PHARMACOLOGY After they have sex, some of the Appalachian women of Virginia and North Carolina take a teaspoonful of seeds from the common weed called Queen Anne’s lace, crush them, stir them Interesting, if not conflicting, research has recently been published on the topic of marijuana and infertility. Here, our experts take a closer look. Research indicates the use of cannabis may affect human fertility, depending on gender, general health, socioeconomic status and several other factors.
After they have sex, some of the Appalachian women of Virginia and North Carolina take a teaspoonful of seeds from the common weed called Queen Anne’s lace, crush them, stir them into a glass of water and drink the gritty preparation. They say it keeps them from getting pregnant.
As it happens, the same plant grows in rural parts of India’s Rajasthan state and peasant women there chew and swallow the seeds dry. They, too, rely on it as a form of contraception.
Though a world apart today, women in both regions possess knowledge that can be traced back at least 2,500 years — to ancient Greek physicians, including Hippocrates, who prescribed seeds of Queen Anne’s lace as both a contraceptive and as an herbal “morning-after pill.”
In fact, according to John M. Riddle, a historian of medicine at North Carolina State University in Raleigh, who unearthed the tradition, evidence is accumulating not only that the venerable methods do work in animal tests but that the knowledge, use and social acceptance of effective, plant-derived birth control drugs was widespread in the ancient world. Riddle recently published his findings in a book, “Contraception and Abortion from the Ancient World to the Renaissance.”
According to Riddle, herbal birth control created much of the wealth of the Greek city-state of Cyrene on the coast of what is now Libya. Cyrenians collected and exported the sap of a plant that the Greeks called silphion and the Romans silphium. An image of the plant even appears on 5th century B.C. Cyrenian coins.
The Roman naturalist, Pliny the Elder, mentions that silphion cost more than its weight in silver and Hippocrates recorded failed efforts to cultivate the plant in Syria and Greece. So well known was silphion that Aristophanes discusses its cost in one of his plays.
Why was the plant so valued? According to the ancient physician Soranus, “Cyreniac juice,” as he called it, when taken by mouth, would prevent conception or induce an abortion, whichever was needed.
Harvested to Extinction
By the 4th century A.D., however, silphium died out, apparently harvested to extinction. Women seeking an alternative turned to silphion’s close relatives in the giant-fennel family, including asafoetida, a key ingredient in today’s Worcestershire sauce. Though said to be less effective than silphium, asafoetida was cheaper and widely prescribed in the ancient world.
Riddle said ancient documents name many other plants used to regulate fertility. Among the more prominent are pennyroyal, rue, willow, date palm, pomegranate, members of the genus Artemisia (such as wormwood) and myrrh. Such concoctions have usually been dismissed by modern medical experts as ineffectual. But tests on laboratory animals in recent years have proved otherwise.
Although silphium can never be tested scientifically, experiments using crude extracts of asafoetida show that it does something. In rats, for example, it inhibited implantation of fertilized ova at rates up to 50 percent. Extracts of asafoetida’s close relatives were nearly 100 percent effective in preventing pregnancy when given within three days of mating.
According to Norman R. Farnsworth, a pharmacologist at the University of Illinois-Chicago who has collected the evidence for years, experiments on animals show that some 450 plant species worldwide contain natural substances that prevent ovulation, block fertilization, stop implantation or reduce fertility in some other way.
Many plants contain estrogen-like compounds that alter the subtle balance of hormones needed for conception and maintenance of pregnancy. Some have substances that simply make the fallopian tube transport the egg so fast that it enters the uterus before it can be fertilized, and dies because it cannot survive there in that state. One plant, Farnsworth said, simply inhibits an enzyme that the sperm must release to penetrate the egg.
Birth Control by Food
Even foods in an ordinary diet can have contraceptive effects, Farnsworth found — peas, for example. The clue emerged from the fact that in the history of Tibet the population has been stable for periods of up to 200 years. During those times Tibetans subsisted largely on barley and peas. When mice were fed a diet of 20 percent peas, litter sizes dropped in half. At 30 percent peas, the mice failed to reproduce at all.
Because natural birth control chemicals exist in so many plants, it is not unreasonable that ancient peoples would have discovered them, Riddle suggested.
He also proposed that the widespread use of these substances would explain periods in ancient history when the population remained stable or even declined. During the first five centuries A.D., for example, historians estimate that the population of Europe fell from 32.8 million to 27.5 million — in the absence of major wars or epidemics.
The population declines have usually been attributed to infanticide, but there is little documentary evidence of the practice. Instead, Riddle cites evidence from the late J. Lawrence Angel, an anthropologist at the Smithsonian Institution, that the number of births per woman declined. Childbirth can produce scarring or pitting on the woman’s pelvis as the ligaments tear. Angel’s case is controversial, but when he examined skeletons from ancient cemeteries, he concluded from the scarring that women were having fewer children than needed to maintain the population. Less controversial was Angel’s finding that the lifespan of adults was increasing at the same time.
“Women in those days had a lot more control over their reproductive lives than we used to think,” Riddle said. “They had access to things that really worked.”
Farnsworth agrees. “It’s obvious,” he said. “They were having sex at least as much as at any other time and they didn’t have condoms. But you don’t see all these fair maidens getting pregnant every year.”
Why, then, did the knowledge fade away?
Riddle cites two factors. One was the change of medicine from something that virtually anyone could practice to the special province of men with formal training. Since the use of herbal birth control agents was probably in the hands of women, it remained outside the canon of male-administered medicine, passed on by word of mouth and used mainly by those without access to the costlier professional physicians.
A more brutal form of suppression arose during the Middle Ages, Riddle believes: Women who possessed the secrets of fertility control were burned as witches.
“You look at the things witches were accused of,” Riddle said. “Most of them have to do with fertility. They’re accused of causing sterility, babies born dead, causing impotence, miscarriages.” He suspects the “witches” were midwives who dispensed the ancient wisdom. He cites a statement repeated during the Inquisition: “The devil works through herbs.”
Though much of the wisdom of the ancients must have been lost, some clearly survived, as the women of Appalachia and Rajasthan can testify.
Among the hundreds of plants cited in ancient medical and herbal texts as useful for birth control are many that really do work, according to modern tests on animals. Some prevent conception and some abort an early pregnancy. The tests also show that some can be toxic. Among the best documented are those shown here.
* Coin from 6th to 5th century B.C. Cyrene depicting the silphium plant, which was renowned in Greece and Rome as an effective contraceptive. It was harvested to extinction by the 4th century A.D.
* ARTEMESIA or wormwood, was used in Roman times for birth control. Animal studies show it delays ovulation and prevents implantation of the early embryo. It also has toxic side effects.
* QUEEN ANNE’S LACE a member of the wild carrot family, grows in much of the world. To this day women as far apart as India and Appalachia swallow its crushed seeds as a “morning after” concoction.
* PENNYROYAL widely used in ancient times as a tea, contains pulegone, which causes abortion in humans and animals. In 1978 a Colorado woman trying to end her pregnancy died after taking pennyroyal oil (a more concentrated form of the active ingredient).
SOURCES: John M. Riddle, American Numismatic Society, Royal Horticultureal Society
Marijuana and Infertility: What You Need to Know
For decades, there has been an ongoing discussion regarding cannabis and infertility. Numerous anecdotal outlets have cited decreased fertility rates among cannabis users (especially a decline in sperm count in males), but is there any clinical or scientific evidence to back up these claims?
In this article, we discuss relevant contemporary research relating to the topic. We’ll also discuss whether “marijuana infertility” is truly a concern. Read on to find out more.
Does Marijuana Cause Infertility?
There is a body of evidence suggesting that marijuana causes infertility. However, even more concerning is relatively recent research that suggests that fertility, especially in males — may be declining overall.
A study published in Human Reproductive Update in 2017 identified a potentially key issue. It looked at 7,500 studies performed from 1973 to 2011. The researchers found that men from Australia, New Zealand, Europe, and North America had an almost 60% decline in sperm count. They also had a sperm concentration decline of 52%.
Researchers offered several hypotheses attributed to the decline in semen quality. These include:
- Increase exposure to pesticides
- Meta-changes in diet
- Exposure to higher-temperature climates
- Meta-changes in Body Mass Index (BMI)
- Other lifestyle/environmental factors
A major underlying concern, particularly given evidence that cannabis use is on the rise (as well as evidence that smoking tobacco affects fertility), is whether or not marijuana causes infertility. Another is whether cannabis use may have a variable impact on males’ and females’ fertility and reproduction potential.
Potential Impact of Cannabis Use on Female Fertility
Data regarding the relationship between female infertility and marijuana use is limited. However, a study published in the Journal of Women’s Health in 2016 suggests that smoking cannabis can delay a woman’s ovulation by several days.
Furthermore, a separate study published by the National Institute on Drug Abuse suggests that cannabinoids can alter hormone secretion related to reproductive function. Authors suggest that cannabinoids, specifically THC, can “inhibit secretion of LH, FSH, [and] prolactin,” resulting in “decreases in sex steroid hormones [as well as] changes in ovulation.”
However, the researchers observed that these effects are reversible when cannabis use is ceased.
Still, most experts recommend that pregnant women and women who are considering becoming pregnant – avoid the use of cannabis altogether both during and before pregnancy. This recommendation is more pressing than ever, as cannabis use among young reproductive-aged women is rising.
In fact, according to currently available statistics, upwards of 8% of non-pregnant reproductive-aged women use cannabis on a relatively consistent basis. As authors of the above publication observe, “prenatal marijuana exposure [can be] associated with poor offspring outcomes,” including an increased prevalence of conditions like low birth weight and impaired brain development.
What About Male Fertility? Does Cannabis Reduce Sperm Count?
Another pressing concern – and an ongoing topic of debate circulating for decades – is whether or not marijuana can cause male infertility.
A study published in the American Journal of Epidemiology in 2015 appears to suggest that it can. The study observed over 1,200 Danish men aged 18-28, 45% of which had smoked cannabis in the previous three months. Twenty-eight percent of study participants used marijuana more than once a week. The study discovered that those who used cannabis regularly had a 29% reduction in sperm count.
The answer may shock you!…
However, a study published in Human Reproduction in 2019 appears to contradict the research above. This study, which took place over 17 years from 2000 to 2017, examined 1,100 semen samples from male patients enrolled in the Massachusetts General Hospital Fertility Center. The study found that cannabis users had a higher sperm count per milliliter of ejaculate (62.7 million sperm compared to 45.4 million in non-cannabis users). Only 5% of cannabis-using test subjects had sperm count levels considered low (below 15 million per milliliter).
Based on the availability of contemporary research data, the impact of cannabis use on male fertility is still largely inconclusive.
Additional Research on Weed and Infertility
Another interesting publication on the broader topic of weed and infertility appeared in 2018 in the peer-reviewed academic journal Fertility and Sterility.
In the study, researchers analyzed nearly 2,000 male and female participants that were trying to conceive. Eleven-and-a-half percent of women admitted to using cannabis during this period, along with 16.5% of men. The study results suggested that cannabis use did not have a negative impact on the time it took for couples to become pregnant.
Again, however, it is highly recommended that cannabis use be avoided among individuals trying to conceive.
Bottom Line on Marijuana and Infertility
The general discrepancy in the observations made from these above-referenced studies means we can’t draw any firm conclusions regarding the ongoing debate of marijuana and infertility. Without a doubt, more research needs to be done on the topic.
Unfortunately, there are still challenges associated with carrying out quality cannabis-based research.
At present, cannabis is only fully legal (on a national level) in Canada and Uruguay. This means that federal research funding for cannabis studies is still difficult for many global research organizations.
Regardless of whether or not marijuana causes infertility, it is best to avoid the consumption of cannabis altogether for those trying to conceive. Likewise, pregnant women should always steer clear of any form of cannabis use.
Effects of Cannabis on the Male and Female Reproductive System, and Fertility
Use of cannabis may affect human fertility, depending on gender, general health, socioeconomic status and several other factors. Here, we look at existing research on cannabis and human fertility, in order to provide readers with an accurate, up-to-date summary of the current state of scientific knowledge.
To understand how cannabis may affect fertility, we must understand the effect it has specifically on males and on females. We’ll start by looking at the effects on the male reproductive system, and then focus on the more complicated effects on female fertility.
Cannabis use and male fertility
Some studies on the effect of cannabis use on male fertility have indicated that regular use may reduce spermatogenesis (the production of sperm in the testes) and testosterone levels.
In 2012, the American Society of Andrology published a review of research on the effects of illicit drug use on male fertility. The researchers found that in the majority of studies, it was consistently concluded that cannabis use had a negative impact on male reproductive physiology.
Another study in 1992 (Vescovi et al.) found that levels of luteinizing hormone(LH), an important pituitary gland hormone involved in reproductive function, were reduced in male chronic cannabis users compared to a non-cannabis-using, age-matched control group. A previous 1986 study (Cone et al.) also found a significant reduction in LH levels immediately after smoking cannabis.
And an even earlier study (Kolodny et al, 1974) into testosterone levels in “chronic” cannabis users found that 6 of 17 subjects had oligospermia (low sperm count), and that average testosterone levels in the cannabis-using group were just over half that of the control group. The effect of cannabis on testosterone levels was observed to be dose-dependent.
Sexing Cannabis: Is My Plant Male or Female?
The endocannabinoid system and male fertility
Clearly, the endocannabinoid system has a role to play in the regulation of processes critical to male reproductive health, such as sperm count, testosterone levels, and levels of other key hormones such as LH.
For healthy adult males, it seems that use of THC does indeed cause some negative effects on fertility, which tend to increase with higher doses. However, THC’s endogenous analogue anandamide appears to be critical to the functioning of the male reproductive system.
The 2002 study found that sperm cells would bind to the agonist CP-55,940, demonstrating the presence of CB1-receptors. The study also concluded that the presence of THC and a synthetic anandamide analogue, AM-356, both reduced sperm motility in vitro. Interestingly, it was found that AM-356 exerted a biphasic dose-dependent effect on sperm motility, causing inhibition at high doses but hyperactivity at low doses.
Anandamide and the “capacitation” of human sperm cells
In a 1994 study, it was found that mammalian sperm, including that of humans, is actually incapable of fertilizing oocytes (eggs) immediately after leaving the testes. It requires a period of exposure to certain crucial hormones, enzymes and proteins on its journey through the vas deferens and ejaculatory ducts of the male reproductive system (as well as the reproductive fluids of the female vagina and oviducts) before becoming “capacitated” and able to fertilize an egg.
The 2002 study provides strong evidence that the presence of the anandamide in the seminal fluid, and its ability to bind to the CB1-receptors of the spermatozoa, are key to the “capacitation” of sperm cells on their way to the ejaculatory ducts. It has to be present in the appropriate concentrations, though. If the level of anandamide is too high, it can instead have a dramatic inhibitory effect on the sperm cells’ ability to fertilize oocytes.
How Does Cannabis Affect the Digestive System?
Why is anandamide beneficial, while THC may not be?
Although THC and anandamide are both agonists of the CB1-receptors, they greatly differ in structure and therefore have different effects on certain metabolic processes. Anandamide has a much shorter half-life than THC (just a few minutes for anandamide compared to as long as 24 hours for THC). So while anandamide will degrade shortly after it contacts a receptor, THC can remain in nearby adipose tissue for much longer periods, and can continue to stimulate the receptors, ultimately causing overstimulation and potential negative effects.
As is so often the case with cannabinoid science, dosage is everything—and it may prove to be the case that very small doses of THC could benefit males who have reproductive issues that can be tied to low levels of anandamide.
Cannabis use and female fertility
While the effect of cannabis use on male fertility appears to be quite straightforward—with male chronic cannabis users being likely to experience some degree of impairment to reproductive physiology—the effect on the human female reproductive system is less clear-cut.
Female reproductive health is vastly complex in itself, as it not only comprises the ability to become pregnant but also the ability to carry healthy offspring to term and successfully give birth.
Past research has indicated that cannabis use may disrupt the menstrual cycle, suppress oogenesis (production of eggs in the ovaries) and impair embryo implantation and development. Chronic use of cannabis has also been repeatedly associated with lower birth weight (as much as a 50% increased risk), decreased birth weight and early (spontaneous) termination of pregnancy.
However, most of these findings are far from conclusive. Either the study included very few participants or confounding factors such as tobacco use aren’t taken into consideration. In fact, more recent research, like this review on infants who were exposed to marijuana in-utero, concludes there aren’t any adverse risks.
For example, a 1985 paper on foetal abnormality (Qazi et al.) after prenatal exposure to cannabis discussed five infants whose mothers acknowledged use of cannabis prior to and during pregnancy and who were born with various symptoms of growth retardation, neurological dysfunction and deformity. While it may provide helpful insight, such a small sample size is far from being enough to draw concrete conclusions, and correlation does not imply causation.
Other studies seen as providing evidence that cannabis use can cause foetal abnormalities are animal studies (Geber & Schramm 1969, Phillipset al, 1971) in which rabbits, hamsters, rats and mice were injected with vast doses of crude cannabis extract (as much as 666mg/kg in one instance!). Such massive doses of cannabis would be practically impossible for a human to consume through conventional means, and are essentially useless as a point of comparison.
In fact, many early studies that indicated a correlation between use of cannabis (or other controlled substances such as cocaine) have been later contradicted by findings suggesting that socioeconomic status and level of poverty are far more causative of low birth weight and poor developmental outcome than use of the substances themselves. This doesn’t imply that use of cannabis or other substances during pregnancy has no adverse effect, but does give weight to the idea that the risks have been overestimated and overemphasized due to politics and anti-drug bias.