The term, ‘nootropic’, was coined by a Romanian psychologist and chemist in 1972 called Corneliu Giurgea from the Greek words that mean ‘mind’, and, ‘turn’ (Lewis, 2009). They are so called ‘cognitive enhancers’ which improve cognitive function, memory, creativity, or motivation in healthy individuals. They are thought to work by modifying neurochemicals in the brain, improving brain oxygen supply, or stimulating brain nerve growth (Joshi, 2013). Chemical nootropics include the racetams and derivatives, such as piracetam, which was the original chemical nootropic first described in the 1970s, and wakefulness enhancers such as modafinil, which is a stimulant. However, while the term nootropic is relatively recent, herbal practitioners have been using plants as a source of rejuvenation for the brain and nervous system for thousands of years (Russo et al., 2005).
In traditional Indian medicine, or Ayurveda, ‘medhya rasayana’, refers to a rejuvenative herb specifically for the mind and nervous system (Russo et al., 2005). These are herbs that were and still are specifically used to treat cognitive problems, as for example, bacopa, is found in the Caraka Samhita an ancient Ayurvedic text, where it is recommended for anxiety, poor cognition, and lack of concentration. Opposed to the chemical nootropics, which have only been around recently and there are some concerns over safety, herbs like bacopa have been fully integrated into the medicinal systems of the world for a long time and have good safety profiles. I will now describe the historical use and review the science of 8 of the best natural nootropics that come from plants.
Bacopa is a creeping medicinal herb found in damp, marshy areas throughout the Indian subcontinent (Russo et al., 2005). It grows purple flowers and oblong shaped fleshly leaves. It is known by locals as ‘brahmi’ a name it shares with another nootropic called gotu kola. The name brahmi is derived from ‘Brahma’, the creator God in Hinduism. The two ancient Ayurvedic texts the Caraka Samhita (2500BC) and Susruta (2300BC) both suggest bacopa improves cognitive powers by enhancing memory and concentration (Dhanasekaran et al., 2007).
These medicinal effects may be related to an anti-oxidant effect observed in the brain of experimental models (Bhattacharya et al., 2000). A study published in a Nature journal, Neuropsychopharmacology, demonstrated significant enhancement of memory retention after 3 months of bacopa application in healthy people. Bacopa is used traditionally in the treatment of Alzheimer’s and dementia, this is supported with studies in vivo models showing reduction of beta-amyloid deposits in the brains of an Alzhemier’s disease animal model with bacopa treatment (Dhanasekaran et al., 2007). These studies point to the importance of bacopa as one of nature’s most powerful nootropics and it is worthy of more human clinical studies.
Ginkgo, otherwise known as the maidenhair tree, grows throughout Asia and has been described as a ‘living fossil’ because it is known to have existed 170 million year ago, in the Jurassic period (Zhou et al., 2003). It has changed little morphologically in the last 100 million years. In the Chinese medical text, Pen Tsao Ching, from 1578, ginkgo is described as a treatment for senility in ageing members of the royal court (Nakanishi, 2005). Ayurvedic physicians in India associated ginkgo with increased life-span (Castleman, 2001).
It is the leaf extract which is used to treat cognitive disorders and it has been speculated that ginkgo interferes with mitochondria dysregulation in Alzhemier’s through its anti-oxidant activity in the brain (Müller et al., 2017). A large double blind placebo controlled trial, published in the journal, JAMA, demonstrated a mild, but significant improvement of dementia with ginkgo treatment compared with the placebo group (Le Bars et al., 1997). This was effect was confirmed in a later study (Mazza et al., 2006). In addition to a multitude of other positive results in high quality clinical trials for various disorders, ginkgo has also been shown to be effective against anxiety in humans (Woelk et al., 2007). Finally, it was observed in a study using rats, that ginkgo increased lifespan as well as cognitive performance (Winter et al., 1998). These studies confirm ginkgo’s importance alongside bacopa as one our top herbal nootropics.
Ashwagandha is a small shrub native to India and is a member of the nightshade family (Castleman, 2001). Ashwagandha, similar to bacopa, is found in the Caraka Samhita (2500BC) where is it recommended as a whole body tonic (rasayana) especially for emancipated elderly people. The roots of ashwagandha contain the withanoloids thought to be responsible for ashwagandha’s medicinal properties, it has been shown they have anti-oxidant properties (Bhattacharya et al., 2001). Furthermore, ashwagandha extracts have been shown to reverse amyloid induced toxicity in human neuronal lines, highlighting their potential for treatment of Alzheimer’s (Kurapati et al., 2013).
A double-blind placebo controlled human study of healthy individuals observed improvement of cognitive and psychomotor performance with ashwagandha treatment compared with the placebo (Pingali et al., 2014). Another well controlled human study found ashwagandha to significantly reduce anxiety in humans compared with the placebo (Chandrasekhar et al., 2012). To summarise, while ashwagandha was not traditionally viewed as a ‘medhya rasayana’, but a more general tonic (rasayana) herb for the whole body, these studies imply it is a capable nootropic.
4. St. John’s wort
If we take a looser definition of nootropic to include herbs that have an anti-depressant or mood balancing action, St. John’s wort is a highly influential herb. St. John’s wort is a medicinal plant native to Europe and yields bright yellow flowers (Benzie, 2011). Its name arises because it flowers around St John’s Day (24th June). The history of its use can be traced back to the ancient Greeks as the physician, Dioscorides (40-90AD) used it in the treatment of sciatica (Castleman, 2001). In modern times it has become known not so much as for nerve pain, but for depression, multiple high quality double blind placebo controlled trials confirm its antidepressant activity (Laakmann et al., 1998; Szegedi et al., 2005; Woelk et al., 2000).
In these trials it has been shown to be as effective as mainstream anti-depressants, but with better tolerance. However, excessive use, has been linked to serotonin syndrome (Dannawi, 2002), sun sensitivity and easy skin burning (Dannawi, 2002), and moderate use with increased pharmaceutical drug metabolism by the liver (Markowitz et al., 2003). This means St. John’s wort may not be suitable for application alongside other pharmaceutical drugs and should not be used in patient’s taking selective serotonin reuptake inhibitors (SSRIs). Regardless of these negative points, St. John’s wort is a potent medicinal herb which when used appropiately and in the correct context is an undoubted ally.
5. Holy basil
Tulsi is a small, fragrant plant that grows purple-green leaves it is found growing wild and also widely cultivated in India (Kuhn and Winston, 2000). Tulsi is sacred to the Hindu God Vishnu, and is often used in prayer and various rituals (Winston, 2007). It is also a rasayana herb similar to ashwagandha and turmeric and so with wide ranging medicinal effects that include effects on human cognition.
One double blind placebo controlled study found significant cognitive boosting effects in a group of healthy individuals (Sampath et al., 2015). A further well controlled study found it effective for reducing stress (Saxena et al., 2011). Researchers have also found that tulsi could reduce the amnesic effect of two chemicals, scopolamine and diazepam, and also aging induced memory deficits in mice (Joshi et al., 2006). These studies point to the potential of tulsi to promote cognitive power in healthy people, while indicating it may be useful for treating degenerative cognitive disorders.
6. Gotu kola
Gotu kola is a creeping herb native to India and Sri Lanka (Kuhn and Winston, 2000). It has small pink flowers and round-lobed bright green leaves. Gotu kola gained a reputation in Sri Lanka as a longevity promoter, and a local proverb went, ‘Two leaves a day keeps old age away’. Similar to bacopa, gotu kola is classified in Ayurveda in the Caraka Samhita (2500BC) as a ‘medyha rasayana’, an herb specific for improving the health of the brain and nervous system (Jana et al., 2010).
Similar to other herbal nootropics described here, using experimental models gotu kola has been shown to act as an anti-oxidant in the mammalian brain and also improve cognition (Veerendra et al., 2003). A study on humans, double blind placebo controlled, found gotu kola may improve anxiety in the short term (hours), although a long term investigation was not performed (Bradwejn et al., 2000). Although slightly less studied than herbs like bacopa, these studies imply the reported nootropic power of gotu kola from the traditional texts may be justified.
Rhodiola is a hardy perennial that grows in harsh conditions from the Artic mountains of Scandinavia through to Siberia (Castleman, 2001). It grows on mountains and in cliff faces and yield bright yellow flowers. Rhodiola may have been used as long ago as the Vikings for its strengthening action to support long hours and heavy work (Panossian et al., 2010). It has been shown to have anti-oxidant activity in the mammalian brain of experimental models, to reduce cognitive damage, and neuronal injury induced by streptozotocin (Qu et al., 2009).
There is good evidence in double blind placebo controlled trials that rhodiola reduces fatigue and stress (Spasov et al., 2000; Shevtsov et al., 2003), with one of these studies reported improvement in capacity for mental work (Shevtsov et al., 2003). Another well controlled study supports the use of rhodiola for depression (Darbinyan et al., 2007). While further clinical studies are required of rhodiola to assess its potential for therapeutic impact, rhodiola is clearly an impressive nootropic.
Turmeric is a perennial which yields characteristic oblong shaped branched roots are brown coloured and the yellow colour inside them is due to curcumin, which is thought to be the medicinal constituent of the herb (Chattopadhyay et al., 2004). Turmeric has long been used in Ayurvedic medicine and traditionally considered a rasayana herb, similar to ashwagandha and holy basil (Winston, 2007). Studies using experimental models show that curcumin reduces oxidative damage and also amyloid pathology in mice with Alzheimer’s disease (Lim et al., 2001). This effect of curcumin has be observed in other animal studies and it was noted that it can partially restore distorted neurites in an Alzheimer’s model (Garcia‐Alloza et al., 2007).
In humans, curcumin has a mild, but significant effect against depression in comparison with a placebo (Lopresti et al., 2014). This supports a view where curcumin could be one herb as part of a formula for treatment, rather than a standalone option. There is a wide array of overlapping in vivo studies of curcumin that support its ability to protect the brain using animal models (Zhu et al., 2004; Scapagnini et al., 2006; Wang et al., 2005). There is a human trial that confirmed curcumin’s mood elevating effects and also supported an increase in cognitive abilities with treatment (Cox et al., 2015). Notably, this study used a special extract of curcumin called longvida which is thought to pass into the brain more effectively. These studies imply that curcumin is an important nootropic in our materia medica.
Scientific research into herbal nootropics in humans is only just starting as high quality studies are emerging in greater numbers. However, it is clear just from this review, that they are already several effective options to choose from with multiple positive results in human clinical trials. Single herbs are a popular and often a very effective option; however, the herbalist tends to opt for formulas of herbs when treating cognitive disorders. For example, David Winston, has found a combination of bacopa, St. John’s wort, ginkgo, and holy basil highly effective in treating patients with brain trauma (Winston, 2007). Combinational effects tend to increase the overall activity of the formula, and herbal medicine this way can be more powerful.
It is good to remember to respect these herbs and act with caution, larger doses tend to produce over sedation, dullness, or over stimulation that is counter productive in either healthy people or in those with a cognitive disease. It may also be dangerous as in the case of St. John’s wort, where overdosing has been linked to serotonin syndrome (Dannawi, 2002). Additionally, the importance of good lifestyle is hard to under estimate with treating cognitive conditions, diet, exercise, and mindfulness can all work together to support the body and mind. Used within the context of good lifestyle decisions, herbs can be far more effective. When used from a sensible position, I think herbal nootropics have more to offer than chemical nootropics. To summarise, we can learn a lot from studying the ancient and successful medicinal traditions of the world while keeping up-to-date with the latest science.
This is not supposed to be a ‘definitive’ list and there are several omissions such as calamus, lion’s mane, lavender, rosemary, lemon balm, and many more. If you are interested, I would refer back to David Winston’s book on adaptogens that includes a nootropics chapter (Winston, 2007) or this online herbal encyclopedia. Many of the adaptogenic herbs have nootropic properties.
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