Consumer preferences for a nettle (‘Urtica Dioica’) based food supplement: a choice-based conjoint experiment with UK consumers

Alongside increasing consumer demand for plant-based supplements to support health and nutrition (1) there is growing interest in exploring the potential of underutilised edible plants such as nettles (‘Urtica Dioica’) owing to their nutritional and environmental benefits (2) . Traditionally used for health and nutrition, nettles contain vitamins and minerals, protecting against cardiovascular disease, allergies and rhematic conditions (2, 3) and are therefore of interest to the supplement market. However, there is inadequate understanding of consumer preferences for products and supplements containing nettles. This pre-registered study aimed to explore the effect of varying levels of five attributes, namely product description, traditional use, nutrition, price and sustainability on consumer decisions for a nettle-based powder supplement amongst UK consumers. We hypothesised that price would have the highest relative importance scores overall. The final sample comprised 605 participants (Female = 49.4%; Age, M= 42.63 years, SD = 16.00) who completed an online choice-based conjoint (CBC) task. First, participants were presented with information about nettles and the powder supplement (e.g., edible native plant, spray drying process used to develop the powder) alongside a photo of the powder. Second, participants were randomly assigned to an independent block of choice sets to explore preferences for the nettle-based powder supplement. Each set consisted of three combined product profiles which included the five attribute categories but varied by attribute level. Participants were asked to select their preferred combination of characteristics. Preferences for carrier ingredients and familiarity with nettle consumption were also explored. Supporting our hypothesis, price was the most influential attribute (44.3%), followed by nutritional claim (30.8%) and product description (11.8%). Whereas sustainability (7.7%) and traditional uses (5.4%) were the least influential attributes of nettle-based supplements. The conjoint model fit was strong, with a McFadden’s pseudo-R2. = 69.7%. Part-worth utilities showed a preference for lower price points, and nutritional claims based on protein and fibre content were more appealing to participants. Across four carrier ingredient choices (Pea protein, potato starch, maltodextrin and gum arabic), pea protein was most preferred by consumers and gum arabic was least preferred. Choices were primarily based on perceived naturalness, familiarity, and healthiness. UK consumers are mostly unfamiliar with nettle consumption, potentially accounting for the lack of appeal of messaging around traditional use and sustainability in this study. Instead, consumers prefer general and likely familiar (or trending) nutritional claims. A strong preference for pea protein as a carrier ingredient was found and therefore pairing nettles as an unfamiliar ingredient with a carrier which has high consumer appeal may serve to increase consumer interest in a nettle-based supplement.