Identifying healthy and unhealthy dietary patterns among Swiss vegan adults
Currently, a diet quality score for vegans does not exist in Switzerland and neither internationally, but such a tool is urgently needed for research purposes and clinical practice.
Factsheet
- Schools involved School of Health Professions
- Institute(s) Nutrition and Dietetics
- Funding organisation Others
- Duration (planned) 01.06.2021 - 31.05.2022
- Head of project Prof. Dr. Leonie-Helen Bogl
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Project staff
Dr. Joyce Haddad
Prof. Dr. Klazine Van der Horst
Natalie Sara Bez - Partner Fördergeber: Stiftung zur Förderung der Ernährungsforschung in der Schweiz
Situation
Veganism has recently gained popularity in Switzerland and elsewhere. Health, climate change, animal welfare and religion are among the most common reasons for adopting a vegan lifestyle. The EAT-Lancet Commission proposed a global shift toward a sustainable and healthy diet based on the decrease in meat consumption and an increase in vegetables. While all reductions in meat deliver climate benefits, vegan diets are the most environmentally sustainable diets as they have the lowest greenhouse gas emissions. Vegans have a high intake of plant-based foods, such as fruits, vegetables, grains, legumes, nuts, vegetable oils but they abstain from all animal products including honey and animal-derived ingredients used in food production, such as gelatin. However, they may also have a higher risk of nutrient deficiencies. Previous studies on vegans have not considered diet quality but rather analyzed vegans as one homogenous group, comparing their nutrition and health status with those of vegetarians and omnivores. Recent large-scale prospective cohort studies suggest that not all plant-based diets are equal, and they distinguish between healthy and unhealthy plant-based diets. The major limitation of these large cohort studies is that they have not studied vegans but instead looked at plant-based food intake as a continuum among mostly omnivores; thus, it is unclear to what extent this applies to vegans.
Course of action
Our primary aim is to examine the heterogeneity of vegan diets in Switzerland by identifying dietary patterns that explain the variation in key nutrients and nutritional status among vegans. It is intended to reach this overall aim by means of the following two specific aims: a) we will develop an a priori-defined diet quality score for vegans (DQS-V) with special attention to potentially critical nutrients among vegans b) we will employ reduced rank regression (RRR) to identify combinations of food groups that explain as much variation as possible in nutrient intakes and blood biomarkers For this study, we will draw upon a dataset that has already been collected by the Human Nutrition Laboratory, ETH Zurich and closely collaborate with Dr Herter-Aeberli, Isabelle. The dataset includes 206 healthy adult female and male subjects between the age of 18 and 50 years, who have been following either a vegan (n=53), ovo-lacto vegetarian (n=53) or omnivorous (n=100) diet for at least 1 year prior to the study.
Result
The development of the DQS-V is based on the Swiss nutritional recommendations for a vegan diet, which we published for the first time. In a sample of 52 Swiss adults, the DQS-V ranged between 15 and 80 points, with an average of 48.9 out of a possible total of 100 points. Many participants achieved the recommended intake of vegetables, vitamin C-rich vegetables, fruit, omega-3-rich nuts, fats, oils and iodised salt. On the other hand, the consumption of green leafy vegetables, vitamin C-rich fruits, whole grains, legumes, nuts and seeds (including selenium-rich nuts), low-energy drinks and calcium-fortified foods was generally rather low. Sweet, salty and fried foods as well as alcohol were consumed more frequently than recommended. The DQS-V was positively associated with the intake of dietary fibre, polyunsaturated fatty acids, potassium, zinc and phosphorus, and negatively associated with the intake of vitamin B12 and niacin. PCA identified two dietary patterns: a ‘refined grains and sweets’ pattern, which was negatively correlated with both DQS-V and beta-carotene and vitamin C status, and a ‘whole grains and nuts’ pattern, which showed a positive correlation with DQS-V.
