Training & Nutrition - Truth about HFC

I've read that high fructose corn syrup can and does cause problems in people who consume high amounts of it. Seeing as how there is a lot of this in almost any energy bar, etc, it almost seems un avoidable. Can anyone here tell me about this?

hhmmm. I don't know about problems, but I can tell you what I do know about it......

Fructose is taken directly to the liver where much of it is slowly converted to glucose and therefore the blood sugar response is very small.

So I guess, if you are looking for a spike in energy, this would not be the best way to get it. That's not to say it's detrimental, you'd just need other "stuff" too.

:)

I finally found the article that I read. It is by Paula Newby Frazier.. who should have some back ground on nutrition:

This is LONG but should explain why it bothers me, and why I want to know more:'



Part I of a two-part series

Fructose derives its name from its fruit origin and has for the last several years, along with high fructose corn syrup (HFCS), been promoted in the lay press and by food bar manufacturers as the "healthy" and natural alternative to commonly consumed dietary sugars (sucrose/glucose). In the world of endurance athletics, fructose has been touted as bringing about everything from improved performance to decreased body fat. However, these claims may be far from the truth. In fact, fructose may be partially, if not largely, responsible for some of the chronic health problems related to what is commonly referred to as Syndrome X (insulin resistance, obesity, heart disease, hypertriglyceridemia and hypercholesterolemia). And its performance-enhancement qualities are questionable at best. So, the next time you reach for some quick "energy," read the label and keep these facts in mind.

The History of Fructose and High Fructose Corn Syrup

Fructose is a naturally occurring sugar that can be found as an intrinsic constituent of many fruits and vegetables, and is widely know as "fruit sugar." Not unlike other simple sugars such as sucrose (simple table sugar) and glucose (which many of us know as blood sugar), fructose provides 4 calories per gram and has a similar taste and a slightly higher degree of sweetness. Due to its solubility and its preservative quality, and because it is inexpensive, fructose has become a common component in many commonly consumed foodstuffs. Recently, fructose and fructose-derived compounds have also been promoted in sport supplement products.
In 1967, high fructose corn syrup was introduced into the U.S. food supply. HFCS, which is manufactured through an isomerization of glucose syrups (usually from corn), is composed of both fructose and glucose, and is generally composed of 50 to 60 percent fructose, but can contain as high as 90 percent. It is not surprising that since its introduction, an increasing number of ready-to-consume foods have started to incorporate HFCS. In fact, since 1975, the average consumption of fructose in the diet has increased ten-fold.

What's So Different About Fructose?

Although, chemically, fructose is composed of the same elements found in glucose (carbon, hydrogen and oxygen), the structural arrangement of these elements directs fructose into an entirely different metabolic pathway. Almost all other sugars are first converted into glucose and follow similar disposal pathways within the body. Therefore, once other sugars are converted into glucose, they can be used either as fuel to generate cellular energy or be stored as glycogen within muscle or the liver.
The metabolic disposal of fructose has two unique characteristics, which may be the primary reasons that its unrestricted consumption may be problematic: 1) It is taken up very rapidly by the liver, and 2) Its entry in glycolysis skips what is thought to be the key regulatory step in carbohydrate metabolism, the enzyme Phosphofructokinase.
These differences in metabolic regulation are not of major concern when fructose is consumed in moderate amounts. Most fruits and vegetables have fructose concentrations of about 2 to 8 percent on a wet-weight basis. And, besides, fruits and vegetables also contain other valuable dietary constituents, such as vitamins, minerals, phytochemicals and fiber. However, when consumed (or better stated, over-consumed) at the rate of the current U.S. average (8 percent or more), fructose has been demonstrated to be associated with a host of metabolic maladies.

Some of the possible metabolic consequences of fructose consumption

Increases in Blood Lipids (cholesterol and triglycerides) and Coronary Artery Disease Risk.

Fructose has long been recommended for persons suffering from diabetes and obesity, due to its decreased stimulation of insulin and glucose levels in the blood. It is this characteristic that has also been hypothesized as being of benefit to athletes. However, it has been continuously shown that increasing amounts of dietary fructose can significantly increase levels of both cholesterol and triglycerides in the blood of these individuals. This result has also been shown in healthy populations consuming fructose. More important is the possibility of fructose, when increased at the expense of other complex carbohydrates (i.e., starch) in a higher fat diet, eliciting even more increases in these parameters. This may not only lead to increases in stored body fat, but the development of coronary artery disease, as well.

Accelerated Aging and Abnormal Blood Clotting

It has been demonstrated that fructose is a potent stimulator of a reaction called the Millard reaction. This reaction takes place within the body between fructose and proteins (or amino acids) and may inhibit the normal metabolism of proteins and other nutrients. These reactions are thought to play a part in the cellular aging process through increasing free-radical production. As most of you realize, endurance athletes already have increased free-radical production due to volume of training and increased sun exposure.
Additionally, it appears that fructose may affect the absorption of dietary copper, which in turn affects the production of hemoglobin, which serves to carry oxygen in the blood. This may not only hinder aerobic capacity, but also may increase the "stickiness" of blood, also termed "spontaneous platelet aggregation."

Hyperuricemia and Gout

Since the majority of ingested fructose is rapidly and efficiently taken up in the liver, and its metabolism is dependent on the phosphorylation of the fructose itself, large doses can cause a depletion of phosphate in the liver and ultimately to an increase of uric acid in the blood not only creates complications for those with pre-existing gout, but may make healthy individuals more susceptible, as well. This not only is related to the reduction of ATP and other high-energy phosphates, but can also disrupt protein and nucleic acid synthesis.
Fructose and Your Performance: Part II
In the previous installment of this column we talked about fructose and high fructose corn syrups in our food. For those of you who may not have read Part I, here are a few highlights concerning fructose that were reviewed: 1) Fructose was introduced to the U.S. food supply in 1967 and, since that time, per capita annual consumption has increased to 50 kilograms per person. 2) Fructose is absorbed and metabolized differently than other sugars in the body. 3) Fructose consumption may play a pivotal role in the increasing amount of obesity in the U.S. and also may be related to the maladies of Syndrome X (insulin resistance, heart disease, high blood pressure, hypertriglyceridemia and cholesterolemia). Also discussed was the possibility of high intakes of dietary fructose being correlated to gout, abnormal blood clotting and the aging process.
So, what does this mean to us as athletes? We get through a great deal of our competitions using products containing high concentrations of sugars and/or fructose. Just look at the labels - it's in rehydration drinks, gel products, energy bars, etc. So, let's look at the use of fructose in athletic parameters.
For initial muscular contraction to take place, the body depends on
phosphate compounds (this gets back to the issue of supplemental creatine use since it is stored in the body as creatine phosphate) as well as glycogen (stored glucose). However, in order for us to survive events lasting hours, we must be able to tap into both blood glucose and free fatty acids as more adequate long-term fuel substrates. Obviously, both the duration of the event and the intensity of the exercise dictate what type of fuel source is used.
Generally speaking, as the intensity of the effort increases, the demand for glucose will follow suit. This is all well and good, but we must keep in mind that as this happens, the amount of lactic acid will increase as well. Due to a lowering of pH, lactic acid build-up in the muscle will eventually cause fatigue in the muscle.
Glucose-containing products were some of the first dietary supplements studied as a means to enhance performance in endurance activities. This is pretty logical since glucose not only supplies fuel to muscles, but also serves as a substrate for the replenishment of glycogen stores. However, this is one of the inherent problems with the sole use of glucose-containing products during exercise, as glucose stimulates the release of insulin into the blood stream. While insulin will function to shuttle glucose into muscle, it will also stimulate glycogen synthesis. And while this may be beneficial as part of the recovery process, it potentially could lower the amount of glucose needed for exercising muscle. It should also be mentioned that exercising muscle can facilitate the uptake of glucose without insulin. So, in theory, it would be best to supply the body with fuel sources, increasing delivery of carbohydrate (i.e., glucose) to the body while at the same time decreasing the insulin response to substrate. Needless to say, this is part of the reason that fructose has been studied as an alternative fuel source for endurance events.
As mentioned in Part I of this series, fructose has the same chemical makeup as glucose, but a different configuration. However, this slight difference is significant because fructose cannot be used to any significant degree directly by exercising muscle. Therefore, upon absorption, fructose is taken up by the liver and goes through a process called phosphorylation. This is a very notable event because while it does not stimulate the release of insulin into the bloodstream, it also does not significantly alter the amount of glucose. It does, however, serve as a sink for phosphate in the liver, which could potentially alter the amount of high-energy compounds used for energy production. And while it is possible to infuse fructose via I.V. to detectable changes in concentration, the possibility of this being feasible through dietary intake while exercising is impracticable.
However, not all studies have shown fructose to be totally useless inendurance events. And as with most things, paying attention to detail and investing a little more time into your dietary strategy can make a critical difference in personal performance. It appears that one of the crucial factors that may come into play during exercise is pre-race glycogen stores. It has been shown that individuals who have elevated levels of muscle and liver glycogen can tolerate higher intakes of fructose during competition. This is important for a variety of reasons: it stresses the importance of a logical taper in training prior to an event and it dictates the importance of dietary manipulation in relationship to performance. These factors coupled with hydration status are likely the most important points to remember when going into competition.
Since the likelihood of fructose and high fructose corn syrups
disappearing from our food supply anytime soon is improbable, it would be wise to start paying attention to our personal consumption of this questionable carbohydrate. When consumed in amounts naturally occurring in fruits and vegetables and as small percentages of other foods and supplements, fructose most likely does not pose any harm. However, when consumed in amounts contributing 10 percent or more of total dietary energy, it appears that fructose may have some deleterious effects in the body and may not be the energy food we once thought it to be.

Honestly, I can't read the whole thing because I don't have that kind of attention span - but I did get as far as her mention of sucrose (refined table sugar). Apparently, she DOESN'T know that sucrose is made of 1 molecule of glucose and 1 molecule of fructose.

And like I said - it has little effect on blood sugar - it doesn't lower it like she claims.

I think she's full of crap.

I don't know, William.

I do know that "high fructose corn syrup" is not fructose. It's a combination of fructose and other sugars.

Fructose, in moderation, can be better for you than sucrose. Although it's a simple sugar, it does provoke less insulin response.
But when you mix fructose with sucrose, much of the benefit is lost.

Such may be the case with HFCS.

Processed foods can present problems. I eat them, but I really try to focus on this concept: eat it as closely as possible to it's original form.

:)

http://www.cnn.com/2004/HEALTH/diet.fitness/03/25/fructose.obesity.ap/index.html

Just an update to this subject I found interesting.

http://www.cnn.com/2004/HEALTH/diet.fitness/03/25/fructose.obesity.ap/index.html

Just an update to this subject I found interesting.

If high intake of fructose is eventually determined to be detrimental to your health it will definitely be in spite of Newby Frasier's efforts to convince us of the fact. Her arguement is just plain baseless. I read research articles every day and found her assertions and support of her hypothesis to be non-existant. For example, the "Willard reaction" is not even recognized by the biomedical community. She's not a researcher herself yet she fails to quote a single source.

Supposition and hand-waving does not justify her concluding remark that "may have some deleterious effects in the body."

The CNN report simply expands upon common logic that if you ingest more calories than you burn, then you will gain weight. In this case, researchers are attempting to pin that blame on fructose which is surely true to some degree.

The bottom line is that more work needs to be done to link high intake of fructose to ANY disease other than obesity.

-mark

An interesting side issue is the pandemic in the U.S. of type II diabetes (so-called adult onset) in the past quarter century. This "adult onset" form of diabetes is increasingly manifesting itself in young adults, teens, and even pre-teens. Can this be attributed to the massive increase in the intake of refined sugars in the American diet? The research is just not conclusive right now, but look for the results of many ongoing studies to made public in the next few years.
If I were the CEO or major stockholder of ADM or General Mills, I'd be very cocncerned about future legal exposure (a la the tobacco suits), if it can be proven that excess consumption of refined carbs is dangerous and that sufficent evidence was in the hands of food processors about its negative effects.
A similar future scandal involves the use of partially hydrogenated oils (trans-fats) in packaged foods (this is nearly universal). I'll go out on a limb and predict this will dwarf the recent tobacco lawsuits in magntiude. Potato chips have killed more people than cigarettes...and like cigarettes, it's not the one that kills you, but a lifetime of consumption of these "food" products.

My understanding of fructose is its a good energy sugar but a bad storage sugar because it is preferentially stored as fat rather than muscle glycogen as other sugars would first be stored.So while I skimmed the previous info I agree it is fine for immediate energy needs and perhaps keeping insulin under control(relative to other sugars) but if you consume enough that you get in a storage situation it will increase fat storage ,triglyceride levels etc. relative to other sugars.So eaten as whole fruit you would probably be hard pressed to eat too much but with the proliferation of refined products you need to use care.

Calcium, sodium, potassium, magnesium, iron and a bunch of other things are used to metabolize refined sugar. So the more you have, the weaker your bones are as your body leeches vital minerals out to make use of it.
Refined sugar is just that, sugar. It needs external supplies to be used.
Whereas stuff like honey or maple syrup is designed to be used as is by growing organisms so they already contain most of what's needed to digest it. Sugar also makes your blood thicker, increases blood pressure, weakens the immune system, increases chrolesterol and I read somewhere hardens arteries within 30 minutes of intake. It also causes your body to dump so much insulin into the blood that after the initial high, it'll suck the life out of you.

HFC = Home Fresh Chicken

Are you saying corn syrup is actually chicken?!

An interesting side issue is the pandemic in the U.S. of type II diabetes (so-called adult onset) in the past quarter century. This "adult onset" form of diabetes is increasingly manifesting itself in young adults, teens, and even pre-teens. Can this be attributed to the massive increase in the intake of refined sugars in the American diet? The research is just not conclusive right now, but look for the results of many ongoing studies to made public in the next few years.
If I were the CEO or major stockholder of ADM or General Mills, I'd be very cocncerned about future legal exposure (a la the tobacco suits), if it can be proven that excess consumption of refined carbs is dangerous and that sufficent evidence was in the hands of food processors about its negative effects.
A similar future scandal involves the use of partially hydrogenated oils (trans-fats) in packaged foods (this is nearly universal). I'll go out on a limb and predict this will dwarf the recent tobacco lawsuits in magntiude. Potato chips have killed more people than cigarettes...and like cigarettes, it's not the one that kills you, but a lifetime of consumption of these "food" products.

Hmmm ... you may be right, but I have yet to see a report indicating that food products are addictive. If they aren't addicitive, then I can't imagine how these manufacturers can be held liable for creating a product that the consumer is freely able to turn away. Recent attempts to sue McDonalds for creating high-fat foods that led to one man's obesity didn't even make it to trial if I remember correctly.

-mark

I can't claim to understand sugar chemistry, but I don't think it is critical to forming an opionion on HFCS.

Like LBM, I believe in trying to eat unprocessed or lightly processed food in preference to highly processed food, just because I believe it makes for a better diet overall. Not just in terms of what is not included, but also in terms of what it does include. For example brown rice is preferred to white rice because it is less refined and it contains more fiber.

Also there is the matter of HFCS adding too much sugar overall to your diet. Do we really need sweetened catsup ?. I would prefer molasses or cane sugar over HFCS, and no sugar at all to molasses or cane sugar.

Dan