Vegetarian and Vegan Diet

  • Author:
    Betty Kovacs Harbolic, MS, RD

    Betty is a Registered Dietitian who earned her B.S. degree in Food and Nutrition from Marymount College of Fordham University and her M.S. degree in Clinical Nutrition from New York University. She is the Co-Director and Director of nutrition for the New York Obesity Research Center Weight Loss Program.

  • Medical Editor: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Quick GuideVegetarian Diet: Tasty, Basic Choices in Pictures

Vegetarian Diet: Tasty, Basic Choices in Pictures

What are the potential dangers from consuming the various kinds of vegetarian and vegan diets?

Cutting out meat is not all that it takes to follow a vegetarian diet. You need to remember that whenever you omit a food group you could potentially be missing some essential nutrients. All kinds of vegetarian diets can be nutritionally balanced, but it will take some planning to do this. Numerous studies have shown that poor meal planning is the cause of nutritional deficiencies in vegetarian diets, not the absence of animal foods. Well-balanced vegetarian diets have been approved for all stages of life, including pregnant and lactating women, children, adolescents, the elderly population, and competitive athletes.

The nutrients for which you are at risk of not getting enough will depend on the foods that you have omitted from your diet. The following are the most common nutrients that may be lacking in a vegetarian diet.

Omega-3 fatty acids

The American Heart Association recommends "consuming fish (particularly fatty fish) at least two times a week." The fat in fish provides the essential omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The omega-3 supplements and the foods fortified with it have varying amount of EPA and/or DHA. Omega-3 fatty acids have been shown to slow the progression of atherosclerosis, reduce triglyceride levels, act as an anti-inflammatory agent, possibly help with depression and other personality disorders, and possibly thin the blood. There is ongoing research to determine if there are other health benefits.

To a limited extent, your body can produce EPA from alpha-linolenic acid (ALA), another essential fatty acid. According to studies, ALA does not produce any DHA, so it does not provide comparable health benefits to omega-3 fatty acids. ALA can be found in nonmeat sources such as flaxseed oil, flaxseeds, canola oil, walnuts, and tofu. Research has shown that microalgae oil can serve as a source of omega-3 fatty acids for vegans and vegetarians. Microalgae oil is rich in DHA like fatty fish and provides an adequate amount of EPA.

One other thing to take into consideration when trying to obtain the health benefits from omega-3 fatty acids is the amount of omega-6 fatty acids that you are consuming. Omega-6 fatty acids are the other essential fat in our diet. These fatty acids are found in abundance in our diets. So much so, that we actually need to cut back on them. Omega-6 fatty acids are found in most vegetable oils, soybean oil, corn oil, sunflower oil, and peanut oil. Some experts believe that we currently consume about 14 times more omega-6 than omega-3 fatty acids. The goal is to bring this consumption closer to an equal intake or, at most, only 3 grams of omega-6 fatty acids for every 1 gram of omega-3 fatty acids. Flaxseed oil and flaxseeds are the only source of ALA that does not also provide omega-6 fatty acids.

While there are no official guidelines for how to get an adequate amount of omega-3 fatty acids in a vegetarian diet, there are some recommendations that you can follow:

  • Use microalgae oil as a replacement for fatty fish consumption.
  • Use flaxseed oil or flaxseeds (ground or crushed) as your source of ALA. Do not heat the oil when you use it.
  • Cut back on your intake of omega-6 fatty acids by replacing plant oils with olive oil or rapeseed oil.

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