Think Twice: Are Vegan And Vegetarian Diets Healthy?

Vegetarian and vegan diets are becoming increasingly popular, especially among the younger population. While some people adopt these diets for ethical or environmental reasons, many believe that they are healthier than omnivorous diets. However, it is important to consider the potential drawbacks of vegetarian and vegan diets before making the switch.

Vegetarian and vegan diets can be deficient in certain nutrients that are crucial for physiological function. For example, these diets often lack vitamin B12, which is essential for DNA synthesis and nerve function. They may also be low in calcium, iron, zinc, and fat-soluble vitamins like vitamins A and D. As a result, vegetarians and vegans are at a higher risk of developing various health issues, including neurological and psychiatric problems, cancer, and bone fractures.

In addition, vegetarian and vegan diets can be restrictive and may not provide all the nutrients needed for optimal health, especially for vulnerable populations such as children, adolescents, pregnant and breastfeeding women, and fetal outcomes in strict vegan mothers. It is important for individuals following these diets to carefully plan their meals and consider supplementing with certain nutrients to avoid potential deficiencies.

Furthermore, the health benefits associated with vegetarian and vegan diets may be due to other lifestyle factors such as physical activity, avoidance of tobacco and alcohol, and socioeconomic status rather than the diets themselves.

Overall, while vegetarian and vegan diets can be healthy when carefully planned, they may also pose certain health risks due to nutrient deficiencies. It is important for individuals to carefully consider their dietary choices and ensure they are meeting their nutritional needs to maintain optimal health.

Vegans and vegetarians are prone to deficiencies in B12, calcium, iron, zinc, and vitamins A and D

Vegetarians and vegans are at risk of developing deficiencies in B12, calcium, iron, zinc, and vitamins A and D.

Vitamin B12 is found in meat, poultry, and eggs, and a lack of it can cause neurological and haematological problems. Vitamin B12 deficiency is especially common in vegetarians and vegans, with studies showing that 68% of vegetarians and 83% of vegans are B12 deficient, compared to just 5% of omnivores. Vitamin B12 is important for the synthesis of DNA and red blood cells, as well as the production of the myelin sheath around nerves and the conduction of nerve impulses. B12 deficiency can cause neurological and psychiatric problems, and the effects on children are especially alarming, with links to lower scores in tests measuring fluid intelligence, spatial ability, and short-term memory.

Calcium intake is similar in vegetarians and omnivores, but much lower in vegans. Vegans are often deficient in calcium, and the bioavailability of calcium from plant foods is affected by their levels of oxalate and phytate, which inhibit calcium absorption. Studies have shown that vegans have a greater incidence of overall fracture, leg fractures, and fractures in other major sites.

Iron intake is similar in vegetarians and omnivores, but the bioavailability of iron from plant-based foods is much lower. Non-heme iron, which is found in plant foods, is less bioavailable and is inhibited by whole grains, legumes, and nuts. This explains why vegetarians and vegans have lower iron stores than omnivores.

Zinc is found in meat, dairy, and eggs, and while some plant foods contain zinc, their bioavailability is poor due to the presence of phytate, which inhibits zinc absorption. Zinc deficiency may be associated with mental health problems, dermatitis, diarrhoea, and alopecia, all of which are more prevalent among vegans.

Vitamin D is found in fatty fish, eggs, and dairy products, and vegans are at risk of vitamin D deficiency. Vitamin D is important for calcium metabolism, immune function, and reducing inflammation, and deficiency is linked to an increased risk of osteoporosis and fracture.

Vitamin A is found in liver, eggs, and dairy products, and while plant foods contain beta-carotene, the precursor to vitamin A, the conversion is inefficient.

Vegan diets are almost completely devoid of certain nutrients crucial for physiological function

Vegan diets are often missing several nutrients that are crucial for physiological function. These include vitamin B12, calcium, iron, zinc, long-chain fatty acids EPA and DHA, and fat-soluble vitamins A and D.

Vitamin B12 is found primarily in animal products, and a deficiency can cause neurological and psychiatric problems. Vegans can obtain B12 from fortified foods and supplements, but these sources may not be as effective as animal-based sources.

Calcium intake is also lower in vegans, as dairy products are a significant source of calcium for non-vegans. While leafy greens like spinach and kale contain calcium, the calcium in these foods is not easily absorbed during digestion.

Iron is also more difficult for vegans to obtain, as plant-based sources of iron have lower bioavailability than animal-based sources. This can lead to lower iron stores and absorption rates for vegans and vegetarians.

Zinc is another nutrient that vegans may not get enough of, as many plant foods that contain zinc also contain phytate, which inhibits zinc absorption.

Long-chain omega-3 fatty acids EPA and DHA are found primarily in marine sources, so vegans may need to take a supplement to obtain these fatty acids.

Finally, vitamins A and D are mostly found in animal products, and vegans may need to supplement their diet with these vitamins as well.

Overall, while it is possible to obtain these nutrients on a vegan diet through careful planning and supplementation, it is more challenging to meet nutrient needs without the inclusion of animal products.

Vegetarians and vegans are at risk of multiple nutrient deficiencies

Vitamin B12 is found primarily in animal products such as meat, poultry, and eggs. Vegans and vegetarians often have low levels of vitamin B12, which can lead to neurological and psychiatric problems. Low B12 intake has also been linked to an increased risk of certain cancers.

Iron deficiency is common among vegetarians and vegans because the iron in plant-based foods (non-heme iron) is not as easily absorbed as the iron in animal products (heme iron). This can lead to fatigue, impaired immune function, and developmental delays in children.

Calcium deficiency is also a concern for vegans, as plant-based sources of calcium have lower bioavailability due to the presence of oxalates and phytates, which inhibit calcium absorption. This can increase the risk of osteoporosis and fractures later in life.

Zinc deficiency is another potential issue for vegetarians and vegans, as plant foods that contain zinc also contain phytates, which inhibit zinc absorption. Zinc is important for immune function, cell growth, and wound healing.

In addition to these nutrients, vegetarians and vegans may also be deficient in long-chain omega-3 fatty acids, fat-soluble vitamins A and D, choline, creatine, and taurine. These nutrients are important for various bodily functions, including cognitive development, immune function, and healthy skin and eyesight.

Overall, while it is possible for vegetarians and vegans to obtain adequate nutrition through careful planning and supplementation, they are at a higher risk of nutrient deficiencies compared to those who consume animal products.

Vegan diets can be detrimental to children's health

Vegan diets have become increasingly popular, especially among younger people. While some studies have shown that vegan diets can decrease the risk of cardiometabolic diseases, they have also been linked to adverse health outcomes, including nervous, skeletal, and immune system impairments, hematological disorders, and mental health problems.

The Risks of Vegan Diets for Children

Secondly, vegan diets can lead to deficiencies in key minerals and vitamins, such as vitamin B12, calcium, zinc, vitamin D, and iron. These deficiencies can have serious health consequences, including neurological and haematological problems, impaired bone mineral density, and an increased risk of fractures.

Meeting Nutritional Needs on a Vegan Diet

It is possible for children to meet their nutritional needs on a vegan diet, but it requires careful planning and supplementation. Here are some tips to ensure children on vegan diets get the nutrients they need:

• Include plenty of vegetables, especially dark, leafy greens, to boost calcium intake.
• Opt for plant-based sources of protein like tofu, beans, lentils, and nuts.
• Include healthy fats like nuts, seeds, avocado, and olive oil.
• Fortify the diet with vitamin B12, vitamin D, and calcium supplements, or include vitamin-fortified foods like cereals, milk alternatives, and orange juice.
• Ensure adequate iron intake through iron-fortified cereals and bread, as well as plant-based sources like dried beans, whole grains, and leafy greens.

Vegans and vegetarians are at risk of low iodine intake

Iodine is a trace element that is essential for the production of thyroid hormones. Adequate iodine intake is important to avoid thyroid dysfunction and maintain normal physiological functions of the body.

Iodine Deficiency in Vegans and Vegetarians

Iodine deficiency has re-emerged as a public health problem in women of reproductive age in the USA, Australia, and Europe, including Norway. Vegans and vegetarians have been identified as a group with an increased risk of iodine deficiency in Europe and the US.

A 2011 study in the *Journal of Clinical Endocrinology & Metabolism* found vegans to be at high risk of iodine deficiency. Low iodine levels can force the thyroid to absorb iodine from the blood, which may lead to hypothyroidism. Iodine deficiency during pregnancy or in young children may also impair cognitive development and increase the risk of intellectual disabilities.

A study in Norway, which included 115 vegans, 55 vegetarians, and 35 pescatarians, found that vegans had a median urinary iodine concentration (MUIC) of 43 µg/L, indicating moderate iodine deficiency. Vegetarians and pescatarians had higher UIC compared to vegans, but still fell within the range of mild iodine deficiency.

Sources of Iodine

In Norway, the main dietary sources of iodine are milk, seafood, and eggs. Iodine fortification of table salt is voluntary and at a low level, so it is not a significant source of iodine in the Norwegian diet. Vegans and vegetarians who exclude or restrict intakes of milk, seafood, and eggs may be susceptible to iodine deficiency.

Iodine-containing supplements and macroalgae, such as seaweed, are important sources of iodine for vegans. However, the iodine concentration in macroalgae can vary considerably, and some may contain toxic amounts.

Addressing Iodine Deficiency

Vegans and vegetarians should be aware of the risk of iodine deficiency and take steps to ensure adequate iodine intake. This may include consuming iodine-rich foods, such as seaweed, or taking iodine supplements.

It is important to note that excessive iodine intake can also be harmful, so it is crucial to monitor iodine levels and not exceed the recommended intake.

Frequently asked questions