zaterdag 16 september 2017

Avocado tegen metabool syndroom

De avocado wordt door zijn hoge gehalte aan goede voedingsstoffen als gezond beschouwd. Het eten van avocado zou ook een goede manier kunnen zijn om een metabool syndroom te voorkomen. Dat blijkt uit een review van Iraanse wetenschappers van de universiteit van Mashhad in een publicatie in het tijdschrift Phytotherapy Research. Zij analyseerden de resultaten van verschillende studies op het effect van schil, zaad, vlees en bladeren van de avocado op de metabole gezondheid.

Het sterkste effect van toevoeging van avocado aan het dieet werd gevonden in een verlaging van bloedwaarden van lipiden (HDL- en LDL-cholesterol, cholesterol totaal en triglyceriden). Ook blijkt avocado gunstig voor gewichtsverlies. Gedurende zes weken elke dag een avocado eten zorgde voor een aanzienlijke afname van het lichaamsgewicht, het percentage lichaamsvet en de BMI. Bij patiënten met hypertensie bleek inname van avocado geassocieerd met verlaging van de bloeddruk. Er werd ook bewijs gevonden dat avocado kan bijdragen aan minder vernauwde en verharde slagaderen, veroorzaakt door opbouw van plaques tegen de vaatwand.

Volgens de Iraanse wetenschappers kan niet alleen het vlees van de avocado de metabolische gezondheid bevorderen, maar ook de schil, het zaad en de bladeren van het fruit. Samenvattend hebben verschillende studies aangetoond dat avocado voor minder vet, obesitas, diabetes, trombose, aderverkalking (atherosclerose) en een lagere bloeddruk kan zorgen. Daarmee biedt avocado bescherming tegen hart- en vaatziekten.

Avocado's zijn het fruit van de avocadoboom ofwel Persea americana uit Mexico en Midden- en Zuid-Amerika. De avocadovrucht is bijzonder voedzaam. In tegenstelling tot de meeste vruchten bevat de avocado zeer veel olie (5 tot 23 gram per 100 g vruchtvlees). De avocado is een bekende bron van carotenoïden, mineralen (calcium, ijzer, zink), fenolen, vitaminen (A, B, C, E) en omega 3-vetzuren.

Tabeshpour J, Razavi BM, Hosseinzadeh H. Effects of Avocado (Persea americana) on Metabolic Syndrome: A Comprehensive Systematic Review. Phytotherapy Research; juni 2017; 31(6):819-837 doi:10.1002/ptr.5805

vrijdag 15 september 2017

Cannabis Taxonomy: The 'Sativa' versus 'Indica' Debate

Marijuana and hemp (Cannabis) and the closely related hop genus (Humulus) are the only widely known genera included in the small, but economically valuable, Cannabaceae family. Swedish botanist Carl Linnaeus, the “father of modern taxonomy,” first published the scientific name Cannabis sativa in his seminal Species Plantarum of 1753. The Latin name Cannabis derives from Greek (kannabis) and may originally have been derived from Scythian. The term sativa simply means “cultivated” and describes the common hemp plant that was widely grown across Europe in Linnaeus’ time. We, the authors, consider C. sativa to be native to western Eurasia and especially Europe, where, for millennia, the plant has been grown for its strong fibers and nutritious seeds, and from where it was introduced to the New World multiple times during early European colonization. Cannabis sativa plants also produce very small amounts of the compound delta-9-tetrahydrocannabinol (THC), the primary psychoactive and a medically valuable cannabinoid found only in Cannabis. Since C. sativa evolved within the geographical limits of western Eurasia, it represents only a small portion of the genetic diversity seen in the genus Cannabis worldwide.1

In 1785, European naturalist Jean-Baptiste Lamarck described and named a second species, Cannabis indica, meaning “Cannabis from India,” where the first samples of the highly psychoactive plant that reached Europe originated. Cannabis indica has the genetic potential to produce relatively large amounts of THC. The species is used for marijuana and hashish production, but in many regions of eastern Asia it also has a long history of cultivation for fiber and seed. Humans make cloth out of C. indica fibers and eat the seeds, but this native eastern Eurasian species is more commonly used today well beyond its original geographical range as a drug plant with widespread social and medicinal importance.1

While Karl Hillig, PhD,  was a doctoral student at Indiana University, he used morphological and chemical characteristics to investigate the diversity of the Cannabis genus and proposed taxonomic groupings (subspecies) that support the original two species concept.2-5 Hillig recognized European cultivated Cannabis as a separate species (C. sativa). Because this species typically has narrow leaflets and is used primarily for hemp fiber and seed production, we refer to it as narrow leaflet hemp (NLH). European C. sativa NLH populations are much less genetically diverse than those found in many other regions.

Hillig assigned the remainder of the world’s cultivated varieties to C. indica and divided them into three subspecies. One of these subspecies, C. indica subsp. indica, includes varieties that span the Indian subcontinent from Southeast Asia to western India and into Africa. These traditional drug varieties produce abundant amounts of THC with little if any cannabidiol (CBD). CBD is the second most common cannabinoid, and is non-psychoactive, but it has been shown to be medically effective for a variety of indications. By the 19th century, high-THC C. indica subsp. indica reached the Caribbean region, and steadily spread throughout Central and South America. Since the 1960s, C. indica subsp. indica has provided most of the drug cannabis exported to North America and Europe. Marijuana users commonly call domestically grown plants of these varieties “sativas” because their leaflets are relatively narrow, and therefore exhibit a superficial resemblance to those of European NLH plants. However, this is a misnomer as C. sativa plants produce little if any THC in our construct. Based on Hillig’s research, we now refer to members of C. indica subsp. indica as narrow leaflet drug (NLD) varieties. Although they have relatively narrow leaflets like NLH (C. sativa) plants, the NLD plants can produce an abundance of THC and are most commonly used for their psychoactive effects. drug content. Based on taxonomic tradition, these plants are properly called “indicas” rather than “sativas."

A second C. indica subspecies originated in Afghanistan where crops were traditionally grown to manufacture sieved hashish, a mechanically concentrated Cannabis drug. From 1974, when descriptions and photos of Afghan Cannabis were published by Harvard professor Richard E. Schultes, PhD, it became readily apparent that it represented a type of drug Cannabis previously unknown outside of Eurasia, belonging neither to Linnaeus’ C. sativa nor Lamarck’s C. indica.6 Its shorter, more robust stature, and broad, dark green leaves easily distinguish it from the taller, lighter green, and more laxly-branched NLD varieties. Because of its limited geographical range and restricted usage, the Afghan genome is less diverse than the NLD genome. By the late 1970s, seeds of Afghan hashish varieties reached Europe and North America and were rapidly disseminated among marijuana growers. At this time, all Cannabis varieties were commonly considered to be members of a single species, C. sativa, and the familiar NLD marijuana varieties were called “sativas” to differentiate them from the newly introduced and quite different looking Afghan varieties commonly called “indicas.” Hillig named them C. indica subsp. afghanica, which we now refer to as broad leaflet drug (BLD) varieties to differentiate them from NLD varieties. On average, populations of BLD plants contain approximately equal amounts of THC and CBD. Although BLD varieties are also considered by us to be members of C. indica, it is more correct to distinguish them from subspecies indica from India by calling them subspecies afghanica, or simply “Afghans."

Hillig’s third grouping within C. indica is subspecies chinensis, which comprises the traditional East Asian fiber and seed varieties and associated feral populations. We refer to this group as broad leaflet hemp (BLH). Like other subspecies of C. indica, varieties of C. indica subsp. chinensis possess the genetic potential to produce psychoactive THC, but East Asian cultural practices, such as Confucianism, have long encouraged the selection of these varieties for their economically valuable fiber and seed, rather than their psychoactive potential. As a result, total cannabinoid production is lower than in subspecies indica and afghanica.

Evolutionary theory predicts that there must once have been a putative ancestor of the two modern species C. sativa and C. indica, often referred to as C. ruderalis, which may have originated somewhere in Central Asia. However, by now it is probably extinct, and seemingly ancestral populations are more likely descendants of feral plants that escaped from cultivation long ago. Evolutionary hypotheses based on plant distribution studies, paleoclimate modeling, archaeological evidence, and the historical record propose that C. sativa NLH most likely originated in a temperate region of western Eurasia, possibly in the foothills of the Caucasus Mountains, from a putative hemp ancestor with diminished biosynthetic potential to produce THC. Cannabis indica likely originated in the Hengduan Mountains, in present-day southwestern China, from a putative drug ancestor that had evolved enhanced ability to produce THC. Early C. indica populations diversified as they were introduced by humans to different geographical regions where they may have further evolved into the three subspecies, all of which produce THC.1

Cultivated plant varieties are called cultivars, and when cultivars are grown and maintained by local farmers over generations, we refer to them as landrace cultivars, or landraces. Landraces evolve in a balance between natural selective pressures exerted by the local environment favoring survival, and human selections favoring a cultivar’s ability to both thrive under cultivation and to produce particular culturally preferred products. Early humans spread Cannabis into many new regions as they moved, and, at each new camp or settlement, they selected seed from superior plants within these early populations that were appropriate for their own individual uses and processing methods. By sowing seeds from the most favorable individuals, traditional farmers developed and maintained the landraces upon which present-day hybrid hemp and drug cultivars were founded.

Hemp cultivars were derived from crosses between different European NLH landraces and East Asian BLH landraces. Traditional Asian, African, and New World drug landraces were, until relatively recently, all pure NLD types. Before the introduction of BLD landraces from Afghanistan in the late 1970s, hybrids between imported NLD landraces formed the core genome of domestically produced drug cannabis in both North America and Europe. It is through crossing NLD and BLD landraces from such geographically isolated populations that modern hybrid sinsemilla (Spanish for “seedless”) cultivars were created.1

Unfortunately, we cannot return today to a region previously known for its fine Cannabis and expect to find the same landraces that were growing there decades before. Cannabis is open-pollinated, with male and female flowers borne on separate plants, and, therefore, two plants are usually required to produce a seed. Random combinations of alleles (forms of a gene) and accompanying variation are to be expected. Cannabis landrace varieties are best maintained by repeated natural and human selection in situ — nature selecting for survival and humans selecting for beneficial traits. Without persistent human selection and maintenance, these landrace varieties will tend to drift back to their atavistic, naturally selected survival mode.

The Western world began using imported marijuana and hashish in the 1960s and all the remarkable imported varieties available then were traditionally maintained landraces. Within a decade, the demand for quality drug Cannabis exceeded traditional supplies, and mass production in the absence of selection became the rule. Rather than planting only select seeds, farmers began to sow all their seeds in an effort to supply market demand, and the quality of commercially available drug Cannabis began to decline. In addition, travelers returned to the supplying nations and introduced seeds of “improved” Western sinsemilla varieties that interbred with the local landraces and thus contaminated the local genomes. Landraces can no longer be replaced; they can only be preserved. The few remaining pure landrace varieties in existence now, some kept alive for decades as seeds and cuttings, are the keys to future developments in drug Cannabis breeding and evolution. It will be a continuing shame to lose the best results of hundreds of years of selection by local farmers. After all, our role should be as caretakers preserving the legacy of traditional farmers for the future benefit of all.

Cannabis research is a work in progress, and not all researchers agree on a single taxonomy.7 DNA sequencing is currently being used to characterize the diversity of many plant and animal groups, including Cannabis. While our knowledge grows and the evolutionary history of Cannabis is revealed, changes in taxonomic nomenclature will continue to reflect our deepening understanding of this medically valuable, yet controversial, plant. More broadly, whether we discover that Cannabis plants belong to one or more species, we can be sure that humans have long known, used, dispersed, cultivated and artificially selected these plants to perpetuate a truly wide range of diversity.

Robert C. Clarke is the author of several Cannabis science books and has traveled extensively throughout Eurasia documenting traditional Cannabis production and use. His breeding interests include selection and preservation of landrace varieties, and developing narrow leaflet drug varieties and hashish cultivars. Clarke is the executive director of BioAgronomics Group, a cannabis industry consultancy, serves as projects manager for the International Hemp Association, and holds a seat on the Phylos Bioscience Cannabis Evolution Project scientific advisory board. He may be contacted at

Mark D. Merlin, PhD, is a professor in the Botany Department of the University of Hawai`i at Mānoa and an elected member of the Linnean Society of London. A large part of his long-term biological and historical research has involved drug plants and their past and present uses by people. He has authored or co-authored a number of books on this general subject, such as Man and Marijuana: Some Aspects of their Ancient Relationships (Fairleigh Dickinson University Press, 1972), On the Trail of the Ancient Opium Poppy (Associated University Presses, 1984), Kava: The Pacific Drug (Yale University Press, co-authored with Vincent Lebot and Lamont Lindstrom, 1992), and, most recently, Cannabis: Evolution and Ethnobotany (RC Clarke and MD Merlin, University of California Press, 2013). He may be contacted at


  1. Clarke RC, Merlin MD. Cannabis: Evolution and Ethnobotany. Berkeley, CA: University of California Press; 2003.
  2. Hillig KW. A chemotaxonomic analysis of terpenoid variation in Cannabis. Biochem Syst Ecol. 2004;32(10):875-891.
  3. Hillig KW. A multivariate analysis of allozyme variation in 93 Cannabis accessions from the VIR Germplasm Collection. J Indust Hemp. 2004;9(2):5-22.
  4. Hillig KW. Genetic evidence for speciation in Cannabis (Cannabaceae). Genet Resour Crop Ev. 2005;52(2):161-180.
  5. Hillig KW, Mahlberg PG. A chemotaxonomic analysis of cannabinoid variation in Cannabis (Cannabaceae). Am J Bot. 2004;91(6):966-975.
  6. Schultes RE, Klein WM, Plowman T, Lockwood TE. Cannabis: An example of taxonomic neglect. Bot Mus Leafl Harv Univ. 1974;23(9):337-364.
  7. Small E. Evolution and classification of Cannabis sativa (marijuana, hemp) in relation to human utilization. Bot Rev. 2015;81(3):189-294.

Helichrysum (Immortelle) Chemistry, Antioxidant Activity, and Chemotaxonomy

Kladar NV, Anačkov GT, Rat MM, et al. Biochemical characterization of Helichrysum italicum (Roth) G.Don subsp. italicum (Asteraceae) from Montenegro: phytochemical screening, chemotaxonomy, and antioxidant properties. Chem Biodivers. 2015;12(3):419-431.

Traditionally, helichrysum (immortelle; Helichrysum italicum, Asteraceae) has been used for the treatment of scars and cuts, as well as used as a liver stimulant and diuretic. The essential oil of helichrysum has been found to have anti-inflammatory, antioxidant, fungicidal, and astringent effects. As an emollient and fragrance in the cosmetic and perfume industry, the chemical composition of helichrysum essential oil has been somewhat characterized. The aim of this study was to further characterize the chemical content and antioxidant activity of helichrysum aerial parts, and to assess the chemotaxonomy of the H. italicum taxa.

The flowering aerial parts of helichrysum (H. italicum ssp. italicum) were collected in May 2011, near Valdanos, Montenegro. The air-dried aerial parts of the plant were extracted with 45% ethanol and dried. The air-dried flowering upper parts of helichrysum were submitted to hydrodistillation to produce the essential oil.

The essential oil was characterized by using chromatography and mass spectrometry techniques. Principal component analysis (PCA) and cluster analysis (CA) were used to compare the main chemical constituents identified in this study with 16 different H. italicum taxa. The dried ethanol extract was dissolved in an aqueous solution for analysis of total phenolics and flavonoids. Both the essential oil and the ethanol extract were assessed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ethanol extract was also evaluated for inhibition of hydroxyl radical (•OH) generation.

The essential oil yield was found to be 0.15 ± 0.02%. A total of 27 compounds were identified, which represented 96.1% of the total oil composition. Most of the compounds were oxygenated monoterpenes (43.9%) and sesquiterpene hydrocarbons (41.2%). [Note: There are discrepancies between the article text and the data in Table 1, which lists these as 43.1% and 42.2%, respectively.] The major compounds found in the oil were neryl acetate (28.2%), neryl propionate (9.1%), γ-curcumene (17.8%), and ar-curcumene (8.3%). [Note: There are discrepancies for three of these compounds among the abstract, article text, and data in Table 1, which lists these as neryl acetate (29.2%), neryl propionate (10.1%), and γ-curcumene (18.8%).] Other compounds found included α-selinene (3.9%), isoitalicene (3.2%), thymol (2.8%), and α-cedrene (2.4%). These concentrations are consistent with previous reports for this plant subspecies.

PCA indicated that H. italicum ssp. italicum from Greece, H. italicum ssp. serotinum from the Iberian Peninsula, and plant material collected from the region of former Yugoslavia could all be clearly differentiated from one another based on different dominant chemical components. Helichrysum italicum ssp. italicum and H. italicum ssp. microphyllum were phylogenetically similar and had similar dominant chemical components. These and other taxa consisting of the main chemical components (e.g., neryl acetate) were found to represent four chemotypes. Two of these chemotypes had subchemotypes. CA indicated similar results in terms of the differentiation of H. italicum ssp. italicum from Greece and H. italicum ssp. serotinum from the Iberian Peninsula. The other taxa were classified in a similar way as that found by PCA, but with some differences, especially for the italicum subspecies.

The yield of the aqueous ethanol extract was 19.77%. The total phenolics and total flavonoids of this extract were found to be 31.97 ± 1.42 mg gallic acid equivalents (GAE)/g of dry extract and 20.68 ± 0.66 mg quercetin equivalents (QE)/g of dry extract, respectively. The radical scavenging capacity (RSC) of the ethanol extract and the essential oil was dose dependent. In terms of DPPH RSC, the half maximal inhibitory concentration (IC50) was significantly lower (more effective) for the ethanol extract (0.99 µg/ml) compared to the essential oil (1.76 mg/ml) (P value not given). [Note: Table 3 lists the essential oil IC50 as 1.37 mg/ml.] The extract had results that were similar to propyl gallate and quercetin dihydrate. Only the ethanol extract was evaluated for •OH scavenging capacity (IC50 = 26.47 µg/ml), but the RSC was significantly less effective compared to its DPPH RSC (P value not given).

The chemical constituents identified from the essential oil of helichrysum aerial parts in this study are consistent with reports assessing the main chemical components of this plant subspecies. Chemotaxonomic analysis suggests that different regions of the world can affect the chemistry of the essential oil. The authors recommend classifying the species further based on these chemical differences. The authors also indicate that helichrysum extracts and essential oils may be effective natural antioxidants for foodstuff and pharmaceuticals. Further studies should be conducted on how differences in chemical composition may affect biological activity, fragrance, and other qualities of the helichrysum extracts and essential oils.

—Laura M. Bystrom, PhD

Herbal medicine use in pregnancy

Herbal medicine use in pregnancy: results of a multinational study

  • Deborah A Kennedy†
  • Angela Lupattelli†,
  • Gideon Koren† and
  • Hedvig Nordeng†

†Contributed equally
BMC Complementary and Alternative MedicineThe official journal of the International Society for Complementary Medicine Research (ISCMR)201313:355

This is the first multinational study of the use of herbal medicine by women during pregnancy and provides insight into the use of these products in several countries, in some, for the first time. Three findings are specifically important. Firstly, we found that the use of herbal medicine in pregnancy varied considerably between countries, but that many of the same herbs are used. Secondly, there were no specific features that characterised the woman who used herbal medicines in pregnancy across all countries. Thirdly, in most countries women relied on informal information sources in their decision to use an herbal medicine in pregnancy.

The use of herbal medicines, overall, was 28.9%, and ranged from a low of 4.3% in Sweden to 69% in Russia. This range is consistent with results in other studies [9, 10, 13, 19, 20, 21, 22, 23]. The previously reported rate of herbal use in Finland was 3.6%; 1/3 of what we find in our study. We found lower prevalence rates of herbal medicine use in Norway, the UK and Italy than previously reported [9, 10, 14], but higher rates in Finland and Sweden [15, 24]. In Australia, previous studies have a reported prevalence of the use of herbal medicine of between 11% to 56%, which is consistent with our results [25, 26, 27]. This variability may reflect differences in data collection or differences in time trends. The broad availability of the study questionnaire might, in fact, promote a more representative study population rather than reflecting just an antenatal clinic or specific geographical area. The highest prevalence rate of the use of herbal medicines in pregnancy in Russia, coupled with the 38% of Russian women indicating that the recommendation to use an herbal medicine came from a physician could, in part, be due to the acceptance of the use of herbal medicines by Russian physicians. A 2008 survey of physicians in Russia found that 76% reported the use of phytotherapy and 71% of herbal medicines in their practice [28]. This country also was found to have the lowest allopathic medication use in the survey (Lupattelli A et al: Medication use in pregnancy: a multinational perspective. 2013 (submitted)).

The top herbal medicines used have been previously reported to include ginger, cranberry, raspberry, chamomile, valerian, and echinacea. This is consistent with the present survey as well. The use of these herbals was primarily for ailments related to pregnancy; nausea, UTIs and preparation for labor, rather than to assist with chronic diseases. Ginger was not only used for nausea but for cold and flu’s, perhaps due to its diaphoretic properties [29], health promotion and gastrointestinal disorders. A literature review the effect of ginger on nausea and vomiting in pregnancy found that ginger maybe helpful; however, the study results were inconsistent [30]. The results of a large cohort study with 1,020 exposed pregnancies demonstrated that there was no increase in congenital malformations or poor pregnancy outcomes after the use of ginger during pregnancy [31].

Cranberry was used for multiple purposes as well; cold and flu’s, UTIs, health promotion and water retention. Cranberry’s effectiveness in UTI prophylaxis and UTI treatment has not been demonstrated [32]. Taking into account the fact that untreated UTIs can increase the risk of pregnancy complications, pyelonephritis, impacting fetal growth and preterm delivery [33], the high use of herbals for UTI in our study is of concern. Health care professionals should inform pregnant women to use antibiotics and not herbals to treat UTI in pregnancy.

Raspberry was used for colds and flu’s and health promotion, where its properties would likely provide little benefit, in addition to the usually associated indication as a uterine tonic in preparation for labor [34]. A recent literature review concluded that there was lack of evidence for safety and efficacy in promoting effective labor and questioned its use in pregnancy in light of the weak evidence that currently exists [35].

Many sources have suggested that women who use CAM medicine are characterized as being between the ages of 31-40 years, having higher education and income levels and used CAM in a previous pregnancy [7, 13]. Overall, the study participants who used herbal medicines were having their first child, more often students and less likely to work as healthcare providers, with an educational level other than high school, non-smokers, using both folic acid and alcohol during pregnancy. Several of the factors associated with herbal medicine users are different from previously reported studies in terms of age and education [13]. However, Forster et al. did find in their study that herbal medicine users were more likely to be nulliparous [27]. These differences from previous studies may simply reflect a more representative user group that we were able to reach via the use of the internet rather than being limited to a specific antenatal clinic or geographical area. Overall, maternal age was not a significant determinant of herbal use during pregnancy apart from Western and Eastern Europe. In the former region use of herbal remedies was less prevalent among women younger than 20 years of age than the 21-30 year counterpart, whereas in the latter it was less prevalent among women of 31-40 years of age and more common among younger women (less than 20 years). Across the regions, there were also differences in the characteristics of herbal users with respect to parity and employment status. In fact, while parity and employment status were not significant determinants of herbal use during pregnancy in either North or South America or Australia, they were so in both Western and Eastern Europe. One consistent characteristic across Europe and North America, which has not been reported previously, is that herbal users were more likely to continue to consume alcohol once they were aware they were pregnant. This finding might reflect a certain open or extravert life style where both herbal medicine and alcohol consumption use is common [36]. Given that alcohol is a known teratogen and there is no known safe amount to consume when pregnant, this would to seem to contradict the objective of using substances that are perceived to be safe that one might associate with the use of herbal medicines [37].

Informal information sources, such as one’s own initiative, friends/family, were the primary sources that women indicated as involved in their decision to use an herbal medicine in pregnancy. As several authors have suggested, this may well reflect a woman’s desire to have a natural approach to pregnancy [7, 38], or perhaps these women feel more active in their health and feel more comfortable making their own decisions or a desire to use less conventional medication. This use could represent a concern, as studies have found that women will often not communicate the use of herbal medicines to their health care providers [14].

There are several strengths in this study. The use of an internet-based survey permitted access by a large number of women regarding their use of herbal medicine in pregnancy and provided insights on its use in regions and countries that have not previously been reported. A comparison of the survey population to the participating countries’ birthing populations found that the responding population were of similar age, parity and smoking habits, but had a higher education level. This may suggest that herbal medicine users may be overrepresented in this survey since higher education levels have been associated with herbal medicine use and higher education was a significant determinant of herbal use in several regions in the survey results. Similarly, internet users cluster in higher socioeconomic classes. The regional variations in the age of herbals users, suggesting that herbal use is higher amongst younger, nulliparous women may reflect an emerging trend in some countries.

There are also several limitations that should be mentioned. Firstly, as an internet based study, this may introduce a population selection bias by access to the internet. Internet penetration rates are high among the target population in many of the participating countries, and recent epidemiological studies indicate reasonable validity of web-based recruitment methods [39, 40, 41]. In Europe, the penetration rates range from about 50% in Russia and Serbia, to 100% in Iceland [41, 42]. In the USA, Canada and Australia approximately 80-90% of the population has access to the internet, though lower rates (about 50%) apply to South America [42, 43, 44, 45]. Hence, the degree to which our findings can be extrapolated to the target population is based on the representativeness of the respondents to the general birthing populations in each country.

Secondly, a conventional response rate could not be calculated because of the utilization of multiple websites in each participating country. However, of the women who expressed their willingness to participate or not in the study, 98.6% took part and completed the online questionnaire. Thirdly, the potential for recall bias cannot be excluded here since we were reliant upon women to recall which herbal medicines were taken and, for 1,351 women (49.3%), the events were up to one year in the past. Also, the duration of use of the herbal medicine in pregnancy was not captured in the survey. However, as 75% of the herbals users used herbal medicines for pregnancy-related health ailments, we assume that short term use was most common. There may also be under reporting of some herbal medicines as herbal names were not specifically queried in the questionnaire. Further, when a multi-herbal product was provided as a response, an internet search for its ingredients was performed. It is possible that the composition of named products could vary from country to country and these differences would not have been captured. Our results must be interpreted with these strengths and limitations in mind.


In this multinational study use of herbal medicine in pregnancy was high. In total, 134 different herbs were used, most frequently ginger, cranberry, valerian and raspberry for pregnancy-related health ailments. There was variability in both the prevalence of the use and users of herbal medicines in pregnancy across regions. Many women primarily used informal information sources in their decision to use an herbal medicine in pregnancy in most regions; however, in the Eastern European countries, physicians’ recommendations were cited most often.


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Pre-publication history
The pre-publication history for this paper can be accessed here:

donderdag 14 september 2017

Poux et lentes terrassés par les huiles essentielles

Comme les bactéries, les poux peuvent devenir résistants aux traitements de synthèse. Des
chercheurs australiens1 ont comparé l’efficacité d’une solution à base d’huiles essentielles et
celle d’une mousse2 neurotoxique antipoux (à base de pyréthrines et de butylate de pipéronyle).
La solution à base d’huiles essentielles contenait 11 % d’Eucalyptus globulus et1 % d’arbre à thé citronné (Leptospermum petersonii). Elle a été appliquée 3 fois à 7 jours d’intervalle sur 40 enfants âgés de 7 ans maximum. La mousse a été appliquée sur 36 enfants aux jours 0 et 7, soit une fois de plus que recommandé par le fabricant.

Après une seule application de la solution naturelle, les 1 418 poux recueillis avaient été tués. Au premier jour d’application les chercheurs n’ont pas constaté de différence d’efficacité entre les deux groupes. Au 7e jour, 83 % du groupe « huiles essentielles » était débarrassé des poux, contre 36 % chez ceux quiavaient reçu la mousse. Des échecs ont été observés chez 7 des 40 enfants du premier groupe mais la cause est attribuée à une nouvelle infestation.
Les scientifiques ont également vérifié l’action sur les lentes in vitro en les immergeant
durant 10 secondes dans la solution d’huiles essentielles. Aucun œuf n’a jamais éclos. Le test témoin effectué avec de l’eau purifiée a montré 92 % d’éclosions au bout de 10 jours.

Les auteurs affirment donc que la solution est excellente car elle « est à la fois
volatile et rapidement efficace et il est peu probable qu'elle cause le développement
de résistance ».

1. Greive KA, Barnes TM. The efficacy of Australian essential oils for the treatment of head lice infestation
in children: a randomised controlled trial. Australas J Dermatol. March 7, 2017; [epub ahead ofprint]. doi : 10.1111/ajd.12626.
2. Banlice® fabriquée par Pfizer Consumer Healthcare Group en Australie.

dinsdag 12 september 2017

Beets: Enhancing Sports Performance and Cognitive Function

Hyped by athletes and sports physiologists, beets (Beta vulgaris, Chenopodiaceae) have emerged as a trendy and promising sports performance supplement ingredient. A growing body of evidence suggests that beetroot, the taproot of the beet plant, has the potential to improve athletic performance and endurance. New research aims to pinpoint its mechanisms of action, and how it may help support body systems and impact blood pressure, heart health, and even cognitive function.

Beetroot contains a variety of health-promoting compounds, including betaines, resveratrol, and quercetin. However, studies of the potential sports performance benefits of beets have focused primarily on nitrates, which have been shown to play a role in blood pressure regulation, cardiovascular function, and mitochondrial energy production.

Exercise Performance

Research supports certain exercise performance benefits of dietary nitrate supplementation. Several studies in recent years have shown that supplementation can decrease the oxygen cost of submaximal exercise (exercise conducted at an intensity less than the maximum of which the individual is capable), increase high-intensity exercise tolerance in recreational athletes, and increase oxygen efficiency in submaximal cycling exercise.1-4

More recently, research is honing in on how and when performance is affected by consumption of beetroot. One 2017 study, led by Oliver Shannon at the Institute for Sport, Physical Activity and Leisure at Leeds Beckett University in the United Kingdom, sought to determine the effects of dietary nitrate supplementation on physiological functioning and exercise performance in trained runners and triathletes during short- and long-distance time trials. The authors measured plasma nitrites, resting blood pressure, and maximal oxygen consumption of eight trained male runners or triathletes. The subjects completed four exercise performance tests, each consisting of a 10-minute warmup followed by either a 1,500-meter or 10,000-meter treadmill time test.5 Three hours prior to each test, the athletes received either 140 mL of concentrated nitrate-rich beetroot juice or 140 mL of nitrate-depleted beetroot juice. Researchers found that nitrate-rich beetroot juice supplementation significantly enhanced performance in the 1,500-meter time trial but not for the 10,000-meter trial.

The findings, the authors wrote, suggest that beetroot juice supplementation may be ergogenic (i.e., performance-enhancing) during shorter-distance time trials at a high work rate, but not during longer-distance time trials at a lower work rate. The authors also noted that the effects of nitrate supplementation are highly variable, and that these results cannot be easily generalized to other populations or conditions and, as such, further study is warranted.

Previous research on beetroot has focused on endurance, but one new study from 2017 examined the impact of beetroot on high-intensity or intermittent-type exercise.6 The double-blind, placebo-controlled crossover study, led by Jean Nyakayiru of the Department of Human Movement Sciences at NUTRIM School of Nutrition and Translational Research in Metabolism at Maastricht University Medical Centre in the Netherlands, investigated whether six days of nitrate-rich beetroot juice supplementation would improve exercise performance in trained soccer players. Soccer players were chosen because the sport requires multiple bouts of high-intensity running and a heavy reliance on type II muscle fibers, which are thought to be the muscle group most impacted by nitrates.

The subjects (N = 32), of similar age, height, weight, and playing experience, ingested two 70-mL doses of beetroot juice (140 mL per day) containing 800 mg of nitrates or two 70-mL doses of a placebo beverage (with similar taste and appearance but depleted of nitrate) for six days.6 The final dose was ingested three hours prior to the exercise test. Subjects then completed two days of high-intensity intermittent running performance using the Yo-Yo intermittent recovery level 1 (YoYo IR1) test, which simulates soccer-specific activities in a controlled setting.

Distance covered during the test was the primary measure of performance, although heart rate was measured continuously, and blood and saliva samples were taken prior to the test. The authors found that nitrate-rich beetroot juice ingestion improved subject performance by 3.4 ± 1.3% compared to the placebo group. Subjects who consumed the nitrate-rich beetroot juice had higher plasma and salivary nitrate concentrations as well.

Interestingly, mean heart rates in the beetroot juice group were lower than in the placebo group during the test. This may have implications for further study on heart function. The results demonstrate that nitrate supplementation could represent an effective nutritional strategy to improve exercise performance in soccer players. Further study, however, is needed to see if these improvements translate to athletes at different performance levels.

Cognitive Function

Beetroot juice also may have important benefits beyond athletic performance that extend to healthy aging of the brain and cognitive function. A brain-imaging study published in 2016 examined whether beetroot juice might have a synergistic effect with exercise on neuroplasticity (i.e., the ability of the brain to reorganize by forming new nerve cell connections). Led by Meredith Petrie of Wake Forest University in Winston-Salem, North Carolina, the study looked at the effects of beetroot juice on the functional brain network of 26 older men (with a mean age of 65.4 years) who were randomly assigned to ingest beetroot juice or placebo for six weeks of exercise.7

Using measurements of peak metabolic equivalent capacity and resting state magnetic resonance imaging, the authors found that the community structure consistency of the somatomotor cortex (an area of the brain that controls motor signals to the muscles) was significantly enhanced in the beetroot juice group compared to placebo.7 They also found significantly increased secondary connections between the somatomotor cortex and insular cortex in the beetroot juice group.

Based on these findings, the researchers wrote that subjects in “the exercise plus beetroot juice group had brain networks that more closely resembled those of younger adults, showing the potential enhanced neuroplasticity conferred by combining exercise and beetroot juice consumption.”


Though these studies shed more light on the benefits of beetroot juice and how dietary nitrates can improve exercise performance and tolerance, many questions remain. In addition to understanding more about when and how much nitrate-rich beetroot juice will have an impact, larger studies with more diverse populations are needed to better understand the potential exercise advantages and the broader health benefits of dietary nitrates. More safety data would also be useful to understand the effects of prolonged intake and the advantages or disadvantages of consuming dietary nitrates from beets alone, as opposed to obtaining the nitrates from other vegetable sources.

—Karen Raterman


  1. Bailey SJ, Winyard P, Vanhatalo A, et al. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. J Applied Physiol. 2009;107(4):1144-1155.
  2. Larsen FJ, Weitzberg E, Lundberg JO, Ekblom B. Effects of dietary nitrate on oxygen cost during exercise. Acta Physiol. 2007;191(1):59-66.
  3. Bailey SJ, Varnham RL, DiMenna FJ, Breese BC, Wylie LJ, Jones AM. Inorganic nitrate supplementation improves muscle oxygenation, O2 uptake kinetics, and exercise tolerance at high but not low pedal rates. J Appl Physiol 2015;118:1396-1405.
  4. Cermak NM, Gibala MJ, van Loon LJC. Nitrate supplementation’s improvement of 10-km time-trial performance in trained cyclists. Int J Sport Nutr Exerc Metab. 2012;22:64-71.
  5. Shannon OM, Barlow MJ, Duckworth L, et al. Dietary nitrate supplementation enhances short but not longer duration running time-trial performance. Eur J Appl Physiol. April 2017;117(4):775-785.
  6. Nyakayiru J, Jonvik KL, Trommelen J, et al. Beetroot juice supplementation improves high-intensity intermittent type exercise performance in trained soccer players. Nutrients. March 2017;9(3):314.
  7. Petrie M, Rejeski WJ, Basu S, et al. Beet root juice: An ergogenic aid for exercise and the aging brain. J Gerontol A Biol Sci Med Sci. 2016. doi: 10.1093/gerona/glw219.

Cannabinoids for migraine prevention

A study has confirmed that cannabinoids are just as suitable as a prophylaxis for migraine attacks as other pharmaceutical treatments.

Cannabinoids suitable for migraine prevention
Interestingly though, when it comes to treating acute cluster headaches they are only effective in patients that suffered from migraine in childhood.

Germany’s recent decision to liberalise the use of cannabis for medical purposes has rekindled policy debate across Europe.

Progress was reflected in the results of a current Italian study presented at the 3rd Congress of the European Academy of Neurology (EAN). A research team led by Dr Maria Nicolodi investigated the suitability of cannabinoids as a prophylaxis for migraine and in the acute treatment of migraines and cluster headaches.

To start with the researchers had to identify the dosage required to effectively treat headaches. A group of 48 chronic migraine volunteers were given a starting oral dose of 10mg of a combination of two compounds. One contained 19% tetrahydrocannabinol (THC), and while the other had virtually no THC it had a 9% cannabidiol (CBD) content. The outcome was that doses of less than 100mg produced no effects. It was not until an oral dose of 200mg was administered that acute pain dropped by 55%.

In phase 2 of the study, 79 chronic migraine patients were given a daily dose of either 25mg of amitriptyline – a tricyclic antidepressant commonly used to treat migraine – or 200mg of the THC-CBD combination for a period of three months. Forty-eight cluster headache patients also received either 200mg THC-CBD or a daily dose of 480mg of the calcium channel blocker verapamil. For acute pain, an additional 200mg TCH-CBD was administered for both types of headaches.

The results after three months of treatment and follow-up after a further four weeks produced various insights. While the TCH-CBD combination yielded slightly better results than amitriptyline (40.1%) with a 40.4% reduction in attacks, the severity and number of cluster headache attacks only fell slightly. When analysing use in the treatment of acute pain, the researchers came across an interesting phenomenon: cannabinoids reduced pain intensity among migraine patients by 43.5%. The same results were seen in cluster headache patients, but only in those that had experienced migraine in childhood. In patients without previous history, THC-CBD had no effect whatsoever as an acute treatment.

Drowsiness and difficulty concentrating aside, the side effects observed during the study were highly positive. The incidence of stomach ache, colitis and musculoskeletal pain – in female subjects – decreased.