Dietary Study Finds Marijuana Users Have Normal Nutritional Status, Risky Lifestyle Habits

By Lois Baker

Release Date: June 11, 2001

BUFFALO, N.Y. -- Smoking marijuana and "the munchies" go together like ham and eggs in anecdotal popular culture.

But how do marijuana users fare nutritionally in their everyday lives?

Data from the Third National Health and Nutrition Examination Survey (NHANES III), analyzed by University at Buffalo researchers, paint a mixed nutritional picture. Their study, published in the June issue of Public Health Nutrition, found that:

• Marijuana users consumed 24-40 percent more calories than non-users, but ate fewer fat calories and had a somewhat lower body mass index, a measure of obesity.

• Users ate fewer fruits and vegetables and had lower levels of helpful antioxidant carotenoids in their blood stream, but levels of most vitamins and minerals were normal.

• Users drank more soda and beer and ate more cheese and salty snacks than non-users.

• Marijuana users smoked more cigarettes.

"We know little about the long-term effects of marijuana on the human body and other health behaviors associated with it," said Ellen Smit, Ph.D., assistant professor of social and preventive medicine in the UB School of Medicine and Biomedical Sciences and lead author on the study.

"It is important that we learn more about the changes in dietary habits that accompany marijuana use and their beneficial or detrimental effect on the development of chronic diseases."

The study examined diet and nutritional status of marijuana users and non-users between the ages of 20 and 59 based on NHANES III data collected between 1988 and 1994. Users were defined as having smoked or consumed marijuana in the past month. The survey involved a complete physical exam and medical history, blood chemistry assessment and questionnaires on foods eaten recently and regularly.

The need for information on the health consequences of using marijuana stemmed from public pressure for approval of the medical use of marijuana, and because marijuana is the most commonly used illicit drug in the U.S.

Earlier research had shown that a third of U.S. residents over the age of 12 have smoked marijuana at some point. The National College Health Risk Behavior Survey found that 59 percent of students 25 years and older had used marijuana and that 8 percent were current users.

In NHANES III, 45 percent of the survey population between the ages of 20 and 59 reported having used marijuana at least once, while 13 percent said they had used it 100 times or more. Nearly 9 percent had used the drug during the past month, with 2 percent qualified as heavy users (11 or more times a month).

Users differed from non-current users in some significant ways: They were younger, less well educated, and more likely to be male and to have lower annual incomes.

After adjusting for these variables, marijuana users in general did not have poor nutritional status, judging by body mass index and an analysis of important blood components, the study showed. However, they smoked more cigarettes, drank more alcohol, consumed more salt and ate fewer fruits, in addition to having lower carotenoid levels.

"These lifestyle habits could increase their risk for chronic diseases such as heart disease and cancer in the long term," Smit said.

Carlos Crespo, Dr.PH, UB associate professor of social and preventive medicine, also contributed to the study.