Posted by Linda Bonvie
October 16, 2014
The scientific evidence that fructose may be hazardous to our health just seems to keep on mounting.
By that, we don’t mean the fructose found naturally in fruit, where it’s mitigated by fiber, or the fructose that’s bound with an equal amount of glucose in sucrose, or table sugar. No, we’re talking specifically about the free-floating fructose in the cheap and widely used sugar substitute high fructose corn syrup.
Past studies have already shown links between HFCS and obesity, diabetes, non-alcoholic fatty liver disease and heart problems – all indicators of metabolic disease –as well as pancreatic cancer and other problems. Now a new one conducted by Harvard Medical School researchers has found that fructose “may have a particularly deleterious effect on health,” according to one its lead authors – and revealed what may be a key reason.
“If you feed animals or people higher-than-normal amounts of fructose, they become obese, less responsive to the key actions of insulin and develop fatty liver disease and abnormal blood lipid levels. All of these increase the risk of developing diabetes and cardiovascular disease,” noted Dr. Mark Herman, HMS assistant professor of medicine at Beth Israel Deaconess Division of Endocrinology, Diabetes and Metabolism.
And recent analysis of soft drinks sweetened with HFCS have found they do indeed contain higher-than-normal amounts of fructose – higher, even than the 55 to 45 percent fructose to glucose ratio that HFCS is supposed to have. Some products, in fact, reportedly use a 90 percent fructose formula.
Now the Harvard team has discovered a previously unknown biological effect of fructose that they believe may help explain why excessive fructose consumption can lead to serious health issues for many people.
What the researchers found is that blood levels of the hormone fibroblast growth factor 21, or FGF21, which helps regulate the accumulation of fat, undergo a rapid and acute elevation following fructose ingestion – a particularly significant revelation in light of previous findings by the study’s other lead author that raised FGF21 levels in both humans and animals are associated with obesity, insulin resistance and non-alcoholic fatty liver disease.
Their conclusion was based on a study involving 21 adult subjects, about half of whom were lean and fit and the rest suffering from obesity and at high risk for diabetes. At various times, they were given either 75 grams of glucose, the same amount of fructose or a mixture of the two to drink.
Fructose reaction: off the charts
In all subjects, the glucose, which is absorbed into the bloodstream and into fat and muscle tissues and converted into energy with the help of insulin, had no immediate effect on levels of FGF21, with only mild changes detected three or four hours later. But the fructose, which is absorbed directly by the liver, resulting in a rise in triglycerides that can lead to problems such as diabetes and heart disease, also caused levels of the hormone to sharply increase by 400 percent on average within just two hours of being consumed.
“This tells us that fructose actively regulates FGF21 in humans,” noted Eleftheria Maratos-Flier, the study’s co-author. “We were totally surprised by this dramatic effect because, to date, there has been no way of assessing the body’s acute metabolic response to fructose ingestion.”
Perhaps even more significant, the rise in hormone levels was much more pronounced in the obese participants, which the research team thought might be resulting in increased resistance to the hormone’s effectiveness. And there were variations reported in the other subjects as well, all of which Dr. Herman said suggested that “different people for whatever reasons have differences in their fructose metabolism.”
The bottom line here is that there’s a huge difference between sucrose, or table sugar, which people consumed for all those years without problems like obesity and diabetes getting out of control, and high fructose corn syrup, whose relatively short time in the marketplace has corresponded to a huge escalation in such concerns. And the more apparent it becomes that something is amiss, the more science is bringing us closer to an understanding of the key role that difference has played in the proliferation of these problems.
And yet, the idea continues to persist among some journalists and health professionals that there is no real distinction between sugar and HFCS. In fact, the day after an account of this latest research was featured in The New York Times, a Salon article critical of Pepsi’s attempts to market supposedly healthier new soda, noted that “a major selling point is that the drink lacks high fructose corn syrup (HFCS) … Nutritionists, however, point out that HFCS isn’t really any less healthy than sugar – it just sounds less natural.”
Really? Well, whoever those “nutritionists” are, both they and the writers who parrot their beliefs sound less and less credible – and knowledgeable — with each new scientific study.