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The Dose Transcript for February 16, 2023

Host: Dr. Brian Goldman

STORIES FROM THIS EPISODE

BRIAN GOLDMAN: Hi, I'm Dr. Brian Goldman. Welcome to The Dose. We've been hearing a lot lately about a specific red food dye that's used in food. There's a petition to have the U.S. Food and Drug Administration ban the dye that caused cancer in rats. So this week we're asking, should I be worried about food dyes? Hi, Joe. Welcome to The Dose.

JOE SCHWARTZ: Hi. Thanks for having me.

BRIAN GOLDMAN: So what are your favorite natural food dyes?

JOE SCHWARTZ: Well, I got to go with paprika. My background is Hungarian. And as you probably know, paprika is the national spice of Hungary. I cook a lot with paprika. I enjoy its beautiful red color. And these days, of course, as manufacturers are trending towards natural colors, paprika enters that picture. So that's what I look for when it comes to natural colors.

BRIAN GOLDMAN: Okay. Before we begin, can you give us a. Hi. My name is, tell us what you do and where you do it.

JOE SCHWARTZ: Hi, I'm Joe Schwartz. I'm a chemistry professor at McGill University in Montreal. But more than that, I direct McGill's Office for Science and Society. So I do that. I also have a radio show on Chemistry, which is the longest running such show in the history of the world that's been going on for 42 years now. And I also write a newspaper column, and I've written 19 books. So that's what I do.

BRIAN GOLDMAN: That's what you do. You do a lot. Okay. Let's let's begin our conversation. Let's start really basic what are food dyes? And more specifically, what are they made of?

JOE SCHWARTZ: Well, there are two categories of food dyes. They're the natural dyes which, like paprika, you know, occur in nature chlorophyl the green coloring, the matter of of plants, curcumin, which is the yellow color and turmeric. So nature gives us a palette of of a number of colors. However, those colors are difficult to deal with when incorporated into foods. They generally don't stand up too well to light or to heat. Well, in 1856, William Henry Perkin in England, in a futile quest to synthesize a drug called quinine, made an accidental discovery. And that was the world's first synthetic dye. He named it mauve, and that triggered the chemical industry to produce a whole number of synthetic dyes from coal tar, which is the substance that is left behind when coal burns. And in the 1800s, they burned a lot of coal to produce coal gas for lighting. So there was a lot of coal tar left behind. And Perkin found that one compound in there called Aniline could be converted to a dye and others followed suit. So we had a whole slew of synthetic dyes, dozens and dozens that were introduced into commerce by the turn of the century. And then in 1906, when the U.S. introduced the first Food and Drug Act. Some of these were removed because they already had a history of some problems when tested in animals. But we are left today with a number of these synthetic dyes. And interestingly enough, not exactly the same ones in Europe, Canada and the U.S. There is some overlap, but there are also some some of these that are allowed in one country and not not in the other. So those are the two classes. They're the natural dyes and they're the synthetic dyes. The industry loves to use the synthetic dyes because they are very potent. You don't need very much of them to color to food. And they also are very stable. So they stand up well to light and to to heat. So they are the darlings of the industry, but not the darlings of consumer organizations who see red when red dyes are put into food because of various issues that have arisen.

BRIAN GOLDMAN: That's that's a very good pun. They're found dyes are found in in a whole bunch of foods. Am I right?

JOE SCHWARTZ: Absolutely. I mean, they are pervasive. And mostly we find them in highly processed foods. And, you know, you'll find them in cereals that are targeting children. And then, of course, we have candies. M&M's are a classic. We're of a whole range of colors. You look at jams, some of them will have coloring, look at some yogurts. They'll be coloring. So food coloring is used in a very, very large variety of foods.

BRIAN GOLDMAN: And are they mainly added to make them attractive to consumers?

JOE SCHWARTZ: Absolutely. I mean, they the only reason is cosmetic, food dyes do not add any nutritional value to the food at all. They are basically eye candy. But studies have shown that people like their food to be colored when a color is removed. Very often consumers gravitate away from that product. You may remember that at one time the COLA companies came out with Clear Cola because the coloring in cola beverages is actually due to caramel, which is the most widely used food coloring. And about 90% of all food coloring that is used in North America is caramel. So anyway, when there was all the controversy starting about food dyes, the COLA companies removed the caramel coloring and they came up with clear colas. People didn't want to colas. They didn't buy them. They wanted the colas to be dark brown. So the color was put back in. So, you know, people get used to having foods of specific colors.

BRIAN GOLDMAN: So you've already said that they don't add the synthetic food dyes, don't add to the nutritional content of the food. Do they change the flavor of the food?

JOE SCHWARTZ: No, they don't change the flavor because they're generally used in very, very small amounts, not enough to impart any kind of flavor. So like I said, nutritionally they are inconsequential, but they make the food more appealing.

BRIAN GOLDMAN: So what do we know about the health effects of food dyes?

JOE SCHWARTZ: Well, actually, a fair bit. The first time that we began to to hear controversies about these dyes was in the 1970s when an allergist by the name of Benjamin Feingold suggested that foods that have dyes in them caused behavioral problems in children that they exacerbate, exacerbate hyperactivity. And he suggested that children who are afflicted by this stay away from foods that have certain additives, particularly the food dyes. And this was then deemed the Feingold diet. And a lot of mothers who had children with behavior problems jumped on the bandwagon, and some claimed tremendous improvement. And the industry, of course, said that, you know, this is all through perception that they their parents were wishing so much that their kids improved, that they actually saw improvement where there wasn't any. Anyway, there was some controversy, but since that time, there have been a number of studies that have linked food dyes with behavioral issues in children. The one that has received the the most publicity was carried out by researchers at the University of Southampton in England, where they tested six dyes, which came to be called the Southampton six. And what they discovered was indeed in controlled double blind studies, parents and and the teachers were asked to evaluate their behavior children's. The children also underwent some computer tests to to measure behavior. And the end result was that there was an effect that the food dyes did, in fact influence behavior. Now, these Southampton six, as they they were called, were not all dyes that were in use in North America. For example, three of the six Karmazin ponds so far are in Quintal and yellow. Never were used in North America. The other three sunset yellow tortures in and Allura red were were used. So anyway, in Europe there was a big commotion about this and manufacturers, because of the publicity, started to remove these dyes from the food. And then the European Safety Association even introduced a regulation, not that the dyes had to be removed, but if they were still in the food, there had to be a warning on the label saying that they had been linked with behavioral problems. So of course, companies didn't want that label, so they tended to remove the the dyes in North America. Action wasn't taken quite so quickly. But here, too, when consumer organizations started to to get into into the mix, many manufacturers just took the bull by the horns, as it were, and started to remove the synthetic dyes in favor of of natural ones. So we have interesting situations here in North America where, for example, Canada where. We have Smarties which are very similar to M&Ms, and they have eliminated all synthetic colors, whereas M&Ms still have the synthetic colors in there. So there are a number of synthetic dyes that are allowed in both in Canada, in North America. Some manufacturers choose to use them. Some choose not to use them. There are controversies and red dye number two is the one that really raised the red flag back in the 1970s. It was widely used in North America, but a couple of Russian studies suggested that it caused cancer in rats. So the Americans said, gee, you know, the Russians must know something about red. And they decided to eliminate red dye number two. Canadian manufacturers stopped using it as well, although it is still on the box that are still legal in Canada. But the US eliminated red dye number two. But the one that CSPI now has really targeted is red dye number three, and that's the one that is the focus of the petition that you mentioned. And this is a curious sort of a story, because studies have shown that when rats fed very high doses, much higher doses than any human would ever be exposed to, did trigger thyroid cancer in those in those rats. Now, based upon that, it was removed from cosmetics. So the FDA banned the use of red dye number three in cosmetics, but not in food. This is why I say it is a bizarre situation because the cosmetic regulations are different from the food regulations. So we'll see how the FDA response to this.

BRIAN GOLDMAN: But what do you think? Do you think that Red three is safe enough to consume in small amounts?

JOE SCHWARTZ: I think it probably is safe, but nevertheless, I'm in favor of eliminating dyes from foods for the simple reason that they do nothing, as I said, but in part in appearance, they are only a cosmetic value. And furthermore, they are usually found in foods that are poor nutritionally anyway. And that's a good enough reason, you know, to to avoid foods that that are highly colored, because those are not the kind of foods that we should be eating anyway.

BRIAN GOLDMAN: I want to switch to another dye. There was a recent study done on mice only that found that the food dye Allura red can potentially trigger inflammatory bowel diseases. What do you know about that?

JOE SCHWARTZ: Yes, Allura red, this is red Number 40, which is the dye that I've mentioned is the one that is used, for example, in Red M&M's. And it's one of the most widely used red dyes. Now, the study that you're referring to was done in mice. And when it comes to toxicology, you know, it's always appropriate to point out that that humans are not giant mice or giant rats, although there are some exceptions to the giant rat. But but it's always difficult to take a mouse study and determine what it means for humans. On the other hand, it is a springboard for further studies because you've got to start somewhere. Now, the question in the in the study that you're talking about, about Allura, red or red dye number 40 in mice, there was a link to colitis, which is an inflammatory disease of the bowel. Nobody really knows what causes colitis. There are theories that it might be an imbalance of gut bacteria. There is possibly a genetic component, but in this particular case they exposed mice to Allura Red to see what would happen. Well, when they exposed them in an intermittent fashion that is irregular, you know, they would sometimes put in the diet, sometimes not, as I think would be parallel to what humans would do. I mean, you know, not everything we eat has dyes, so it would be sort of intermittent. Then they found that that there was no link to to colitis. However, when it was given to the mice on a regular basis, especially if it was given to them when the mice were very young, then that was associated with colitis. So what? What does this really mean? It means that it is worth exploring this further. And of course, if someone suffers from colitis, there's absolutely no risk in trying to avoid red dye number 40 or other food dyes, I think that's a logical thing to do. But we cannot conclude based on this study with mice that the same thing will happen in in humans. So it really doesn't mean much more than to say, hey, you know, this is something to be followed up, something to be looked at out further.

BRIAN GOLDMAN: Let's turn to another another color, sunset yellow. How about that one?

JOE SCHWARTZ: Well, sunset yellow is again. It's a very popular color. It's also known as yellow number six. And this is allowed in in both Canada and the U.S.. Aside from some rare allergic reactions, there doesn't seem to be much problem with this. But the allergic reaction may be a bit difficult to to link because it can be gastric. And normally, when we think of an allergic reaction, you think of a rash or an itch and not gastrointestinal problems. But there have been some reports of people who have very significantly linked pain in the stomach. Those gastric problems to to sunset yellow. And when I say that they have linked this, you know, significantly, it is because when they have removed from their diet, the pain ceased and they put it back in the diet and they got the pain again. So once more, if someone is experiencing pain that has not been diagnosed, intestinal pain, then you start thinking what might be causing it? Can it be something in the food supply? And there are signs that yellow would be a candidate. But the reports have been very few, and because sunset yellow is very widely used, you would think that if there was a highly significant link to two gastric problems, we would have heard more about it. But, you know, there there still is, you know, a bit of a red flag over sunset yellow.

BRIAN GOLDMAN: Since there's been so much talk about cancer. I mean, is that an ever present concern? Is that something that troubles you a lot?

JOE SCHWARTZ: Well, there just is no human evidence for that. As I said, the concern about cancer comes from animal studies, but those are cases where the animals have been fed just gigantic doses, which is, you know, a standard way to carry out experiments because one has to assume that giving a large dose to an animal over a short term which were, you know, destined to tend to do because mice and rats don't live very long. That that gives us indication of what might happen when humans are exposed over a longer period to smaller amounts. And there there is no study in humans that has shown cancer, you know, linked to to food dyes. So it all comes from animal studies.

BRIAN GOLDMAN: So bottom line, should people be worried about food dyes?

JOE SCHWARTZ: I think so. I think maybe concern is a better word then than worry. But, I mean, you know, my main argument here is that by avoiding foods that have food dyes, you will automatically making your diet better. Because you will be avoiding foods that are generally high in fat, high in sugar and high in salt. That's that's enough of a motivation to be circumspect about foods that that are diet.

BRIAN GOLDMAN: So I guess bottom line is that you should be looking to avoid foods that are overly processed and foods that have and certainly read the label.

JOE SCHWARTZ: Absolutely. I mean, you know, we see more and more studies coming out about the devilish nature of processed foods. If a food is colored, it has to be listed on the label. If it is just natural colorings, you can just list natural colorings. You don't have to say what what they are. So you can very easily check labels and you'll see that color is added. And then if you further scrutinize that label, you will also see that there generally tends to be a higher amount of sugar, higher amount of salt and higher amount of fat.

BRIAN GOLDMAN: Okay, eat healthier, avoid heavily processed foods and read the label. That's all good advice. Joe Schwartz, thank you so much for appearing on the dose and and bringing some clarity to this subject.

JOE SCHWARTZ: Thanks very much.

BRIAN GOLDMAN: Joe Schwartz is a professor of chemistry and director of McGill University's Office for Science and Society. Here's your dose of smart advice. Broadly speaking, there are two kinds of dyes found in foods. Natural dyes include paprika and chlorophyll. These are safe to consume. Synthetic dyes have been around since the mid-19th century. They're found in highly processed foods such as breakfast cereals, candies and processed luncheon meats. Food manufacturers put them there to make foods more appealing to the eye. They have no nutritional value. In the 1970s, a number of studies first linked food dyes to hyperactivity in children. And food manufacturers voluntarily removed the dyes in question. Also, in the seventies, manufacturers voluntarily removed red dye number two after reports that the dye caused cancer in mice. Red dye number 40 was also removed voluntarily because of reports that the food dye was sometimes contaminated with a cancer causing chemical. Studies have also shown that red dye number three in high doses has been linked to thyroid cancer in animals. Although that food coloring was banned in cosmetics by the U.S. Food and Drug Administration more than 30 years ago. It's still approved as a food additive. There's a current petition to the FDA to also ban red dye number three in foods in Canada. Red dye number three, also known as Erythromycin, continues to enjoy Health Canada approval for use in food products. There is no strong evidence linking synthetic food dyes to cancer in people, in part because it would take very large doses of dye to uncover a link. Allura or red dye number 40 has been shown to trigger colitis in mice. But researchers need to do additional studies to see if colitis occurs in humans. Sunset Yellow dye number six has been linked to rare cases of abdominal pain caused by an allergic reaction in the gastrointestinal tract. Overall, synthetic dyes should trigger concern, but not excessive worry. You can avoid synthetic dyes in your diet by staying away from highly processed foods. Always read food labels. If the food in question contains synthetic chemicals, they must be listed clearly on the label. Since highly processed foods have higher amounts of sugars and fats, eliminating those foods will improve your diet overall. If you have topics you'd like discussed or questions answered, our e-mail address is the dose at cbc.ca. You can find the dose wherever you get your podcasts. If you like this episode, please rate us five stars so more people could find us. This edition of the Dose was produced by Stephanie Dubois. Our senior producer is Colleen Ross. The dose wants you to be better informed about your health. If you're looking for medical advice, see your health care provider and Dr. Brian Goldman until your next dose.

Should I be worried about food dyes?- Transcript

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