[ Recent news article on rats preferring sugar water to cocaine is
substantated in this article available in full at the link below with
the abstract as follows. ]

Full Article
http://www.plosone.org/article/info:...l.pone.0000698



Intense Sweetness Surpasses Cocaine Reward

Magalie Lenoir#, Fuschia Serre#, Lauriane Cantin, Serge H. Ahmed*

University Bordeaux 2, Université Bordeaux 1, CNRS, UMR 5227, Bordeaux,
France

*Abstract*

Background

Refined sugars (e.g., sucrose, fructose) were absent in the diet of most
people until very recently in human history. Today overconsumption of
diets rich in sugars contributes together with other factors to drive
the current obesity epidemic. Overconsumption of sugar-dense foods or
beverages is initially motivated by the pleasure of sweet taste and is
often compared to drug addiction. Though there are many biological
commonalities between sweetened diets and drugs of abuse, the addictive
potential of the former relative to the latter is currently unknown.
Methodology/Principal findings

Here we report that when rats were allowed to choose
mutually-exclusively between water sweetened with saccharin–an intense
calorie-free sweetener–and intravenous cocaine–a highly addictive and
harmful substance–the large majority of animals (94%) preferred the
sweet taste of saccharin. The preference for saccharin was not
attributable to its unnatural ability to induce sweetness without
calories because the same preference was also observed with sucrose, a
natural sugar. Finally, the preference for saccharin was not
surmountable by increasing doses of cocaine and was observed despite
either cocaine intoxication, sensitization or intake escalation–the
latter being a hallmark of drug addiction.
Conclusions

Our findings clearly demonstrate that intense sweetness can surpass
cocaine reward, even in drug-sensitized and -addicted individuals. We
speculate that the addictive potential of intense sweetness results from
an inborn hypersensitivity to sweet tastants. In most mammals, including
rats and humans, sweet receptors evolved in ancestral environments poor
in sugars and are thus not adapted to high concentrations of sweet
tastants. The supranormal stimulation of these receptors by sugar-rich
diets, such as those now widely available in modern societies, would
generate a supranormal reward signal in the brain, with the potential to
override self-control mechanisms and thus to lead to addiction.

Citation: Lenoir M, Serre F, Cantin L, Ahmed SH (2007) Intense Sweetness
Surpasses Cocaine Reward. PLoS ONE 2(8): e698.
doi:10.1371/journal.pone.0000698

Academic Editor: Bernhard Baune, James Cook University, Australia

Received: April 24, 2007; Accepted: July 4, 2007; Published: August 1, 2007

http://www.plosone.org/article/info:...l.pone.0000698