This article was first published in聽
鈥淏etcha can鈥檛 eat just one鈥� is one of the most successful advertising slogans ever fashioned. Introduced by the Frito-Lay snack food company in 1963, it was crafted to promote its potato chips. For its television campaign, the company hired Bert Lahr, who had endeared himself to audiences playing the role of the Cowardly Lion in the 1939 film classic The Wizard of Oz. Although the term 鈥渇ood addiction鈥� wasn鈥檛 on anyone鈥檚 lips at the time, the slogan insinuated such a possibility. The choice of Bert Lahr turned out to be auspicious.
Fans of the film will recall how the Wicked Witch of the West conjures up a poppy field in front of the Emerald City to prevent Dorothy, the Lion, the Tin Man and the Scarecrow from entering. As the four meander through the field, Dorothy and the Lion mysteriously fall asleep, succumbing to the narcotic vapours released by the poppies. The Tin Man and the Scarecrow, not possessed of human or animal biology, are unaffected. Morphine, the major narcotic in poppies, has been shown to increase dopamine release in the brain, a factor that contributes to the pleasurable effect and is a major contributor to morphine鈥檚 addictive potential. Researchers are now wondering whether certain foods can also lead to addiction by triggering a surge of dopamine.
The possibility of food addiction was first raised by Dr. Paul Kenny in a 2010 paper titled 鈥溾�� The study involved allowing rats to eat as much high-fat, high-sugar food like sausage, bacon and cheesecake as they desired. They ended up consuming twice as many calories as a group of control rats fed the normal laboratory diet and unsurprisingly became obese. Amazingly, even when dining at the high-fat, high-sugar buffet was associated with the rats getting an electric shock, they continued to overeat. And when the obese rats were offered what the researchers called 鈥渢he salad bar option鈥� instead of the fatty and sugary foods, they refused to eat. The rats were obviously highly motivated to eat the food they found palatable!
A clue to the rats鈥� behaviour came from implanting electrodes in the pleasure centre of the brain that allowed for the monitoring of the activity of a receptor that responds to dopamine, a neurotransmitter that is released in response to pleasurable experiences such as sex or drugs like cocaine. It turned out that the highly palatable food overstimulated the pleasure centres causing receptor activity to be reduced. In turn, this created an increased desire to stimulate them again with more dopamine. It seems the rats require constant stimulation from palatable food to release more dopamine to produce the expected pleasure. And there you have the basis of addiction!
Humans, of course, are not giant rats, and it would be difficult to find volunteers willing to have electrodes implanted in their brains to monitor activity in response to diverse diets. But it is not difficult to have people eat a high-fat, high-sugar diet. You don鈥檛 need an experiment to do that; it is happening every day. We are talking about the ultra-processed foods that have become a mainstay of the Western diet. Think frozen pizzas, hotdogs, ice cream, candy bars, cakes, supermarket bread, sweetened breakfast cereals, TV dinners and chips. Just about every day, some new study comes out linking an ultra-processed food diet to cancer, cardiovascular disease, Type 2 diabetes and various mental disorders. Why, then, do we keep eating them?
The simple answer is that in a competition between the tastebuds and willpower, tastebuds win. Food and beverage producers know that and carry out extensive research aimed at increasing palatability. What they have learned is that combining fats and sugars makes food tastier and that the pleasure they deliver can be further increased by modifying texture with additives such as emulsifiers so that the fats and sugars enter the bloodstream quickly. Vegetables, fruits and whole grains do contain fats and sugars, but not both in amounts comparable to what is found in processed foods. Throw in some salt, monosodium glutamate and artificial flavours, and you have an even more palatable mix.
Then, of course, there is advertising. Children are attracted to sweetened cereals by cartoon characters like Toucan Sam (Froot Loops) or Tony the Tiger (Frosted Flakes). And their parents, who for years have watched Simon Cowell judge talent on TV, might give Domino鈥檚 pizza a try when they discover that 鈥渙nstage isn鈥檛 the only place Simon demands excellence.鈥�
But is there more than taste and advertising that makes these foods appealing? Could we be looking at addiction as in the case of the rats? Possibly, if we go by the , which was developed in 2009 and asks 25 questions modelled on ones used to detect drug addiction. For example, 鈥淒o you continue to consume certain foods though you are no longer hungry?鈥� 鈥淒o you have withdrawal symptoms such as agitation or anxiety when you cut down or stop eating certain foods?鈥� 鈥淲hen you cut down certain foods, do you want them more?鈥� Based on answers to such questions, it is estimated that about 14 per cent of adults show signs of food addiction.
On the other hand, Dr. Kevin Hall, one of the world鈥檚 leading researchers in nutrition, explored the problem of addiction using positron emission tomography, a technique that can actually detect dopamine levels in the brain. There was no increase when subjects ate ultra-processed foods. So, the jury is out on whether ultra-processed foods are addictive in the same way that morphine or cocaine are addictive. But when it comes to the charge of current levels of ultra-processed food consumption being linked to disease, the verdict is in. Guilty as charged!
As far as the 鈥渂etcha can鈥檛 eat just one鈥� challenge goes, I feel a kinship to the Cowardly Lion. I fear I would lose the bet.
