HFCS: Worse than Sugar?
Ahh the 1970s — the era when polyester, bell bottoms, disco, and shag carpets on walls and chests alike were introduced.
Luckily, most of these guests were asked to leave by the ’80s, but there’s is one child of the ’70s that has been embraced, even though it’s way scarier than a white polyester suit and platform shoes with goldfish – it’s high fructose corn syrup (HFCS).
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| Can we just agree to forget this decade? | |
Yup, HFCS was introduced way back in the 1970s. Unlike toga parties and 8-track tapes, HFCS is still around and even more popular. Its use increased 1000% (yes, that’s one thousand percent) from 1970 to 1990 [1].
What is high fructose corn syrup?
The name high fructose corn syrup is kinda misleading, since most HFCS is only about 55% fructose.
HFCS is referred to by its fructose composition. HFCS-42 (42% fructose) is used in things like baked goods, while HFCS-55 (55% fructose) is often used in sodas and juices. HFCS-90 (90% fructose) is rarely used in anything you’d eat; manufacturers use it to make other things like less-concentrated HFCS.
Table 1 shows how HFCSs compare with other sweeteners like sugar (sucrose) and honey [2].
TABLE 1 Carbohydrate composition of common nutritive sweeteners1
| Component | HFCS-42 % |
HFCS-55 % |
Corn syrup % |
Fructose % |
Sucrose % |
Honey % |
| Fructose | 42 | 55 | 0 | 100 | 50 | 49 |
| Glucose | 53 | 42 | 100 | 100 | 50 | 43 |
| Others | 5 | 3 | 100 | 0 | 0 | 51 |
| Moisture | 29 | 23 | 20 | 5 | 5 | 18 |
1 Mostly sucrose.
Since HFCS is cheaper than other sweeteners, it has ended up in pretty much everything that needs sweetening – from soda pop to ketchup.
HFCS and obesity: the great debate
| How bad is fructose? Experts weigh in
If you’re interested in reading a scientific debate between scientists, take a look at an American Journal of Clinical Nutrition editorial and the rebuttals. How bad is this HFCS stuff anyway? vs Where’s the smoking HFCS gun? In the end they all pretty much agree: more research needs to be done to prove a link between HFCS and obesity. |
Since the 1970s and the introduction of HFCS, the US population has become increasingly obese. Some researchers think there is a link [2] while other researchers disagree [1]. Problem is, there isn’t a heck of a lot of data to prove that long-term exposure to HFCS causes obesity.
When I picked up this week’s review I fully expected read a study about HFCS causing obesity, but what I got was very much different.
Bocarsly ME, Powell ES, Avena NM, Hoebel BG. High-fructose corn syrup causes characteristics of obesity in rats: Increased body weight, body fat and triglyceride levels. Pharmacol Biochem Behav. 2010 Feb 26. [Epub ahead of print]
Methods & results
This article is actually two studies: one short term and one long term.
Since all the studies were done on rats, “short term” is 2 months and “long term” is 6 to 7 months. Keep in mind that a rat’s lifespan is about 2-3 years, so 6 months is about a quarter of their lifespan. That translates to about 20 years for a human’s lifespan.
Experiment 1 – Short-term effects of high fructose corn syrup
For the short term the scientists compared 4 groups of male rats:
- Control:– water only + rat chow
- 12 hours high fructose corn syrup (12h-HFCS): 8% (0.24 cal/ml) high fructose corn syrup available for 12 hours/day + water + rat chow
- 12 hours sugar (12h-sucrose): 10% (0.4 cal/ml) sugar available for 12 hours/day + water + rat chow
- 24 hours high fructose corn syrup (24h -HFCS) – same as 12h-HFCS, but with 24 hour access to HFCS
Results – Experiment 1
The headline result for this experiment goes something like this, “Daily 12 hour access to high fructose corn syrup leads to more weight gain than equal access to sugar.” And it’s true: the 12h-HFCS group gained more weight than the sugar group – but there is a little problem.
Pretty definitively, HFCS causes more weight gain than sugar!
But what about the rats that got HFCS for 24 hours — they must have gotten huge, right? Nope, take a look at figure 1.
As you can see, things get messy. The 24-hour HFCS rats actually weighed less than the 12-hour HFCS and the 12-hour sucrose rats!
Messy is never good for a sound bite or a press release.
Figure 1 – Body weight (grams) of rats male rats after 8 weeks on with access only to water (control), 12 hour access to sugar (12 h sugar), 12 hour access high fructose (12h HFCS) or 24 hour access to high fructose corn syrup (HFCS)
There are two main points of messiness:
- More time to drink HFCS didn’t mean the rats drank more.
- The sugar group actually took in the most extra calories of any group (about 31 cal/day).
Both HFCS groups (12 hour and 24 hour access) drank the same amount of HFCS (about 20.5 cal/day, give or take 2 calories), but somehow the 12 hour HFCS group gained more weight than the 24 hour HFCS group.
How can you have weight gain with the same calories and same solution — but different period of consumption? This is a big problem with the study.
Since the initial concentration of sugar water is higher than HFCS (0.4 cal/ml vs. 0.24 cal/ml) this difference is probably why the sugar group drank more calories.
Why not the same concentration for the sugar and HFCS groups? This is a minor problem with the study, but still makes it hard to compare sugar to HFCS.
Experiment 2 – Long-term effects of high fructose corn syrup
For the long term (6 month) study, male rats were put into three groups:
- Control group;
- 12 h HFCS group; and
- 24 h HFCS group
Notice there was no sugar group. Why? Honestly, I can’t think of a sound scientific reason why the researchers decided not to include a group with access to sugar, since experiment 1 had this group.
Results – Experiment 2
The not-so-surprising results: access to HFCS caused more weight gain than the control.
Weird thing is in this experiment, compared to the first, 24 hour access to HFCS did cause more weight gain than 12 hour access – take a look at figure 2 below.
Figure 2 - Body weight (grams) of male rats after 6 months on with access only to water (control), 12 hour access high fructose (12h HFCS) or 24 hour access to high fructose corn syrup (24 h HFCS). There is no data on 12-hour sucrose consumption.
The researchers also took a look at female rats and found that only the 24h HFCS group gained more weight than the other groups. This time, researchers did include a sugar group. Figure 3 below is a summary of female weight gain.
Figure 3 - Body weight (grams) of female rats after 6 months on with access only to water (control), 12 hour access to sucrose (12 h sugar), 12 hour access high fructose (12h HFCS) or 24 hour access to high fructose corn syrup (24 h HFCS)
Conclusion
“High-fructose corn syrup prompts considerably more weight gain, researchers find” Science Daily.
“A sweet problem: Princeton researchers find that high-fructose corn syrup prompts considerably more weight gain” Princeton Review.
Despite the promising press releases and sound bites, this article has too many big problems to be able to believe the results.
The first problem is the finding that in the short term, rats gain more weight with 12 hour HFCS access than 12 hour sugar access, but not with 24 hour HFCS access.
Then later on in the long term study, we do see that 24 hour HFCS access leads to more weight gain than 12 hour access, but this time there is no sugar group to compare with HFCS.
Karen Kaplan of the LA times got it right with her headline: “A not-so-convincing case that high fructose corn syrup is worse for you than sugar.”
Bottom line
Do I think high fructose corn syrup (HFCS) is good for you? Definitely not.
Do I avoid HFCS? Heck yes.
Does this study convince me that HFCS causes more weight gain than sugar? Nope, this study has too many problems both in design and in results to prove anything.
Further reading
All About “Natural” Sweeteners
Sources
- 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;79:537–43. (Published erratum appears in Am J Clin Nutr 2004;80:1090.)
- White JS. Straight talk about high-fructose corn syrup: what it is and what it ain’t. Am J Clin Nutr. 2008 Dec;88(6):1716S-1721S. Review.