Ashwagandha eased insomnia in clinical trial, without side effects 10/28/2019
Ashwagandha is India’s most popular herb, thanks to its prominence as a major “tonic” herb in that nation’s Ayurvedic medicinal tradition, on which some 90% of Indians still rely to some extent.
Traditional Ayurvedic practitioners customize a patient’s treatment based on which type of bodily energy or “dosha” they’re judged to possess, using herbal or dietary prescriptions, yoga, massage, meditation, and breathing exercises.
It’s difficult to design clinical trials able to test the validity of the complex, subjective Ayurvedic system of diagnosis and prescription, which also explains the absence of a licensing system for practitioners.
Accordingly, rather than trying to test the efficacy of Ayurvedic diagnoses and prescriptions, scientists have focused on testing the efficacy of traditional Ayurvedic herbs for conditions they’re claimed to alleviate.
Unlike most Ayurvedic herbs, there’s a substantial body of laboratory and clinical evidence demonstrating ashwagandha’s overall safety, as well as its potential efficacy in specific medical contexts.
Before we get to the promising results of the first clinical trial to test ashwagandha as a sleep aid, let’s quickly review the herb’s scientific record to date, which includes animal research concerning its effect on sleep and sleep-related anxiety.
Ashwagandha’s promising research record
The results of several small, preliminary clinical studies have supported ashwagandha's ancient reputation as a tonic, endurance-enhancing "adaptogenic" ally against stress, and indicate that it possesses significant anti-cancer properties.
Ashwagandha's apparent adaptogenic effects explain its nickname, “Indian ginseng”. For more on that topic — and the related effects of the Central Asian herb rhodiola — see Got Burnout? Recent Studies See Herbal Solutions.
Other clinical trials published to date have tested the effects of ashwagandha on muscle strength and recovery, cardio-respiratory fitness, obsessive-compulsive disorder (in conjunction with SSRI drugs such as Prozac), female libido, and cancer patients undergoing chemotherapy.
In every case, the results indicated that ashwagandha was helpful, and the authors called for further study in larger trials.
Ashwagandha, sleep, and insomnia
The scientific name for ashwagandha is Withania somnifera, with somnifera meaning “sleep”.
The scientists who picked ashwagandha’s Latin name included somnifera because of the herb’s folk reputation as a sleep aid — and the results of several rodent studies support that tradition.
Ashwagandha helped the rodents in these studies resist anxiety-induced sleep disturbances and reduced the adverse effects of sleep deprivation on their memory and thinking — without making them drowsy or confused.
While evidence from animal studies — along with ashwagandha’s ancient reputation as a sleep aid — is important, we’ve lacked supporting evidence from human clinical trials.
But scientists recently reported the results of a double-blind, randomized, placebo-controlled human clinical trial that tested ashwagandha’s ability to improve sleep quality and reduce insomnia-related anxiety.
First-ever clinical trial supports ashwagandha’s potential as a sleep aid
Insomnia is associated with obesity, type 2 diabetes, cardiovascular disease, neurological issues (i.e., dementia), mood swings, and increased risk of premature death.
Given the adverse side effects of standard pharmaceutical sleep aids, it’s important to find safer, comparably effective alternatives.
The new, 10-week trial was conducted by physicians and pharmacologists from two medical schools and a hospital located in or around Mumbai, India (Langade D et al. 2019).
For their trial, the researchers recruited 60 diagnosed insomnia patients and randomly assigned them to one of two groups, each of which took their assigned capsule twice a day:
- 20 patients took placebo capsules.
- 40 patients took ashwagandha capsules containing 300 mg of KSM-66 brand ashwagandha root extract.
The researchers monitored the volunteers’ rest and activity patterns through a combination of sleep logs, self-reports, and actigraphy, which is a standard tool for studying a person’s sleep patterns and circadian rhythms. (The participants each wore a Respironics Philips Actiwatch on the wrist of their non-dominant arm, to record their movements and exposure to light over the course of the trial.)
At the end of the 10-week trial, the KSM-66 ashwagandha group showed statistically significant improvements in eight standard measures of sleep quality: sleep onset latency, total sleep time, wake after sleep onset, total time in bed, sleep efficiency, the Pittsburgh sleep quality index, subjective sleep quality assessment, and mental alertness on rising.
The volunteers assigned to the ashwagandha group also experienced significant reductions stress — a finding consistent with previous studies showing that KSM-66 ashwagandha significantly reduced blood levels of the stress hormone cortisol and produced greater self-reported feelings of ease.
None of the paper’s authors received support from or had any financial relationship with the manufacturer of the KSM-66 ashwagandha extract used in the trial.
Why would ashwagandha promote restful sleep?
The active constituents in ashwagandha that have received the most study — called withanolides — exert anti-stress/anxiety effects in animal and human studies.
However, withanolides don’t appear to be the active sleep-inducing compounds in ashwagandha.
Instead, recent research in rodents identified an ashwagandha constituent called triethylene glycol as the compound that promotes restful sleep (Kaushik MK et al. 2017; Dey A et al. 2018).
Ashwagandha root versus leaf extracts
Ashwagandha root has always been more highly prized and prescribed in Ayurvedic medicine than ashwagandha leaf.
Likewise, there are significantly more published studies concerning the effects of root extracts versus studies on the effects of leaf extracts, while the Indian, British. and U.S. Pharmacopeias base their specifications on ashwagandha root, not leaf.
However, ashwagandha leaf extracts have shown promise in laboratory and clinical studies, so their efficacy can’t be dismissed.
Ashwagandha leaves cost less than ashwagandha root but contain high levels of withanolides. However, makers of ashwagandha leaf extracts don’t charge less for the withanolides in their cheaper-to-make products, they just pocket higher profits
Consumers can be misled by the fact that ashwagandha leaf extracts typically contain 10% withanolides, while root extracts typically contain 5% withanolides.
Despite that apparent advantage for leaf extracts, ashwagandha root extracts typically contain comparable amounts of withanolides per gram, while leaf and root extracts typically cost about the same on a withanolides-per-dollar basis.
Look for certified-pure ashwagandha supplements
One aspect of traditional Ayurvedic medicine, called rasa shastra — which translates as the “science of mercury” — involves the deliberate addition of metals (including lead, mercury and arsenic), minerals, or gems to herbal preparations.
Advocates for ancient Ayurvedic tradition claim that toxic metals are somehow rendered safe and therapeutic by the ancient methods of preparing rasa shastra herbal remedies, but those claims lack scientific credibility (Koch I et al. 2011).
Unfortunately, several studies conducted in the U.S. have found unsafe levels of heavy metals in a substantial minority of Ayurvedic herbal formulas imported from South Asia, as well as elevated lead blood levels among many regular users of such products (Saper RB et al. 2008; Mikulski MA et al. 2017).
Because U.S. law does not require pre-market FDA approval of dietary supplements, or regular safety testing of supplements, it makes sense to choose herbal products that are independently certified to meet U.S. purity and safety standards.
That cautionary stance certainly applies to Ayurvedic herbs such as ashwagandha, especially when it comes to brands manufactured in China or South Asia.
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