Excluding meat and animal products from your diet can bring health benefits, but you have to follow a few rules. A closer look.
Nearly 85,000 Swiss people claim to be vegan, according to a Swissveg survey conducted in early 2020. Still on society’s fringes just 10 or 15 years ago, veganism is becoming increasingly popular. Three-quarters of followers of the vegan diet live in German-speaking Switzerland and are women. The same study found that more broadly 5.1% of the Swiss population says that they are vegetarian. Veganism is a philosophy whose proponents reject any form of exploitation of animals and therefore abstain from all products derived from animals (leather, wool, silk, etc.). In terms of food, this means excluding meat, fish, eggs, dairy products and honey, and instead eating fruits and vegetables. A diet rich in plant-based foods features a number of advantages. It provides the body with high amounts of fibre, vitamins (B1, B6, C) and useful minerals.
A large study conducted by the Swiss Federal Food Commission (COFA) in 2018 found that a diet rich in plant-based foods, combined with low amounts of saturated fats and the absence of meat, could reduce the risk of non-communicable diseases such as type 2 diabetes, cardiovascular disease and certain forms of cancer.
“Some patients practise veganism for its potential curative virtues, especially in oncology,” says Muriel Lafaille Paclet, a dietician and chief of the CHUV’s Service of Endocrinology, Diabetes and Metabolism. “However, a dietician should guide them,” she warns.
While a meat-free diet offers health benefits, it also has its downsides. Excluding animal-based products may cause insufficient protein intake. Plant-based proteins provide a lower diversity of amino acids and are not absorbed as easily as animal proteins. But proteins are important because they contribute to the growth and development of muscles. Calorie intake is also lower with a vegetarian diet. “Often rich in fibre and water, vegetable take up a lot of space in the stomach. The person feels full, but the food is not densely concentrated. This can result in malnutrition that prevents proper growth and cognitive development,” says Nicoletta Bianchi, deputy chief dietician at the CHUV’s Dietetics Unit. Another risk is deficiency of vitamin B12, which comes almost exclusively from animal products. Excluding dairy products from the diet removes a significant source of calcium intake. Although many vegetables contain calcium, they must be chosen carefully because foods high in oxalates can interfere with its effect. Calcium is essential for children in achieving their optimal bone density, and for adults, especially older ones, in strengthening their bones and teeth. Vitamin D, found in fatty fish and eggs, can also be lacking from a vegan diet. In addition, vegans may not get enough long chain omega-3s. Contained in fish, these compounds have an anti-inflammatory action and support cognitive function. Flaxseed, walnuts and canola oil are sources of omega-3s, but their shorter chains make them less effective. Lastly, veganism can be associated with a zinc deficiency. Signs of this include poor wound healing, brittle nails, hair loss, recurrent diarrhoea or stunted growth.
The vegan diet can lead to deficiencies at any age, but vulnerable population groups will feel it more than others. In young people in particular. “Teenagers are growing fast. Vegan teenagers may have a lower than normal body mass index (BMI). As a result, they may not reach their genetic potential for growth if they have a deficient diet,” Nicoletta Bianchi warns. In fact, the younger a child adopts a vegan diet, the higher the risk of malnutrition and repercussions on his growth and neurological development. This is particularly true for teenage girls. “A vegan diet rarely provides an adequate iron intake. But iron requirements increase when young women begin to menstruate,” says Laëtitia-Marie Petit, a paediatric gastroenterologist at the Department of Woman, Child and Adolescent Medicine at Geneva University Hospitals (HUG)*. Pregnant and breastfeeding women have specific needs that can also affect her health and that of her baby. For example, if a breastfeeding mother is deficient in vitamin B12, the child may show muscle hypotonia, have serious and irreversible neuropsychological disorders. Another category of the population is likely to experience unpleasant consequences of a diet without animal products. “Older people need more protein to compensate for the loss of muscle mass. People don’t absorb nutrients as well as they get older and may have problems chewing. But some plants have fibres that are hard to chew,” says Muriel Lafaille Paclet, from the Service of Endocrinology, Diabetes and Metabolism at CHUV.
To compensate for these deficiencies, you should up your consumption of plant-based foods rich in useful nutrients (see insets). The sun’s ultraviolet rays can also be beneficial. They synthesise vitamin D generally cover our required intake. Spending 10 minutes a day in the sun is believed to supplement intake from plant-based foods. “Young children are protected in this respect because vitamin D intake is systematic until the age of 3,” Nicoletta Bianchi explains. Eating vegetables can also be supplemented with micronutrients (see inset). “All toddlers should be given supplements. Children need to be monitored with blood tests from the age of 1,” says Laëtitia-Marie Petit from the Department of Woman, Child and Adolescent Medicine at HUG. However, little data is available on whether taking supplements as a child reduces disease in adulthood, the expert says.
“Some patients practise veganism for its potential curative virtues. However, a dietician should guide them,” warns Muriel Lafaille Paclet, a dietician and chief of the CHUV’s Service of Endocrinology, Diabetes and Metabolism.
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* Senior physician with the Unit of Paediatric Gastroenterology, Hepatology and Nutrition, Service of Medical Specialities, Department of Woman, Child and Adolescent Medicine at Geneva University Hospitals
1. Protein can found in soy, chickpeas, lentils, nuts, or whole grains. You should combine several of these foods to improve nutritional quality.
2. For adequate calcium (without the negative effects of oxalates), you should choose foods such as broccoli, kale or ornamental cabbage, and certain mineral waters.
3. To improve the absorption of the iron contained specifically in legumes and whole grains, you should combine them with a source of vitamin C (bell pepper, broccoli, kiwi, orange, etc.). But you’re advised to avoid drinking black tea or coffee right after, which reduce the absorption of iron.
4. Brewer’s yeast and wheat germ supplement zinc intake.
5. You should prefer flaxseed, walnut and canola oils, as they are rich in omega-3.
