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Why You Shouldn't Feel Bad About That Burger and Diet Coke, According to a Pediatrician

Artificial sweeteners cause cancer? Only in mice. Eggs increase cholesterol? Nonsense. Red meat is dangerous? The alternative is a lot more so. Dr. Aaron Carroll, author of 'The Bad Food Bible,' wants to put sanity back on the dinner table



NEW YORK – Few Americans have earned the dubious honor of receiving a court order ordering them to reveal their email correspondence. One of them is Aaron Carroll, who went through the ordeal two and a half years ago. “An advocacy organization in California used open-access laws in Indiana to demand that I hand over all my emails about artificial sweeteners and any companies that might sell diet soda,” he relates in his 2017 book “The Bad Food Bible: How and Why to Eat Sinfully.” The experience, though it did not have any legal repercussions for him, was nothing short of traumatic. “It was a terrible violation of my privacy, and it ruined a month of my life,” he writes.

Prof. Carroll’s case is a genuine anomaly, if we take into account that his privacy was invaded not in the name of homeland security. He’s an esteemed pediatrician, a columnist for the New York Times, associate dean for research mentoring at Indiana University’s School of Medicine and director of the university’s Center for Pediatric and Adolescent Comparative Effectiveness Research.

It all started, he told me in a phone conversation last month, with an article he wrote for the Times in 2015 “saying that the evidence doesn’t say that artificial sweeteners are that bad for you. Given that the choice is often between artificial sweeteners and added sugars – and we know that added sugars are bad – I would choose diet [beverages] at any given time, for me and my kids.”

Readers’ reactions were swift in coming and vitriolic. “People lost their minds,” he recalled. “The comments at the Times were: Why wasn’t my license to practice medicine taken away from me, and even, why were my children not being taken away from me for letting them have diet soda.” He added, “I was accused of having secret agreements with corporations that produce these things, of being paid off – they even tried to go through my email to show that I was paid off. None of it is true. But people are very passionate about it.”

Marina Waters

At the same time, Carroll wants to make it clear that he is not advocating the consumption of artificially sweetened beverages – all he wants is for things to be kept in proportion. From his point of view, it’s like milk, he explained: “You don’t have to drink it. All I am saying is that the evidence against artificial sweeteners is weak.”

How do you explain all the recent studies that have indicated a clear connection between drinking Diet Coke and such diseases as cancer, dementia and others?

Carroll: “Some studies on mice lead to remarkable advances in medicine for human beings. But to take studies of mice alone and to extrapolate from those small studies to major ideas about human nutrition is problematic, especially when we often have much better and larger studies of people. Artificial sweeteners are a perfect example. They gave mice a huge amount of artificial sweeteners, and eventually some of them developed bladder cancer. From that they extrapolate that human beings, too, would develop bladder cancer. Yet we have huge numbers of human beings consuming large amounts of artificial sweeteners without any significant increase in bladder cancers. So, to rely on small studies of mice to make these generalizations doesn’t make much sense.”

Are you suggesting that we ignore these studies entirely? After all, you yourself maintain that experiments on laboratory animals are often very important.

“More often than not, these studies don’t bear out when we stretch them to human beings. It’s a bad interpretation of science. We should take those [studies] and move on to the next step. It’s not that they don’t have value, but we should be very careful about generalizing about people based on a small study of a small number of mice.”

A case in point, he notes, is saccharin, the first artificial sweetener, invented in the late 19th century and still considered the most famous and most widely used of its type in the world. “It turns out that scientists had to work pretty hard to come up with evidence that ‘determined’ a causal link between saccharin and cancer,” he writes in “The Bad Food Bible,” and elaborates: “More than fifty studies had been published looking at the use of this sweetener in rats In only one of those studies did huge amounts of saccharin produce cancer, and it was in a type of rat that is frequently infected with a bladder parasite that would leave it susceptible to saccharin-induced bladder cancer.” In fact, he notes, “this link between saccharin and bladder cancer has never been confirmed in humans.”

Just as Carroll is skeptical about the possible harm caused to humans by artificial sweeteners, so he is definitive and decisive concerning the destructive consequences of sugars. “The epidemiologic evidence suggests correlation – not causation, mind you, but a distinct correlation – between sugar consumption and death,” he writes in his book. In addition, “while artificial sweeteners are calorie-free, added sugar is a source of empty calories. Sugar drinks don’t fill you up; they just add to your energy intake. How can that be good?”

Of course, no one needs soft drinks, he adds. “Nor does anyone need beer, scotch, cheesesteaks, pizza, or apple pie. But the fact is, I love these things, and I like to have them once in a while.”

What doesn't kill you

In many cases, Carroll maintained, the conclusions reached by nutrition studies are mutually contradictory. Accordingly, it’s impossible to know which are valid. “There was a great study that was published in 2012,” he related. “They took a cookbook and picked 40 random ingredients. The researchers looked at more than 260 studies, and for every ingredient you could find a study that said either that it prevented cancer or it caused cancer.”

Nevertheless, in recent years, if there is one subject on which consensus exists among scientists, it’s the serious damage caused to human beings by artificial sweeteners. Just last April, a comprehensive study on the subject was published by scientists from the neurology department of Boston University’s medical school. The widely quoted research indicates a direct correlation between artificial sweeteners and brain damage, including the possibility of stroke and dementia. That study, by the way, was not done on mice.

Bloomberg

For ten years, the researchers monitored the beverage consumption of almost 3,000 people over the age of 45, and of about 1,500 more aged over 60. “After adjustments for age, sex, education (for analysis of dementia), calorific intake, diet quality, physical activity and smoking, higher recent and higher cumulative intake of artificially sweetened soft drinks were associated with an increased risk of ischaemic stroke, all-cause dementia and Alzheimer’s disease dementia,” the co-authors write.

A study that appeared last year in the journal of the Canadian Medical Association found an association between consumption of artificially sweetened food and possible weight gain and damage to the digestive system and the body’s metabolism. Researchers from the University of Manitoba reviewed 37 studies on the subject, which between them observed more than 400,000 individuals who ate foods containing “nonnutritive sweeteners.” “The trials did not show a consistent effect of artificial sweeteners on weight loss, and the longer observational studies showed a link between consumption of artificial sweeteners and relatively higher risks of weight gain and obesity, high blood pressure, diabetes, heart disease and other health issues,” according to a press release from the University of Manitoba.

According to one of the study’s authors, Dr. Ryan Zarychanski, from the University of Manitoba’s Faculty of Health Sciences, “data from clinical trials do not clearly support the intended benefits of artificial sweeteners for weight management.”

In addition to examining the results of seven randomized, controlled trials that followed 1003 people who were asked to follow a specific diet over some six months, the survey also looked at another 30 studies that observed more than 400,000 people for average periods of a decade, during which the subjects were not requested to change their eating and drinking habits. There, too, a worrisome picture emerged, in which consumption of artificial sweeteners was associated with bigger waistlines, an increasing tendency to weight gain and greater likelihood of digestive tract problems.

According to Dr. Meghan Azad, who specializes in the study of pediatrics and chronic diseases at Manitoba, and who headed the Canadian study, “Based on all of the research done so far, there is no clear evidence for a long-term benefit, but there is evidence of potential adverse effects from the long-term consumption of artificial sweeteners.” At the same time, even Azad added, in an email, the results need to be taken with a grain of salt, because “overall, there is a lack of evidence for the long-term health effects of these products, and more research is needed.”

What would be your recommendations to the public?

“This should inspire consumers to think about whether they want to be consuming artificial sweeteners, especially on a regular basis, because we do not know if they are a truly harmless alternative to sugar. People are generally consuming NNS [nonnutritive sweeteners] believing they are a ‘healthy choice,’ but this may not be true.  More importantly, our results send a strong message to researchers and research funding bodies that more studies are needed to understand the long term health impact of artificial sweeteners.”

Carroll is not impressed by these studies. They are, in his view, further evidence of a tendency toward hysteria and, in large measure, even toward manipulation by researchers of conclusions involving human beings. “Fine,” he says with unabashed disdain for the primary University of Manitoba conclusion, adding that he won’t even argue with their primary conclusion, namely that the consumption of artificial sweeteners doesn’t help keep weight down. There are studies in which people were asked to drink diet beverages and lost weight, and other studies in which consuming diet drinks didn’t lead to weight loss, Carroll points out. In sum, he says, he does not tell people to drink diet beverages in order to lose weight; what he’s saying is that people shouldn’t be afraid to drink those beverages, because it won’t kill them.

What about the 30 observational studies that suggested a correlation between the consumption of diet beverages and obesity?

“They’ve done these studies before, and they find that those who drink diet soda tend to be overweight. But it could be that people who are overweight tend to drink more diet soda – not that drinking diet soda causes overweight, but that people who are overweight tend to drink more diet soda in order to lose weight. Randomized controlled trials find that you don’t gain weight on artificial sweeteners, and you often lose weight.” In short, Carroll says, “The explanation that being overweight and being not healthy make you want to drink more diet soda makes much more sense.”

Milk = beer

Besides targeting the widespread skepticism toward diet drinks, Carroll’s book is out to overturn some of the most deeply rooted concepts about the global food industry. In chapter after chapter, dealing with butter, eggs, beef, milk, coffee, alcohol and fish, the author slaughters sacred cows and debunks prevailing notions. Eggs elevate cholesterol? Arrant nonsense. Red meat is dangerous? The alternative – a diet heavy on carbohydrates is far more so. Concern about salmonella bacteria in uncooked eggs? That's a false fixation. Milk is healthy for the bones? A tall tale.

Not that Carroll says that it doesn’t matter what you eat. He just wants to lower the pressure level a bit, to redraw the line between awareness and hysteria, and to allow us to enjoy the occasional meal of a steak oozing with fat and washed down with a large Diet Sprite.

“My job is to try to take data and evidence and help people make better decisions about health and health policy,” he says, explaining why he wrote the book. “As I read more and more about food and nutrition, I realized how bad the evidence is, and how little there is to tell us what we should and shouldn’t do in respect to eating. Yet this hasn’t stopped different groups around the world from making sweeping proclamations about which food is good and bad for you.” His aim, then, is to show how flimsy the “facts” and “evidence” can be, and to make people understand that they “probably don’t need to worry as much as they do.”

In a reverse image of the legitimacy Carroll bestows on diet beverages, milk is high on his blacklist. “The U.S. Department of Agriculture (USDA) recommends that adults may potentially drink 3 cups a day [of milk] to meet their daily dairy requirement,” he writes in the book, and “Milk is good for our bones, dairy producers tell us; it contains calcium and vitamin D But there’s not much evidence for these types of claims. In fact, the research often flat out contradicts them.”

Illustrating his point, Carroll cites a 2011 meta-analysis published in the Journal of Bone and Mineral Research. “Six studies of almost 200,000 women could find no association between drinking milk and lower rates of fractures,” he writes. He also points to a 2014 study, involving almost 100,000 men and women, which again found no evidence that milk consumption correlates with less likelihood of hip fractures later in life.

Yet another research study, carried out at Uppsala University, in Sweden, monitored the milk consumption of almost 110,000 men and women aged 39 and above. “These researchers,” Carroll writes, “found similar results, reporting that drinking milk was not associated with any protection for men, and was actually correlated with an increased risk of fractures in women, and an increased risk of death in both sexes.”

It follows, Carroll writes, that “Any recommendation to drink 3 cups of anything (besides water) daily should raise a red flag. Milk is not a low-calorie beverage. Even if people drink nonfat milk, 3 cups a day means they’re consuming 250 calories. Low-fat or whole milk has even more calories. In an era when seemingly every other caloric beverage is being demonized out of concern that it’s causing obesity, doesn’t it seem strange that milk still gets a pass?”

Don’t you think it’s overdoing it to tell people to avoid milk? There are worse things, aren’t there?

“I don’t think milk is bad, I just think we should put it in the same category that we put every beverage with calories. You can have it if you want it, but you don’t need to be under the illusion that you need it, that it makes our bones strong, gives us good teeth.”

In fact, in the book you say that we should treat milk the same way we treat alcohol.

“There is a large amount of research that shows that the consumption of light or moderate amounts of alcohol is often associated with health benefits. And the same studies that show that it might increase the chances of some kind of cancer also show that it decreases the chances of heart disease, diabetes and even death. We should treat all beverages with calories that way: They are fine if you have them in moderation, but you shouldn’t be under the illusion that you need them, and in that respect I would put milk in the same category as alcohol.”

Still, he writes in the book, “there are some pretty compelling reasons why you would want to consume milk – reasons that have more to do with pleasure than with health. What else would you put on your cereal? And cookies without milk would be unthinkable. There’s nothing wrong with having an occasional glass of milk just because you like it.”

When it comes to milk, there’s at least one other point on which Carroll finds himself in good company. An article, titled “Calcium and Milk,” published recently on the website of Harvard University’s School of Public Health, states explicitly that “high intake [of calcium and dairy products] can increase the risk of prostate cancer and possibly ovarian cancer.” The first of five recommendations in this connection states, “Limit milk and dairy foods to no more than one to two servings per day.”

An even more assertive approach is taken by Dr. Charles Platkin, director of the New York City Food Policy Center at Hunter College.

“I try not to drink milk, first of all because it’s animal fat, but that’s not the only reason,” he told me, in a phone conversation. “When a beverage or any food has such a powerful lobby behind it, I grow suspicious and I want to be very careful about its true nutritional value. With regard to both milk and red meat, the public has not been given the real information about the consequences of eating them. The reason is that they have the backing of a very powerful industry that has vast strength and considerable political influence, which funds quite a few of the studies we read on the subject.”

As a nutritionist and as the director of the NYC Food Policy Center, how can you help people navigate among so many studies, which are often mutually contradictory?

“I agree with you that it’s very confusing. Still, there are things that we know today, such as that there are problems with animal meat. We’re not sure exactly what the problem is, but we know there is a problem. We know that of all the things we can eat, vegetables are apparently the optimal possibility. As for sweetened or diet beverages, the answer is clearer to me than for anything else: drink water or water with [whole] fruits or soda water.”

Do you recommend avoiding beef?

“I personally don’t touch meat. I stopped with that 25 years ago. At the time, a lot of studies were published about the danger involved in beef consumption. It’s true that since then new studies have appeared that contradicted the earlier ones. But I still feel great concern about animal protein. If you eat beef, I recommend not more than once a week.”

Recent years have indeed seen growing calls to limit or totally avoid red meat, particularly the processed kind. One of the most troubling, and comprehensive, studies on this subject was published in 2015 by the International Agency for Research on Cancer, a division of the World Health Organization. The authors examined more than 800 studies and experiments conducted worldwide connected to the effects of beef on human beings. The unequivocal findings generated a global scare. For one thing, the agency’s researchers maintain that an average daily consumption of one meat sausage increases the risk of contracting intestinal cancer by 18 percent. The report also found that no fewer than 34,000 people die worldwide every year from cancer that is related to diets rich in processed meat. By comparison, about one million people die each year from lung cancer caused by smoking, and 600,000 a year from drinking alcohol.

But here, too, Carroll bucks the trend. “It’s possible that no food has been attacked as widely or as loudly in the past few decades as meat,” he writes in “The Bad Food Bible,” and elaborates, “Advocates of meatless diets push them for lots of different reasons, perhaps the biggest being the claim that they can reduce the risk of cancer.”

That campaign has borne fruit, Carroll says. In 1950, according to data he cites in the book, the average American consumed 49 kilograms (107 pounds) of red meat a year. Fifty years later, it was 52 kilos. But in 2012, in the wake of growing awareness generated by the many studies cautioning about the dangers that reside in eating red meat, per capita annual consumption of beef decreased to 32 kilos (71 pounds) a year.

“If meat, especially red meat, is all that bad for you, the United States should be seeing massive declines in obesity rates or deaths from cardiovascular disease,” Carroll writes. “But Americans are not getting any less fat, nor does their decline in meat consumption seem to be lowering their likelihood of dying from heart disease.”

The explanation is obvious, Carroll avers. The avoidance of red meat did not create a vacuum on the plates of millions of hungry Americans. They replaced the hot dogs and the hamburgers with other foods that are more fattening and less healthy. “When people cut fats and meat out of their diets, they must eat something else. For diners in the late 20th century, this meant turning to grains and other carbohydrates. The results weren’t pretty. Obesity rates shot through the roof, as did the incidence of diabetes and heart disease,” Carroll writes.

He accuses some researchers of deliberately manipulating their findings to make them sound more extreme. In many studies, Carroll notes in the book, “people in the highest consumption group were defined as eating one to two servings of red meat a day. The people in the lowest group ate about two servings a week. If you’re eating multiple servings of red meat a day, then, yes, you might want to cut back. But if you’re eating only a couple of servings a week, you’re probably doing great.”

Beneficial cholesterol

But before dinner comes breakfast, which for many Americans can sometimes mean a choice between pancakes with chocolate chips dripping with maple syrup, a Belgian waffle topped with whipped cream, muffins, or a three-egg omelet with a few strips of bacon and French fries on the side. Those who want to feel a bit better with themselves will forgo the bacon, and the extremists will eat an omelet made from egg whites. Carroll, as is probably clear by now, is not one of them.

“In an attempt to try to find a way to eat eggs without getting all that cholesterol, I turned to egg-white omelets,” Carroll relates in his book. “Disagree with me if you want, but I think egg-white omelets are a crime against nature. They have no taste. The texture is all wrong. They don’t hold together well. And they don’t feel satisfying as you eat them – or after. I choked them down, but with great protest. Over the course of my life, I have tried all the egg substitutes as well. They’re similarly flawed.”

Carroll, it should be emphasized, doesn’t deny that eggs contain cholesterol, but in the same breath, he explains that “many factors have been linked to heart disease, and cholesterol is just one of them. In fact, we need cholesterol. It’s not poison,” he asserts in the book, and elaborates, “The liver makes about 1,000 mg of it [cholesterol] a day, because it’s absolutely necessary to create certain vitamins and hormones, build parts of your cells, and help digest and move fat around your body. All told, our bodies synthesize three to four times more cholesterol than most people eat in a day. Clearly, it’s important.”

He also quotes studies that refute the connection between the number of eggs we eat and blood cholesterol level. A 2004 study, he writes, “randomized participants into two groups. One group was given the equivalent of more than three eggs a day for thirty days, and the other received a placebo. Then they switched the groups, so that those who had been consuming the eggs started to get the placebo, and those who had been receiving the placebo started to eat the eggs. To see how egg consumption affected their blood, the researchers measured the participants’ cholesterol after the first thirty days and then after the second thirty days. What they found is that about 70 percent of people are what we call ‘hyporesponders’ to dietary cholesterol. This means that their blood cholesterol levels have almost no relationship to how much cholesterol they eat.”

So we can eat eggs to our heart’s desire, is that what you’re saying?

“Part of the problem with cholesterol is nutrition-related, and a lot of it is genetic. But we now know that it is absolutely wrong to say that eating cholesterol will give you high cholesterol [levels]. You don’t need to worry about eating cholesterol, eggs are fine. When it comes to cholesterol, besides genes, some of it may be diet and exercise, but what it’s not [caused by] is the cholesterol that you eat. I’d rather see my kids have a breakfast full of protein like that than a breakfast full of carbs.”

To sum up, let’s quantify. How much red meat, eggs and dietetic beverages do you and your family consume every week?

“I drink two-three cans a week, my kids probably drink more. I eat red meat three times a week. I probably have six-seven eggs a week, but I wouldn’t be surprised if my kids have 10-12 eggs a week. It’s a good source of protein, it’s healthy.”

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