About Vegetarian Diets

There are a wide variety of different reasons for people deciding which foods they will and will not eat, especially when it comes to meat and other animal products. Since animal products have been claimed to provide high-quality protein in our diets as well as a array of other essential nutrients, it is important to consider the effect of animal food consumption (or lack thereof) on issues related to nutritional status. Consider some of the following issues if you are, or decide to become, a vegetarian to some degree.
What is a vegetarian?
A vegetarian refers to a person who does not eat any meat, poultry, or fish or their related products, such as milk and eggs.
What is a lacto-OVO-vegetarian?
A lacto-ovo-vegetarian is a type of vegetarian who consumes dairy products and eggs in an otherwise plant-based diet.
What is a pescatarian?
A pescetarian/pescatarian or pesco-vegetarian is the practice of following a diet that includes fish or other seafood, but not the flesh of other animals.
What is a vegan?
A vegan is a type of vegetarian who consumes no animal products.

What Are The Risks?

It really depends on what kind of vegetarian a person is. Vegetarian diets can provide many of the essential nutrients, but care must be taken to make sure sufficient protein, iron, calcium, zinc, vitamin D, vitamin A, omega-3 fatty acids, and vitamin B12 are consumed. In general, a well-balanced lacto-ovo- or pescatarian diet can easily provide adequate protein, energy, and micronutrients. Dairy products and eggs are convenient sources of high-quality protein and many vitamins and minerals. However, meat is often claimed to be a primary source of bioavailable heme iron, therefore, according to some researchers, eliminating meat may lead to iron deficiency. Furthermore, vegans may be at increased risk of being deficient in several micronutrients, as mentioned. However, a properly balanced diet concurrent with high quality supplements can fulfill many nutritional deficiencies. This micronutrient deficiency risk increases during pregnancy, lactation, and periods of growth and development such as infancy and adolescence. Since cholesterol is made by the body, vegans who do not eat animal products are not at risk of cholesterol deficiency. Be mindful of getting enough vitamin B12; because this vitamin is naturally found only in foods that come from animals, although more research regarding vitamin B12 is needed. 

In summary, while plant-based diets, veganism, and vegetarianism can all offer significant health benefits, it is crucial to plan these diets carefully to avoid nutritional deficiencies. Incorporating a variety of nutrient-rich foods and, in some cases, dietary supplements can help mitigate these risks.

A Potentially Lesser Evil

From a nutritional point of view, ideally all foods should come from a whole food source. If you do decide to adopt a vegetarian lifestyle, you may be bombarded by the availability of processed food-like products marketed towards veganism. The key to a healthy vegetarian diet, like any diet, is to enjoy a wide variety of foods and to consume them in moderation. No single food provides all the nutrients the body needs, eating a wide assortment of foods can help ensure that vegetarians get the necessary nutrients and other substances that promote good health.

Vitamin B12: A Vitamin Only Made by Microorganisms

Vitamin B12, also called cobalamin, was the last of the B vitamins to be discovered. As a complex molecule, vitamin B12, gets its name from the fact that it contains the trace element cobalt (Co) and several nitrogen (N) atoms. Vitamin B12, not only directly influences metabolism in every cell throughout your brain and nervous system, it also regulates and synthesizes DNA and how your blood is formed. Vitamin B12 is required for new cell production and maintenance, cell coordination, and DNA synthesis. In addition, vitamin B12:
  •  is needed for ATP production
  • is necessary for the conversion of homocysteine to methionine
  • is involved in the production of adrenaline from noradrenaline
  • plays a role in myelin synthesis

Vitamin B12 is a unique vitamin due to the fact that it cannot be made by plants or higher animals (such as mammals and birds) but only by microorganisms (such as bacteria and fungi). Therefore, the presence of vitamin B12 in food is actually the result of its being made by microorganisms living in the food source’s environment (generally the case for plants) or GI tract (more typical with animals).

Vitamin B12 Deficiency

Vitamin B12 participates as a coenzyme in only two reactions. One reaction catalyzes the production of an intermediate in the citric acid cycle, ultimately allowing the body to use some amino acids and fatty acids for energy (ATP) production. The other reaction catalyzes the conversion of homocysteine to the amino acid methionine. Without adequate vitamin B12, homocysteine levels build up in the blood, “trapping” folate in its inactive form. In other words, vitamin B12 deficiency can cause secondary folate deficiency.

The primary vitamin B12 deficiency is sometimes seen in vegans. Secondary vitamin B12 deficiency can occur when gastric cells stop producing hydrochloric acid (HCl); which often occurs as we age and results in poor absorption of vitamin B12.

A vitamin B12 deficiency can result in neurological problems or inefficient blood cell production. One indication of such a deficiency is a “pins and needles” sensation due to low oxygen levels. Other symptoms of vitamin B12 deficiency may include:
Dizziness
Unexplained fatigue
Pale complexion
Poor vision
Forgetfulness
Muscle weakness
Anemia
Menstrual difficulties
Diarrhea
Nervous system damage
Mouth sores
Weight loss
Researchers have observed a weak though significant inverse association of vitamin B12 levels with fracture risk, and a significant association of homocysteine levels (vitamin B12 converts homocysteine to methionine) with fracture risk (Van Wijngaarden et al., 2013). A separate group of researchers also found that vitamin B12 deficiency may also increase the incidence of fractures among elderly men (Lewerin et al., 2013). Regarding pregnant women, according to a review of 18 studies spanning 11 countries, a vitamin B12 deficiency is associated with a higher risk of low birth weight in newborns (Rogne et al., 2017).

​Nutritional yeast, spirulina and other foods fortified with vitamin B12 offer one way individuals that are B12 deficient can supplement their B12 intake through their diet. However, ideally all nutrients should obtained from a whole food source, rather than fortified foods.

Iron

Vegetarians may have difficulty consuming enough iron because only meat provides substantial amounts of highly bioavailable heme iron. The Institute of Medicine estimates that vegans have dietary iron requirements 80% higher than requirements for nonvegetarians.

Tofu

Soybeans are a type legume, but they deserve their own special mention because of the extreme misconceptions of their supposed health value. There are a large number of companies seeking to profit from the alleged health benefits of soy, such as soy milk, powders, cheese, breakfast bars, cereals and various other products. The truth of the matter is that these products largely do more harm than good. “But what about the link between soy and the low rates of breast, colon and prostate cancer among Asian people, whose diets tend to be high in soy?” you may ask. Consider that Asians eat a diet that includes significantly higher quantities of vegetables and much lower quantities of processed foods, and a much better balance of omega-3 to omega-6 fat ratios. Asians as a whole are consuming a far healthier diet overall, which provides relative protection from the harmful effects of soy. It should also be noted that Asians eat a significant portion of soy in the recommended fermented form such as natto, amakaze, miso and tempeh, which nullifies the negative effects of soy. While an entire book will be available in spring 2004 on how soy harms your health, The Whole Soy Story by Dr. Kaayla Daniel, here are some essentials you should know:
  • Soybeans are high in natural toxins, also known as “antinutrients.” This includes a large quantity of inhibitors that deter the enzymes needed for protein digestion. Further, these enzyme inhibitors are not entirely disabled during ordinary cooking. The result is extensive gastric distress and chronic deficiencies in amino acid uptake, which can result in pancreat- ic impairment and cancer.
  • Soybeans contain hemaglutinin, which causes red blood cells to clump together. Soybeans also have growth depressant substances. And while these substances are reduced in processing, they are not completely eliminated.
  • Soy contains goitrogens, which frequently lead to depressed thyroid function.
  • Most soybeans are genetically modified, and they contain one of the highest levels of pesticide contamination of all foods.
  • Soybeans are very high in phytates, which prevent the absorption of minerals including calcium, magnesium, iron and zinc, all of which are co-factors for optimal biochemistry in the body. Eating meat reduces the mineral-blocking effects of these phytates, and so it is helpful if you do eat soy to also eat meat.
  • In an effort to remove the antinutrients from soy, soybeans are taken through a series of chemical processes including acid washing in aluminum tanks. This leaches high levels of aluminum, a toxic heavy metal, into the final soy products. Many soy foods also have toxic levels of manganese. Soy formula has up to 80 times higher manganese than is found in human breast milk.

Pea Protein

Pea protein has gained popularity as a plant-based alternative to animal proteins, especially among vegans and those with dietary restrictions. However, despite its benefits, there are significant concerns associated with its production and consumption. These issues include high water usage, contamination with heavy metals, high lectin content, and the highly processed nature of the product.

One major problem with pea protein is the substantial amount of water required for its production. Growing peas, like many other crops, demands considerable irrigation, particularly in regions where water resources are already scarce. The process of extracting protein from peas is also water-intensive. This environmental impact is a crucial consideration in evaluating the sustainability of pea protein as an alternative to animal-based proteins.

Another significant concern is the potential contamination of pea protein with heavy metals such as lead, arsenic, and cadmium. These contaminants can be present in the soil where peas are grown and can accumulate in the protein isolate during processing. Studies have found varying levels of heavy metals in different brands of pea protein, raising concerns about the long-term health effects of regular consumption. Chronic exposure to heavy metals can lead to serious health issues, including kidney damage, neurological problems, and an increased risk of cancer.

Lectins are naturally occurring proteins found in many plants, including peas. While some lectins can be beneficial, others are known to cause digestive issues and interfere with nutrient absorption. Pea protein contains a relatively high amount of lectins, which can lead to gastrointestinal discomfort, bloating, and other digestive problems in some individuals. Additionally, lectins have been shown to disrupt the gut lining, potentially contributing to a condition known as leaky gut syndrome.

Pea protein is a highly processed product. The manufacturing process involves several steps, including extraction, isolation, and purification of the protein from the pea. This extensive processing can strip the peas of their natural nutrients and result in a product that is far removed from its original form. Highly processed foods are often less nutritious and may contain additives or preservatives that could have adverse health effects over time.

While pea protein offers a plant-based alternative to animal proteins and can be beneficial for those with dietary restrictions, it is essential to consider its potential downsides. The high water usage required for its production, the risk of heavy metal contamination, its high lectin content, and its highly processed nature all raise concerns about its overall sustainability and health impact. Consumers should weigh these factors carefully and consider incorporating a variety of protein sources into their diet to ensure a balanced and nutritious intake.

References

Lewerin, C., Nilsson-Ehle, H., Jacobsson, S., Johansson, H., Sundh, V., & Karlsson, M. et al. (2013). Low holotranscobalamin and cobalamins predict incident fractures in elderly men: the MrOS Sweden. Osteoporosis International, 25(1), 131-140. http://dx.doi.org/10.1007/s00198-013-2527-y

Öner, T. , Guven, B. , Tavli, V. , Mese, T. , Yilmazer, M. , et al. (2014). Postural orthostatic tachycardia syndrome (pots) and vitamin b12 deficiency in adolescents. Pediatrics, 133(1), e138.

Rogne, T., Tielemans, M., Chong, M., Yajnik, C., Krishnaveni, G., & Poston, L. et al. (2017). Associations of Maternal Vitamin B12 Concentration in Pregnancy With the Risks of Preterm Birth and Low Birth Weight: A Systematic Review and Meta-Analysis of Individual Participant Data. American Journal Of Epidemiology. http://dx.doi.org/10.1093/aje/kww212

Van Wijngaarden, J., Doets, E., Szczecińska, A., Souverein, O., Duffy, M., & Dullemeijer, C. et al. (2013). Vitamin B12, Folate, Homocysteine, and Bone Health in Adults and Elderly People: A Systematic Review with Meta-Analyses. Journal Of Nutrition And Metabolism, 2013, 1-19. http://dx.doi.org/10.1155/2013/486186