More Fructose

I wrote an article for this month’s news letter for my practise, SCSP. I wrote it on the work I did for my grand rounds. Enjoy.

in 1964 Walt Disney purchased The “It’s a Small World” ride from the New York World’s Fair. It became a staple of the American experience and became as beloved a part of Disneyland as mouse ears. In 2007 the ride had to be refurbished, in part due to the increased average size of passengers. The boats had been built for men weighing 175 pounds and women, 135 pounds. The overloaded boats were now routinely running aground in shallow areas, delaying the ride and frustrating patrons.

While this seems to be an innocent anecdote on our expanding waist sizes it serves to remind us that we are different than we used to be. The diseases of today have not always been with us. Obesity is not the only disease of indulgence which newly plagues us. Diabetes and hypertension were both rare diseases at the beginning of the twentieth century: Hypertension used to occur in 6% of adults; it now attacks a third. Diabetes was a one in a thousand diagnosis, now it is found in one fifth of hospital admissions.

These three diseases: obesity, diabetes and hypertension lie near the origin of the major health challenges facing our civilization.

One explanation of why these diseases emerged in the last 100 years is the fundamental change in our diet: a dramatic increase in the amount of sugar we eat. In 1700 Europeans ate one pound of sugar a year. Americans now eat 80 pounds a year.

Table sugar, sucrose, is a disaccharide, which means it is made from binding two simple sugars together: one molecule of glucose and one of fructose. Glucose is the simple sugar our body is tuned to use. The carbohydrates found in breast milk, lactose, is 50% glucose. Every tissue of the body is able to turn glucose into energy, in fact, glucose is the only carbohydrate the brain can use as a fuel supply.

The other half of sucrose, fructose is less useful than glucose. It is only metabolized in the liver. Glucose metabolism is a tightly regimented, stepwise process. Meticulous control is maintained over the breakdown of glucose at three separate steps in its initial metabolism. Fructose, on-the-other-hand, enters the liver and is consumed as fast as possible. The liver goes crazy over fructose and metabolizes it in a haphazard and unregulated process. Since the energy is produced without immediate need, a lot of the metabolic energy is directed into storage, which in the liver takes the form of triglycerides and fat. Fructose consumption leads to non-alcoholic fatty liver disease and has surpassed alcoholism as the number one cause of hepatitis.

The fructose consumption also increases the production of uric acid and raises serum uric acid level. While classically, uric acid is associated with gout, it is increasingly being accepted as a cause of chronic kidney disease and hypertension.

Fructose appears toxic and we are eating more than ever. But there is general confusion about the source of fructose in our diet. High fructose corn syrup was introduced in the 60’s and has increased from non-existent in the food supply to an average annual consumption of about 40 lbs a year. HFCS replaced sucrose in both Pepsi and Coke in 1984. HFCS is largely found in two varieties: HFCS-42 and HFCS-55. The number indicates the percent of the which is fructose, 42% in the former and 55% in the latter.

Regardless of which variety of HFCS one encounters, they all have roughly the same amount of fructose as common table sugar. Despite the scary sounding name, HFCS does not contain any more fructose than your sugar bowl. We are eating more fructose than ever but it not because of HFCS, it is because we love sweets.

Happy Valentines Day

6 Replies to “More Fructose”

  1. Hi,
    I just came from a website that was arguing about the validity of Dr. Lustig's video. It is
    refreshing to read something that objectively looks at the effects of excess fructose.
    I beg to differ about either grade of HFCS being essentially similar to sucrose. It may appear that HFCS-55 (55%fructose:45 fructose)is fairly close to the 50:50 in sucrose, that is until you do the math.
    55%:45% = 55/45 = 1.22. This means that in every Coke there is, compared to glucose, 22% more fructose. What does this mean in everyday terms? Drinking five HFCS-55 Cokes is equivalent to drinking 4.25 Cokes sweetened with with SUCROSE + 0.75 Coke sweetened with pure FRUCTOSE. Considering that the average teen chugs a few cans of soda daily, that is a lot of extra fructose assaulting the liver, right? In my former life I was a medical research technician and did column chromatography. If I made a solution that was 55:45 instead of 50:50, I felt honor obligated to throw it down the sink! The CRA is being deceptive when they say that HFCS is essentially similar to sucrose with respect to the ratio of fructose to glucose. And this is the reason:
    Because the %fructose + %glucose must = 100%,
    when you increase the %fructose, the %glucose
    must DECREASE. For the function x/y vs. x
    50:50 = 1.00
    51:49 = 1.04
    53:47 = 1.13
    HFCS-55 55:45 = 1.22
    57:43 = 1.33
    60:40 = 1.50
    You can see that the relationship is not linear. I am concerned by this because I don't
    know their range of error in production. Let's say ADM is brewing up a batch of HFCS-55 and
    the fructose concentration is just 2% greater than planned. The resultant fructose soln. = 56.1% and the fructose: glucose ratio.
    (56.1):(43.9) = 1.28
    Fortunately, the glucose isomerase conversion
    of glucose to fructose is the expensive step in the production of HFCS and is probably tightly controlled. I still prefer sucrose.
    You know exactly what you are getting, precisely 1:1.
    Ditch HFCS, especially HFCS-55.
    To your health.

  2. Interesting post by Cynthia1770.

    The magnitude of sugar we now consume is staggering.

    This seems to have coincided with the rise of cheap plentiful HFCS made possible through government subsidized corn production.

    Does it follow that we need to amend this to address a root cause of the obesity, HTN and DMII epidemic?

    I feel like we need a systemic fix as at the individual practitioner level we face a default high caloric low activity lifestyle that is cheap and temporarily gratifying.

    Some folks are able to modify but the majority have major trouble with sweet and fatty foods being tasty and cheap.

    To really bend the healthcare spending curve we need to identify and stop the systemic causes of our expensive epidemic diseases.

  3. I disagree with Cynthia1770, the issue is not the ratio of glucose to fructose but merely the amount of fructose in our diet. In that regard HFCS doesn't look too bad: a 12 oz coke has 40.5 grams of HFCS 55 which is 22.275 g of fructose. If you were to use sucrose, like they do in Mexican Coke (no corn subsidies means that sugar cane is nearly the same price as HFCS) you get 20.25 g of fructose. 22.275 g vs 20.25 g. Not so different.

    My primary concern is that if we focus on HFCS, and through legislation or public shame we eliminate this sweetener but it is replaced with sucrose we will not significantly reduce fructose consumption.

    People will expect health benefits from the loss of HFCS but the sucrose will provide all the fructose needed to continue the epidemics of obesity, hypertension and diabetes.

    The enemy is fructose and HFCS is a ubiquitous source but it is not the only source. We need to focus on reducing fructose and not just HFCS.

  4. I am able to buy glucose at the local home brew supply store. It is a powder, and we substitute it for sucrose when we can. The key difference is that the glucose is not as sweet as the sucrose, so we have to use a bit more to get the same effect.

  5. It seems hard to conceive of a public health solution short of a) disasterous headlines affecting consumption, b) an outstandingly appealing substitute and/or c) a huge awareness campaign funded by a punative fine levied from the food manufacturers (a la big tobacco).

    As a side note, Mexico heavily controls their sugar industry. Besides being an important industry for the country, the government owns roughly 20% of the mills.

  6. Mark,

    I am in favor of all three of your extreme solutions.

    Does the Mexican government regulate the sugar industry for anything more than economic efficiency? Is public health even considered?

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