A, C, D, E, K and the eight Bs: There's a lot that can go wrong when we don't get sufficient amounts of these 13 chemicals in our diets. Things like pellagra, caused by a B3 deficiency and characterized by delusions, diarrhea and "scaly skin sores," or beriberi, which occurs in the dearth of B1 and can affect either the nervous or cardiovascular system, depending on which type you've got.
But in North America, vitamin deficiencies are a rarity. The nutrition-related health problems we do have to worry about are a lot different: obesity comes to mind, as does diabetes and hypertension. Incredibly enough, argues science writer Catherine Price, it's the fact that we've solved the former that's contributing to the latter: food companies add synthetic vitamins to otherwise unhealthy fare, preventing us from developing scurvy but also, at the same time, from following truly nutritious diets. "We use vitamins as insurance policies against whatever else we might (or might not) be eating," Price writes in "Vitamania: Our Obsessive Quest for Nutritional Perfection," "as if by atoning for our other nutritional sins, vitamins can save us from ourselves."
"The irony of our vitamin obsession," Price argues, is that "by encouraging the idea that isolated dietary chemicals hold the key to good health, our vitamania is making us less healthy."
Salon spoke with Price about this paradox, and about the best way to follow a healthy, vitamin-rich diet. (Hint: it doesn't involve shopping at GNC.) Our conversation, which follows, has been lightly edited for length and clarity.
What are vitamins and, more importantly, what are they not?
I'm glad you started with that question, because it's something people get confused about all the time. Vitamins are technically only 13 dietary chemicals: A, C, D, E, K and then the eight B vitamins. There's actually no concrete chemical definition of what a vitamin is; they're basically these 13 chemicals that we get in small amounts from food to prevent specific deficiencies.
"Dietary supplements" is often also used synonymously with "vitamins," but that's a much larger category of basically any substance that can be used to supplement your diet. What I found really interesting when I was researching the book is that when I'd say I was writing a book about vitamins, most people would ask questions about things that weren't vitamins, which really showed how often we confuse those two terms.
"Dietary supplements" would be things like herbs?
Herbs, botanicals, basically anything at GNC that's not one of those chemicals. It's kind of funny: now, when I go into a drugstore, I try to pay attention to the aisles. What I've started to notice is that they'll have, like, greeting cards and then eye care and then vitamins, but if you look, it's just an entire aisle's worth of dietary supplements that they call vitamins.
There was that big scandal recently where a lot didn't even contain those herbs and botanicals, either.
It's weird because some people are saying they may have used the wrong testing methods, and there may be some validity to that, but it is true that there are huge quality-control problems with the supplement industry. It's dangerous to apply the aura of health that we associate with vitamins to all these other supplements.
That aura of health we associate with vitamins, especially when it comes to supplements -- how legitimate is it? Do we over-attribute health benefits to them?
I think the aura of health we give to vitamins, in terms of safety, is pretty legitimate if we're taking vitamins in the amounts we could get from our diet. A multivitamin is probably not going to hurt people, even if there's disagreement over whether it will help. We tend to think that if a little is good then more is better, and that's definitely not true with some of the vitamins like A, where there's acute toxicity: if you take too much it'll damage your liver. And then, in general, we just don't know what the long-term effects are of taking high doses of any of the vitamins over time, and some studies suggest it can be harmful; taking beta carotene was shown to increase the risk of lung cancer, which is unfortunate.
In the broader idea of health, vitamins really are miraculous to someone with a true deficiency -- for someone with scurvy or rickets, it's a cure that acts almost like a drug -- but there really aren't that many benefits that have been proven to be associated with taking higher-than-normal doses of them. I think a lot of the things we assume about both vitamins and supplements aren't really substantiated by science.
A lot of the misconceptions you highlight in the book, like our adherence to recommended daily allowances (RDAs), seem to have occurred when vitamins jumped from scientists to food marketers.
We take RDAs as the gospel truth; someone out there knows exactly how much of each vitamin I need. It was interesting to realize that that's not the case at all. They change a lot. You know those labels on the back of food that tell you how much of your RDA of, say, vitamin E you're getting? Those are actually based on the recommendations from 1968, and there have been many updates since then. It's like, wait a second -- this is based on out-of-date information.
You also argue that when we isolate vitamins in this way, we miss out on the other beneficial properties of the food that naturally contains them. Could you expand on what you mean by that?
First of all, when we focus too much on vitamins we lose sight of the fact that there are other things in food to begin with. If you look at a breakfast cereal, for example, you'll see that it's supposedly 100 percent of your RDA of these 13 chemicals and a bunch of minerals and you think, okay, my bases are covered and it's fine for me to eat whatever else I want. That does not take into account the fact that your cereal may actually have had a lot more stuff in it before it was refined and turned into cereal, and we don't understand what the potential benefits are of those other things in the wheat. So that's one thing.
There are a lot of chemicals that are now being investigated for potential health benefits. That's why you see so many headlines about resveratrol in red wine and things like that. The other thing I find particularly fascinating is the idea of how things can work differently in combination than they do when they're isolated. I mention in the book about broccoli, where giving people the particular chemical in broccoli did not work as well as when it was given to people as broccoli florets. My hypothesis is that there's some kind of enzyme or other substance in the whole broccoli that helps with the absorption and activation of this chemical, and you don't get it if you just put it in the pill.
Much like the way you don't know how a crowd of people is going to act compared to the individual people as you encounter them on their own, we just don't know how, exactly, dietary compounds are going to react in our bodies together versus when they're isolated and put into pills. It's an interesting cautionary thing to keep in mind, especially as the food industry and the supplement industry are putting out more of these food extracts and trying to take compounds that are in fruits and vegetables and put them in a pill. We just just keep in mind that that transformation doesn't always work.
And just because a food product is fortified with vitamins, that doesn't mean it's healthy.
Exactly. You can have a cupcake that gives you 100 percent of all your recommended dietary allowances, but it's still a cupcake.
Are there any laws or regulations restricting what claims food marketers can make about that sort of thing? Are you allowed to market a vitamin-enriched cupcake as a health food?
Yes, there are a lot of regulations about that that I would not be able to tell you about off the top of my head. For example, any of the breakfast cereals will say that they're an excellent source of Vitamin C, or whatever, and there are specific rules about what percentage of your RDA it has to contain in order to have that claim. They do have to follow the rules about how much this stuff actually has before they can put it on the label.
The book gets into the structure/function claims about immune system support, where supplement makers can make some very suggestive claims on their label that mean one thing to a consumer. They make it sound like you're going to treat a disease, but they don't actually say that -- so they don't get in trouble for it.
Your book ends with a modest proposal for a better way to think about health and nutrition. Do you want to talk about what that is, and how it's different from what we're being told right now?
At the end of the day, my conclusion was, in practical terms, similar to what we all know we should be doing anyway, which is eating fewer refined and processed products and supplements and more foods that naturally contain vitamins. The more interesting thing to me is the broader philosophical point of using vitamins as an example of how we've been manipulated into thinking about nutrition, making us think we can get away with eating whatever we want as long as we have vitamins. My hope is that once we recognize that, maybe we'll continue to eat some of the same things, but we'll at least be able to make intelligent decisions and recognize what's really healthy and what's not.
I was also really captivated by the idea of the protective diet, which was a term made up by this chemist in the '20s named Elmer McCollum, who played an important role in discovering vitamins A and C. He was writing a column for the popular press and he told the housewives he was writing for that they should serve their families these protective diets that had lots of green, leafy vegetables and foods that had a lot of vitamins to protect their health. The reason he used that terminology is that no one could really measure vitamins at that point, so you couldn't tell how much was in a particular food.
I love the idea of that now because I think we've swung way too far in the other direction, where we're trying to analyze our foods on the chemical details -- it's too much. I decided to abandon that mathematical approach to our diets and just say, hey, we know what foods are "protective," so let's just eat more of them.
I also think Americans really like to self-identify by a diet. We want to be able to say, I'm gluten-free, or I'm vegetarian, or I'm paleo, or whatever, but it's really boring to say something like, I eat according to the USDA's recommendations. It's kind of nice to be able to say, yeah, I eat a protective diet. I kind of like that! It gives you a catchphrase; it gives you a cool thing to say about the way you're eating, to kind of defend you against these other dietary trends. Like, you go ahead with your gluten-free; I'm just protective. It makes me feel superior!
I'm hoping this gives readers the reason to sort through all the news stories you see about vitamins and nutrition. We're so captivated by nutrition and there are so many studies that get done and that get covered by newspapers and magazines, but they're such preliminary science. One day vitamin D is going to make you live until 120 and the next it's going to give you cancer, you know what I mean? I'm hoping the book will give readers a better toolkit to tell which headlines to trust and not get so swayed by everything that shows up in the media. Now we have some of the scientific basis to know why that diet is preferable to what most of us are eating now, but we don't need to get too wrapped up in the scientific details in order to follow it.
Are there things we should be looking for in these studies? Things that we still really haven't figured out that would be useful?
We still don't know the long-term effects of most things. That's what makes nutrition such a difficult field to study: there are so many confounding variables because we all eat such different food every day, and you can't really do a randomized controlled trial on one particular food compound over 20 years, just to see what happens.
It's important for people to keep in mind that while it's great that we're studying this and while there has been a lot of great work done, there are some questions that we might never ultimately know the full answer to -- and maybe that's okay in terms of our day-to-day lives. We can figure out a work-around to that, and that's basically eating that protective diet.