A plant-based diet can provide an ample supply of all the nutrients needed for optimal health. But whether you’re a vegetarian, vegan, or meat-eater, a healthy body requires a balanced and varied diet that includes all the necessary nutrients.
HEALTH
The advantages of a plant-based diet
Numerous studies have shown the preventive potential of following a plant-based diet. As a result, plant-based eating is increasingly recommended by scientists and nutrition societies around the world as a healthy diet that, if followed on an ongoing basis, can reduce the risk of many lifestyle diseases.
A vegan diet offers great variety
Plant-based diets can vary greatly in their composition. While an exclusively plant-based diet excludes all animal-based products, the range of foods available is still huge. A plant-based diet is considered particularly healthy if it is based mainly on vegetables, fruits, legumes, and whole grains, as well as nuts and seeds.
Nutrient intake of vegans
The consumption patterns of people who follow a plant-based diet are usually closer to the recommended daily amounts for the intake of protein, carbohydrates, and fat than for people who follow a conventional diet. In addition, the intake of dietary fibre, beta-carotene (provitamin A), and vitamins C and E, as well as biotin and magnesium, is often higher in a purely plant-based diet. Other nutrients that people eating a plant-based diet need to pay special attention to include vitamin B12, calcium, zinc, and omega-3 fatty acids, as well as iodine, iron, and vitamin D (which the general population often also lacks in sufficient amounts).1 Neither a conventional diet nor a vegan/vegetarian diet automatically protects against deficiencies, but, when properly planned to include all essential nutrients, a whole-food plant-based diet is beneficial to your health.
Plant-based Nutrients
Prioritize plant-based foods
When it comes to healthy eating, international health experts agree that plant-based foods are preferable, while diets with a high proportion of animal foods are considered unfavourable. In 2015, the World Health Organisation (WHO) classified processed meat as a Group 1 carcinogen because there is sufficient evidence from epidemiological studies that foods such as bacon, sausage, and ham cause cancer. In addition, red meat has been classified as a Group 2A carcinogen, meaning that foods such as beef, veal, and pork are likely to cause cancer.2
Milk has come under criticism
Milk is also increasingly coming under scrutiny. A review of several cohort studies found that dairy consumption can increase the risk of prostate cancer (the most common cancer in men) by 3-9%.3 A different analysis, based on a sample size of over 500,000 women, found that women consuming 750 g or more milk per day had a higher risk of ovarian cancer than women with low milk consumption (250 g of milk per day or less).4 This carcinogenic potential is supported by a recent study involving more than 52,000 women. The results show that women who consume 60-80 ml (about half a cup) of cow’s milk per day had a 30% higher risk of developing breast cancer.5
A vegan diet is suitable for all stages of life
More and more nutrition societies, including the US Academy of Nutrition and Dietetics (the world’s largest association of nutrition professionals), are recognising a plant-based diet as nutritionally appropriate. The academy’s position paper states that a well-planned vegan diet is in line with current dietary recommendations and is suitable for any stage of life, including pregnancy, lactation, childhood, and adolescence.6 The Canadian and Australian nutrition societies both agree.7 8
Lower risk of cardiovascular disease on a plant-based diet
Various studies show that a plant-based diet can have a positive effect on health. One such study is the Oxford Vegetarian Study, based on a sample of around 11,000 participants, 6,000 of whom were vegetarians (including 10% vegans). The study showed that blood levels of total and LDL cholesterol rose with increasing consumption of animal foods. Calculations based on the study’s results showed that, compared to meat-eaters, the risk of developing cardiovascular disease was 24% lower in long-term vegetarians and as much as 57% lower in long-term vegans. The risk of dying from cardiovascular diseases also rose with increasing consumption of meat, cheese, eggs, and animal-based fats. Participants who did not eat meat had a 20% lower overall mortality than the meat-eaters.9 10
The BMI of vegans is usually lower
An evaluation of the EPIC-Oxford study (European Prospective Investigation into Cancer and Nutrition), which involved almost 38,000 participants, showed that the BMI (body mass index) of vegans is significantly lower than that of meat eaters.11 This is also confirmed by the results of the Adventist Health Study, based on a sample of over 22,000 men and 38,000 women. In this study, the average BMI of vegans was 23.6 kg/m², which is within the range for normal weight, whereas the average BMI of people following a conventional diet was 28.8 kg/m², which puts people into the “overweight” category.12 The preventive and therapeutic potential of plant-based diets for those who are overweight or obese has also been confirmed by a recent study carried out by the Max Planck Institute for Human Cognitive and Brain Sciences.13
Lower risk of type 2 diabetes on a vegan diet
In addition to the generally healthier lifestyle of many vegans, their increased intake of dietary fibre and lower intake of high-fat and high-protein foods (compared to the general population) are considered to be the main reasons for their lower BMI.14 On average, people following a conventional diet consume too much protein and saturated fatty acids of animal origin, especially in industrialised nations. After the data of the Adventist Health Study was adjusted for factors such as age, education, income, physical activity, alcohol consumption, and BMI, the results also showed that those eating a plant-based diet had the lowest risk of developing type 2 diabetes.15
A plant-based diet may have protective function against cancer
A further evaluation of the Adventist Health Study also showed that vegans have a 16% lower risk of cancer in general and a 34% lower risk of women-specific cancers such as breast cancer or ovarian cancer. In their conclusion, the researchers thus explicitly highlight the potentially protective function of a plant-based diet against cancer compared to other diets.16
A balanced plant-based diet offers numerous health benefits
- A balanced plant-based diet is in line with current dietary recommendations and constitutes a healthy diet to follow on an ongoing basis.
- Vegans are usually closer to the recommended daily amounts for protein, carbohydrate, and fat intake. In addition, they have a higher intake of dietary fibre, beta-carotene, vitamins C and E, as well as biotin and magnesium, than people who follow a conventional diet.
- Their high-fibre diet presumably leads to a lower BMI in vegans than in people following a mixed diet. Consequently, a shift to plant-based eating can also be used to treat those who are overweight or obese.
- A vegan diet reduces the risk of cardiovascular diseases, type 2 diabetes, and certain cancers.
Other factors that influence health, including physical activity and the consumption of tobacco and alcohol, as well as socio-demographic data such as education level and income, should not be ignored. Nevertheless, studies show that a plant-based diet provides numerous health benefits, independent of these factors.
A paradigm shift in health care through VegMed
Although numerous studies on plant-based nutrition have been published in recent years, the number of studies is still low compared to other areas. In particular, more studies are needed on the effects of plant-based diets on pregnant or breastfeeding people, as well as on children, adolescents, and athletes.
The increasing interest in a plant-based diet requires not only a significant expansion of the scientific examination, but also competent guidance from the media and those who work in the health sector. VegMed, a congress initiated by ProVeg, is pursuing such a paradigm shift in health care. The only event of its kind in Europe, VegMed focuses on medicine and vegan/vegetarian nutrition and is aimed at doctors as well as students and other health professionals who focus on nutrition. The aim of VegMed is the scientific establishment and use of plant-based nutrition in medicine and society.
References
- Weder S., C. Schaefer, M. Keller (2018): The Gießen vegan food pyramid. Ernährungsumschau 2018; 65(8), p. 134–43, doi: 10.4455/eu.2018.031.
- WHO (2015): Q&A on the carcinogenicity of the consumption of red meat and processed meat. Available at: http://www.who.int/features/qa/cancer-red-meat/en/ [15.03.2021].
- Aune, D., D. A. Navarro Rosenblatt, D. S. M. Chan, et al. (2015): Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. The American Journal of Clinical Nutrition 101(1), 87–117, doi:10.3945/ajcn.113.067157.
- Genkinger, J. M., D. J. Hunter, D. Spiegelman, et al. (2006): Dairy products and ovarian cancer: a pooled analysis of 12 cohort studies. Cancer Epidemiol. Biomarkers Prev. 15, p. 364–372
- Fraser, G. E., K. Jaceldo-Siegl, M. Orlich, et al. (2020): Dairy, soy, and risk of breast cancer: those confounded milks. International Journal of Epidemiology 49(5), 1526–1537, doi:10.1093/ije/dyaa007.
- Academy of Nutrition and Dietetics (2016): Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. J Acad Nutr Diet 116: p. 1970–1980.
- Dietitians Association of Australia (2020): Vegan diets: everything you need to know. Verfügbar unter https://daa.asn.au/smart-eating-for-you/smart-eating-fast-facts/healthy-eating/vegan-diets-facts-tips-and-considerations/ [15.03.2021].
- American Dietetic Association (2003): Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets. Journal of the Academy of Nutrition and Dietetics. Volume 103, Issue 6, p. 748–765, doi: https://doi.org/10.1053/jada.2003.50142.
- Appleby, P. N., M. Thorogood, J. I. Mann, et al. (1999): The Oxford Vegetarian Study: an overview. The American Journal of Clinical Nutrition 70(3 Suppl), p. 525S–531S.
- Thorogood, M., J. Mann, P. Appleby, et al. (1994): Risk of death from cancer and ischaemic heart disease in meat and non-meat eaters. BMJ. 308, p. 1667–1670.
- Spencer, E. A., P. N. Appleby, G. K. Davey, et al. (2003): Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans. Int. J. Obes. Relat. Metab. Disord. 27, p.728–734
- Tonstad, S., T. Butler, R. Yan, et al. (2009): Type of vegetarian diet, body weight, and prevalence of type 2 diabetes. Diabetes Care. 32, p.791–796
- Medawar, E., C. Enzenbach, S. Roehr, et al. (2020): Less Animal-Based Food, Better Weight Status: Associations of the Restriction of Animal-Based Product Intake with Body-Mass-Index, Depressive Symptoms and Personality in the General Population. Nutrients 12(5), 1492, doi:10.3390/nu12051492.
- Appleby PN, Thorogood M, Mann JI, Key TJ (1999): The Oxford Vegetarian Study: An overview. Am J Clin Nutr 70 (3 Suppl), p. 525-531
- Tonstad, S., T. Butler, R. Yan, et al. (2009): Type of vegetarian diet, body weight, and prevalence of type 2 diabetes. Diabetes Care. 32, p.791–796
- Tantamango-Bartley, Y., K. Jaceldo-Siegl, J. Fan, et al. (2013): Vegetarian diets and the incidence of cancer in a low-risk population. Cancer Epidemiology, Biomarkers & Prevention. 22(2), p. 286–294, doi:10.1158/1055-9965.EPI-12-1060.