Overweight and obese individuals consuming fructose-sweetened beverages also showed signs of increased levels of lipids in the blood (dyslipidemia), according to findings published this week in the Journal of Clinical Investigation.
Taken together, such changes are symptomatic of the metabolic syndrome, a condition characterised by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type 2 diabetes and CVD.
The 10-week study involved was led by Peter Havel from the University of California at Davis.
In an accompanying editorial, Susanna Hofmann from the University of Cincinnati College of Medicine, and Matthias Tschöp from the German Institute of Human Nutrition Potsdam-Rehbrücke said the new "carefully designed" study had taken our "knowledge of metabolism of these sugars in humans to the next level".
Fructose and HFCS
While the research could heap even more misery on high fructose corn syrup (HFCS), an ingredient extensively used to sweeten soft drinks, it is important to note that that this sweetener contains 55 per cent fructose and 42 per cent glucose, not dissimilar to table sugar (sucrose), which contains 50 per cent glucose and 50 per cent fructose.
Campaigners against HFCS point to epidemiological studies that have linked the consumption of sweetened beverages and obesity, as well as some science that claims that the body processes the syrup differently than other sugars due to the fructose content, leading to greater fat storage.
However, industry associations like the Corn Refiners Association (CRA) have repeatedly claimed there is no scientific evidence to suggest that HFCS is uniquely responsible for people becoming obese.
In addition, Hofmann and Tschöp said: "It is not known whether the adverse effects of sucrose and HFCS consumption are ‘diluted’ by their lower fructose content relative to pure fructose.
"In the absence of studies comparing the long-term effects of consuming HFCS and/or sucrose with 100 per cent fructose, it is not certain what levels of these sweeteners might increase the risk for atherosclerosis, CVD, and type 2 diabetes."
In order to answer these questions, more studies with HFCS, sucrose, and pure fructose in different doses and in different populations are needed, they said.
Public opinion turns against HFCS?
"However, what is now clear is that chronic over consumption of dietary sugars in general is detrimental to our health and these effects may be synergistic with chronic increases in caloric intake," said Hofmann and Tschöp.
(The average consumption of both HFCS and table sugar in the USA is about 65.8 kg (145 pounds) per year.)
"Nevertheless, […] public perception may already be anticipating results, since beverages promoted as not containing HFCS have started to surface in advertisements and the source of sugars or carbohydrates in general is becoming, more and more, a standard label on food items," they added.
Havel and his co-workers used state-of-the-art metabolic measurements to assess the effects of fructose- or glucose-sweetened beverages at 25 per cent of energy requirements in 32 male and female subjects (average age 50 , and average BMI 29 kg/m2) consumed either fructose- (n = 17) or glucose-sweetened (n = 15) beverages.
Results showed that both groups gained on average about 1.5 kg (3.3 lbs), but those consuming the fructose-sweetened beverages accumulated about twice as much fat around their organs (visceral fat) than the glucose group. Visceral fat is linked to an increased risk of both type 2 diabetes and heart disease.
Furthermore, the fructose consuming participants experienced 14 per cent increase in their LDL-cholesterol levels, while insulin sensitivity decreased by around 17 per cent, compared to the glucose group.
Source: Journal of Clinical InvestigationPublished onlhttp://www.jci.org/articles/view/37385/PDF"Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans"Authors: Kimber L. Stanhope, J.M. Schwarz, N.L.. Keim et al.
I am writing to express concern related to your editorial “Anti-fructose science may be swaying public opinion.”
Your editorial reports on an article by Havel and co-workers and an accompanying editorial by Hofmann and Tschöp. The Havel article is based on an experiment comparing high levels of pure fructose compared to pure glucose, neither of which is commonly found in the diet in the United States or anywhere else, for that matter.
While you correctly identify that High Fructose Corn Syrup and table sugar (sucrose) are essentially the same substance from a biochemical standpoint, throughout your editorial you link the findings of the Havel experiment to HFCS, which is highly misleading. The metabolic effects of HFCS should be compared with sucrose, honey and invert sugar, since all of them are virtually the same from a chemical and metabolic standpoint. All are absorbed identically through the human GI tract, all have the same sweetness and all have the same number of calories per gram. Research in my laboratory has shown that there are no differences between HFCS and sucrose in any parameter yet measured in human beings.
The continued, unfortunate and scientifically inaccurate grouping together of HFCS and fructose is a classic case of mistaken identity. Contrary to your headline the public is not being swayed by science in this area, but by the misperceptions and confusions which are created by such inaccurate comparisons.
Members of the scientific community essentially created this problem with the misguided notion (now thoroughly discredited throughout the scientific community) that HFCS somehow represents a unique cause of obesity. Now, unfortunately, the problem is being compounded by studies performed on pure fructose versus pure glucose with findings inaccurately extrapolated to HFCS.
Is it any wonder that the public is confused? It is not reasonable to expect the public be able to distinguish between pure fructose and HFCS. HFCS should be compared with sucrose (table sugar) not pure fructose.
The scientific community owes it to the public to state unequivocally and repeatedly that studies performed utilizing a pure fructose model cannot be extrapolated to HFCS anymore than they can be extrapolated to sucrose, or any other fructose/glucose sweetener. What are urgently needed are more studies on the real world situation of HFCS and sucrose with comparisons to the pure fructose model. Until then the public will be swayed by hearsay and misperception, not science.
James M. Rippe, M.D.