Sugar wears many cloaks, some more ominous than others


Robert Lustig is a popular lecturer and the author of “Fat Chance.” He’s smart, articulate, and probably right in many of his dramatic observations. If so, the entire field of nutrition has been steering us toward the rocks for decades. Consider some of Lustig’s claims:

A calorie is not a calorie. Different substances are metabolized differently, one from another. Some are very damaging.

Exercise has beneficial effects, but they aren’t caused by burning calories. The numbers don’t work. Stimulating muscle growth changes metabolic pathways.

Common sugar is half-glucose and half-fructose. After our body breaks them in two, the components go their own way.

Fructose is the evil twin. Its ring structure is metabolized in the liver like a fat. All the cells in our body utilize glucose but fructose is almost entirely dumped into the liver. It results in an overload condition and the release of toxic byproducts. It’s sweeter than glucose and doesn’t promote satiety. It drives us to ask for more. It promotes insulin resistance and inflammatory responses that contribute to heart disease, strokes, and, probably, dementia. It is a bigger enemy and a different one than obesity. It should be the target when we change of our eating habits. We need to adopt dietary modifications, not diets.

Lustig points out that the rate of heart disease has dropped, but obesity has increased. Does that mean that obesity isn’t the main cause of cardiovascular disease?

He reports some 20 percent of obese people don’t show signs of metabolic syndrome and up to 40 percent of normal weight people do manifest the disorder. The 20 percent have no insulin resistance, and don’t suffer from hypertension, etc.

It is clear to me that both statements are true. We became fatter by 25 percent in 25 years, but we have lower rates of cardiac disease. The American Heart Association attributes the lower cardiac risk to lower cholesterol, less smoking and other factors. Obesity is a serious issue but not the whole story. Controlling it is only part of developing a healthier society.

The economic and political aspects of the problem are troubling.

Our government has protected sugar producers and the close to 150,000 jobs the industry creates. The U.S. supports corn for ethanol programs. The Farm Bill dates back to tough times, family farms and the need to create cheap calories.

High fructose corn syrup has a bit higher fructose/glucose ratio than the sugar in your bowl, but it is much cheaper to produce. It has been added to almost everything, but the amount in soft drinks and fruit juices is enough to account for much or all of our weight gain problem and the risks of many chronic diseases.

A huge part of the problem lies with the soft drink industry, but fruit juices are also loaded with sugar.

Even freshly squeezed juice is bad for you. Lustig points out that “God protected us from sugar by linking it to fiber.” That is very close to the quote he gave in a speech, in which he noted that you could squeeze six oranges into a glass of juice, drink it and begin a meal. If you eat three oranges, you will probably be full. Fiber makes the difference.

I find Lustig’s claims to be credible. There are some caveats. Fructose and glucose generally come in one package in nature. That makes the epidemiology hard to assess. The political implications are consistent with my observations and experience.

I lobbied for the American Cancer Society to eliminate cigarettes from airplanes, and I worked to get funding for a Mayo Clinic-based research program. I’m no expert on government affairs, but I’ve had a taste of the way the system worked at one time. I doubt that any of you would argue that today’s legislators are less influenced by outside pressure than they were in the ’70s.

The chemistry is complicated and it’s beyond my ability to critique it as an expert. I’d love to engage chemists in the exchange. If Lustig is on target, the damage to our children and the costs to society are frightening. We can’t afford our next big gulp, even if it is handed to us as a gift.

Let me explain basic fructose metabolism, to the best of my ability. I won’t try to rebut the claims in “Fat Chance.” I respect the extent to which the author references his conclusions.

Insulin resistance indicates the presence of a complex of health problems called the metabolic syndrome. Researchers have found fructose promotes insulin resistance.

The problem originates in the liver. It becomes overloaded with energy that it has to do something with. It accumulates fat and discharges triglycerides. Vascular damage follows. Insulin resistance forces the pancreas to overproduce that hormone.

High insulin levels promote cell growth. There are links to cancer development. Fructose metabolism is similar to alcohol, although 10 percent of alcohol is metabolized in the brain and that accounts for its neurotoxicity and addictive capacity. These pathways are easily obtainable in many publications. I have only highlighted some of the central points.

Another conclusion: We have probably been duped into following certain diets and believing in food pyramids that are based on faulty science and influenced by politics and economics. Soft drinks and juices are dangerous to our health.

Maybe the banning of soda drinks by the bucket isn’t so crazy. Some data has shown improved health in students after soft drink machines were yanked out of schools. We need to become better informed, more skeptical and take actions that could make our community healthier.

Maybe next time would be appropriate to move away from the issue of sugar and the diseases it promotes. I’ll return to that subject, but I want to cover the question, “Do diets work?”

A note of correction

A reader contacted me and noted that in my last column I created a new form of water. Water is made up of two hydrogens and one oxygen, not the other way around. It was a silly typo. I’m sure that some of you find fault with content. Email me about those, too. Thanks for the heads up, Don.

Dr. Larry Mulkerin is a retired clinical professor. He can be reached at


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