Vegetarian and vegan diets: The background

Vegan and vegetarian diets are in vogue. The proportion of vegetarians worldwide has been growing for decades. Most vegetarians decide to stop eating animals for ethical reasons: Factory farming, animal transportation, cruelty to animals and the slaughter process are - justifiably - off-putting.

A few choose not to eat meat for health reasons. Even those who become vegetarians for ethical reasons see their decision confirmed by the health benefits.

In recent years, many people have taken a further step and become vegan, i.e. they refuse to eat (and in many cases use) animal products. This means that dairy products, eggs and honey are also disappearing from the diet. This is because the use of living animals also involves cruelty to animals.

For this reason, many vegetarians decide to become vegan. Climate change is also a frequently cited argument: forests - including tropical rainforests - are being cleared in favor of animal husbandry and methane, a gas that cattle emit through belching and intestinal winds, contributes to global warming. These arguments cannot be dismissed out of hand. But is a vegetarian or even vegan diet appropriate for humans?

Anatomical features

Humans are commonly referred to as omnivores. Our species is extremely fortunate to be able to eat a wide range of foods. This advantage allows us to find food in a wide variety of climates and seasons. In contrast, there are specialists, such as koala bears, which only eat eucalyptus leaves, or panda bears, which only eat the leaves, shoots and twigs of the bamboo plant.

Our anatomy is also that of a classic omnivore. Although we do not have the fangs of carnivores, we also do not have the huge molars of pure herbivores. The fibrous material of plants - especially wild plants - is not easy to grind and requires long chewing and grinding movements.

When humans learned to make fire and use it for cooking, eating both plants and meat became easier. Our jaws became smaller. Cooking allowed humans to consume more calories in less time.

The pH of our stomach is more like that of dogs and lions than that of a goat, so it is that of a carnivore. Species that eat meat have a greater risk of becoming infected with harmful microorganisms than herbivores.

An acidic stomach kills most unwanted microbes. With its long small intestine and relatively short large intestine, our digestive tract is also that of an omnivore. The cell walls of plants contain a carbohydrate called cellulose. No higher animal has the enzymes necessary to break down cellulose. Only microorganisms in the large intestine can do this. A diet consisting exclusively of raw plant material requires a long large intestine in which the microflora have plenty of time to break down cellulose. A gorilla has such a Intestine, we humans do not.

The "Expensive Tissue Hypothesis" states that it is not possible for an organism to have both an energy-hungry intestine and an energy-hungry brain. The human brain, which makes up only about 2 percent of our body weight, consumes about 20 percent of the available energy.

By comparison, the brain of a chimpanzee costs it only 9 percent. Its digestive tract, however, requires up to 25 percent of the available energy. No animal can maintain both an expensive brain and an expensive digestive tract. You couldn't eat that many calories.

Vegan/vegetarian: healthy in terms of nutrients?

Just because we could use a wide range of different foods doesn't necessarily mean we have to eat them all. As long as a vegetarian or vegan diet provides all the nutrients we need, there is no reason to eat animals or animal foods. But does a vegan diet in particular provide all the nutrients?

A complete diet must contain all macronutrients (protein, fat and carbohydrates) as well as certain micronutrients (vitamins, minerals and phytochemicals). Every food - with the exception of most fats - contains all macronutrients.

Protein

Not all macronutrients are equal. There are four reasons why animal protein is superior to plant proteins:

1. Animal protein is highly bioavailable in the human body.
2. It is rich in nutrients.
3. Protein from animal sources contains a higher content of essential amino acids than plant protein.
4. Animal proteins contain higher levels of sulphur-containing amino acids, which are crucial for many aspects of physiological function.

It is not just how much protein a food contains, but also the composition of that protein. The digestible essential amino acid score (DIAAS) is a scientifically validated system for assessing the amino acid profile and bioavailability of dietary proteins.

On the DIAAS scale, animal proteins consistently rank higher than plant proteins in terms of their amino acid profile and bioavailability. On the DIAAS scale, higher scores represent robust amino acid values and high bioavailability, while lower scores represent the opposite. For example, the DIAAS score for eggs is 1.13, beef is 1.10 and peanut butter is only 0.46.

Beta-alanine is a non-essential amino acid that is the precursor to carnosine, a protein molecule required for optimal muscle and brain function. Beta-alanine is found in meat, poultry and fish. A small study found that vegetarians and vegans have 50 percent less carnosine in their muscles compared to omnivores, which may affect strength, fitness and healthy aging.

Taurine is a non-essential amino acid that is synthesized with the participation of vitamin B6 from the essential amino acids cysteine and methionine. So although you don't necessarily have to eat foods containing taurine to have taurine, cysteine and methionine do. It is important for the functioning of the cardiovascular and skeletal muscles and stabilizes cell membranes. It has been shown that vegans have low taurine levels, probably because the underlying essential amino acids are not available in sufficient quantities.

Fats

There are two essential fatty acids that the body cannot synthesize and must therefore be obtained from food. These are the polyunsaturated omega-3 and omega-6 fats. Although there are plant-based omega-3 fats (contained in flax, hemp and chia seeds, walnuts and pumpkin seeds, for example), these are short-chain fats. However, for the health of our cell membranes and especially for nerve cells, for the production of hormones and hormone-like molecules, we need long-chain omega-3 fatty acids (EPA and DHA), which the body can produce from plant-based omega-3.

However, this conversion is not only inefficient, but also easily unbalanced. As a rule, only 5 to 9 percent of plant-based omega-3 fats can be converted. Animal foods - especially fatty sea fish, but also meat and dairy products from pasture farming - already contain ready-made, long-chain omega-3 fatty acids that can be used as they are.

Vegetarians can increase the proportion of long-chain omega-3 fatty acids by eating "omega-3 eggs". This involves adding omega-3-containing grains such as linseed to chicken feed. Nevertheless, vegetarians and especially vegans should supplement EPA and DHA.We can recommend our fish oil capsules with omega 3.

Carbohydrates

Vegetarian diets often contain less protein but more carbohydrates. Vegans cannot avoid an increased carbohydrate intake, as their protein sources are usually also linked to carbohydrates: Grains, legumes and nuts contain protein but also carbohydrates.

While animal protein contains all the essential amino acids and is therefore "complete protein", vegans have to combine grains with legumes to cover all the essential amino acids. This results in increased carbohydrate intake for many vegetarians and all vegans, which can have an unfavorable effect on blood sugar levels.

Micronutrients

Just because a diet is vegetarian does not automatically make it healthy. Most vegetarians and vegans know this, inform themselves comprehensively and make their diet as varied and nutritious as possible. Nevertheless, especially without supplementation, there are often deficiencies in certain micronutrients, particularly those found primarily in animal proteins.

Vitamin B12 is essential for the formation of red blood cells, the cardiovascular and nervous systems and is found almost exclusively in animal proteins, with the exception of a certain type of seaweed and wild mushrooms. B12 deficiency is common worldwide, especially among vegetarians and vegans who consume little animal protein. Well-informed vegans are aware of this and therefore either buy foods that have been artificially enriched with B12 or take a B12 supplement, such as For example, Vita B12 from Arktis Biopharma.

Iron is required for the formation of red blood cells, nerve function and other physiological processes. Heme iron is the form of iron found exclusively in animal protein. This type of iron is easily absorbed and is quickly available to the body. Non-haem iron, as found in cereals, beans, vegetables, nuts and seeds, on the other hand, is much less easily absorbed by the human body. Iron deficiency is widespread among vegetarians and vegans, as these diets do not provide any heme iron. In women, iron is lost with every menstrual period, especially if the bleeding is heavy. Vegetarians and vegans should definitely have their iron levels checked regularly.

Iodine is needed for the production of thyroid hormones. As the best sources of iodine are of animal origin, vegetarians, and especially vegans, are often found to have low iodine levels. Regular consumption of seaweed and iodized salt can help here.

Zinc is crucial for cell growth and division, wound healing, immune function and the nervous system. Foods of animal origin, such as oysters, red meat, beef liver and poultry, contain bioavailable zinc. Meatless diets are associated with low zinc status.

Healthy on a vegetarian or vegan diet?

Physiologically, we are omnivores. A balanced omnivorous diet consisting of real foods provides the human body with everything it needs. The omnivorous diet is (still) the most common form of human nutrition - but we are not healthy because we increasingly rely on mass-produced and highly processed industrial foods.

Many vegetarians and vegans are much better informed about our nutritional needs than the average consumer and go to great lengths to include all the essential nutrients in their diet. Nevertheless, vegans in particular cannot avoid supplementation. Suitable products that we recommend are amino acids (e.g. Arktiamin) omega-3 fatty acids (e.g. Lindaren Omega-3-D3-Plus for vegetarians who eat fish), vitamin B12 and Arktibiotic Premium

If you would like to learn more about this topic, we recommend listening to episode no. 102 of Julia Gruber's Darmglück podcast, in which she talks to biologist and nutritionist Julia Tulipan about vegan and vegetarian diets.


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