The impact of a vegetarian diet on human health

1. Types of Vegetarian Diets

The vegetarian diet includes various forms that differ in the range of excluded foods:

1. Lacto-vegetarianism – allows the consumption of dairy products but excludes eggs and meat.
2. Lacto-ovo-vegetarianism – allows dairy products and eggs.
3. Veganism – eliminates all animal-derived products.
4. Semi-vegetarianism (flexitarianism) – reduces but does not completely eliminate meat.

Each of these variants carries specific health consequences.

2. Health Benefits of a Vegetarian Diet

1. Cardiovascular Diseases

As shown in studies described in “Dieta roślinna na co dzień” by Julita Bator (2020), a plant-based diet contributes to lowering LDL cholesterol levels, reducing blood pressure, and decreasing the risk of atherosclerosis and heart attacks. Vegetarians often have a lower body mass index (BMI), which also benefits heart health.

2. Type 2 Diabetes

According to “Żywienie człowieka zdrowego i chorego” edited by Jan Gawęcki (2010), a vegetarian diet rich in fiber, whole grains, and vegetables helps stabilize blood glucose levels and improves tissue sensitivity to insulin.

3. Cancer

The book “Żywienie człowieka. Podstawy nauki o żywieniu” by Stanisław Berger (2012) points out that people following a vegetarian diet have a lower risk of developing certain types of cancer, particularly colorectal, stomach, and breast cancer. This effect is attributed to the high intake of antioxidants, phytochemicals, and fiber.

4. Obesity

Vegetarians generally have a lower body weight. This results from the lower caloric content of meals, high fiber content, and greater volume of plant-based foods consumed.

3. Potential Risks Associated with a Vegetarian Diet

If poorly balanced, a vegetarian diet may lead to nutrient deficiencies. The most common concerns include:

1. Vitamin B12 – mainly found in animal products. Prolonged deficiency can lead to megaloblastic anemia and neurological disorders.
2. Iron – plant sources of iron have lower bioavailability.
3. Calcium – particularly in vegan diets, deficiency may occur, increasing the risk of osteoporosis.
4. Omega-3 fatty acids (DHA, EPA) – deficiency may negatively affect the nervous and cardiovascular systems.

For these reasons, as Hanna Stolińska writes in “Wege. Dieta roślinna w praktyce” (2019), careful meal planning and often supplementation (e.g., B12) are necessary.

4. Vegetarian Diet at Different Stages of Life

The literature emphasizes that a well-composed vegetarian diet is safe at every stage of life: from childhood to old age, including pregnancy and lactation (“Żywienie człowieka. Podstawy nauki o żywieniu”, Berger 2012). The condition is proper meal planning.

A vegetarian diet can bring significant health benefits, especially in the prevention of lifestyle diseases, provided it is properly balanced. People following this dietary model should pay attention to the intake of key nutrients and, if necessary, use supplements.