The young woman’s hands were shaking as she doled out cash in exchange for the white, powdery substance. She then rushed back to her car, where she could be alone to experience the rush of pleasure that she had been craving. The few bites of sugared donuts and a 64-ounce soda would satisfy her addiction until lunchtime.
Many scientists and health professionals worry that the US is a sugar-addicted nation. That addiction is causing widespread health problems, including obesity and poor nutrition. One study published in JAMA suggests a strong association between added sugar intake and cardiovascular disease.
Is Sugar Addiction Possible?
Addiction is a disease that, in the brain and nervous system, causes detectable changes that result in craving and other characteristic behaviors. If sugar addiction is possible, scientists should be able to see the same changes in the brains of sugar junkies as they do in drug addicts. A 2007 study published in Neuroscience & Biobehavioral Reviews examined the behavioral and neurochemical effects of excessive but intermittent sugar intake. Nicole M. Avena and her colleagues wanted to determine whether scientists should consider sugar to be a substance of abuse and whether its abuse can lead to addiction.
As part of the evolutionary process, the human brain has developed neurological pathways of response to reward. Sex is rewarding, for example, as an incentive toward procreation. Food addiction is plausible because the same pathways that respond to natural rewards also respond to addictive drugs. In other words, the brain responds to sugar in much the same way as it does to heroin.
The part of the nervous system that evolved to motivate food foraging is also involved in the drug-seeking and self-administration behaviors that characterize addiction. Many people—chocolate lovers, for example—say they feel compelled to eat sweets in much the same way that an alcoholic is compelled to drink or an addict is to use drugs.
Using rats, Avena and her colleagues developed an animal model for sugar addiction. The researchers withheld food from the rats for 12 hours daily, then gave them access to a sugar solution and chow for 12 hours. The lab animals learned to drink copious amounts of the sugary beverage, especially as it became available after the fast. After 1 month, the rats developed behaviors normally associated with drug addiction, such as bingeing, withdrawal, and craving. The scientists also noted repeated, intermittent increases in extracellular dopamine in the rats’ nucleus accumbens, a part of the brain associated with rewards. Such increases are a well-known characteristic of drug addiction.
The study also showed that sugar acts on the opioid system, which is the same body system that interacts with codeine- and morphine-based drugs, including heroin. Because food and opioid drugs work on the same body system, withdrawal can cause similar symptoms.
Measuring Sugar Addiction
It is difficult to know how many people are addicted to sugar. One gauge of addiction is to measure consumption, and modern Americans are consuming more sugar than ever before. In the 1950s, the typical American ate nearly 110 pounds of sweeteners each year, according to the U.S. Department of Agriculture, with sugar being the most common sweetener at 96.7 pounds per person per year. Today’s average American gulps down an astounding 152 pounds of sweeteners yearly. This amounts to 52 teaspoons of sweeteners per person per day.
Sugar-sweetened beverages account for much of the increase in sugar consumption. In 2000, carbonated beverages provided 22% of the refined and added sugar in the US food supply as compared with only 16% in 1970.
In addition to addictive behaviors, the excessive consumption of sugar can cause significant health problems, including obesity, diabetes, and heart disease. The largest problem is that sugar provides no vitamins, minerals, or nutritional value; it offers only flavor and calories. Sugar does not provide bulk either, so the consumer still feels hungry after downing a 500-calorie drink.
While scientists debate whether it is possible to be addicted to sugar, the average consumer can reduce his or her risk for obesity and other health issues by restricting sweetener intake. The American Heart Association recommends that women limit sugar intake to 100 calories per day and men limit sugar to 150 calories daily.
- Avena NM, Rada P, Hoebel BG. Evidence for sugar addiction: behavioral and neurochemical effects of intermittent, excessive sugar intake. Neurosci Biobehav Rev. 2008;32(1)20-39. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2235907/#!po=47.5000.
- Profiling food consumption in America. USDA website. http://www.usda.gov/factbook/chapter2.pdf.
- Sugar 101. American Heart Association website. http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Sugar-101_UCM_306024_Article.jsp.
- Sugars, granulated (sucrose). Self Nutrition Data website. http://nutritiondata.self.com/facts/sweets/5592/2.
- Yang Q, Zhang Z, Greg EW, Flanders WD, Merritt R, Hu FB. Added sugar intake and cardiovascular diseases mortality among US adults. JAMA Intern Med. 2014;174(4):516-524. http://archinte.jamanetwork.com/article.aspx?articleid=1819573.