Sugar is a key ingredient in most junk food, so they offered rats sugar syrup, similar to the sugar concentration in a typical soda beverage, for about 12 hours each day, alongside regular rat feed and water. After just a month on this diet, the rats developed behaviour and brain changes that Avena and Hoebel claimed were chemically identical to morphine-addicted rats. They binged on the syrup and showed anxious behaviour when it was removed - a sign of withdrawal. There were also changes in the neurotransmitters in the nucleus accumbens, a region associated with reward.
Of a separate study done by a different group it said:
Kenny wondered whether rats that eat junk food would have a similar response to the cocaine-addicted rats he had already studied. He used three groups of rats. The first was a control group that only had access to standard rat feed. The second group could eat junk food - bacon, sausage, icing and chocolate - for only 1 hour each day with regular rat feed and water available for the rest of the time. The third group had an all-you-can-eat, around-the-clock buffet that included junk food and rat feed. After 40 days, Kenny stopped access to the junk food in both experimental groups. The rats with unlimited access to junk food essentially went on a hunger strike. "It was as if they had become averse to the healthy food," says Kenny. It took two weeks before the animals began eating as much as those in the control group.
The obese, unlimited junk food rats had dulled reward systems and were compulsive eaters. They would even tolerate electric shocks to their feet designed to deter them from eating junk food when the rat feed was still available shock-free. Cocaine-addicted rats behave the same way towards their drug.
Yesterday afternoon, after reading the New Scientist article, I attended a regional conference held by the LDS church, in which President Packer was one of the speakers. At one point during his talk he said something like, "We don't use harmful or addictive substances." I'm not sure of the exact wording, but using the words "harmful" and "addictive" is pretty common among leaders of the LDS church, and the subject is related to what is termed the "Word of Wisdom".
[The Word of Wisdom refers specifically to Section 89 of the Mormon book Doctrine and Covenants, in which certain dietary prescriptions and proscriptions are made, and also to the set of requirements for full church membership made by the church organization today. The two aren't exactly the same. For example, nowhere in the text of Section 89 does it mention "harmful drugs" or something similar, yet the use of drugs is explicitly considered to be a violation of the Word of Wisdom and of the requirements for full church membership. A third Word of Wisdom definition might be a more abstract and nebulous injunction to "do things that cause you to be healthy".]
Anyway, when President Packer stated that we don't use addictive substances the first though that came to my mind was sugar, since I'd just read the article about junk food addiction.
Should excessive consumption of sugar be considered to be against the Word of Wisdom? Well, it's not against the text of Doctrine and Covenants Section 89. It's not now a violation of the specific requirements for LDS church membership. It would be against the abstract injunction to be healthy, though being healthy isn't particularly novel or insightful, except perhaps the idea that God is asking us explicitly to take steps toward being healthy. It is, though, a violation of the command to avoid harmful and addictive substances.
I still eat sugar. And I did use the weasel word "excessive". Take it as food for thought. Or thought for food.