Skip to comments.Is sugar a toxin? Experts debate the role of fructose in our obesity epidemic
Posted on 09/10/2013 12:55:38 PM PDT by Red Badger
American eaters love a good villain. Diets that focus on one clear bad guy have gotten traction even as the bad guy has changed: fat, carbohydrates, animal products, cooked food, gluten. And now Robert Lustig, a pediatric endocrinologist at the University of California at San Francisco, is adding sugar to the list. His book "Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease" makes the case that sugar is almost single-handedly responsible for Americans' excess weight and the illnesses that go with it. "Sugar is the biggest perpetrator of our current health crisis," says Lustig, blaming it for not just obesity and diabetes but also for insulin resistance, cardiovascular disease, stroke, even cancer. "Sugar is a toxin," he says. "Pure and simple."
His target is one particular sugar: fructose, familiar for its role in making fruit sweet. Fruit, though, is not the problem; the natural sugar in whole foods, which generally comes in small quantities, is blameless. The fructose in question is in sweeteners table sugar, high-fructose corn syrup, maple syrup, honey and others which are all composed of the simple sugars fructose and glucose, in about equal proportions.
Although glucose can be metabolized by every cell in the body, fructose is metabolized almost entirely by the liver. There it can result in the generation of free radicals (damaged cells that can damage other cells) and uric acid (which can lead to kidney disease or gout), and it can kick off a process called de novo lipogenesis, which generates fats that can find their way into the bloodstream or be deposited on the liver itself. These byproducts are linked to obesity, insulin resistance and the group of risk factors linked to diabetes, heart disease and stroke. (Lustig gives a detailed explanation of fructose metabolism in a well-viewed YouTube video called "Sugar: The Bitter Truth.")
Everyone agrees that fructose can be metabolized that way, but not that it always is metabolized that way when people consume it in moderate amounts. In rats, the link between fructose and metabolic diseases is so well established that researchers who want to study insulin-resistant rats feed them fructose to get them to that state. Fructose metabolism research in people, though, is limited by scientists' inability to kill their human subjects in order to dissect their livers and is further complicated by variation from human to human: Race, sex, exercise, melatonin, probiotics and antioxidants, among other things, affect how our bodies deal with fructose.
In some human studies, large doses of fructose have certainly been shown to do harm, and alarmingly quickly. One 2009 study fed 16 men a controlled diet, then that same diet plus a fructose supplement that added 35 percent to their calorie consumption, and found fat deposits on their livers, increased triglycerides and insulin sensitivity after just one week. But as the fructose dose decreases, so does the strength of the link to disease. Luc Tappy of the University of Lausanne in Switzerland concluded in a recent paper that, although large doses of fructose undoubtedly cause problems, "there is no solid evidence that fructose, when consumed in moderate amounts, has deleterious effects."
Tappy, one of the prominent participants in the fructose debate that Lustig ignited, gives voice to the position that many doctors and scientists share: Sugar is a bad guy, but not the one, overarching bad guy. "Telling people the problem is all fructose is completely wrong," says Walter Willett, chair of the nutrition department at the Harvard School of Public Health. "In the amounts being consumed, sugar can lead to serious damage and premature death. I think it's fair to say that's toxic," he says. "But it doesn't mean everything else is good."
Read Lustig's book carefully, and it's clear that his position isn't as radical as his sound bite implies: He believes that moderate consumption of fructose is safe. The "likely" safe threshold, he says, is 50 grams per day which translates to 100 grams, or a quarter-cup, of sugar that's half fructose. Average daily American consumption of added sweeteners, according to the USDA, is 95 grams just under Lustig's threshhold. And our consumption is decreasing, down from a peak of 111 grams in 1999.
Lustig's colleagues may be less frustrated by his assessment of fructose than they are by his campaign to vilify it. He chooses not to emphasize his position that the average American intake of fructose is safe: He mentions it once in his book and not at all in his 90-minute video. He's also familiar with all the fructose research and concedes that the evidence for its toxicity isn't ironclad.
Yet he's willing to call it a poison because he believes that waiting for a fuller understanding is not a responsible option.
Lustig works with obese children; he's deeply concerned about their health and their prospects, and he wants to tackle head-on the problem he believes is at the root of their suffering. "The only thing that matters is fixing it," he says. "The fact is that everyone, whether they believe the mechanism or not, is saying we need to reduce our sugar intake."
Asked whether he uses words like "poison" and "toxin" to attract attention to the problem of sugar, he says, "In part, of course." And it's a strategy that's working. The fructose controversy has been featured in prominent media outlets, including the New York Times Magazine, Scientific American and National Geographic, which put the story on its cover.
But there's a downside to Lustig's tactics. A recent editorial in the journal Nature acknowledged the resonance of simple messages and addressed the problem of sacrificing nuance to get attention: "It is risky to oversimplify science for the sake of a clear public-health message Simple messages and themes are seductive Black-and-white messages can cause confusion of their own."
Frank Hu, an epidemiologist at the Harvard School of Public Health who studies the link between sugar and health, gives Lustig credit "for raising awareness about sugar," but he shares other scientists' concerns: "People think if they take care of fructose, their diet is healthy."
Tappy believes that, given the complexities of how foods interact with each other and with the human body, focusing on any single nutrient is a mistake: "An approach to fight obesity has to be targeted at multiple components of our diet and lifestyle." Willett agrees, saying, "We have to find a way to say something is a big problem, a serious problem, but only part of the bigger picture."
Until we do, we'll have to be content with the idea that sugar is a big problem, a serious problem, but only part of the bigger picture.
saying sugar is a toxin is nearly as foolish as saying water is a toxin. or oxygen. or carbon dioxide. and so on.
junk science writ large.
Cancer cells love high fructose corn syrup
Researchers from the University of California, Los Angeles (UCLA) recently conducted a study revealing that cancer cells have a particular liking for refined fructose. In tests, pancreatic cancer cells quickly fed on refined fructose and used it to divide and proliferate rapidly within the body.
Published in the journal Cancer Research, the findings also reveal that not all sugars are the same, a widely held belief in mainstream medicine. Tumor cells love both glucose sugar and fructose sugar, but fructose directly causes cancer cells to reproduce and spread in a way that glucose does not.
“Importantly, fructose and glucose metabolism are quite different,” wrote the team in the study paper.
So the study solidifies the fact that there is a major difference between high fructose corn syrup, a highly-refined sugar commonly used in processed American foods and beverages, and refined sugar cane. Both can lead to health problems, but high fructose corn syrup is worse in terms of cancer growth.
Take pop, candy, pastries and chips off the foodstamp list and there will be fewer fat people in this country.
all high metabolic cells ‘high sugar’.
why does cancer spread so fast?
they are metabolic runaway trains.
The process of making both sugars on a large scale is very similar. I worked with both.
Sugar is not a toxin. It is a fuel source. Now in the US it is in EVERYTHING to the point where I won't buy red sauce anymore, so the calorie count is higher than my home made stuff.
There is some discussion over if it is addicting or not, but since there are people who are addicted to stamp collecting (the areas in the brain that drive addiction are activated), it is probable.
We are in a point in history where the world is so wealthy that a major problem for poor people is getting fat. That has NEVER been the case in human history, till now.
Do I think we put sugar in to many things? Yes. It is in everything.
Is gay sex unhealthy?
Is promiscuous teen sex setting the stage for unwanted teen pregnancies and STDs?
But let’s focus our attention on sugar as the evil in society while all else goes to hell.
left out the word love. all high metabolic cells love any ‘food’ sugar.
Just as the left is trying to confuse the open-borders argument by crowding out the words “illegal alien” or “illegal immigrant” with the simple word “immigrant”, the corn lobby is trying to confuse the high-fructose-corn-syrup argument with the words “sugar”, “sugar-sweetened beverage” (which actually includes HFCS) and “fructose”. This is fundamentally not serious.
I remember reading, some years ago, that the reason sugar is "in everything", is because we went thru that anti-fat craze. Where any kind of fat was evil, to the point that pediatricians had to come out with a statement telling parents that very young children should not be fed non-fat milk because their brain development needs the fat.
Well, fat makes things tasty. So, to keep the taste of the foods they were producing, they added the sugar to try to make up for the loss of the flavor that the "fat" provided. So, yes, sugar is now in everything.
The Snackwells scenario! Take out the fat, add in more sugar. As it turns out, fat is actually good for us. Even some saturated fats such as coconut oil. It keeps me fuller longer, so I’m less inclined to grab a sugary snack.
It is not an epidemic! Nobody is dying because they’re fat. And if they are it isn’t something somebody else should do anything about. Liberals make something a war or an epidemic to generate support for controlling what we do or for getting money. For goodness sake stop seeing fat as a disease. AIDS, Cholera, Measles are epidemics. Fat is just ugly. Ugly isn’t a disease that needs controlling.
Oh, gosh...I’m so exhausted from the effort of writing this note, I’ve just got to get some chocolate...
Overuse of almost anything can cause one problem or another.
Interesting, ...I have severe insulin resistance, and gout attacks at least once a month, presently in both feet, and my fructose intake has been next to zero for decades now. The last time I ate something with fructose in it was about four months ago, a doughnut and small glass of milk to offset low blood sugar. I was too weak to get out of my chair. If the damage is offset by ceasing to eat fructose, or fructose products, I wish it would start getting offset in me. About fourteen years ago I had a colon resection, and the doctor went over every inch of my liver. He said it looked perfect and healthy.
I don’t doubt the validity of this research. We all know fructose is the real villain in type 2 diabetes, but it would seem some livers have the ability to produce copious amounts of fructose without any help. Not even large doses of Metformin turns mine off. ...A strict Akins diet, with limited calories works to lower my blood sugar, but my uric acid levels go through the roof.
Do I think we put sugar in to many things? Yes. It is in everything.
Here’s a great site to help people see how much sugar is in common products that we all consume. It’s an eye opener.
There seems to be a difference between high fructose corn syrup and pure cane sugar. At least for me. Stopped drinking things with the corn syrup and went sugar only. Made it much easier to lose weight. Started drinking it again and put on 10 lbs.
Probably just me, but seems like there is a difference
Thanks for the link. Great visuals.
Don't I know it. I've been on a low carb diet for the past 4-5 months (down 35 lbs now!), and have become quite used to reading food labels at the grocery store as a result. It's amazing the foods where sugar is added, often gratuitously it seems.
In fact, it's hard to find foods without added sugar, vs. natural sugars. You pretty much need to stay away from the "center aisles" in most grocery stores, and just go around the perimeter where vegetables, fruits, meats, eggs & dairy products are sold.
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