Is All Sugar Created Equal? | Chris Kresser
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Is All Sugar Created Equal?

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There are so many varieties of sugar. But is all sugar the same? istock.com/tashka2000

You’ve probably heard it countless times, especially in low-carb circles: sugar is sugar is sugar. This is true in principle – the glucose, fructose, and sucrose found in table sugar or high fructose corn syrup (HFCS) are the same molecules as the glucose, fructose, and sucrose in honey, fruit, and starchy vegetables.

But when it comes to the way your body uses these sugars, these foods are hardly comparable. In this article, I’ll show you why all sugar is not created equal, and why you should care.

Does sugar from fruit and starchy vegetables have the same impact on your health as a candy bar?

Fructose and High Fructose Corn Syrup Are Not the Same Thing

In my previous post in this series, I compared HFCS with white sugar and concluded that these two sweeteners are more or less metabolically equivalent. In the comments section, a few people brought up research showing that fructose is metabolized very differently from glucose; in fact, it’s metabolized more like alcohol.

I’ll address that research in a second, but first, understand this: high fructose corn syrup is not the same thing as fructose. Fructose is a simple sugar molecule with a specific chemical structure, while HFCS is a mixture of fructose and glucose in a roughly 1:1 ratio.

Now, there are certainly some scary studies about the metabolic effects of pure fructose. In animal models, fructose administration can cause dyslipidemia, non-alcoholic fatty liver disease, insulin resistance, and even type 2 diabetes. (1)

But these harmful effects result from animals being fed large amounts of pure, isolated fructose. In this form, fructose does act much like a toxin in the body, and it would be a terrible idea to start sweetening your food with pure fructose. But because fructose isn’t found in isolation in nature or even in our food supply, these studies are largely irrelevant to practical nutrition.

Already, we’re beginning to see that all sugar is not created equal, and that form and “packaging” makes a huge difference in metabolic effect. In this case, pure fructose does not affect the body the same way as fructose in sugar or HFCS. Now, what about fructose in fruit?

Fruit: More Than Just a Hit of Sugar

Although conventional wisdom holds that fruit is unquestionably a health food, the push to avoid sugar and excess carbohydrates has in many cases left people hesitant, even afraid to eat fruit. While it’s typically acknowledged that eating an apple is better than eating a bag of candy, fruit is still often seen as a source of sugar that should be consumed in strict moderation, and the phrase “sugar is sugar” is a common refrain, especially in Paleo or low-carb communities. The problem with this viewpoint is that added sweeteners and fruit have completely different metabolic effects.

First of all, the fiber and water found in whole fruit increase satiety, which makes it less likely that you’ll go into caloric excess. Studies going back more than forty years have shown that naturally occurring sugars in fruits are beneficial to health and do not promote weight gain, and we can see these effects in traditional cultures such as the Kuna, who obtain a significant percentage of their calories from fruit while remaining lean. (2, 3)

And despite some claims to the contrary, there’s no evidence that we should avoid whole fruit simply because it contains fructose. (4) Far from being a health hazard, like pure fructose or added sweeteners, studies overall suggest that eating whole, fresh fruit may actually decrease the risk of obesity and diabetes. (5) Additionally, randomized controlled trials have shown that eating fruit reduces oxidative stress markers and blood glucose in diabetics. (6) Further, limiting fruit intake has no effect on blood sugar, weight loss, or waist circumference. (7)

For most people, 3-5 servings of fruit per day is perfectly fine, although certain people with insulin resistance, diabetes, or metabolic syndrome may see improvements by restricting fruit intake to one to two servings a day, and by choosing fruits that are lower in sugar. Additionally, some benefits of fruit restriction for digestive issues come more from avoiding high FODMAP fruits as opposed to fruits altogether.

Solid Sugar vs. Liquid Sugar

Another angle to consider is the issue of sweeteners in beverages versus sweeteners in solid foods. Countless studies have demonstrated that drinking your sugar has uniquely harmful effects, primarily because most people fail to reduce their caloric intake to compensate for the extra calories they’re consuming in sweetened drinks. (8)

For example, a study of 323 adults found that subjects who increased the number of calories they obtained from sugar-sweetened beverages didn’t decrease their caloric consumption from other sources. (9)

Another study showed that total calorie intake among sixteen patients was greater on the days that sugar-sweetened beverages were given at lunch than on the days they weren’t. So even when the sweetener used is the same (usually sugar or HFCS), consuming it in a beverage will have different health effects than consuming it in a food.

Real Honey vs. Fake Honey

I’ve already written about the unique metabolic effects of honey, and there have been studies comparing the effects of honey and “artificial honey” on blood lipids, insulin response, and blood sugar. Although artificial honey is a mixture of glucose and fructose in the same ratio as was found in natural honey, its metabolic effects are completely different.

In one study, supplementation with real honey decreased triglycerides and LDL cholesterol, increased HDL cholesterol, and even decreased plasma homocysteine. (10) On the contrary, the artificial “honey” raised triglycerides and LDL cholesterol. Other similar studies have found that natural honey results in more stable postprandial blood sugar and insulin response when compared with artificial honey. (11, 12)

There are further examples that I won’t get into, but I hope I’ve demonstrated that the phrase “sugar is sugar” is simply not accurate when it comes to nutrition and “real” food. The source of sugar does make a difference, and we as a community need to be careful about generalizing study results where they may not apply, and demonizing foods that don’t deserve to be demonized.

If you missed any of the previous articles in this series on sweeteners, be sure to check them out below, and stay tuned for the final post where I’ll tie everything up and give you some practical tips on where sweeteners should fit in a healthy diet. If you’re looking for a great brand for natural raw honey, I recommend Beekeeper’s Naturals.

Now, I’d like to hear from you. Did you believe that all sugar is created equal? Do you now? Share your thoughts in the comments!

Previous articles in this series:

104 Comments

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  1. Chris, you stated “studies overall suggest that eating whole, fresh fruit may actually decrease the risk of obesity and diabetes. (5)”
    But when I followed the link what the study actually said was “Separately, quantity of vegetable intake (0.76 [0.60-0.97]), but NOT fruit, was inversely associated with T2D in adjusted analysis”

  2. All I know is that I’m sick of people refusing to eat a freaking banana because it’s going to make them fat – sheesh.

    Thanks for the article Chris – very edifying!

  3. What’s the verdict on agave, then? I hear it is a way lower GI sweetener and yet it’s a refined product made up largely of fructose.

    And what about the sugars in say, kefir? Does the fat and protein blunt the blood sugar response? Ditto for fruit when consumed with fat or protein?

    And does low blood sugar raise cortisol, which in turn draws upon glycogen stores and raises blood sugar? Could eating too little therefore also impair metabolism?

    Sugar is confusing.

  4. Hi – which would be better base for a sport drink powder, fructose or glucose?
    There is a lot of contravesy, as an athelete we need these beverages but which is the better option?
    Thanks so much
    Diane

    • Hi DIanne, dr. jaminet addresses that question here -http://perfecthealthdiet.com/2012/01/is-it-good-to-eat-sugar/

      He concludes that a 70% glucose, 30% fructose/galactose mix is best.

  5. I understand what you wrote and thank you. I have a question, I have taken most carbs (breads, pastas etc) out of my kids diet. Now they eat fruit all day long for a snack. I tell them it is still sugar…they get moody ( I am guessing the high and then low when the sugar wears out) and go for more food. And my youngest just seems to get tired so easily (she eats the most fruit). So is your article saying it isn’t the fruit in sugar giving the highs and lows? I am always suggesting something with protein for a snack too but they eat all day and are skinny and I run out of food ideas. Thanks

    • Have raw veggies cut up and ready to go in the fridge. And also having cooked veggies ready to nuke (I know but hey I’m being realistic here) gets them to eat those too.
      Enforce the rule they have to have protein with EACH piece of fruit. We only have fruit for dessert here. Very rarely have it alone — only if I’m desperate and they’ve had alot of veggies that day and are sick of them lol
      Protein can be nuts and seeds, cheese, plain yogurt (stevia glycerite sweetened maybe), nut butter. Doesn’t have to be meat.
      You could even just say, hey 3 pieces of fruit a DAY is it. What you eat with a meal counts twds that. And then enforce it.
      Fruit can be just like junkfood, becoming a junkfood itself…cravings, filling up on it to the exclusion of dairy and veggies. NOT GOOD.

  6. As somebody with insulin resistant pcos, I’ll stick to low fruit. I’ve had to increase carbs recently while treating SIBO, so I’ve added small amounts potatoes, apples, banana, mandarins, always with added fat, but still I’ve noticed difference with my appetite control and I regained small amount of weight. As much as I’ve enjoyed eating these, they’re natural, they taste good etc, I’m looking forward to removing them again. I’ve lost 40 kg, but it’s taken 3 years, and I’ve had long periods where my weight would not budge in that time. Last thing I want to do is go backwards.

      • The referenced study is directly linked in this article. Chris has made it very easy to do your homework.

        • I looked up the links, per your suggestion. The 2 links/articles reference “honey-comparable glucose-fructose” and “simulated honey and D-glucose using oral glucose”. I’m not sure that I would call that “fake honey” – it doesn’t really sound like honey to me. At any rate, I believe that Chris should have defined this term a little more, at least in this case. In my opinion, “honey substitute” or “honey equivalent” seems more apt than “fake honey”. I always appreciate Chris’s articles, but this mention left me confused.

        • You might also do a search for counterfeit foods–honey isn’t the only food sold in this country that’s been faked to make more affordable to the masses!

          We’re talking olive oil, “scallops” (that turn out to actually be circle cuts of white fish), etc.

    • “Although artificial honey is a *mixture of glucose and fructose in the same ratio as was found in natural honey*, its metabolic effects are completely different.”

  7. I’ve had type one diabetes for 22 years, And I agree that I do have to limit my fruit intake. On the advice of several including Dr. Bernstein’s book, I went very low carb cutting fruit out almost entirely. I think the result of that is a very slowed metabolism, a slowdown of my thyroid, and failure to heal my hurting adrenals. I am slowly adding back berries kiwi grapefruit and occasionally more sweet fruits. I have to do more experimentation with things like honey and sweet fruits, But I have to be careful with things like bananas, As my body can read them as just plain sugar. I wish I had been more aware growing up, and was not in a situation where I have to restrict healthy foods. I will tell you that my body reads bagels and other things with Whiteflower is just plain sugar also. The insulin spike maybe slowed because of added fat, But still a metabolic nightmare

    • Bananas are like white sugar to my body too! I can feel the effects even. Which sucks, becuz the flavor of smoothies with even 1/2 a banana just cant be beat, no matter how much stevia glycerite I use!
      I stick to raspberries, blackberries and occasionally blueberries when on the rare occasion I even have fruit at all in my smoothie. It’s usually greens only with stevia.
      Sometimes I get really mad at my parents for feeding me crap and teaching me to destroy my metab. But I know they were ignorant. Parents nowadays don’t have this excuse. The info is EVERYWHERE. WheatBelly is a household word!

  8. Great insights Chris! My picture is that sugar bound up with fiber (as in fruit) is primarily metabolized in the gut by gut bacteria creating short chain fats which are what actually enter the body. Processed sugars mostly avoid the gut bacteria and go straight into the body, raising sugar levels in the blood. Does that story seem right to you?

    • I hope thats is true & fruit is thus metabolized easier. I think many diabetics would disagree?
      I grew up on Omohundro Dr. in TN. I always thought it was an unusual name.

  9. I had heard that “sugar is sugar no matter where it comes from”. And as usual I believed it:(
    BUT Chris, now that you have almost the final word in my dietary life, I will definitely add more honey to my diet – gladly and I will pass it on to my grandchildren as well.
    Thanks.

  10. I think the SCD diet is onto something. Eating fresh fruit doesn’t result in an overgrowth of bacteria in the small intestine, it’s mostly metabolized in the stomach when eaten on it’s own. Same with raw honey. Manufactured sugars and grains negatively effect gut flora. I don’t get that lightheaded sugar high from a big bowl of fresh fruit that I get from even half a muffin. I suspect it’s related to gut flora. Every organism is unique, and we need to keep reminding ourselves of this. Different genes, different diets in infancy, different probiotic profile from the birth canal…. We can only correct so much, and then we have to do what allows us to feel the best we can, and live our lives.

  11. “For most people, 3-5 servings of fruit per day is perfectly fine, although certain people with insulin resistance, diabetes, or metabolic syndrome may see improvements by restricting fruit intake to one to two servings a day, and by choosing fruits that are lower in sugar” This is from your blog post BUT the problem is…..most of society is not in a place where they can eat 3 to 5 servings of fruit per day. Being a nutrition coach, if my clients need to lose weight, especially more than 30 pounds “which a good majority do” I limit their fruit intake to 1 to 2 servings per day or their weight loss stops. From my experience “which is 30 years in the industry” when on a weight loss journey fruit is not your best friend and in fact can be a hindrance. A better option is to go to cruciferous and high leafy green veggies for the vitamins, mineral, antioxidants and fiber you need and leave the fruit to a minimum.

  12. I love how you tackle topics like this with reviewing the science, putting it in perspective and getting into enough detail without being too scientific. Just a thanks for all you do. Sharing this on social media and will include links to it in future writing.

  13. I have glucose intolerance and find that even low-glycemic fruits can give me sugar spikes in the 140-180 range. Including things like Blackberries, blueberries… If fruits are metabolized via the liver rather than via insulin why should this be?

    • Fruits contain both glucose and fructose. Some fruits contain more glucose than fructose, others vice versa.

    • According to http://nutritiondata.self.com

      Blackberries and blueberries contain almost as much glucose as fructose. The ratio is practically 1:1, like table sugar or HFCS.

      You don’t mention how much you’re eating, or what other macronutients you are having with your berries, so, maybe it’s worth mentioning to keep the portion small, and add fats like cream, coconut milk, etc. to slow down the burn.

    • A glucose spike can also come from glucose production in your body via cortisol. So even though the food didn’t have a lot of glucose, you see the huge spike because something in the food caused a stress response, and increased cortisol. The cortisol then increased blood glucose. I’ve heard of this happening to people with wheat intolerance when they eat wheat.

    • Let’s not forget that the varieties we have access to today have been bred and hybridized to within an inch of their lives to amp up the sweetness and shelf life. This is NOT the same fruit Grok ate.

  14. You said, “For most people, 3-5 servings of fruit per day is perfectly fine, although certain people with insulin resistance, diabetes, or metabolic syndrome may see improvements by restricting fruit intake to one to two servings a day”.

    I’ve read most Americans are insulin resistant. Thoughts?

    • BINGO!

      It’s obvious, too, that we have metabolic disorders when you simply look at our waistlines and activity levels. Lots of Americans are fairly active (not formal exercise, but not just sitting all day either), yet so many of us have that broken metabolism belly look.

      We should be careful to clarify the CONTEXT of a recommendation. Fruits are healthy? Yes, but only provided you are already healthy.

    • “people with insulin resistance, diabetes, or metabolic syndrome” – I’d say this covers a very large percentage of the population!

    • Current research suggests about 1/3 of Americans have impaired glucose tolerance and/or insulin resistance. Diabetes and metabolic syndrome are less common.

      In my audience, and my patient population, both are less common than the numbers above. There’s no reason for lean, metabolically healthy people to significantly restrict fruit consumption, but of course if someone has a blood sugar issue they will need to exercise caution.

      • I have not read such a low percentage in a long time. Everything I read is double that. Depending on the age population it’s can be even higher.
        I think it’s epidemic and it’s only that the inclusion of young ppl are skewing it so it doesn’t appear as bad as it is for anyone over 30, maybe even 25. There are so many FAT young ppl now tho, in another decade that’ll be gone lol
        I fear a diabesity invasion in westernized countries.

        • Not everyone overweight is insulin resistant though. Most overweight people don’t develop diabetes from what I’ve read, because you need the genes for it.

    • I think 2-3 fruits a day is plenty for anyone, including normal metabolisms. For everyone else (the other, oh, 65-80% of Americans) 1-2 LOW glycemic fruits daily is more than plenty. You still want to be able to eat some healthy starchy vegs too so I’d say one fruit a day, max. Unless you’re a young person who has not killed their metab yet. AND you are active so you are not in the process of killing ur metab LOL
      Keto diets rly allow no fruit or starchy vegs. They work to regain some metabolic function in sick ppl. Once you’ve stablized you can add in some fruit and starchy vegs, as you can tolerate it. Remember MOST Americans are sick. Their metabolisms are screwed. Recovery is not complete healing, it’s making it *better* for most ppl.
      If you have good genes and this doesnt affect you, thank your lucky stars. But it DOES affect most adults.
      It’s too bad we poison our kids’ metabolisms. I wish parents understood this instead of thinking theyre loving their kids by feeding them CRAP and/or too much of any healthy thing they mite happen to accidentally give them 🙁

  15. The problem with understanding high fructose corn syrup is understanding the meaning of “high fructose.”

    Regular corn syrup is almost 100% glucose. So if you converted only 10% of the glucose to fructose, the fructose level would be high in relation to regular corn syrup and would be HFCS, even though it contained less fructose than table sugar (sucrose), which has 50% fructose .

    But most people think “high fructose” means a lot of fructose, a lot more than table sugar.

    Ironically, a lot of people who are afraid of “high fructose” corn syrup with 55% fructose are substituing agave syrup, which is almost 90% fructose because it’s marketed as all natural and low-glycemic.

    • Thanks for writing this! I was confused when the article stated “HFCS is a mixture of fructose and glucose in a roughly 1:1 ratio.” That makes it about a third fructose – how could it be higher fructose than sucrose? Now I understand it is not higher in fructose than sucrose – just higher in fructose than ordinary corn syrup. I always assumed HFCS had more fructose than glucose. Thanks for clearing this up!

      • Wouldn’t a 1:1 ratio mean 50% glucose and 50% fructose, not 1/3?

        Sucrose is also 50% glucose and 50% fructose, since sucrose is just fructose bound to glucose. Therefore, the amount of fructose in HFCS and plain sugar is about the same: 50%.

        (HFCS is usually stated as being 55% fructose, but that’s why Chris said the ratio is “roughly” 1:1. Incidentally, this means HFCS does have more fructose than glucose, but not by a lot.)

  16. Chris,
    Thanks for the nice summary. Will you be addressing the issue of others equating complex carbohydrates with sugar digestion. Or did you do this elsewhere? for instance recently i saw someone on twitter talking about bagels being equal to 14 spoons of sugar. I can’t believe the rate of digestion (GL) is the same, the same point has been made about wholemeal bread
    Cheers
    James

    • James, the bagel/sugar discussion you’ve seen was talked about a lot in the book Wheat Belly (a great read, incidentally).

      While the total effect of eating a bagel vs straight up sugar is certainly not the same, the book’s authors explained that it is indeed the same from an insulin-load perspective. That is, eating either caused a similar response in blood glucose levels.

      Not surprisingly, eating whole wheat bread causes a similar response as eating a candy bar.

      While this does not mean the entire impact on the body is identical between these foods, it does show a relationship that leads to at least some of the most serious modern ills (diabetes, obesity, hormone signaling, etc)

      While I agree that sources of natural whole foods sugars are not the same as processed forms, it’s worth remembering: grain based foods are not unprocessed whole foods (can you find bread in the wild?)

      And while I agree with Chris’s general point here, I also think context is important. Someone with a broken metabolism (that is, someone who has abused sugar to the point where their insulin sensitivity is wonky) already has a problem dealing with large amounts of sugar. While fruit is indeed better than table sugar, it seems to me the lifetime abuse of sugar in the past necessitates a reduction of all sugar in order to return to balance. That is, unless there is a study showing that fruit does not trigger an insulin response (which of course you will never find).

      • I don’t think it’s that useful to compare plain bread and bagels to sugar when normally these are consumed with varying amount of butter and cheese or dipped in olive oil which can have a huge effect on the overall GI of the meal/snack. Likewise a pack of greasy peanut butter cups has a much lower GI than a bag of skittles. I don’t recommend eating these things, just food for thought.

      • I don’t buy the argument that eating a bagel has the same effect as eating 14 spoons of sugar. Of course I don’t advocate eating either bagels or 14 spoons of sugar, but I’d be willing to wager a lot that if we did post-meal blood sugar and insulin testing on a group of people eating those foods, we’d see *very* different responses.

        • That’s exactly the point the book’s making. It DOES affect bld levels, spiking insulin, with both those foods.
          My own sugar testing bears this out.

          • And as far as “sugar is sugar” is concerned, IT IS when you’re talking to a diabetic or a potential diabetic.

          • Back in the 1920s a scientist decided to put people on a high sugar diet.

            The results? Improved insulin sensitivity, meaning that the insulin was more effective at getting sugar into the cells on a high sugar diet compared to the baseline diet.

            It’s counter-intuitive, but it’s true.

            • Janket SJ, Manson JE, Sesso H, Buring JE, Liu S. A prospective study of sugar intake and risk of type 2 diabetes in women. Diabetes Care. 2003 Apr;26(4):1008-15.

              Smith U. Carbohydrates, fat, and insulin action. Am J Clin Nutr. 1994 Mar;59(3 Suppl):686S-689S.

        • Chris is especially right in regards to sourdough based breads. Maybe this warrants an article “not all breads are created equal”. I looooong ferment sourdough all my breads. I ferment them for 3-4 days sometimes.

          “With the sourdough, the subjects’ blood sugar levels were lower for a similar rise in blood insulin,” says Graham, whose findings are to be published in the British Journal of Nutrition.
          He continues, “What was even more interesting was that this positive effect remained during their second meal and lasted even hours after. This shows that what you have for breakfast influences how your body will respond to lunch.”

          5 Benefits to Sourdough Preparation

          1- Increases beneficial lactic acid
          The longer rise time needed for sourdough increases the lactic acid and creates an ideal pH for the enzyme phytase. This enzyme breaks down phytates (read more about the dangers of phytic acid here) more effectively than in yeast breads. Sourdough rye has the least amount of phytates (somehow the Swiss culture mentioned above must have known this) making it a healthier bread.
          2- Predigestion of starches
          The bacteria and yeast in the sourdough culture work to predigest the starches in the grains, thus making it more easily digestible to the consumer.
          3- Breakdown of gluten
          Here again, the longer soaking and rising times in the preparation of sourdough breaks the protein gluten into amino acids, making it more digestible.
          4- Preservative
          The acetic acid which is produced along with lactic acid, helps preserve the bread by inhibiting the growth of mold.
          5- Better blood glucose regulation
          There has been some research suggesting that sourdough bread — sourdough white bread — showed positive physiological responses. The subjects’ blood glucose levels were lower after eating sourdough white bread compared to whole wheat, whole wheat with barley and plain white bread. Interestingly, the subjects tested after eating whole wheat bread fared the worse — with spiking blood glucose levels.
          Additionally, the researchers found that the positive response lasted through the next meal and for several hours after that. They concluded that what you have for breakfast will influence how the body responds to the next meal.
          This is all well and good, but the most pressing reason is the TASTE! That tangy, slightly sour taste is awesome! If you eat grains, make sourdough your primary source of grains.
          – See more at: http://realfoodforager.com/5-reasons-to-make-sourdough-your-only-bread/#sthash.rnaaqEpV.dpuf

          • Great feedback on sourdough bread- I’ve started eating sourdough bread about once per month now with good raw cheese, pate, and smoked wild salmon. I started doing after this after influences from WAPF and Michael Pollan (Cooked and Omnivore’s Dilemna). This is one place where food traditions are very important- a good quality sourdough bread is so much different nutritionally than a cheap mass produced white bread.

      • the biggest distinction between sugar and bread is that atarch breaks down to 100% glucose, while sugar is 50% fructose. The GI or insulin spikes following ingestion are irrelevant, sugar has a lower GI because fructose doesnt spike insulin, but fructose is still more insulinogenic.

      • Hello Chris- I was curious about your thoughts on agave necter as compared to other sugars or sweeteners. I like using it in replace of refined sugar because I thought it was better.
        Also- I have begun using beet sugar in my baking. Thoughts on this as well?
        Thanks!
        Christy

        • Don’t use beet sugar. Sugar beets are all genetically modified. I’m curious to hear Chris’s thoughts on palm sugar.

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