The COPLANT Study - Research on Plant-Based Nutrition

COPLANT means COhort on PLANT-based diet and is up to this date the largest planned cohort study on plant-based nutrition in all German-speaking countries. From the beginning of 2023, the German Federal Institute for Risk Assessment (BfR), together with the Max Rubner Institute (MRI), the Research Institute for Plant-Based Nutrition (IFPE), and five university partners - Friedrich Schiller University in Jena, Rheinische Friedrich Wilhelms University Bonn, Ruprecht Karl University Heidelberg, University of Regensburg, University of Vienna - will recruit around 6,000 women and men aged 18-69 for the study across Germany. The Thünen Institute is involved in the study to work on the topic of sustainability. The term “plant-based diet” is an expression that has been coined recently, especially within the last years. It defines diets, only containing plant-based components, as there are vegetables, fruits, nuts, seeds, oils, (whole grain) cereals and legumes. Depending on the diet, dairy products, fish, seafood and eggs may be added. The following plant-based diets are the subject of the COPLANT study:

• Vegan (no animal products)
• Vegetarian (no meat and fish, but dairy products and eggs)
• Pescetarian (no meat but fish)

The aim is to gain new insights into the advantages and disadvantages of plant-based forms of nutrition. For example, the study examines which vitamins and minerals are consumed sufficiently and which are neglected. What happens to your metabolism if animal-based foods are completely left out? How does each diet affect body composition and bone health? Do plant-based diets differ from mixed diets in terms of intake of contaminants, residues, or other undesirable substances? In addition, the scientists intend to identify what ecological, social and economic effects the diets are associated with and how sustainable they are.

Finding missing data

Although interest in vegan and vegetarian diets is constantly growing, there is currently little scientifically reliable data on plant-based diets. The results of earlier studies on the subject cannot necessarily be transferred to today's forms of nutrition. For example, the range of vegan foods and meat substitutes, some of which are highly processed and high in sugar, fat and salt, is increasing.

Current larger epidemiological projects in Germany include almost no vegans at all. In addition, the nutritional survey instruments used in these studies are not suitable for plant-based diets. Internationally, only limited data on plant-based diets - especially vegan diets - is available to date. The health classification of these diets in terms of risk prevention and early detection is almost completely impossible at present. Findings on the sustainability effects of different diets are only available in individual aspects, but not within an overall view of all relevant dimensions of health, environment, society and economy.

COPLANT aims to change that, supply missing data and thus enable evidence-based nutritional recommendations for plant-based and sustainable nutrition.

Specifics of data collection

The nutrition of all participants is recorded in detail on different days using a cell-phone based app specially adapted for the study. In contrast to previous studies, the consumption of newly invented vegan and vegetarian foods can also be comprehensively determined. In addition, the study will examine whether the respective diet is accompanied by the intake of heavy metals, mould toxins or other undesirable substances. Nutritional status is measured using biomarkers in blood and urine. Submitting a stool sample makes it possible to investigate associations between the different diets and the microbiota. There are no limitations for pregnant and breastfeeding women in COPLANT. They can also take part in the study. To complete the information taken, aspects relevant to sustainability in nutritional behaviour are analysed too.

Prevention and treatment of common diseases

In order to establish connections between diet and typical widespread diseases such as e.g., type 2 diabetes, cardiovascular diseases and cancer, it is planned to follow up with the study participants after at least 20 years. The collected data can provide valuable insights for new prevention and therapy concepts in the future.

Key data on the course of study

In addition to the detailed nutritional survey collected via the app, basic examination includes measurement of:

• Body composition
• Bone health
• Physical activity

The following biosamples will be taken from all participants:

• Blood tests while fasting
• Urine samples collected over 24 hours
• Stool samples

The following points, among others, will be determined via a questionnaire:

• Specific aspects of the diet, e.g., duration of diet, motivation
• General characteristics, e.g., age, gender, education and occupation
• Health, including general well-being and the presence of medical conditions (e.g., allergies)
• Lifestyle factors, e.g., smoking and physical activity
• Sustainability in relation to nutritional behaviour and lifestyle
• Lifestyle changes caused by the COVID-19 pandemic

COPLANT in figures

• Eight study centres (Federal Institute for Risk Assessment (Berlin), Research Institute for Plant-Based Nutrition (Giessen), Friedrich Schiller University (Jena), Max Rubner Institute (Karlsruhe), Rheinische Friedrich Wilhelms University (Bonn), Ruprecht Karl University Heidelberg, University of Regensburg and University of Vienna)
• Approximately 6,000 subjects aged 18-69 years on a vegan, vegetarian, pescetarian or mixed diet (800 per study centres, 200 per diet).
• 20 year follow-up