Cocaine: Users Show Lower Levels of Leptin Hormone in Blood Stream

Cocaine is a purified extract that comes from leaves of the Erythroxylum coca bush. This plant grows in the Andes region of South America. Different chemical processes can produce two main forms of the drug in a powdered form, with the street name "coke" or "blow" or crack cocaine, commonly referred to as "crack " or "rock" and is usually smoked.

As the drug has been known to reduce the body's ability to store fat, researchers at the University of Cambridge suggest that metabolic changes for cocaine users during recovery can actually cause the opposite phenomenon.

"Our findings challenge the widely held assumptions that cocaine use leads to weight loss through appetite suppression. Rather, they suggest a profound metabolic alteration that needs to be taken into account during treatment," said Dr Karen Ersche, from the Behavioural and Clinical Neuroscience Institute at the University of Cambridge, via a press release. "Notable weight gain following cocaine abstinence is not only a source of major personal suffering but also has profound implications for health and recovery. Intervention at a sufficiently early stage could have the potential to prevent weight gain during recovery, thereby reducing personal suffering and improving the chances of recovery."

Researchers scanned over sixty men in order to evaluate body composition, diets and eating behaviors. Half of the men in the study were addicted to cocaine while the other half had no personal or family history of drug abuse. They also looked at the volunteers' leptin levels, a hormone that plays an important role in regulating appetite and energy use.

Researchers found that cocaine users showed a preference for fatty foods and carbohydrates, some of which had uncontrollable patterns in their dieting when it came to following balanced nutrition. However, despite their bad eating habits, they would often lose weight compared to those who were not regularly taking cocaine. Leptin, hormone that plays a key role in regulating energy intake and expenditure, including appetite, hunger and metabolism, was also found in low levels among cocaine users. This can create an impaired energy balance and possibly lead to weight gain.

"We were surprised how little body fat the cocaine users had in light of their reported consumption of fatty food. It seems that regular cocaine abuse directly interferes with metabolic processes and thereby reduces body fat. This imbalance between fat intake and fat storage may also explain why these individuals gain so much weight when they stop using cocaine," Dr. Ersche said, via the release. "For most people weight gain is unpleasant but for people in recovery, who can gain several stones, this weight gain goes far beyond an aesthetic concern but involves both psychological and physiological problems. The stress caused by this conspicuous body change can also contribute to relapse. It is therefore important that we better understand the effects of cocaine on eating behaviour and body weight to best support drug users on their road to recovery."

More information regarding the study can be found in the journal Appetite. 

About 14 percent of U.S. adults have tried cocaine. One in 40 adults has used it in the past year. Young men aged 18 to 25 are the biggest cocaine users, with 8 percent using it in the previous 12 months.