TCS Daily

Are Fast Foods Addictive?

By Iain Murray - February 20, 2003 12:00 AM

A number of studies have emerged recently that try to claim that fast food is "as addictive as heroin." This cancerous cluster caused the once-respectable magazine New Scientist to ask the question on its front cover, "Can Fast Food Alter Your Brain in the Same Way as Tobacco and Heroin?" A four-page article within the magazine came to the conclusion that the science doesn't matter, because the courts would decide the issue anyway. Such is the nature of scientific inquiry today.

The issue hinges on the behavior of lab rats.

Dr. John Hoebel of Princeton University observed that rats fed a diet containing 25 percent sugar behave anxiously once the sugar diet is withdrawn. They display, in fact, all the symptoms of people suffering from withdrawal of nicotine or morphine - chattering teeth, shakes and the like. From this observation, Dr. Hoebel theorizes that sweet, high-fat foods stimulate opioids, the pleasure chemicals within the brain that are stimulated by certain drugs.

This research was backed up by rat studies at the University of Wisconsin Medical School, which indeed found changes in rats' neurochemistry that were similar to those inflicted by heroin and morphine. However, in this case the experiment was reversed. The researchers stimulated the rats' brains with a synthetic opioid, and then found that the rats ate up to six times their normal intake of fat, sweet and salty foods.

It has long been known that it is not just drugs that stimulate opioids. Aerobic exercise is just one of the things that can give you a pleasurable "buzz." Does it therefore follow that exercise is addictive, or that things that are addictive are harmful?

The difference may be the old philosophical one between hedonism and utility (general happiness), but that is probably beside the point. The researchers have not yet proved that fatty foods are addictive. All that has been done so far is to prove that rats that are fed enormous amounts of sugar end up missing it when they are deprived of it, and that rats whose brains are altered chemically start behaving differently. One might suggest that neither of these events is unexpected.

Nor is the assertion that people find fatty foods pleasurable particularly novel. Gourmands from Apicius onwards have pointed out the delight with which people receive pate de foie gras and other high-fat foods that hardly fall into the category of junk food.

A former colleague of mine once pointed out how a team of visiting Russian scientists astounded their hosts when taken to the university canteen because they insisted in covering everything in bacon fat. This probably has less to do with the so-called addictive qualities of the food and more with the body's desire to ensure the acquisition of essential nutrients that fat contains in abundance.

So it is not at all surprising that fatty foods should stimulate our pleasure centers. Does this quality imply addictiveness, however? It is saying something when a representative of the nutritional lobbying group the Center for Science in the Public Interest, which has called for restrictions on soda advertising and campaigns against too much cheese in the national diet, thinks the argument goes too far. Dr. Michael Jacobsen off CSPI told New Scientist, "Considering the paucity of evidence, I think that the burden is on advocates of the addiction argument to provide evidence of addictiveness."

Yet, as the New Scientist implies, there may not be time for more studies. We have already seen the first shot fired in a war of litigation over the fast food issue. Caesar Barber, a middle-aged New York City janitor, claimed that he suffered diabetes and two heart attacks as a result of the fat in fast-food sold to him by McDonald's, Wendy's, Burger King and KFC. He lost his case, but more lawyers are sharpening their quills in anticipation of a lucrative crusade against "Big Fat." As New Scientist says, "Some time soon the allegation that fast food is addictive will be made in court, and once that happens the terms of the debate are out of the scientists' hands."

The issue is therefore a microcosm of the way the scientific process is distorted today. Scientists come up with a tentative set of research results. The subsequent press release spins the results so as to grab public attention, which presumably will help gain more funds for further research.

In the meantime, the resulting headlines are seized on by litigators, who take the issue out of the realm of scientific research and into courtrooms. The scientific process is pre-empted and the search for truth suffers while people go after a quick buck. And, doubtless, some people will grow fat on the proceeds. High-class restaurants need not worry that foie gras will be declared addictive.

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