Ethnic Skin Types Research Articles

Turn Your AART into a HIT Using a Complete Range of Aesthetic Injectables: Methodology for Combining Products to Maximise Patient Outcomes.

Optimizing outcomes of aesthetic treatments with injectable products usually requires a consideration of the entire face to ensure balance, along with combination treatments that align with the patient's goals. To help injectors, a method of assessing the patient and developing an individualized, holistic treatment plan was developed. This methodology is termed Assessment, Anatomy, Range, and Treatment (AART™) and Holistic Individualized Treatments (HITs™). This article aims to describe and evaluate the novel and systematic AART-HIT™ methodology. The AART-HIT™ methodology, including its associated diagnostic tool the Facial Assessment Scale (FAS™), were developed to aid injectors in completing a patient assessment in which the entire face is evaluated, the relevant anatomy is considered, the science behind the available range of products is understood, and the treatment plan is individualised for the patient. Specifically, the HITs™ are methodologic tools for practitioners to perform a standardized, full facial assessment and to create an individualized treatment approach to holistically address a patient's aesthetic concerns. The use of this methodology in clinical practice was assessed via a survey, deployed to twenty-eight clinicians. Over 85% of participants agreed that the AART-HIT™ methodology was adequate for their needs. Additionally, 100% of participants agreed that the temporal sequencing of HITs™ and the FAS™ diagnostic tool was useful in clinical practice. Furthermore, over 70% of participants agreed that the anatomical locations identified in each HIT™ were sufficient, while over 80% responded that the HITs™ adequately represented the range of products. Finally, over 85% of participants agreed that the HITs™ covered different ethnic skin types and various patient ages and, over 80% of participants responded that they would not add additional elements to any of the 5 HITs™. The AART-HIT™ methodology, including the FAS™ were comprehensive enough for clinical use in providing a personalised treatment plan for individual patients.

Representing Black, Asian and Minority Ethnic Skin in Dermatology Education Amidst the COVID-19 Pandemic: An Evaluation of an E-learning Resource.

BackgroundRecently published literature has shed light on the lack of representation and exposure to Black, Asian and Minority Ethnic (BAME) skin types in dermatology education and training. This may lead to diagnostic uncertainty and impact the overall quality of care delivered. Thus, this paper discusses the design and development of an e-learning resource as an innovative solution to address this educational need during the pandemic.MethodsA focus group was conducted to assess the learning needs of trainees on cutaneous manifestations of BAME patients. An e-learning resource was created using instructional design, educational and multimedia principles such as the ADDIE (Analysis, Design, Development, Implementation, Evaluation) model and Gagne’s nine steps. The e-learning was disseminated to trainees across a one-month period. Feedback on the content and relevance of the e-learning was collected on the completion of the module.ResultsOverall, 84% (n=42) of trainees reported that the module improved their confidence and knowledge acquisition of common skin conditions in BAME skin types (p<0.0001 when compared to pre-course confidence). 94% (n=47) of trainees agreed or strongly agreed that the e-learning met their learning needs as an educational tool. Of 50 trainees, the results show that trainees agreed or strongly agreed that the resource was accessible (94%, n=47), reusable (94%, n=47) and promotes a sustainable way of teaching in dermatology (96%, n=48).ConclusionA well-structured virtual learning module can be an effective tool to deliver teaching remotely whilst complying with public health measures to prevent the spread of COVID-19. This e-learning also highlights the need for further BAME representation in published dermatological resources.

Combined Treatment of Rolling Acne Scars in Ethnic Skin Using Extensive Subcision, Trichloracetic Acid Peel, and Fractional Ablative Erbium Laser.

BACKGROUNDSuccessful treatment of acne scars in ethnic skin requires procedures that are safe and effective with a low incidence of hyper or hypopigmentation postoperatively.OBJECTIVEIn this study, the safety and efficacy of a combined treatment protocol including tumescent anesthesia, subcision, trichloracetic acid peel, and fractional erbium laser resurfacing was evaluated.METHODSThis is a retrospective study of 56 patients (22 women and 34 men) with predominantly rolling acne scars and Fitzpatrick skin Types IV–VI who were treated using a combination of tumescent anesthesia, extensive subcision, fractional ablative erbium laser, and a blending 20% trichloracetic acid (TCA) peel.RESULTSThe mean improvement after a single treatment, assessed by 3 independent evaluators (2 dermatologist and 1 dermatology physician assistant), was 2.52 (SD = 1.04) on a scale of 1 to 4.CONCLUSIONThe combination of tumescent anesthesia, extensive subcision, fractional ablative erbium laser resurfacing, and a blending 20% TCA peel (combined procedure) is both safe and effective in the treatment of rolling acne scars in ethnic skin types with acceptable temporary adverse effects.

Melanogenic Difference Consideration in Ethnic Skin Type: A Balance Approach Between Skin Brightening Applications and Beneficial Sun Exposure.

Human skin demonstrates a striking variation in tone and color that is evident among multiple demographic populations. Such characteristics are determined predominantly by the expression of the genes controlling the quantity and quality of melanin, which can alter significantly due to the presence of small nucleotide polymorphism affecting various steps of the melanogenesis process and generally linked to the lighter skin phenotypes. Genetically determined, constitutive skin color is additionally complemented by the facultative melanogenesis and tanning responses; with high levels of melanin and melanogenic factors broadly recognized to have a protective effect against the UVR-induced molecular damage in darker skin. Long-term sun exposure, together with a genetic makeup responsible for the ability to tan or the activity of constitutive melanogenic factors, triggers defects in pigmentation across all ethnic skin types. However, sun exposure also has well documented beneficial effects that manifest at both skin homeostasis and the systemic level, such as synthesis of vitamin D, which is thought to be less efficient in the presence of high levels of melanin or potentially linked to the polymorphism in the genes responsible for skin darkening triggered by UVR. In this review, we discuss melanogenesis in a context of constitutive pigmentation, defined by gene polymorphism in ethnic skin types, and facultative pigmentation that is not only associated with the capacity to protect the skin against photo-damage but could also have an impact on vitamin D synthesis through gene polymorphism. Modulating the activities of melanogenic genes, with the focus on the markers specifically altered by polymorphism combined with differential requirements of sun exposure in ethnic skin types, could enhance the applications of already existing skin brightening factors and provide a novel approach toward improved skin tone and health in personalized skincare.

Facial skin mapping: from single point bio-instrumental evaluation to continuous visualization of skin hydration, barrier function, skin surface pH, and sebum in different ethnic skin types.

Dry skin is one of the most important concerns of consumers worldwide. Despite huge efforts over several decades, the personal care industry still does not offer a perfect solution to satisfy the unmet needs of consumers for moisturising treatments in different ethnic groups. The paucity of data for the underlying cellular and biochemical problems in, and the effects of moisturisers on photodamaged facial skin may partly explain this. Mainly, single point measurements are used to understand the effects of products on skin physiology even on surrogate skin sites such as the non‐photodamaged volar forearm. Some groups have developed discontinuous facial maps of skin biophysical properties, however, in 2014 a continuous facial analysis of bio‐instrumental evaluations was developed using a heat map approach. These maps enabled a continuous visualization of features that not only revealed an unexpected complexity of facial skin but also indicated that use of surrogate skin sites for facial skin is inappropriate. We have demonstrated that remarkable gradients of skin hydration, TEWL, skin surface pH and sebum exist within short distances across the face and the gradients are distinctive among different ethnic groups. In addition, these studies have demonstrated that darkly‐pigmented individuals do not necessarily have a better skin barrier function than their less‐pigmented counterparts and that Caucasians have a lower facial skin surface pH compared with more pigmented subjects. Overall, there are no correlations between capacitance, TEWL and skin surface pH including individual topology angle values. Novel 3D camera approaches have also been used to facilitate a more precise assignment of measurement sites and visualisation. The 3D facial colour mappings illustrated precisely the local moisturising effects of a moisturising cream. There were subtle ethnic differences in efficacy that may be related to underlying skin biochemistry and/or ethnic differences in product application. A placebo‐controlled study using conductance measurements in Chinese subjects is also reported. Finally, a new whole face statistical approach has been taken to prove differences in skin parameters but also of moisturiser treatment that adds further to our understanding of the ethnic differences in skin physiology and product application. This paper reviews the background of the development and application of this methodology.

Aging in skin of color

Ethnic skin is quickly emerging as the norm in the United States, and as the population becomes more diverse, there is also a projected rise in the number of aging adults. Given the paucity of data regarding aging in ethnic skin, the authors have consolidated available information for this population. Literature examining structural and functional variation of aging in ethnic skin types was primarily found through PubMed and supplemental textbook chapters. Aging is comprised of two synergistic processes, intrinsic or chronologic aging, and extrinsic aging. Caucasian, African American, East Asian, and Hispanic skin each have distinguishing features of aging, but all populations share dyspigmentation, rhytides, and skin laxity. Increased melanin content predisposes skin of color to a greater degree of hyperpigmentation, but skin thickness may protect against the formation of rhytides. Tailored prevention and treatment are also paramount in attaining favorable outcomes for this growing cohort.

640 Effects of short-term moisturizer application in different ethnic skin types - non-invasive assessment with optical coherence tomography and reflectance confocal microscopy

640 Effects of short-term moisturizer application in different ethnic skin types - non-invasive assessment with optical coherence tomography and reflectance confocal microscopy

Effects of Short-Term Moisturizer Application in Different Ethnic Skin Types: Noninvasive Assessment with Optical Coherence Tomography and Reflectance Confocal Microscopy

Background/Aims: Ethnic skin types are known to differ in their morphological and physiological features. Thus, treatment responses may vary among different races. We aimed to assess skin morphology of different ethnicities and to compare the effect of short-term moisturizer application using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM). Methods: Thirty healthy female subjects of European, Asian and Black ethnicity at 30–45 years of age were included in the study. OCT and RCM imaging was performed on the cheek to compare morphology. Following the 2-week application of a moisturizer cream (Sebamed® lotion) on one forearm, imaging was performed on both forearms to assess and compare treatment responses. Results: Epidermal thickness and morphology of pores varied between the three ethnic groups, with Black subjects displaying the thickest epidermis and largest skin pores. On the treated forearm, OCT measurements revealed a significantly thicker epidermis in all groups as compared to the untreated forearm. Width of skin folds on the treated forearm was measured by RCM to be significantly lower in all ethnic groups as compared to the untreated forearm. Conclusion: Different ethnic skin types showed variations in skin morphology and treatment response to short-term moisturizer application. OCT and RCM were useful methods for noninvasive, real-time, repeated assessment of ethnic skin.

175 Effects of short-term moisturizer application in different ethnic skin types - non-invasive assessment with optical coherence tomography and reflectance confocal microscopy

175 Effects of short-term moisturizer application in different ethnic skin types - non-invasive assessment with optical coherence tomography and reflectance confocal microscopy

Fractional resurfacing in the Asian patient: Current state of the art.

Fractionated photothermolysis (FP) has revolutionized modern laser technology. By creating selective columns of microthermal damage, fractionated devices allows for greater treatment depths to be achieved without the prolonged downtime and risk of complications seen in traditional fully ablative laser resurfacing. Fractional resurfacing is a proven method to treat a variety of cutaneous conditions. In the Caucasian patient, a wide range of devices and treatment settings can be utilized safely and effectively. However, ethnic skin requires special consideration due to its unique pigmentary characteristics and clinical presentations. In this review article, we detail the current indications and strategies to optimize results and mitigate complications when utilizing fractional resurfacing for the Asian patient. A review of the MEDLINE English literature was conducted on fractionated laser devices studied in the Asian population. Articles included describe non-ablative devices including fractionated erbium glass, thulium fiber, diode, and radiofrequency devices; and ablative devices including fractionated carbon dioxide (CO2 ) laser, erbium yttrium aluminum garnet and yttrium scandium gallium garnet (YSGG) laser. These data were integrated with the expert opinion of the authors. Taking into account the unique characteristics and cosmetic concerns of the Asian population, fractional resurfacing can be considered a safe and effective option for the treatment of atrophic and hypertrophic scarring, and photorejuvenation in ethnic skin types. Select cases of melasma may be treated with fractionated non-ablative devices, but utilized with caution. The predominant complication associated with fractional resurfacing for these conditions is post-inflammatory hyperpigmentation (PIH) and rebound worsening of melasma. A greater number of treatments at lower density settings and wider treatment intervals typically produce the lowest risks of PIH without compromising treatment efficacy. Lasers Surg. Med. 49:45-59, 2017. © 2016 Wiley Periodicals, Inc.

Variations of Structural Components: Specific Intercultural Differences in Facial Morphology, Skin Type, and Structures

Analysis of the differences in facial morphology and skin structure and tone among ethnic groups within the realm of plastic surgery is relevant due to the increasing number of ethnic individuals seeking cosmetic surgery. Previous classifications of ideal facial morphologic characteristics have been revised and challenged over the years to accurately reflect the differences in facial structure that are aesthetically pleasing to individuals of differing ethnic groups. The traditional neoclassic canons reflected the European Caucasian facial morphology and cannot be used to classify facial characteristics in ethnic groups due to drastic differences in measurement and proportion. In addition, differences in biophysiologic properties of ethnic skin types influence the progression of aging and the ability of skin to withstand environmental insults. Thickness of the stratum corneum, water content, and melanin composition are important factors that were analyzed in varying ethnic groups. Although it appears that Caucasian Americans are subject to earlier onset of skin wrinkling and sagging than are African Americans due to thinner stratum corneum layers and decreased water content, more research needs to be conducted to be inclusive of other ethnic groups. These data will enable plastic surgeons to treat these groups more effectively while preserving their unique characteristics.

The Use of Lasers in Darker Skin Types

The demographics of the US population continue to change at an extremely rapid pace. As of 2008, Asians, Hispanics, and African Americans accounted for 31% of the US population, and it is estimated that by the year 2050 half of the population of America will be represented by darker ethnic skin types. With the increase in the total number of individuals of skin of color, the demand for safe and effective laser therapy in darker skin types continues to increase. However, despite the increase in demand, the current literature regarding the use of lasers in darker skin remains limited. Most of the treatment parameters defined for laser platforms have been established primarily through extensive testing on skin phototypes I to III, and those studies that have been conducted on darker skin phototypes have been overwhelmingly conducted on Asian skin. Nevertheless, it has become clear that effective cutaneous laser surgery in darker skin types can be accomplished despite a relative overall greater risk for complications. Therefore, as the diversity of America continues to grow, the laser surgeon needs to maintain a clear understanding of the complexities associated with treating ethnic skin and remain mindful of the current, and ever-changing, therapeutic modalities available. This will allow the conscientious physician to maximize outcome and minimize risk when performing laser surgery on darker skin types.

Ethnic skin types: are there differences in skin structure and function?1

People of skin of colour comprise the majority of the world's population and Asian subjects comprise more than half of the total population of the earth. Even so, the literature on the characteristics of the subjects with skin of colour is limited. Several groups over the past decades have attempted to decipher the underlying differences in skin structure and function in different ethnic skin types. However, most of these studies have been of small scale and in some studies interindividual differences in skin quality overwhelm any racial differences. There has been a recent call for more studies to address genetic together with phenotypic differences among different racial groups and in this respect several large-scale studies have been conducted recently. The most obvious ethnic skin difference relates to skin colour which is dominated by the presence of melanin. The photoprotection derived from this polymer influences the rate of the skin aging changes between the different racial groups. However, all racial groups are eventually subjected to the photoaging process. Generally Caucasians have an earlier onset and greater skin wrinkling and sagging signs than other skin types and in general increased pigmentary problems are seen in skin of colour although one large study reported that East Asians living in the U.S.A. had the least pigment spots. Induction of a hyperpigmentary response is thought to be through signaling by the protease-activated receptor-2 which together with its activating protease is increased in the epidermis of subjects with skin of colour. Changes in skin biophysical properties with age demonstrate that the more darkly pigmented subjects retaining younger skin properties compared with the more lightly pigmented groups. However, despite having a more compact stratum corneum (SC) there are conflicting reports on barrier function in these subjects. Nevertheless, upon a chemical or mechanical challenge the SC barrier function is reported to be stronger in subjects with darker skin despite having the reported lowest ceramide levels. One has to remember that barrier function relates to the total architecture of the SC and not just its lipid levels. Asian skin is reported to possess a similar basal transepidermal water loss (TEWL) to Caucasian skin and similar ceramide levels but upon mechanical challenge it has the weakest barrier function. Differences in intercellular cohesion are obviously apparent. In contrast reduced SC natural moisturizing factor levels have been reported compared with Caucasian and African American skin. These differences will contribute to differences in desquamation but few data are available. One recent study has shown reduced epidermal Cathepsin L2 levels in darker skin types which if also occurs in the SC could contribute to the known skin ashing problems these subjects experience. In very general terms as the desquamatory enzymes are extruded with the lamellar granules subjects with lowered SC lipid levels are expected to have lowered desquamatory enzyme levels. Increased pores size, sebum secretion and skin surface microflora occur in Negroid subjects. Equally increased mast cell granule size occurs in these subjects. The frequency of skin sensitivity is quite similar across different racial groups but the stimuli for its induction shows subtle differences. Nevertheless, several studies indicate that Asian skin maybe more sensitive to exogenous chemicals probably due to a thinner SC and higher eccrine gland density. In conclusion, we know more of the biophysical and somatosensory characteristics of ethnic skin types but clearly, there is still more to learn and especially about the inherent underlying biological differences in ethnic skin types.

Photoaging and Nonablative Photorejuvenation in Ethnic Skin

Advances in nonablative skin rejuvenation technologies have sparked a renewed interest in the cosmetic treatment of aging skin. More options exist now than ever before for reversing cutaneous changes caused by long-term exposure to sunlight. Although Caucasian skin is more prone to ultraviolet light injury, ethnic skin (typically classified as types IV to VI) also exhibits characteristic photoaging changes. Widespread belief that inevitable or irreversible textural changes or dyspigmentation occurs following laser- or light-based treatments has been challenged in recent years by new classes of devices capable of protecting the epidermis from injury during treatment. Demographic changes in the US population favor an increasing trend of older, ethnically diverse patients requesting treatment to recapture a youthful appearance. The purpose of this article is to review the recent literature regarding clinical recognition and treatment of photoaging changes in ethnic skin. This article provides a basis for classification of current and future nonablative technologies with regard to the safety and efficacy of treatment in ethnic skin. Nonablative technologies have emerged to meet the public demand for no-downtime treatment of aging skin. As these technologies continue to evolve and improve, physicians are challenged to define realistic goals, expectations, and limitations for treatment. Whenever possible, ongoing and future studies should attempt to address treatment in ethnic skin types. Photoaging changes in ethnic skin can be recognized and successfully treated with nonablative technology with minimal risk and downtime.

Use of superficial glycolic acid chemical peelsfor varied indications in darker racial ethnic skin types

Use of superficial glycolic acid chemical peelsfor varied indications in darker racial ethnic skin types

Ethnic Variation in Tyrosinase and TYRP1 Expression in Photoexposed and Photoprotected Human Skin

The relative expression of a number of key mediators of human pigmentation including tyrosinase, tyrosinase related protein-1 (TYRP1), endothelin-1 and adrenocorticotrophic hormone (ACTH) proteins were analysed and quantified in immunohistochemically stained skin sections using semiquantitative computer assisted image analysis. Comparisons were made between a range of different ethnic skin types including European, Chinese, Mexican, Indian and African at both chronically photoexposed and photoprotected sites. Melanocyte number varied little with ethnicity except in the European group which had 60-80% more melanocytes than other skin types (P < 0.01, n = 10; Student Neuman-Keuls). However, melanocyte number was increased approximately twofold in chronically photoexposed skin of all ethnic groups (P < 0.001, n = 48; paired t-test). Tyrosinase protein expression in melanocytes did not vary with ethnicity, but TYRP1 protein was significantly elevated (approximately 2.6-fold) in darkly pigmented African and Indian skin types compared with lightly pigmented Mexican, Chinese and European skin types. In melanocytes from chronically photoexposed skin, there was a modest but significant increase in the expression of tyrosinase protein (approximately 1.2-fold, P < 0.001, n = 48; paired t-test), together with a significant and slightly larger increase in the expression of TYRP1 protein (approximately 1.6-fold, P < 0.005, n = 48; paired t-test). In contrast, the expression of endothelin-1 and ACTH showed no significant variation with either ethnicity or photoexposure. These data are consistent with the view that maintenance of a chronically hyperpigmented phenotype in chronically photoexposed human skin is largely the result of a stable increase in the number of tyrosinase positive melanocytes at these sites. Moreover, the observed ethnic variation in TYRP1 protein expression suggests that TYRP1 may play a significant role in mediating ethnic differences in melanogenesis and constitutive skin pigmentation in vivo.

The impact of epidermal melanin on objective measurements of human skin colour.

Objective measurements of human skin colour were made with a tristimulus (L*a*b*) chromameter in a range of different ethnic skin types. These were compared with biochemical measurements of melanin content, melanin composition and melanosome size in skin biopsies obtained from the same sites. L*, a* and b* values were found to vary significantly with ethnicity. In general, constitutively dark skin types have lower L* values, higher a* values and higher b* values than constitutively light skin types. Total epidermal melanin content appears to be the primary determinant of L* values in human skin (r = -0.88; P < 0.00001), whilst melanosome size also has a significant but more subtle influence on L* values (r = -0.73; P < 0.00001). There is also a strong positive contribution to a* values from epidermal melanin (r = 0.66, P < 0.00001), which accounts for the ethnic variation in a* values observed in this study. Melanin is also a major contributor to b* values in lighter skin types (r = 0.71, P < 0.00001). However, this relationship breaks down in darker skin types where b* values actually reach a maximum and then decrease as the concentration of melanin in the skin increases. This appears to be because of optical masking of yellow light by high concentrations of melanin in the epidermis. Analysis of the relationships between L*, a* and b* values in human skin indicate that they are very closely interrelated, and suggest that the optical properties of melanin in the epidermis are very similar to those of a dye on a fabric substrate.

Ethnic variation in melanin content and composition in photoexposed and photoprotected human skin.

We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) and chronically photoexposed (dorsal forearm) skin from a range of different ethnic skin types including African, Indian, Mexican, Chinese and European. The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much epidermal melanin as the most darkly pigmented (African and Indian) skin types. However, the composition of melanin in these lighter skin types is comparatively more enriched with lightly coloured, alkali-soluble melanin components (up to three-fold). Regardless of ethnicity, epidermal melanin content is significantly greater in chronically photoexposed skin than it is in corresponding photoprotected skin (up to two-fold). However, by comparison there is only a modest enrichment of lightly coloured, alkali soluble melanin components in photoprotected skin (up to 1.3-fold). Analysis of melanosomes extracted from the epidermis in these subjects indicates that the proportion of spheroidal melanosomes is low in all skin types examined (<10%). This suggests that in human skin, pheomelanin is a very minor component of epidermal melanin, even in the lightest (European) skin types. Analysis of melanosome size revealed a significant and progressive variation in size with ethnicity: African skin having the largest melanosomes followed in turn by Indian, Mexican, Chinese and European. On the basis of these findings, we propose that variation in skin pigmentation is strongly influenced by both the amount and the composition (or colour) of the melanin in the epidermis. Variation in melanosome size may also play a significant role. However, the data also suggest that in human skin there are subtle differences in the mechanisms associated with the maintenance of constitutive pigmentation and facultative hyperpigmentation, respectively.

The epidermal nerve fibre network: characterization of nerve fibres in human skin by confocal microscopy and assessment of racial variations.

As a first line of defence, the skin is equipped with a complex and interactive nerve fibre system to detect irritants and maintain homeostasis. The dermal component of this fibre network has been well characterized and fibres are known to extend throughout the viable epidermis as free nerve endings. To date, this epidermal component remains poorly characterized. We have visualized human volar forearm epidermal nerve fibres by laser-scanning confocal microscopy using the pan-neuronal marker, protein gene-product 9.5 and specific antibodies to substance P. calcitonin gene-related peptide and nerve growth factor. In addition to the varicose free nerve endings, there is a 3-D fibre network in normal human epidermis, with frequent branching of fibres. Branching can be seen to converge on a central trunk apparently extending to the dermis. Thin unmyelinated fibres can be seen in all layers of the viable epidermis. Substance P staining is rarely observed and is much less intense than the protein gene-product 9.5 staining. Calcitonin gene-related peptide and nerve growth factor were not detected in volar forearm epidermis by this method. Pretreatment of the skin in vivo with the neuropharmacological agent, capsaicin, resulted in loss of epidermal fibre staining indicating that these are sensory fibres of the primary C-afferent type. Epidermal innervation in racial and ethnic skin types was also assessed. No apparent difference in innervation was observed between European caucasian and Japanese/Chinese skin at the architectural or biochemical level, i.e. the presence, properties and biochemical content of fibres was similar in all cases tested.