High Fructose Corn Syrup is Not a Grocery Store Assassin

A step-by-step approach to evaluating medical claims on social media

Photo Credit: Bill Oxford

I’ve been asked about medical misinformation at almost every stop on my book tour. I'm glad this question is coming up because misinformation is an epidemic and can cause real harm, whether it results in taking unregulated pharmaceuticals (i.e., supplements, with the insinuation they can do things like “support” organs or improve “vitality”), making extreme dietary choices, or turning away from care that would have been helpful. Recently, a mom asked me how to get through to her teen daughter, who wants to go swimming when she has her period but is terrified to use tampons because TikTok has her convinced they are full of chemicals and, therefore, are harmful. Oh, how I hate the menstrual charlatans.

Medical misinformation is everywhere, and this is a problem because not only is it hard to escape, but you will almost always see it repeated multiple times on social media, and repetition breeds the perception of accuracy. And with social media, once you’ve seen the incorrect information, you will likely see it multiple times because the algorithm will feed more of what you have already watched. Propaganda and repetition work; that’s why this combination is a favorite tool of both snake oil salespeople and wannabe dictators. 

Because of the misinformation crisis, we often tell people to fact-check, but the problem is we don't teach people how to fact-check, so more often than not, “doing your own research” ends up with people finding incorrect information that falsely confirms the misinformation as truth. This is because most people head to Google and enter their questions or keywords, but Google is no replacement for a medical librarian. It won’t give you a well-curated answer; it will just give you the most linked to and viewed posts, whether they are correct or not.

Snake oil is short on research but amazingly skilled at optimizing web pages for search engines. Because many “alternative” claims are ludicrous, they are often repeated in headlines as clickbait, and while the truth may be buried deep in the article, most people don’t read beyond the headline or the first paragraph. In addition, many snake oil aficionados are repeating the same piece of misinformation across multiple websites, blogs, and podcasts. Unfortunately, Google trawls through the websites of chiropractors and supplement shills, as well as those for the CDC and the New York Times.

Here’s another important consideration. If the topic hasn’t been covered heavily in legacy media, by government agencies, or by medical professional organizations, which will be the case when something is either very new or utter bullshit, the result is a data void that allows crap to float to the surface. Remember, Google can’t distinguish credible from laughable, which is how fringe theories, like the claim that everyone should use a continuous glucose monitor to track their blood sugar, take hold. No legitimate medical professional or news source would have written about such an incredibly ludicrous concept, so there would be no true information to counter the fabricated misinformation. Multiple posts and podcasts from people promoting continuous glucose monitors over several months fill that data void with misinformation, and now a Google search produces something that looks credible but is not. In politics, Google’s algorithms tend to push people towards extreme and even false views, and I suspect the same is likely true of medical claims as well. Basically, misinformation is sexier to everyone, even your search engine. 

So, what should you do when experts tell you to vet the medical information you find online? I want to walk you through how I research health claims to give you some practical tips and tricks. 

Let’s look at this recent claim about high fructose corn syrup, made earlier this year by Mind Pelz, a chiropractor with over 500,000 followers on Instagram. As Pelz promotes herself as someone with expertise in nutrition, her claim is particularly concerning.

Some Background Information

High fructose corn syrup, or HFCS, is a dietary sugar or sweetener, like honey, table sugar, or maple syrup. HFCS is a misnomer as it doesn’t have a lot of fructose relative to other sugars; it is high in fructose in relation to regular corn syrup (think the Karo syrup you might have in your pantry). Regular corn syrup is 0% fructose (it’s all glucose), and HFCS is either 55% fructose (this is the kind used in sodas) or 42% fructose (used in baked goods and jams). Comparatively, table sugar is 50% fructose, and honey is 49% fructose. 

If you are rolling your eyes about how HFCS with either 42% or 55% fructose makes it evil while honey with 49% fructose might be natural and good, then you are on the right track. 

Let’s dig in. 

1. Is the Claim Fantastical?

Catastrophic or hyperbolic claims are almost always clickbait. So when you see fantastical statements, such as “High fructose corn syrup is the deadliest carbohydrate on the planet…” you should ALWAYS pause and fact-check. 

Real experts don’t tweet, post, or write medical content in hyperbole unless it’s truly catastrophic. For example, if the water supply at a sports arena were contaminated with botulinum toxin, you might see people legitimately tweeting and posting, “For the love of all that is holy, please don’t go to the game in Smallville tonight.” The water supply at a stadium being contaminated with botulinum toxin was a real storyline from Quincy (played by Jack Klugman), an amazing T.V. show from the 1970s and 1980s about a medical examiner who solved crimes (The episode was called Deadly Arena, and I remember it in detail because fear plus a good story sells!). High fructose corn syrup is not botulinum toxin in the drinking water, a venomous sea snake, or an assassin like Jason Bourne.

The fact the claim is so over the top and clearly trying to frighten you is a first sign that it is highly suspicious.

2. Evaluate the Source.

Pelz is a chiropractor, and their training does not make them medical experts. I don’t know what they are experts in, but it doesn’t appear to be evidence-based medicine. And while it’s possible that she, and other chiropractors, might post some good information some of the time, along the lines of getting more exercise and eating more vegetables, this content serves to create a bullshit sandwich, where misinformation is sandwiched between actual facts you probably already know. So you, the consumer, transfer the beneficence from the good advice (exercising and eating vegetables) to the misinformation (HFCS is a grocery store assassin). 

If the source sells supplements or advertises them or other products in the space, that is also a reason to be highly suspicious of their content. If there were a “Dr. Jen Gunter Vaginal Support Gummy,” you should rightly discount my advice on vaginal health as you wouldn’t know which of it was biased towards promoting my supplement.

If the information isn't from a credible source, you can discount it and not dive into the subject further. You might also reconsider whether this is an account worth your time.

3. Is there a Conspiracy Theory Involved?

The idea that high fructose corn syrup is out there murdering people in droves is a soft sell for a conspiracy theory. If you follow the implied “logic,” the only reason it’s not banned is the unnamed “THEY,” a collective who “don’t want you to know.” If people were really dropping dead from HFCS, it would be something we’d all have heard about through legitimate news sources and government agencies. 

4. Find Actual Experts and Cross Check

Google is no substitute for a medical librarian, which most of us don’t have access to, so we need to consider who would be a good expert instead. As this particular example involves food, registered dietitians are experts here, as are food scientists and many doctors, for example, endocrinologists and obesity medicine experts. My go-to evidence-based dietician is Abby Langer, and the food scientist I used is Erin, who goes by the handle Food Science Babe. The FDA is involved with food safety and dietary guidelines, so they are a good government source in the U.S., and the Harvard T. Chan School of Public Health and U.C. Davis Department of Nutrition typically also have good information. I tend to avoid legacy media, like The New York Times or the Washington Post, as they frequently dabble in “both side-ism,”  presenting misinformation with no scientific backing with equal weight as information backed by evidence, high-quality scientific studies, and presented by experts. Look, conflict makes a story.

You can jerry-rig the search engine to give you more factual results by including the expert (person or organization) you want in the search, for example, “High fructose corn syrup FDA.” 

Here’s what I found:

FDA

FDA receives many inquiries asking about the safety of HFCS, often referring to studies about how humans metabolize fructose or fructose-containing sweeteners. These studies are based on the observation that there are some differences between how we metabolize fructose and other simple sugars.

We are not aware of any evidence, including the studies mentioned above, that there is a difference in safety between foods containing HFCS 42 or HFCS 55 and foods containing similar amounts of other nutritive sweeteners with approximately equal glucose and fructose content, such as sucrose, honey, or other traditional sweeteners. The 2010 Dietary Guidelines for Americans recommend that everyone limit consumption of all added sugars, including HFCS and sucrose. FDA participated in the development of the Dietary Guidelines and fully supports this recommendation.

UC Davis

The Dietary Guidelines for Americans recommends that Americans eat less added sugars. This includes not just regular sugar, but also HFCS. There is no specific recommendation for HFCS.

Harvard T. Chan

High-fructose corn syrup isn’t necessarily worse for us than table sugar, but there is just too much of it in our food supply, says Harvard School of Public Health nutrition expert Frank Hu…While high-fructose corn syrup often gets blamed for the nation’s obesity epidemic, “we should worry about sugar in general,” Hu said.

Abby Langer

…even though your body may process some sugars differently, in the end, it’s all the same to your body. So for example, when a product advertises that it’s made with maple syrup instead of high fructose corn syrup (HFCS), that’s nothing but a cheap marketing ploy. Nothing about maple syrup is healthier than any other sugars…There’s no convincing evidence that one sugar is worse than the others for our health. That being said, as a population, it’s common knowledge that we eat too much added sugars, and no one will dispute that.

In my search, I also found an excellent article about HFCS from Daniel Feldman, a registered dietitian with a Master of Science in Human Nutrition. And, of course, his conclusion was the same as the sources I’ve already cited:

If other aspects of your nutrition are on point (total calories, macronutrients, vitamins, minerals, fiber, and water) then there is no need to worry about HFCS. That being said, since HFCS is a sweetener found in processed foods, and processed foods tend to be less nutrient dense and more calorically dense than unprocessed foods, foods with HFCS should generally constitute a small part of your diet (especially if your goal is weight loss). But there is nothing inherently bad about HFCS.

I also looked at several review articles and clinical trials, mostly to make sure they were being quoted or cited appropriately. And they all were.

So no, HFCS is not “deadly.”

A Deeper Dive

So where did the idea that HFCS is uniquely bad originate? Pelz is certainly not unique in promoting it.

The idea apparently stems from a 2004 American Journal of Clinical Nutrition paper that hypothesized a specific connection between HFCS in beverages and obesity. According to a 2013 review article on HFCS, sucrose, and fructose in the journal Advances in Nutrition, this original 2004 paper..

…triggered a debate about “metabolism and potential health effects of sucrose, HFCS, and fructose subsequently ensued. This debate has involved not only the scientific community but also major media outlets, the public at large, and policymakers. Controversies concerning these 3 sugars have been fueled by conditions that, in our view, created a “perfect storm” for confusion and mistaken identity. Even though the original authors of the AJCN commentary were clear that they were simply offering a hypothesis, other investigators, food manufacturers, and the public at large have contributed to this controversy, often without distinguishing between an association and cause and effect, while frequently confusing the sugars used in research studies, or exaggerating the implications of animal work.

This is what Dr. Popkin, one of the authors of that 2004 paper, told the New York Times in 2006,

It was a theory meant to spur science, but it's quite possible that it may be found out not to be true…I don't think there should be a perception that high-fructose corn syrup has caused obesity until we know more.

Sigh. Yes, a theory that spawned an industry.

Multiple Reliable Sources Provide the Same Answer

On the one hand, we have multiple credible sources with the same science-backed message–most of us eat too much added sugar, and HFCS is one of those added sugars, but it’s not uniquely bad; on the other, we have a chiropractor (and likely other folks) making an unsupported, fantastical claim. 

So, at this point, you could conclude that there is a vast conspiracy among all of the sources that have been cited and think through how all of these people and organizations coordinate with each other and try to come up with some explanation as to why they might all be in cahoots with big HFCS. OR, you could conclude the simpler, evidence-backed answer that a chiropractor is incorrect. Just because someone has many followers does not make them a credible source of information. I would trust Taylor Swift for information on making hit pop songs, but I would not trust her opinion regarding medical information (fortunately for us, she doesn’t comment on these kinds of things).

What Next

That might seem like a lot to go through to verify a claim, but it only took about 15 minutes to find three legitimate sources that reached the same conclusions. And that is what the data tells us we need to do. Protecting yourself from misinformation is worth those 15 minutes! 

If you can find experts and professional organizations who are true experts (and I know that can be hard), you can quickly search for the subject matter and their names. For example, I hope you Google content and my name or The Vajenda when you are trying to validate something related to gynecology or menopause. And now you know to add Abby Langer and Food Science Babe to your list for food-related claims. There are, of course, many others with good information!

One Last Step

When you find someone spreading misinformation, I recommend blocking them on all social media platforms. Misinformation is like wolves; it travels in packs, so this isn’t going to be the last piece of misinformation they share. When you block them, you tell the algorithm that you want less of that kind of content. This is critical as repetition creates a sensation of accuracy, and you don’t want HFCS truthers popping up left and right on your feed. Also, if someone is holding themselves out as a medical expert but is not interested in fact-checking their content or doesn’t know how to fact-check before they send their content out into the ether, in my opinion, they don’t deserve your attention. And don’t let FOMO, the fear of missing out, get to you; plenty of people out there are promoting good information and aren’t trying to convince you that HFCS is a grocery store assassin.

References

Aslett, K., Sanderson, Z., Godel, W. et al. Online searches to evaluate misinformation can increase its perceived veracity. Nature 625, 548–556 (2024). https://doi.org/10.1038/s41586-023-06883-y

Rippe JM, Angelopoulos TJ. Sucrose, high-fructose corn syrup, and fructose, their metabolism and potential health effects: what do we really know? Adv Nutr. 2013 Mar 1;4(2):236-45. doi: 10.3945/an.112.002824.

White JS. Straight talk about high-fructose corn syrup: what it is and what it ain't. Am j Clin Nutr 2008;88: P1716S-1721S.

Moeller SM, Fryhofer SA, Osbahr AJ 3rd, Robinowitz CB; Council on Science and Public Health, American Medical Association. The effects of high fructose syrup. J Am Coll Nutr. 2009 Dec;28(6):619-26. doi: 10.1080/07315724.2009.10719794

Feldman D. High-Fructose Corn Syrup: Should We Be Afraid? https://biolayne.com/articles/nutrition/high-fructose-corn-syrup-should-we-be-afraid/

Bray GA, Nielsen SJ, Popkin BM. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. Am J Clin Nutr. 2004 Apr;79(4):537-43. doi: 10.1093/ajcn/79.4.537.

Lowndes J, Kawiecki D, Pardo S, Nguyen V, Melanson KJ, Yu Z, Rippe JM. The effects of four hypocaloric diets containing different levels of sucrose or high fructose corn syrup on weight loss and related parameters. Nutr J. 2012 Aug 6;11:55. doi: 10.1186/1475-2891-11-55. 

Lustig, R. H. (2010). Fructose: Metabolic, Hedonic, and Societal Parallels with Ethanol. Journal of the American Dietetic Association, 110, 1307-1321