In the next few weeks, Nicholas DiPatrizio’s lab at UC Riverside will receive a shipment of marijuana.

DiPatrizio, a professor of biomedical sciences, then will begin giving mice precise doses of cannabis oil to see how marijuana impacts their weight and a host of serious health conditions often linked to obesity.

The study marks the first time UC Riverside has received federal approval to conduct research on marijuana — or any other substance in the Drug Enforcement Administration’s strict Schedule I category. It also marks the school’s first cannabis-related grant, with $744,000 from tobacco taxes being used to finance this three-year research project on how marijuana affects metabolic health.

Nicholas DiPatrizio, a biomedical sciences professor at the UCR School of Medicine, center, goes over a brain atlas with students at his lab on campus in Riverside on Tuesday, June 18, 2019. DiPatrizio and students have received the university’s first grant and federal approval to study cannabis. (Photo by Watchara Phomicinda, The Press-Enterprise/SCNG)

Nicholas DiPatrizio, a biomedical sciences professor at the UCR School of Medicine, holds a vile containing the body’s natural cannabis-liked molecules called endocannabinoids at his lab on campus in Riverside on Tuesday, June 18, 2019. DiPatrizio and students have received the university’s first grant and federal approval to study cannabis. (Photo by Watchara Phomicinda, The Press-Enterprise/SCNG)

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Nicholas DiPatrizio, a biomedical sciences professor at the UCR School of Medicine, holds a vile containing the body’s natural cannabis-liked molecules called endocannabinoids at his lab on campus in Riverside on Tuesday, June 18, 2019. DiPatrizio and students have received the university’s first grant and federal approval to study cannabis. (Photo by Watchara Phomicinda, The Press-Enterprise/SCNG)



UC Riverside is now one of seven schools in the University of California system that have successfully navigated the challenging regulatory process required to study the impact of cannabis on human health.

Scientists at UC Irvine, UCLA, UC Davis, UC San Diego, UCSF and UC Santa Cruz also have received federal approval for marijuana research projects, according to Sara McBride, spokeswoman for the University of California Office of the President.

Those scientists are looking at everything from how cannabis affects drivers to the drug’s possible use in controlling infant seizures. And they’re doing so despite roadblocks that can make marijuana research a complex, lengthy and pricey endeavor.

DiPatrizio says the effort will be more than worth it if he can help the world better understand and harness marijuana’s potential to lower obesity and boost metabolic health.

“This field is sort of still in its infancy,” he said. “But that’s exciting. We have a lot to learn.”

Marijuana and hunger

The concept behind DiPatrizio’s upcoming study on how cannabis might reduce obesity-linked conditions might seem paradoxical to people who assume marijuana always leads to the munchies.

There is truth to that stereotype. Twenty years ago, when DiPatrizio was an undergraduate student at Temple University, research showed that rats tended to binge on food the first day they were exposed to significant doses of THC, the main compound in marijuana that makes people feel high. And Nielsen Research group released a study this week showing that sales of sweet and salty snacks grew at faster rates in states that have legalized recreational marijuana.

But the process that links THC with appetite doesn’t work in only one direction.

Based on the “munchies” phenomena, a drug company developed an anti-obesity pill called rimonabant that, though it did not receive approval in the United States, entered the European market in 2006 under the trade name Acomplia.

To understand how the drug worked, and how DiPatrizio’s study might work, you have to first understand a bit about the endocannabinoid system.

Humans produce a range of chemical compounds called endocannabinoids, which are similar to compounds found in marijuana. These naturally occurring compounds help keep our bodies stable by binding to cannabinoid receptors on cell membranes throughout the body. They also control the release of chemical messengers that regulate everything from how we experience pain to our moods and appetites.

What the makers of rimonabant found was that if they could block naturally occurring endocannabinoids from binding to cell receptors in the gut, they could effectively control hunger impulses, boost metabolism and help patients lose weight.

However, humans also have cannabinoid receptors in their brains. And when those receptors were blocked by rimonabant, patients experienced depression and suicidal thoughts. So in 2008, the drug was yanked from the European market.

Since then, researchers have been working on alternatives, hoping to come up with a drug that blocks hunger-related endocannabinoid signals in the gut without crossing the blood-brain barrier.

But what DiPatrizio and others have found is that the opposite approach also might be effective.

His theory is connected to the Temple University study he worked on in the late 1990s.

While the rats in that study binged on food on the first day they were exposed to marijuana, they stopped overeating by day three. And DiPatrizio said that pattern held for the rest of the week.

Observational studies have similarly shown that chronic cannabis consumers tend to be leaner than the average population and therefore have lower risks of dangerous metabolic conditions linked to obesity, such as Type 2 diabetes, heart disease and stroke.

DiPatrizio and others have hypothesized that introducing cannabis into the system initially sends endocannabinoid receptors into overdrive, which can make food taste better and stop consumers from feeling full. But after repeated cannabis exposure, the body seems to adapt, slowing those hunger impulses.

Mice meet THC

That doesn’t mean DiPatrizio is recommending people who want to lose weight start smoking marijuana. In fact, today, he has more questions than answers about this theory.

That’s where his new study comes in.

DiPatrizio, plus a team of four graduate students and an “army” of undergraduate researchers, will soon begin feeding separate groups of mice two types of diets. Some will get lean foods, while others will be fed high-fat, high-sugar “western style” diets. The researchers also will give some mice pure THC, and give other mice all of the compounds found in marijuana. The idea is to learn if THC alone, or in combination with other chemicals found in marijuana, can be effective at regulating weight and metabolic conditions.

Since tobacco use is linked to Type 2 diabetes, grant funding for the study came from the Tobacco-Related Disease Research Program, which is administered by the UC system.

DiPatrizio said over the next few weeks they expect to order some cannabis from the only federally sanctioned supplier of research-grade cannabis, at the University of Mississippi. Then they’ll get to work, with hopes of publishing an initial round of findings in about a year.

Cannabis studies in high demand

With both hemp and marijuana now legalized, interest in rigorous studies and effective products made from cannabis are both in high demand. So, without actually administering marijuana, UC Riverside researchers have been collecting data and doing observational studies on other potential health benefits, risks and uses of cannabis.

For example, DiPatrizio has been working with an immunologist at the school to look at how cannabis consumption might help reduce complications from hookworm.

And chemical and environmental engineering students at UC Riverside have received up to $15,000 from the Environmental Protection Agency this spring to study greener ways to make construction materials from hemp, a type of cannabis plant that contains almost no THC.

Hempcrete, as construction materials made from hemp are called, are sustainable and energy efficient. But the common method for making hempcrete produces toxic waste. So UC Riverside students, led by Prof. Charles Cai, are trying to use a technology invented at the school to produce hempcrete without generating any toxic byproducts.

They hope to get up to $100,000 more in EPA funds to take their new hempcrete product method to market, with Cai noting they’ve already been contacted by interested businesses.