Monthly Archives: April 2017

Marijuana’s popularity in the US is on the rise

Marijuana’s popularity among American adults is on the rise — and use of the recreational drug is expected to continue to increase, according to several surveys.

The increase in popularity, along with more permissive attitudes toward marijuana use, may be due in part to its changing legalization status in many parts of the country, experts say.

Forty-five percent of adults in the U.S. have used marijuana at least once in their lives, according to a Gallup poll released in mid-July — the all-time highest percentage in the 48-year history of Gallup asking Americans this question. [25 Odd Facts About Marijuana]

Trying marijuana at least once as an adult isn’t the same as being a user of the drug, but the percentage of current smokers is on the rise as well: The same Gallup poll revealed that 12 percent of U.S. adults — 1 in 8 — said they use marijuana, up from 7 percent in 2013.

Meanwhile, data from two large national surveys done by the federal government also finds increasing rates of marijuana use among adults. (Gallup does its poll by telephone interviews, while federal surveys conduct face-to-face interviews. An in-person interview could possibly influence results because marijuana is still illegal in most states and people may be hesitant to admit they use it.)

One of these large surveys, published in 2015 in JAMA Psychiatry, found that the prevalence of marijuana use in the United States more than doubled over a decade. After interviewing about 36,000 people, ages 18 and older, the researchers found that the percentage of adults who reported using marijuana in the past year jumped from 4.1 percent in 2001–2002 to 9.5 percent in 2012-2013.

The data showed that marijuana use was increasing in males and females in many age groups, although it was increasing a little faster in young adults, ages 18 to 29, and in males, said Deborah Hasin, one of the study authors and a professor of epidemiology at Columbia University’s Mailman School of Public Health in New York City. The rates of use were also increasing among middle-age and older adults, she said.

But the trends in increasing use appear to be limited to adults: Marijuana use is not increasing among teenagers, Hasin said. Two major studies have shown that marijuana use has been relatively stable in adolescents over the last few years, she said.

The top four reasons people give for using marijuana are to relax, to relieve pain, to have fun and to help them be social, according to a survey by Yahoo News/Marist College done in March.Unwinding and fitting in may explain why many people decide to smoke pot, but what are some reasons for its rising popularity among adults?

One explanation is the growing perception that marijuana has few risks, Hasin told Live Science. In the 1960s and ’70s, scare tactics were used to discourage young people from smoking pot, and there was a perception that marijuana could lead to a person becoming addicted to heroin, she said.

These days, teens and adults increasingly see marijuana as a natural substance that’s basically safe, Hasin said. However, one of the known risks of immediate use of the drug is impaired driving ability, she said.

Many people probably consider smoking marijuana as less likely to lead to drug dependence than using other illegal substances. But many of the studies that concluded marijuana may be less addictive than other drugs were done 25 years ago when marijuana was less potent than it is now, Hasin said.

And not only are tetrahydrocannabinol (THC) concentrations, marijuana’s main psychoactive ingredient, higher now than in the past, but people may be using these more potent forms in different ways, such as vaping or consuming them as edibles. Researchers don’t truly know yet how higherpotencies and newer delivery methods will affect marijuana use disorders, Hasin said.

The changing legal status of marijuana in many states may also be responsible for shifting attitudes toward its use and perceived dangers. Twenty-nine states have passed medical marijuana laws, and voters in eight states have approved limited recreational use in adults, Hasin said. [3 More States Legalize Recreational Use of Marijuana: How the Map Looks Now]

There is some evidence from states that have passed medical marijuana laws that shows faster increases in overall marijuana use in adults, compared with states without medical marijuana laws, Hasin said.

Data from California and Colorado, two early adopters of medical marijuana laws, has shown that increased availability of marijuana has led to more overall acceptability of marijuana use, in general, as well increasing perceptions of the drug’s safety, Hasin said. All of these factors seem to increase recreational use of marijuana by adults within these two states, she said.

Marijuana’s popularity can also be explained by a simpler factor: Many people find the drug enjoyable to use. [7 Ways Marijuana May Affect the Brain]

When a person gets high, marijuana has the same effect on the release of the brain chemical dopamine as other psychoactive substances, such as cocaine or heroin, said Francesca Filbey, the director of Cognitive Neuroscience Research in Addictive Disorders at the Center for BrainHealth at the University of Texas at Dallas.

THC binds to cannabinoid receptors, which are found all over the brain, Filbey told Live Science. When THC binds to the receptors, it stimulates the increased release of dopamine, which activates the brain’s reward system and contributes to marijuana’s pleasurable effects, she said.

But marijuana doesn’t only affect areas of the brain involved in feeling good. THC can also attach to receptors in the brain that play a role in modulating other types of behavior, Filbey said. It works like volume control, “turning down” areas of the brain that influence memory, concentration, decision-making, movement and pain perception, she said.

Does Talcum Powder Cause Ovarian Cancer?

Some people may sprinkle on powder after showering and never think much of it. But recent court cases have shined a spotlight on the possible link between women’s regular use of talcum powder on their genitals and an increased risk of developing ovarian cancer.

Yesterday (Aug. 21), a jury in Los Angeles ordered Johnson & Johnson to pay a record $417 million to a woman who claims that the company’s baby powder led to her ovarian cancer. The woman, Eva Echeverria, said in the lawsuit that she developed ovarian cancer as a “proximate result of the unreasonably dangerous and defective nature of talcum powder,” according to the Associated Press. (Johnson & Johnson’s baby powder is made from talcum powder or talc, which is a mineral made up of magnesium, silicon and oxygen.)

In a case that was settled in February, a jury determined that the family of a 62-year-old Alabama woman, who died from ovarian cancer in 2015 after decades of using talcum powder for feminine hygiene, was entitled to $72 million in damages from Johnson & Johnson. The company did not inform customers of the potential dangers of its powders despite being aware of the possible health risks, the jury ruled, according to The Washington Post.

In an earlier case against the same manufacturer, a jury in 2013 found Johnson & Johnson guilty of negligence for not warning women of the risk of ovarian cancer linked to the daily use of the company’s talc-based powders. However, the jury in this case did not award the woman who developed the cancer any monetary damages.

Although these lawsuits have resulted in more publicity about a potential connection between women’s use of talcum powder as a feminine hygiene product, the suggestion of a possible association has been raised in scientific circles for more than 30 years. (Such use means applying powders directly on women’s’ genitals, or on sanitary napkins, tampons, underwear or diaphragms.)

It’s a controversial topic because manufacturers claim there is no causal connection between talc use and ovarian cancer, and researchhas demonstrated conflicting results. [5 Things Women Should Know About Ovarian Cancer]

The American Cancer Society has weighed in on the available science, and said that the “findings have been mixed.” Some studies report a slightly increased risk of ovarian cancer among women who have regularly used talcum powder in their genital areas, while other studies have found no increased risk, the society said.

Based on limited evidence, the International Agency for Research on Cancer, which is part of the World Health Organization, has designated women’s use of talc on their genitals as “possibly carcinogenic to humans.”

Some, but not all powders, such as baby powders and body powders, contain talc, a mineral that may help prevent odor, moisture and chafing when applied to the skin. Before the 1970s, talc products may have contained asbestos, now a known carcinogen, but since then, talcum powders are required by law to be asbestos-free.

Cornstarch-based powders, which have no talc in them, are considered safe for women to use on the genital area and have no known link with any female cancers. And there’s no evidence that sprinkling talc-based powders on other parts of a woman’s body, such as on her feet or her back, influences ovarian cancer risk.

Arguing for strong evidence

Dr. Daniel Cramer, a professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and director of the OB/GYN Epidemiology Center at Brigham and Women’s Hospital in Boston, conducted one of the earliest studies to suggest a link between genital talc use in women and cancer of the ovaries. That research was published in 1982.

Since then, Cramer’s studies have been among those finding a link between women’s regular use of talc and an increased risk of ovarian cancer.

In his opinion, there is strong evidence from about two-dozen epidemiological studies for a significant association between genital talc use and ovarian cancer, Cramer told Live Science. These studies have found that regular talc use may increase a woman’s overall risk of ovarian cancer by about 30 percent, Cramer said.

It has been only in more recent studies that a dose-response effect has been observed in premenopausal women, especially nonsmokers and women who are heavier, and in postmenopausal women who used hormone therapy, Cramer said. A dose-response means that a woman’s risk for ovarian cancer appeared to increase the longer she used talc on her genitals or the more applications she had used over time, he explained.

One factor that has been hard for researchers to quantify is how much talc each woman uses in each application, and how much of it gets into the vagina, Cramer told Live Science. [5 Myths About Women’s Bodies]

Talc is a potent inflammatory agent, and chronic inflammation may predispose a person to cancer, said Cramer, who served as an expert witness in one of the recent court cases and provided written testimony in another. He said that pathologists who have examined tissue from the ovaries of cancer patients under a microscope have found that there is talc in the tissue. The mineral has also been found in women who don’t have ovarian cancer; talc can be found in tissue from lymph nodes in women who have used talcum powder on their genitals.

The exact mechanism by which talc may promote the development of ovarian cancer in women is not known. But Cramer said he suspects that when talc is applied to the genitals, the mineral’s particles can get into the vagina and eventually make their way into the upper genital tract, where the ovaries are located. Once there, talc can induce a potent inflammatory response and probably disrupt the immune system, he said.

Hormones, such as estrogen, may also play a role in the development of ovarian cancer in some women who use talc, but more studies are needed to tease out this effect, Cramer said.

Focus on other risks

Not everyone who examines the research on talc and ovarian cancer draws a conclusion similar to Cramer’s.

The scientific evidence for a link between women’s use of talcum powder and ovarian cancer is not that strong, said Dr. Sarah Temkin, an associate professor of gynecological oncology at the Johns Hopkins School of Medicine in Baltimore. Two newer prospective studies have failed to show any difference in ovarian cancer risk between women who used talc on their genitals and those who never did so, she said.

The older studies that suggested an increased risk tended to be case-control studies, which are open to more bias because they involve asking women to recall their use of powder after they have been diagnosed with cancer, Temkin said.

She said she does not think the evidence is strong enough to warrant forcing manufacturers to place a warning label on talcum powder to alert women to a possible health risk from using the product.

Ovarian cancer is a rare disease, and two well-established risk factors for it are a family history of ovarian cancer and a family history of breast cancer, Temkin told Live Science. Scientists have known about these two links for decades, and even so, health providers may miss the opportunity to inform women who have these risk factors about opportunities for genetic counseling, she said.

It’s also known that women who have used birth control pills for at least five years may reduce their risk for developing ovarian cancer by about 50 percent compared with women who have never used such oral contraceptives, Temkin added. [7 Surprising Facts About the Pill]

She typically does not ask her ovarian cancer patients about their talc use when taking a medical history, Temkin said, and women don’t usually ask her many questions about it. However, with news stories about recent court verdicts making headlines, two or three women have inquired about the use of talc, she said.

If an association between talc use and ovarian cancer risk exists, it is very small, Temkin said. “There are other risk factors for ovarian cancer that are better to focus on than talc,” she said.

Eclipse Watchers’ Plane Crashes on Return Trip

A small plane carrying four people who were returning from an eclipse-watching trip crashed just short of an airport in northern California.

No one was hurt in the crash, which occurred Monday evening (Aug. 21) about a mile short of an airport in Byron, California (a town about 60 miles, or 96 kilometers, east of San Francisco), according to The Mercury News.

The pilot and three passengers were returning to the Bay Area after viewing the solar eclipse in Oregon on Monday, The Mercury News said.

The plane began to experience problems on the return trip; the pilot tried to make an emergency landing at the airport, but the plane landed in an irrigation pond close to the airport.

Officials are still investigating the cause of the crash, but it may have been a fuel shortage on the plane.

Small planes were popular vehicles for traveling to watch Monday’s solar eclipse. An airport in Madras, Oregon — a hotspot for watching the eclipse — typically gets three flights arriving per hour. But in the days leading up to the eclipse, the airport was getting one flight arriving every 3 minutes, according to CBS News. On Saturday, Aug. 19, a small plane crashed en route to Madras, killing one person.

I Used Solar Eclipse Glasses, So Why Do My Eyes Feel Funny?

After viewing the historic solar eclipse yesterday (Aug. 21), some watchers reported that their eyes felt funny, even though they wore certified eclipse glasses. But what might have caused this, and should you be concerned if it happened to you?

Experts say that if your eyes felt a little strange after the eclipse, it’s not necessarily a reason to worry. That’s because this funny feeling is not a sign of “solar retinopathy,” or damage to the eye’s retina that can occur from looking at the sun.

“The retina has no sensory nerve fibers,” so you can’t feel damage to this part of your eye, said Dr. Vincent Jerome Giovinazzo, the director of ophthalmology at Staten Island University Hospital in New York City. “If your eyes feel funny, it’s going to be [a feeling] on the surface.” [Photos: 2017 Great American Solar Eclipse]

Giovinazzo said he has already seen several patients who told him that their eyes felt funny after watching yesterday’s eclipse. In every case, the patient actually had dryness on their eyes’ outer surface from holding their eyes open too long — a condition known as exposure keratitis, Giovinazzo said.

Dr. Nathan Podoll, a spokesperson for the American Academy of Ophthalmology, agreed that eye damage after observing an eclipse would not typically show up as pain or discomfort in your eyes. Instead, people with solar retinopathy have visual symptoms. These symptoms include blurriness or blind spots in your vision, or a dark or dim spot in your central vision, Podoll said. People may notice these symptoms within 4 to 6 hours of the viewing event, Podoll said, or the symptoms could appear the next day.

Looking at the sun without proper eye protection — even for a few seconds — is dangerous and can cause solar retinopathy. But if you used authentic, certified eclipse glasses to view yesterday’s eclipse, and the glasses’ filters were intact, then you won’t have damage to your eyes, Giovinazzo said.

Still, “if you have any concern about the health of your eyes,” you should see an eye doctor, Podoll said.