- Non-alcoholic fatty liver disease is a new pandemic in the U.S., where more liver problems are caused by sugar than by alcohol.
- Fructose, stripped of its natural fruit host that includes the fiber necessary to process the fruit sugar, seems to be at the heart of the problem.
- Fructose, often in the form of high-fructose corn syrup can be found in nearly every possible processed food, from bread to infant formula.
It is a common misconception to associate cirrhosis of the liver with alcohol abuse, but the truth is that more and more people who either don’t drink alcohol at all, or drink very little, are being diagnosed with non-alcoholic fatty liver disease (NAFLD), which can range in severity from simple excess fat in the liver to cirrhosis or end-stage liver disease.1 The disorder has become so prevalent in the U.S. and other developed countries that doctors are calling it “the pandemic of the 21st century” and are estimating that it affects up to one-third of the population of the Western world.1
At the same time, we are seeing sharp and associated increases in other disorders such as obesity, diabetes and the metabolic syndrome, a cluster of conditions including high blood pressure, insulin resistance and abnormal cholesterol levels—all conventionally linked to lifestyle choices and blamed primarily on overdoing the dietary fats.2 3
Any trip to a grocery store will show that the heart-healthy, low-fat American Heart Association’s dietary guidelines4 vigorously promoted, beginning more than half a century ago, has been embraced by Americans and changed the way people shop and eat today. Skim milk flies off the shelf, food labels boast “cholesterol-free” or “no trans fats,” and there’s a plethora of products proclaiming themselves lite, low fat, or heart healthy. Low-carb choices have become a booming industry. So why aren’t we seeing the expected disappearance of fat-related health woes?
Spotlight on a Hidden Player
Health professionals are now pointing to a new culprit, and it may be worse than the old one: Sugar. Not your run-of-the-mill table sugar necessarily (though that is not an innocent bystander), but fructose. Wait, what? Fructose is from fruit… fruit is good, fruit is natural, we’re supposed to eat fruit; how can that be the problem?
The apparent smoking gun is that the fructose added to our processed foods has been removed from its natural element, the fruit itself. As Dr. Robert Lustig, University of California at San Francisco (UCSF) Professor of Pediatrics in the Division of Endocrinology, says in his lecture on the biologic impact of fructose, “God packaged the poison with the antidote.”5 In nature, along with the fructose, there’s fiber for processing it; any fruit can be looked at as an example.
The roots of the fructose invasion began in response to several things that happened in the late 1940s and 1950s to bring attention to the influence of diet on heart health. There was the Framingham Heart Study, a major undertaking designed and implemented by the National Heart Institute to study cardiac disease; then the roles played by cholesterol subtypes high-density lipoproteins (HDL, the “good cholesterol”) and low-density lipoproteins (LDL, the “bad cholesterol”) were identified; and third, American scientist Ancel Keys observed that other cultures, such as the Japanese and Mediterranean populations whose diets were low in fat, had a fraction of the heart disease seen in the U.S. and he hypothesized that dietary fat was the link to understanding heart health.6
The aforementioned American Heart Association diet and a massive campaign aimed at reducing fat in the American diet began in the 1960s with a report issued in 1961 urging a low-fat diet for those at risk for cardiovascular disease,7 followed up in the early 1980s by the U.S. government recommending the same low-fat diet for everybody, although the American Heart Association didn’t endorse that recommendation.8 With the introduction of nutrition labeling in 1990, the public started paying attention to product ingredients and demanding low fat, nonfat, lite alternatives to higher-fat options.
Attempting to satisfy consumers, the food industry was faced with a dilemma: When the fat was removed from products, the food tasted terrible, like cardboard. The public wasn’t buying it. Literally. Something had to be added to take the place of the lost fat. And that something was, you guessed it, sugar. Most recently, high-fructose corn syrup, a substance we were never exposed to before 1975,9 and a cheaper alternative to other types of sugar, thanks to farm subsidies. The average intake of sugar in the U.S. is estimated to have risen from 120 pounds per year per person in 1970 to 150 pounds per year per person by 1995.10
A Sugar by Any Other Name
Sugar is not a specific descriptor, though it is generally taken to refer to sucrose, the white stuff in a sugar bowl. There are many kinds of sugar and once we understand that any ingredient name that ends with the suffix “ose” is a sugar, it’s easy to see that the stuff is everywhere, whether it is listed as glucose or sucrose or dextrose or maltose or fructose. In addition to obvious food products like soda, juice and fruit drinks, it’s also in ketchup and bread, luncheon meats and soups, crackers, breads, spice blends and (this one opens up its own can of worms) infant formula, which is said to contain the sugar equivalent of a can of cola.11
That’s not to say all sugar is all bad. The human body—in fact, every living cell on the planet— is designed to run on glucose, also known as dextrose. It is what we convert our food into, primarily from carbohydrates but also from fat protein. It is so essential that if food is scarce, our bodies manufacture it from our own storages.12 When we take in glucose, almost all of it goes directly to our organs and provides our energy for living. Whatever we don’t need or use right away (about 20%) goes to the liver, where it is converted to glycogen for storage. This is a normal process and there’s no cap on how much glycogen can be safely handled this way.13
Table sugar, or sucrose (cane or beet sugar), on the other hand, is about 50/50 glucose/fructose. It is metabolized differently from naturally occurring glucose, because of the fructose in there, and differently from fructose because of the glucose component. High fructose corn syrup (HFCS) has closer to 55% fructose over glucose. The fructose element in any of these sugars is poison, and it is what led the American Liver Foundation to suggest that, “sugar may just be the new alcohol.”14
Fructose Metabolizes Like Alcohol
Fructose, which is much sweeter than glucose, can only be metabolized in the liver, and acts on that organ in much the same way as other toxins do.
Experts agree that sugar, and fructose in particular, is a toxin that is particularly dangerous to the liver.15 16 17 Unlike other substances, which are processed by the body as either carbohydrate or fat, fructose is a carbohydrate but is metabolized like a fat. Several of the processes involved in metabolizing fructose have unwelcome consequences: Release of a waste product known as uric acid blocks the enzyme that controls blood pressure and can lead to hypertension; excess fructose can overwhelm the actions of leptin, the hormone that signals that we have had enough to eat, leading to obesity; other processes can lead to hyperlipidemia, insulin resistance, type 2 diabetes, nonalcoholic fatty liver disease (NAFLD) and chronic, low-level inflammation to name a few.18
Dr. Lustig explains that fructose more closely resembles ethanol (alcohol), another nonessential energy source, than it does the life-enabling glucose. He calls fructose “alcohol without the buzz,”19 and says that it has many of the same effects as ethanol on the liver. That lack of a recognizable “buzz” may be at the root of what makes it so dangerous. Fructose impacts on the same pleasure pathways and addiction centers as alcohol, but because alcohol is partially metabolized in the central nervous system, we can feel its effects, there are clear signals associated with overdoing the ethanol. Fructose is not metabolized in the brain at all but goes straight to the liver, so it does not give us the same warning signs.
We also don’t have the years’ worth of understanding about how fructose damages the liver, as we do with ethanol, so there isn’t the same social or medical concern over trying to control and limit people’s exposure to it. If we go further and glance at the enormous profits involved, it isn’t hard to figure out why there is so much backlash against any suggestion that it is sugar and not fat that is making our nation fatter and more unhealthy than ever before.
Sugar Addiction: Not Just a Catch Phrase
One animal study showed that extremely sweet taste is significantly preferred over cocaine, which is considered to be one of the most addictive substances in the world, and the researchers concluded that the evolution of sweetness receptors took place in an environment that was largely devoid of sugars so overstimulation of those receptors, as is so common in the modern diet, triggers “a supranormal reward signal in the brain, with the potential to override self-control mechanisms and thus to lead to addiction.”20 A different study showed that fructose quickly initiated liver damage, even without weight gain.21
If we accept the fact that sugar in all of its processed forms is a drug as addictive and toxic as cocaine and as damaging to the liver as alcohol, then the fact that the U.S. Department of Agriculture estimates that the average American eats “12 teaspoons of sugar a day, which equates to about two tons of sugar during their lifetime”22… it seems that it just might be time for rehab.
1 Machado MV, Cortez-Pinto H. Non-Alcoholic Fatty Liver Disease: What the Clinician Needs to Know. World J Gastroenterology. NCBI Sept. 28, 2014.
2 Riccardi G, Giacco R, Rivellese AA. Dietary Fat, Insulin Sensitivity and the Metabolic Syndrome. Clin Nutr. August 2004.
3 Freire RD et al for the Japanese-Brazilian Diabetes Study Group. Dietary Fat Is Associated With Metabolic Syndrome in Japanese Brazilians. Diabetes Care. July, 2005.
4 The American Heart Association. The American Heart Association’s Diet and Lifestyle Recommendations. Jan. 22, 2015.
5 Lustig RH. Sugar: The Bitter Truth. UCSF’s Osher Center for Integrative Medicine July 30, 2009.
6 Story C. The History of Heart Disease. Health Line Apr. 10, 2012.
7 Page I et al, Ad Hoc Committee on Dietary Fat and Atherosclerosis. Dietary Fat and Its Relation to Heart Attacks and Strokes. Circulation 1961.
8 Teichoiz N. What if Bad Fat Isn’t so Bad? NBC News, Men’s Health Dec. 13, 2007.
9 Lustig RH. Sugar: The Bitter Truth. UCSF’s Osher Center for Integrative Medicine July 30, 2009.
10 Howard BV, Wylie-Rosett J. AHA Scientific Statement: Sugar and Cardiovascular Disease. Circulation 2002.
11 Mercola J. Sugar: Eliminate This ONE Ingredient and Watch Your Health Soar. Mercola.com May 2, 2011.
12 Definition of Blood Glucose. Medicine.net June 14, 2012.
13 Mercola J. Fructose Attacks Your Liver Like Alcohol – Is This What’s Making You Flabby and Sick? Mercola.com May 7, 2012.
14 Patel A. Foods For Liver: 20 Detoxing Things To Cook With This Year. Huffington Post Dec. 31, 2013.
15 Ratini M. Surprising Things That Can Damage Your Liver. WebMD Mar. 19, 2015.
16 Lustig RH. Fructose: It’s “Alcohol Without the Buzz.” Advances in Nutrition March 2013.
17 Mercola J. Fructose Attacks Your Liver Like Alcohol – Is This What’s Making You Flabby and Sick? May 7, 2012.
18 Mercola J. Sugar: Eliminate This ONE Ingredient and Watch Your Health Soar. Mercola.com May 2, 2011.
19 Lustig RH. Fructose: It’s “Alcohol Without the Buzz.” Advances in Nutrition March 2013.
20 Lenoir M, Serre F, Cantin L, Ahmed SH. Intense Sweetness Surpasses Cocaine Reward. PLoS ONE 2(8), 2007.
21 Kavanagh K, Wylie AT, Tucker KL, et al. Dietary Fructose Induces Endotoxemia and Hepatic Injury in Calorically Controlled Primates. The American Journal of Clinical Nutrition June 19, 2013.
22 Mercola J. Sugar: Eliminate This ONE Ingredient and Watch Your Health Soar. Mercola.com May 2, 2011.