If you think you eat too much because of a lack of willpower, think again. Dr. Mark Hyman walks us through a powerful study which proves foods that are higher in sugar and rate higher on the glycemic index are addictive in the same way as cocaine and heroin. If you have kids, keep them away from regular access to the candy jar and reserve sweets for special treats!
The Research
In a groundbreaking study published in the American Journal of Clinical Nutrition, Dr. David Ludwig and his colleagues at Harvard proved that foods with more sugar — those that raise blood sugar quickly or have what is called a high glycemic index — trigger a reaction in a special region in the brain called the nucleus accumbens. This part of the brain is known to be ground zero for conventional addictions, such as gambling and drug abuse. When this pleasure center becomes activated, it makes us feel good and drives us to seek out more of that feeling.
Previous studies have shown how this region of the brain lights up in response to certain kinds of images or when a person eats sugary, processed, or junk food.
However, many of these studies compared very different foods. When comparing cheesecake to boiled vegetables, as expected, the pleasure center lights up to the cheesecake and not to the vegetables. This is for a number of reasons — from the texture, smell, and form of the cheesecake, the way the cheesecake was presented, how many other people were present during the tasting of the cheesecake, etc. In other words, it’s interesting data, but not hard proof of the addictive properties of these foods.
A newer study took on the hard job of proving the biology of sugar addiction. To confirm their results, the researchers did a randomized, blind crossover study using a rigorous research method. They took 12 overweight or obese men between 18-35 and gave each a low-sugar, low-glycemic-index (37 percent) milkshake.
Four hours later, they measured the nucleus accumbens, the previously mentioned section of the brain which controls addiction. They also measured blood sugar and hunger levels.
Days later, researchers had the same subjects back for another round of milkshakes. This time, they switched them. The new milkshakes tasted and looked exactly the same as the first round — except in the amount of sugar the consumed. Compared to the first shakes, the second batch of milkshakes contained more sugar and had a higher glycemic rating (the ranking was 84 out of 100 on the glycemic index).
Not only were the two sets of shakes engineered to deliver precisely the same flavor and texture, they also had exactly the same amount of calories, protein, fat, and carbohydrate. Think of the sets as trick-milkshakes.
Participants didn’t know which milkshake they were getting and their taste buds couldn’t tell the difference. According to the study results, though, their brains sure could. Each participant received a brain scan and blood tests for glucose and insulin after drinking each version of the milkshake. Without exception, they all experienced the same response: the high-sugar, high-glycemic-index milkshake caused a much greater spike in blood sugar and insulin levels, and also yielded reports of increased hunger and cravings four hours after they consumed it.
The Findings
The study’s findings were not surprising and had actually been shown in many previous studies. The breakthrough finding: When the high-glycemic shake was consumed, the nucleus accumbens lit up like a Christmas tree.
By contrast, the low-glycemic shake triggered no response in the nucleus accumbens. This pattern occurred in every single participant and was statistically highly significant.
This study proved that the body responds quite differently to different calories, even if the protein, fat, carbs, and most importantly, taste are exactly the same. Foods that spike blood sugar are biologically addictive. Simply put: Food addiction is very real.
Food Addiction is Real
In fact, it’s the root cause of obesity and myriad illnesses because people become stuck in a vicious cycle of cravings. They eat sugary foods that spike their blood sugar, causing their brain’s pleasure center to light up. This triggers more cravings, driving them to seek out more and more of the substance that gives them this “high.” These people become powerless against their brain’s hardwired response to seek out pleasure. It’s no wonder so many people feel trapped!
How Do You Know Whether You’re Addicted?
While at Yale’s Rudd Center for Food Policy and Obesity, my friend and colleague Kelly Brownell (PhD), created a scientifically validated food questionnaire to help you determine whether you are a food addict. Here are some clues you may be addicted to sugar, flour, and processed food. The more intensely or more frequently you experience these feelings and behaviors, the more addicted you are:
- You consume certain foods, even when not hungry, because of cravings.
- You worry about cutting down on certain foods.
- You feel sluggish or fatigued from overeating.
- You have spent time dealing with negative feelings after overeating certain foods, instead of spending time preoccupied with important activities such as time with family, friends, work, or recreation.
- You have had withdrawal symptoms such as agitation and anxiety when you cut down on certain foods (do not include caffeinated drinks such as coffee, tea, and energy drinks here).
- Your behavior with respect to food and eating causes you significant distress.
- Issues related to food and eating decrease your ability to function effectively (daily routine, job/school, social or family activities, health difficulties), yet you keep eating the way you do despite these negative consequences.
- You need more and more of the foods you crave to experience any pleasure or to reduce negative emotions.
If you find yourself nodding to these clues, don’t worry — you’re far from alone. Millions of people in every corner of the world have fallen into the food addiction trap.
Lack of Willpower Isn’t the Problem
The important thing to remember is that food addiction is not your fault. It is not because you are lazy or lack willpower to resist sugary, processed foods. It makes me furious to see patient after patient blame himself or herself for his or her weight problems and diabesity.
The real blame for our weight and health problems lies less with the individuals who’ve inadvertently become addicted to processed foods than with the food companies that designed food products with highly addictive properties in the first place.
Yes, we all have choices, and personal empowerment and responsibility do have a part to play here, but they are not enough if we are trapped in a food coma induced by the toxic influences of sugar and processed foods.
No one chooses to be fat. Think about it. If you grew up not being able to identify a vegetable because you never ate one, if your school had only deep-fried food or the kind that came out of a box/can and was stocked with vending machines full of sweetened sports drinks, juices, or sodas, or was ringed by convenience stores where you could buy a 64-ounce Big Gulp on your way home every day, it’s no surprise that your habits and taste buds got wired that way.
If nearly every restaurant chain near you serves jumbo portions of sugar and fat and salt (what David Kessler (MD) calls “hyper-palatable” foods), and if your workplace lunchroom is a toxic food dump, good luck staying healthy.
If, unbeknownst to you, your yogurt contains more sugar than a Coke, and the main ingredient in your barbecue sauce is high-fructose corn syrup, how can the food industry point the finger at you for not taking personal responsibility?
Peer pressure to fit in is strong, and Big Food knows this. Big Food preys on people’s desire to be eating and drinking the “in” thing and uses manipulation to get customers hooked. Remember the Coca-Cola ad, “I’d like to buy the world a Coke”? Let’s get the whole world hooked! Now North Korea and Cuba are the only countries to which Coke is not distributed. Mission accomplished!
There are specific biological mechanisms that drive addictive behavior. Nobody chooses to be a heroin addict, cokehead, or drunk. Nobody chooses to have a food addiction either.
These behaviors arise from primitive neurochemical reward centers in the brain that override normal willpower and, in the case of food addictions, overwhelm the ordinary biological signals that control hunger.
Why is it so hard for obese people to lose weight despite the social stigma, despite the health consequences such as high blood pressure, diabetes, heart disease, arthritis, and even cancer, and despite their intense desire to lose weight?
It is not because they want to be fat. It is because, in the vast majority of cases, certain types of food — processed foods made of sugar, fat, and salt combined in ways kept secret by the food industry — are addictive. We are biologically wired to crave these foods and eat as much of them as possible.
The Science of Addiction
While some of us may be more genetically predisposed to the addictive properties of food (or heroin or alcohol), if you examine your own behavior and your relationship to sugar, in particular, you will likely find that your behavior around sugar matches up perfectly with why you can’t control your diabesity.
Based on psychological criteria and new neurological research, many of us, including most obese children, are “addicted” to industrial food. Let’s review some of the scientific findings confirming that food can, indeed, be addictive:
- Sugar stimulates the brain’s pleasure or reward centers–through the neurotransmitter dopamine–exactly like other addictive drugs.
- Brain imaging (PET scans) shows that high-sugar and high-fat foods work just like heroin, opium, or morphine in the brain.
- Brain imaging (PET scans) shows that obese people and drug addicts have lower numbers of dopamine receptors, making them more likely to crave things that boost dopamine. This is, in part, genetically determined.
- Foods high in fat and sweets stimulate the release of the body’s own opioids (chemicals like morphine) in the brain.
- Drugs we use to block the brain’s receptors for heroin and morphine (naltrexone) also reduce the consumption and preference for sweet and high-fat foods in both normal-weight and obese binge eaters.
- People (and rats) develop a tolerance to sugar— they need more and more of the substance to satisfy themselves; this is also true of drugs such as alcohol or heroin.
- Obese individuals continue to eat large amounts of unhealthy foods despite severe social and personal negative consequences, just like addicts and alcoholics.
- Animals and humans experience “withdrawals” when suddenly cut off from sugar, just like addicts detoxifying from drugs. Just like drugs, after an initial period of “enjoyment” of the food, the user consumes it not to get high but to feel normal.
If you want to understand more about how the food industry keeps us addicted, please read The End of Overeating. In this riveting book, Kessler, the former head of the Food and Drug Administration (FDA), describes the science of how food is made into drugs by the creation of hyper-palatable foods that leads to neurochemical addiction.
Read more of Dr. Mark Hyman’s writing here.
