A staggering two-thirds of Americans are now overweight, and one in four are either diabetic or pre-diabetic.
Carb-rich processed foods are a primary driver of these statistics, and while many blame Americans’ overindulgence of processed junk foods on lack of self-control, scientists are now starting to reveal the truly addictive nature of such foods.
Most recently, researchers at the Boston Children’s Hospital concluded that highly processed carbohydrates stimulate brain regions involved in reward and cravings, promoting excess hunger.1 As reported by Science Daily:2
“These findings suggest that limiting these ‘high-glycemic index’ foods could help obese individuals avoid overeating.”
While I don’t agree with the concept of high glycemic foods, it is important that they are at least thinking in the right direction. Also, the timing is ironic, considering the fact that the American Medical Association (AMA) recently declared obesity a disease, treatable with a variety of conventional methods, from drugs to novel anti-obesity vaccines…
The featured research is on the mark, and shows just how foolhardy the AMA’s financially-driven decision really is. Drugs and vaccines are clearly not going to do anything to address the underlying problem of addictive junk food.
Brain Imaging Shows Food Addiction Is Real
The study, published in the American Journal of Clinical Nutrition3 examined the effects of high-glycemic foods on brain activity, using functional magnetic resonance imaging (fMRI). One dozen overweight or obese men between the ages of 18 and 35 each consumed one high-glycemic and one low-glycemic meal. The fMRI was done four hours after each test meal. According to the researchers:
“Compared with an isocaloric low-GI meal, a high-glycemic index meal decreased plasma glucose, increased hunger, and selectively stimulated brain regions associated with reward and craving in the late postprandial period, which is a time with special significance to eating behavior at the next meal.”
The study demonstrates what many people experience: After eating a high-glycemic meal, i.e. rapidly digesting carbohydrates, their blood sugar initially spiked, followed by a sharp crash a few hours later. The fMRI confirmed that this crash in blood glucose intensely activated a brain region involved in addictive behaviors, known as the nucleus accumbens.
Dr. Robert Lustig, Professor of Pediatrics in the Division of Endocrinology at the University of California, a pioneer in decoding sugar metabolism, weighed in on the featured research in an article by NPR:4
“As Dr. Robert Lustig… points out, this research can’t tell us if there’s a cause and effect relationship between eating certain foods and triggering brain responses, or if those responses lead to overeating and obesity.
‘[The study] doesn’t tell you if this is the reason they got obese,’ says Lustig, ‘or if this is what happens once you’re already obese.’ Nonetheless… he thinks this study offers another bit of evidence that ‘this phenomenon is real.’”
Previously, Dr. Lustig has explained the addictive nature of sugar as follows:
“The brain’s pleasure center, called the nucleus accumbens, is essential for our survival as a species… Turn off pleasure, and you turn off the will to live… But long-term stimulation of the pleasure center drives the process of addiction… When you consume any substance of abuse, including sugar, the nucleus accumbens receives a dopamine signal, from which you experience pleasure. And so you consume more.
The problem is that with prolonged exposure, the signal attenuates, gets weaker. So you have to consume more to get the same effect — tolerance. And if you pull back on the substance, you go into withdrawal. Tolerance and withdrawal constitute addiction. And make no mistake, sugar is addictive.”
The Extraordinary Science of Addictive Junk Food
Previous research has demonstrated that refined sugar is more addictive than cocaine, giving you pleasure by triggering an innate process in your brain via dopamine and opioid signals. Your brain essentially becomes addicted to stimulating the release of its own opioids.
Researchers have speculated that the sweet receptors located on your tongue, which evolved in ancestral times when the diet was very low in sugar, have not adapted to the seemingly unlimited access to a cheap and omnipresent sugar supply in the modern diet.
Therefore, the abnormally high stimulation of these receptors by our sugar-rich diets generates excessive reward signals in your brain, which have the potential to override normal self-control mechanisms, thus leading to addiction.
But it doesn’t end there. Food manufacturers have gotten savvy to the addictive nature of certain foods and tastes, including saltiness and sweetness, and have turned addictive taste into a science in and of itself.
In a recent New York Times article, Michael Moss, author of Salt Sugar Fat, dished the dirt on the processed food industry, revealing that there’s a conscious effort on behalf of food manufacturers to get you hooked on foods that are convenient and inexpensive to make.
I recommend reading his article in its entirety, as it offers a series of case studies that shed light on the extraordinary science and marketing tactics that make junk food so hard to resist.
Sugar, salt and fat are the top three substances making processed foods so addictive. In a Time Magazine interview6 discussing his book, Moss says:
“One of the things that really surprised me was how concerted and targeted the effort is by food companies to hit the magical formulation. Take sugar for example. The optimum amount of sugar in a product became known as the ‘bliss point.’ Food inventors and scientists spend a huge amount of time formulating the perfect amount of sugar that will send us over the moon, and send products flying off the shelves. It is the process they’ve engineered that struck me as really stunning.”
It’s important to realize that added sugar (typically in the form of high fructose corn syrup) is not confined to junky snack foods. For example, most of Prego’s spaghetti sauces have one common feature, and that is sugar—it’s the second largest ingredient, right after tomatoes. A half-cup of Prego Traditional contains the equivalent of more than two teaspoons of sugar.
Novel Flavor-Enhancers May Also Contribute to Food Addiction
Another guiding principle for the processed food industry is known as “sensory-specific satiety.” Moss describes this as “the tendency for big, distinct flavors to overwhelm your brain, which responds by depressing your desire to have more.” The greatest successes, whether beverages or foods, owe their “craveability” to complex formulas that pique your taste buds just enough, without overwhelming them, thereby overriding your brain’s inclination to say “enough.”
Novel biotech flavor companies like Senomyx also play an important role.
Senomyx specializes in helping companies find new flavors that allow them to use less salt and sugar in their foods. But does that really make the food healthier? This is a questionable assertion at best, seeing how these “flavor enhancers” are created using secret, patented processes. They also do not need to be listed on the food label, which leaves you completely in the dark. As of now, they simply fall under the generic category of artificial and/or natural flavors, and they don’t even need to be tested for safety, as they’re used in minute amounts.
Source: Dr. Mercola.com
Image credit: Hungry for change.com