Tag Archives: fructose

February 16, 2015 · 2:00 AM

Is Excessive Fructose Consumption the Cause of Type 2 Diabetes?

Lumps of Diabetes

Cubes of Diabetes?

A Pharm.D (Dr of Pharmacology) and a pair of MD’s surveyed much of the available scientific literature—both animal and human studies—and concluded that fructose is a major culprit in the rise of type 2 diabetes and prediabetes. Fructose does its damage by increasing insulin resistance. ScienceDaily has the details.

Be aware that their conclusion is certainly not universally accepted. I just read “Pathogenesis of type 2 diabetes mellitus” at UpToDate.com and saw no mention of fructose. Under dietary factors, they mainly talked about obesity and how that increases insulin resistance, leading to elevated blood sugars, while the reverse happens with weight loss. I haven’t looked at all the research so I have no definite opinion yet on the fructose-diabetes theory; I’m skeptical.

Fructose is a type of simple sugar. Common dietary sources of fructose are fruits, table sugar (aka sucrose, a 50:50 combination of glucose and fructose molecules), and high-fructose corn syrup (which is usually 42 or 55% fructose).

Damaging effects, if any, of fructose in these fruits may be mitigated by the fiber

Damaging effects, if any, of fructose in these fruits may be mitigated by the fiber

A few quotes from ScienceDaily:

“At current levels, added-sugar consumption, and added-fructose consumption in particular, are fueling a worsening epidemic of type 2 diabetes,” said lead author James J. DiNicolantonio, PharmD, a cardiovascular research scientist at Saint Luke’s Mid America Heart Institute, Kansas City, MO. “Approximately 40% of U.S. adults already have some degree of insulin resistance with projections that nearly the same percentage will eventually develop frank diabetes.”

*   *   *

While fructose is found naturally in some whole foods like fruits and vegetables, consuming these foods poses no problem for human health. Indeed, consuming fruits and vegetables is likely protective against diabetes and broader cardiometabolic dysfunction, explained DiNicolantonio and colleagues. The authors propose that dietary guidelines should be modified to encourage individuals to replace processed foods, laden with added sugars and fructose, with whole foods like fruits and vegetables. “Most existing guidelines fall short of this mark at the potential cost of worsening rates of diabetes and related cardiovascular and other consequences,” they wrote.

If you’re eating a typical Western or American diet, you’ll reduce your fructose consumption by moving to the Mediterranean diet, the Advanced Mediterranean Diet, Low-Carb Mediterranean Diet, or the Paleobetic Diet.

RTWT.

Steve Parker, M.D.

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June 10, 2013 · 4:58 AM

Is Sugar the New Fat?

Lumps of Death

Lumps of Death

In the 1950s, John Yudkin wrote a book, Pure, White, and Deadly (amazingly still available at Amazon), blaming sugar as the primary cause of heart disease (coronary heart disease).  The idea didn’t gain sufficient traction and the dietary fat theory of heart disease became the reigning dogma.  Now that the latter theory has been discredited, researchers are looking at sugar again.

The British Medical Journal has a pertinent article you’ll undoubtedly enjoy, if you’re the sort of person who enjoys these things.  I quote:

“In recent years, and slowly, the sugar hypothesis has been making a comeback, driven in part by the emerging perception of heart disease as a consequence of what’s now described as the metabolic syndrome: obesity, dyslipidaemia, raised blood pressure, and insulin resistance. Although there is still no consensus about the causes of the syndrome, an excess of fat in the liver—a response to dietary sugar—is one of the acknowledged possibilities.  Fructose, found in large quantities in nearly all added sugars, is known to increase lipogenesis in the liver and the synthesis of hepatic triglyceride.”

Steve Parker, M.D.

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October 5, 2012 · 9:22 PM

Is Fructose Unfairly Demonized as a Cause of Obesity?

Mainly because of its low cost, HFCS [high fructose corn syrup] consumption replaced approximately one-third of the total sugar consumption in the USA between 1970 and 2000, paralleling to some extent the increasing prevalence of obesity during this period. Consequently, HFCS has been a particular focus of possible blame for the obesity epidemic. However, HFCS consumption has remained very low in other parts of the world where obesity has also increased, and the most commonly used form of HFCS contains about 55% fructose, 42% glucose, and 3% other sugars, and hence is associated with similar total fructose and glucose intakes as with sugar. Furthermore, sucrose is hydrolyzed in the gut and absorbed into the blood as free glucose and fructose, so one would expect HFCS and sucrose to have the same metabolic consequences. In short, there is currently no evidence to support the hypothesis that HFCS makes a significant contribution to metabolic disease independently of the rise in total fructose consumption.

Given the substantial consumption of fructose in our diet, mainly from sweetened beverages, sweet snacks, and cereal products with added sugar, and the fact that fructose is an entirely dispensable nutrient, it appears sound to limit consumption of sugar as part of any weight loss program and in individuals at high risk of developing metabolic diseases. There is no evidence, however, that fructose is the sole, or even the main factor in the development of these diseases…

— Luc Tappy in BMC Biology, May 21, 2012 (the article is a review of fructose metabolism and potential adverse effects of high consumption)

PS: Luc Tappy believes that excessive calorie consumption is an important cause of overweight and obesity.

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June 18, 2010 · 2:00 AM

Sugar-Sweetened Beverages: Bane of Mankind?

Over the last 30 years in the U.S., consumption of sugar-sweetened beverages (SSBs) has increased from3.9% of total calories to 9.2% (in 2001).  In that same time span, the percentage of overweight American adults increased from 47% to 66%.  The obesity percentage rose from15 to 33% of adults. 

[Did the beverages cause the weight gain, or are they just associated?] 

Those are just a few of the many facts shared by the authors of “Sugar-sweetened beverages, obesity, type 2 diabetes mellitus, and cardiovascular disease risk,” published recently in Circulation.  Sugar-sweetened beverages, by the way, include soft drinks, fruit drinks, energy drinks, and vitamin water drinks. 

ResearchBlogging.orgSounds like an interesting article, doesn’t it?  It’s written by some of the brightest lights in nutritional science, including George Bray and Frank Hu.  Unfortunately, the article is a little too boring and technical for most of my readers.  Here are a few tidbits I enjoyed:

  • Fructose (found in similar amounts in sucrose (table sugar) and high fructose corn syrup) may particularly predispose us to deposit fat in and around our internal abdominal organs (“visceral fat,” which some believe to be more unhealthy than fat  in our buttocks or thighs).
  • Fructose may also lead to fat deposits in cells other than fat cells, potentially interfering with cell function.
  • Fructose may adversely affect lipid metabolism (higher triglyceride levels and lower HDL levels, which could promote heart disease).
  • Fructose raises blood pressure and reduces insulin sensitivity.
  • In the liver, fructose is preferentially converted to lipid, causing high triglyceride levels (associated with heart disease and insulin resistance).  [The authors did not mention the common condition of “fatty liver” (aka hepatic steatosis) in this context.]

Some of the authors conclusions:

  • SSBs are the largest contributor to added-sugar intake in the U.S.
  • SSBs contribute to weight gain.
  • SSBs may cause type 2 diabetes and cardiovascular disease—separate from their effect on obesity—via high glycemic load and increased fructose metabolism, in turn leading to insulin resistance, inflammation, pancreas beta cell impairment, high blood pressure, visceral fat build-up, and adverse effects on blood lipids.

I especially like their final sentence:

For these reasons and because they have little nutritional value, intake of SSBs should be limited, and SSBs should be replaced by healthy alternatives such as water.

Steve Parker, M.D.

Reference: Malik, V., Popkin, B., Bray, G., Despres, J., & Hu, F. (2010). Sugar-Sweetened Beverages, Obesity, Type 2 Diabetes Mellitus, and Cardiovascular Disease Risk Circulation, 121 (11), 1356-1364 DOI: 10.1161/CIRCULATIONAHA.109.876185

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