These are big gaps in knowledge that we do need to fill through our research.
Vennela Damarla:Well. Thank you for simplifying that. Dr Desai, moving on to next question, if there were one or two policies you would recommend to better protect consumers from dietary toxicants, what would they be?
Dr. Gauri Desai:So I think the first is to set reference levels for elements that don't currently have them. So arsenic and cadmium are prime examples. Those are coming in future, hopefully soon. The other is to test the final products, and not just ingredients, for toxicant levels. So a lot of recent studies have found that many baby food companies tested individual ingredients for metal levels, but not the final product. So what they found was each individual ingredient had a very low level of toxicant. And that's probably true. A lot of individual ingredients might have a low level of a toxicant, but when you combine all of these ingredients, the final product could have high levels. So that's what we need to regulate. Testing just ingredients is not sufficient. Testing the final product is equally important. So those are some regulations that I think are absolutely essential.
Vennela Damarla:Well, any final concluding thoughts that you want, you would want to tell our audience? Dr Desai,
Dr. Gauri Desai:sure, so I want to go back and reiterate the importance of a diverse and varied diet. Toxicants are there in our food supply. It's very difficult to completely avoid them, so we need to remember that, yes, foods probably do contain some degrees of toxicants, but foods are incredibly important sources of nutrition that we need throughout our life. So a diverse diet is going to ensure that we get the nutrients we need while not exposing us to very high levels of one element through one food that we eat every single day. So a diverse diet is something that is important, and that's what I would like to reiterate towards the end.
Vennela Damarla:thank you so much, Dr Desai, for your time and for sharing your valuable knowledge with us. Thank you so much.
Dr. Gauri Desai:Absolutely. I was happy to be able to come here and thank you for having me.
Vennela Damarla:Yeah, and also, there were so many surprising facts also that we have learned today. Yeah, see you on another episode on buffalo healthcast. Thank
Dr. Gauri Desai:you. Thank you. You.