Recreational Marijuana: Are There Health Effects?

ByKathleen Doheny
WebMD Health News Reviewed byBrunilda Nazario, MD

Dec. 11, 2012 -- On Monday, Colorado Gov. John Hickenlooper signed an order legalizing recreational marijuana use for adults.

Last week, Washington was the first state to OK adult recreational use of the drug. Several other states are considering similar laws.

While much research has focused on the value of medical marijuana to help chronic pain and other problems, what about the health effects of purely recreational marijuana?

WebMD turned to two experts, recently published studies, and the National Institute on Drug Abuse to draw up a scorecard of possible major health effects.

Health Effects of Marijuana: Lungs

"Putting smoke in your lungs is not good for the lungs," says Roland Lamarine, HSD, professor of public health at California State University, Chico. He reviewed published studies on the health effects of marijuana earlier this year for the Journal of Drug Education.

Smoking marijuana produces a nearly threefold increase of inhaled tar compared with tobacco, according to some studies. Other research suggests that marijuana smokers, compared to cigarette smokers, inhale more deeply and hold their breath longer.

"There are still questions that aren't answered about lung damage," Lamarine says. For cigarette smokers who also smoke marijuana, there may be an additive effect, he says.

Combining the two appears to be a trend, he says. "Some of the [college] kids tell me they buy cigars and put in some marijuana, so there is both marijuana and tobacco," Lamarine says.

Marijuana smoke contains cancer-causing substances, according to the National Institute on Drug Abuse. Some research shows that marijuana smoke has up to 70% more cancer-causing substances than tobacco smoke, it says.

"Nobody is advocating that routinely inhaling carcinogenic smoke is healthy," says Paul Armentano, the deputy director of NORML (National Organization for the Reform of Marijuana Laws).

However, he says, many marijuana users these days have turned to alternate delivery methods, such as oral, tinctures, and vapor forms. In research, he says, the vaporized forms have fewer adverse chemicals than the inhaled form.

Those who keep marijuana use light do not appear to lose lung function, according to a 2012 study in the Journal of the American Medical Association.

Researchers compared tobacco and marijuana users. Tobacco use was associated with lower lung function, and the function got worse as smoking levels increased.

For the study, low levels of lifetime exposure to marijuana, defined as one joint a day for seven years, did not show evidence of adverse effects on lung function. The study does not confirm these findings with heavy users.

Health Effects of Marijuana: Brain Impairment

Long-term, heavy use of marijuana can lead to impaired thinking skills and memory problems, Lamarine says, citing published studies.

The impairments can be especially hazardous when trying to do everyday activities such as driving.

1 | 2 Next Page > #url_reference {display: none};#url_reference { display: block; line-height: 150%; margin-bottom: 10px; }#logo_rdr img { visibility: visible; }.titleBar_rdr .titleBarMiddle_fmt { padding-top: 1.5em !important;} Top Picks Smoking and Heart Disease: What's the Link? Smoke When You Drink? Here's Why Surprising Ways Smoking Affects Your Looks and Life 14 Natural Ways to Quit Smoking What Your Teeth Reveal About Your Health Smoking: Leading Cause of ED Smoking Cessation Health Center Overview Health Tools Why Do You Smoke? Thinking About Quitting? Planning Your Strategy to Quit Ready to Quit Today? Dealing With Relapse Staying Smoke-Free Why Quit? Other Places To Get Help Related Information References Credits See what others are asking about

Visit WebMD Answers

Related to Smoking Cessation Bad Breath COPD Emphysema Heart Disease & Smoking Hypnosis Living Healthy Lung Cancer Lung Disease Mouth Care Oral Cancer Questions and Answers Smoking and Oral Health Stress Management Reference Today in Smoking Cessation ARTICLE Smoking & Heart Risks: Get the Facts Slideshow Ways Smoking Affects Your Looks   USER REVIEWS Research Smoking Cessation Medications Quiz Cigarettes and Your Health   Article Smoking and Risk for Dupuytren's Contracture VIDEO Which Quit Smoking Aid Is Right For You?   SLIDESHOW Lung Cancer Risks: Myths and Facts Quiz COPD: How Much Do You Know?   SLIDESHOW ED and Smoking: What’s the Link? VIDEO How to Quit Smoking Forever   SLIDESHOW Smoking: A Contributor to Dry Mouth SLIDESHOW Smoking and Other Factors That Affect Blood Sugar   Subscribe to WebMD Newsletters

WebMD Daily Women's Health Men's Health Weight Loss Wisdom I have read and agree to WebMD's Privacy Policy. Submit Sign up for more topics! WebMD Special Sections Stop-Smoking Support and Tips Slideshow: 13 Best Quit-Smoking Tips Ever Health Solutions From Our Sponsors Vaccine Questions? Low Testosterone? Bipolar Disorder Facts Birth Control for Moms Blood Sugar Control Bent Fingers? Diagnosed With Low T? Fibromyalgia & Exercise Depression & Adults Child with Diabetes? Vaccines for All Ages Knee Pain Relief Itchy, Scaly Skin? Hearing Aid Alternative Relapsing MS Help In-depth coverage: Psoriasis Treatment on Target?|Healthy Mouth Help|RA Assessment|Living Healthy Guide|Family & Pregnancy Toolbox|Check Your Heartburn Symptoms Find us on:URAC: Accredited Health Web SiteHonCode: Health on the Net FoundationAdChoicesAbout WebMD Advertise With Us Terms of Use Privacy Policy Sponsor Policy Site Map Careers Contact UsMedscape Reference eMedicineHealth RxList Medscape MedicineNet BootsWebMD WebMD CorporateMedical Dictionary-->First Aid WebMD Magazine WebMD Health Record WebMD Mobile Newsletters Dictionary Physician Directory

©2005-2012 WebMD, LLC. All rights reserved.

WebMD does not provide medical advice, diagnosis or treatment. See additional information.

View the Original article