Nutrition: Vegetarian and Vegan Diets, What Benefits, What Are the Critical Issues? Interview with Dr. Letizia Astrologo.

#Veganuary January, for some years, has been associated with vegetarian and vegan diets, complete with a dedicated hashtag. We asked some questions to Dr. Letizia Astrologo, nutritionist at UPMC Salvator Mundi International Hospital, to try to shed some light on the ongoing diatribe between "omnivores" and non-omnivores.

Doctor, why do you choose a vegetarian or vegan diet?

Usually, those who decide to approach these diets do so because they are convinced that it is a better choice for their health. Still others do it to respect the dignity of animals, or to protect the environment. The truth is that the scientific community is still uncertain about the harms and benefits of such restrictive diets.

What is the difference between the vegetarian diet and the vegan diet?

The vegan diet excludes all animal foods and derivatives, allowing any food of plant origin, as well as algae, fungi and bacteria (for example, lactic ferments). Vegetarian diets, on the other hand, are many, each with its own peculiarity. The most widespread is the lacto-ovo-vegetarian diet, in which animals are not eaten but derived products are consumed (milk and dairy products, eggs, honey and other bee products), which are instead excluded in the lacto-vegetarian and ovo-vegetarian variants. Then there is the pescetarian diet, the only one in which the direct consumption of the animal is allowed, to move on to the most drastic: the raw food (food is not subjected to heat treatments over 40 ° C); and the fruitarian, in which we eat exclusively fruit, dried fruit and fruit vegetables such as tomatoes, peppers, zucchini and cucumbers.

Do these diets fully cover man's nutritional needs?

Systematically eliminating certain classes of foods from the traditional Mediterranean diet, which provides all the micro and macronutrients necessary for the development and physiological maintenance of the organism (except, of course, pathological metabolic deficits), can make us meet nutritional deficiencies. In some cases, it may help to consume certain foods particularly rich in the necessary micronutrient, or favor specific food combinations. In others, however, the use of supplements is preferable when not necessary to avoid malnutrition and consequent potential development of cardiovascular, gastrointestinal or other disorders.

Can you give us some examples?

Omega 3 fatty acids are polyunsaturated fats essential in maintaining proper triglyceride and cholesterol levels, and for the normal functioning of the heart. They are mainly found in fatty fish, but also in nuts, flaxseeds and their oil and in soybean oil, although with lower bioavailability. Pescetarian diets remedy this deficiency; the others can make use of vegetable supplements derived from algae, or increase the consumption of soy milk or fruit juices, possibly without added sugar, and investigating with a professional if there are any contraindications to the use of soy.

Another point to watch out for in vegetarian and vegan diets is the intake of iron. That present in plant foods is a non-heme type iron, much less usable than the heme contained in foods of animal origin. For this reason, it is necessary to understand that those who follow a vegetarian or vegan diet will have an increased need for iron that must be monitored scrupulously. To avoid incurring a deficiency and increase the bioavailability of iron taken from plant sources, you can soak legumes before consuming them, accompany foods rich in iron with those rich in vitamin C, avoid the consumption of coffee, tea, wine, cocoa and herbal teas near meals.

Some studies show that, especially in vegans, the risk of bone fractures is increased due to calcium and vitamin D deficiencies. In fact, apart from mushrooms, plant-based foods do not contain significant amounts of vitamin D. For this reason, it is advisable to ensure good exposure of the body to sunlight, use calcium waters and favor fortified foods and reduce those rich in oxalic acid (to name just a few: chard, spinach and cocoa). It is understood that, if you encounter deficiencies confirmed by blood samples, it will be necessary to resort to food supplements.

Finally, vitamin B12 is essential for the metabolism of nucleic acids (DNA, RNA) and fatty acids, and for the formation of red blood cells and bone marrow. It is found exclusively in animal products. It is very important to constantly check the levels of homocysteine and methylmalonic acid, and use supplements.

In short, vegetarian or vegan diets are not harmful in themselves, but must be followed under strict control of the nutrition professional who will evaluate the dietary needs, developing specific and complete plans for those who choose them.

To learn about UPMC Salvator Mundi International Hospital's Nutrition service, click HERE.