Vegan Diets: Nutritious Or Malnourishing?

Veganism, a diet that excludes all animal products, has gained popularity in recent years, especially among younger people. While veganism is often promoted as being beneficial to heart health, there are concerns that it may lead to nutritional deficiencies and negative health consequences.

Research has shown that a vegan diet may lead to deficiencies in vitamin B12, omega-3, calcium, zinc, iron, magnesium, and high-quality protein. These deficiencies have been linked to an increased risk of certain cancers, stroke, bone fractures, preterm birth, failure to thrive, and higher rates of depression and anxiety.

However, it is important to note that a well-planned vegan diet can provide all the necessary nutrients and be safe for people of all ages, including children, pregnant and breastfeeding women. To ensure a balanced diet, vegans should focus on including a variety of whole foods such as fruits, vegetables, legumes, nuts, seeds, and fortified plant-based dairy alternatives in their daily meals.

In conclusion, while veganism can be a healthy and ethical choice, it is important to be aware of the potential risks and ensure that the diet is properly balanced and supplemented as needed.

Vegan diets are associated with low intakes of vitamins B2, B3, B12, D, iodine, zinc, calcium, potassium, and selenium

Vegan diets are often associated with a range of health benefits, including a reduced risk of cardiometabolic diseases such as cardiovascular disease, type 2 diabetes, obesity, and non-alcoholic fatty liver disease. However, vegan diets are also associated with low intakes of several vitamins and minerals, including vitamins B2, Niacin (B3), B12, D, iodine, zinc, calcium, potassium, selenium.

Vitamin B12 is found primarily in animal-based foods such as meat, poultry, and eggs, and low vitamin B12 intake is a significant concern for vegans. Vitamin B12 deficiency has been linked to neurological and haematological problems and can increase the risk of certain cancers. Vegans must ensure their vitamin B12 levels are regularly checked and may need to take supplements or consume fortified foods to meet their daily requirements.

Vitamin D and calcium are two other nutrients that vegans may not get enough of. Vitamin D is naturally present in only a few foods, including fatty fish, eggs, and mushrooms, and vegans may not consume enough of these foods to meet their vitamin D requirements. Calcium is also more readily available from dairy products, and while it can be obtained from plant-based sources like leafy greens, beans, and seeds, vegans may need to focus on including these foods in their diet to ensure adequate calcium intake.

Zinc is another nutrient that may be lacking in vegan diets due to its higher bioavailability from animal-based sources. Meat, dairy, and eggs are all good sources of zinc, and while some plant foods like nuts, seeds, and whole grains contain zinc, their bioavailability is lower due to the presence of phytate, which inhibits absorption in the gut.

In addition to zinc, vegans may also have lower intakes of iodine, selenium, and potassium. Iodine and selenium are found in higher concentrations in animal-based foods, and while seaweed is a concentrated source of iodine, its iodine content can vary, and overconsumption may lead to excessive iodine intake.

Overall, while vegan diets can offer health benefits, they may also be associated with low intakes of several important vitamins and minerals. It is crucial for individuals following a vegan diet to be aware of these potential deficiencies and take steps to ensure adequate nutrient intake, such as through supplementation or careful dietary planning.

Vegans are at risk of vitamin B12 deficiency

Vitamin B12 deficiency can cause neurological and haematological problems, including anaemia and nervous system damage. The symptoms of vitamin B12 deficiency may be subtle and are often attributed to stress or other lifestyle factors. Cognitive changes such as depression, memory impairment, confusion, psychosis, and tiredness are common. In addition, vitamin B12 deficiency during pregnancy can lead to adverse fetal outcomes, including developmental anomalies, spontaneous abortions, preeclampsia, and low birth weight.

Vegans are at a particularly high risk of vitamin B12 deficiency due to the exclusion of vitamin B12-rich foods such as meat, poultry, and eggs from their diets. To prevent vitamin B12 deficiency, vegans should either consume fortified foods two to three times a day or take daily or weekly B12 supplements.

Vegans are at risk of calcium deficiency

• Soybeans and foods made from soybeans, such as tofu, tempeh, and natto
• Beans, peas, and lentils
• Nuts, especially almonds and Brazil nuts
• Seeds and their butters, such as tahini and chia seeds
• Certain vegetables and leafy greens, such as spinach, turnip greens, mustard greens, and collard greens
• Fortified foods and drinks, such as plant-based milk, orange juice, and cereals
• Blackstrap molasses

However, the amount of calcium in these plant-based sources is often lower compared to dairy products, and some of these sources, such as vegetables, also contain substances that block the body's ability to absorb calcium. For example, spinach contains oxalic acid, which prevents the body from absorbing most of the calcium it contains.

Research has shown that vegans tend to have lower calcium intakes than vegetarians and meat-eaters, and are at a higher risk of calcium deficiency. Connie Weaver, head of Purdue University's Department of Foods and Nutrition, doubts that many people could follow a strictly vegan diet and get enough calcium. She suggests that in order to get enough calcium, vegans may need to rely on fortified foods or supplements in addition to plant-based sources.

Health Risks of Calcium Deficiency

Calcium deficiency can lead to several health issues, including:

• Osteoporosis: A condition that weakens bones, leading to an increased risk of fractures and other injuries. It affects around 35 million Americans, with women being more susceptible than men.
• Increased risk of certain types of cancer: Low calcium intake has been linked to an increased risk of breast cancer, cervical cancer, and gastrointestinal tract cancers.
• Bone fractures: Vegans have been found to have a higher risk of hip fractures and overall fractures compared to meat-eaters, which may be due to their lower calcium intake and reduced dietary protein intake.
• Pregnancy and fetal outcomes: Vegan mothers may be at risk of vitamin deficiencies, including calcium deficiency, which can lead to small-for-gestational-age infants and low birth weight.
• Mental health issues: Vegans have been found to have a higher prevalence of mental health problems, such as depression and anxiety.

Vegans are at risk of zinc deficiency

Zinc is an essential mineral that plays a crucial role in various physiological functions, including immune function, growth, and development. It is required for the activity of over 300 enzymes and is involved in gene expression, cell division, and protein synthesis. Zinc also plays a vital role in wound healing, DNA synthesis, and the maintenance of the body's antioxidant defence system.

Zinc deficiency can lead to impaired immune function, loss of appetite, growth retardation, hair loss, eye and skin lesions, and hypogonadism in males. It can also cause diarrhoea, delayed sexual maturation, weight loss, taste abnormalities, delayed healing of wounds, and lethargy.

Vegans tend to meet the recommended daily allowance (RDA) for zinc, but due to the lower bioavailability of zinc from plant foods, some vegans might need more than the RDA. A modest zinc supplement of about 50-100% of the RDA might be beneficial for vegans who experience symptoms of zinc deficiency, such as frequent colds, angular cheilitis (cracks in the corners of the mouth), diarrhoea, or hair loss.

Several studies have shown that vegans have lower blood zinc levels than meat-eaters, and a significant proportion fall below the reference range for zinc. However, the average zinc intake of vegans from various studies met the RDA, except for the EPIC-Oxford study, which found that vegan men had slightly lower zinc intakes than the RDA.

Overall, while vegans may be at risk of zinc deficiency due to the lower bioavailability of zinc from plant foods, careful planning and supplementation can help ensure adequate zinc intake and prevent potential health issues associated with zinc deficiency.

Vegans are at risk of selenium deficiency

Selenium is an essential nutrient for humans, playing a role in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage. Selenium levels have been positively associated with greater bone mineral density.

The amount of selenium in the soil varies by geographic location, and the selenium content of plant foods depends on the amount of selenium in the soil the plants were grown in. Vegans in the US and Canada have adequate intakes of selenium, but vegans in other areas of the world where soil selenium is low may be at risk of selenium deficiency. For example, vegans in Denmark, the UK, Finland, and Sweden have been found to have lower selenium intakes and lower blood selenium compared to non-vegetarians.

Brazil nuts are the food highest in selenium, on average, but the selenium content of Brazil nuts can vary widely depending on where they are grown. Selenium can also be found in whole grains, whole-wheat bread and pasta, oatmeal, barley, brown rice, soy products, and beans.

It is recommended that vegans who live in selenium-depleted areas take a multivitamin with selenium to ensure adequate selenium intake.

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