WHAT THEY’RE SAYING
Appropriately planned vegetarian diets are not only nutritionally beneficial and may prevent and treat certain diseases, but they are also more environmentally sustainable because they use fewer natural resources than diets rich in animal products.
WHAT THE RESEARCH SHOWS
The Journal of the American Academy of Nutrition and Dietetics is a voice of authority on nutrition, as the official research publication of the Academy of Nutrition and Dietetics (Academy), the United States’ organization of food and nutrition professionals, representing over 100,000 credentialed practitioners in the field of nutrition. Their verdict is in: vegetarian diets, including vegan diets, are healthful and may prevent and treat various diseases. Approximately 3.3% of American adults are vegetarian, and about 46% of vegetarians are vegan. The umbrella term “vegetarian diet” encompasses several different types of vegetarianism:
- Vegetarian: May or may not include egg or dairy products
- Lacto-ovo-vegetarian: includes eggs and dairy products
- Lacto-vegetarian: includes dairy products, but not egg products
- Ovo-vegetarian: includes eggs and egg products, but no dairy
- Vegan: excludes eggs and dairy products, and may exclude honey
- Raw vegan: Based on vegetables, fruit, nuts and seeds, legumes and sprouted grains. The amount of uncooked food varies from 75% to 100%
Vegetarian diets have been controversial in the past. Opponents of vegetarian diets claim that they are low in essential nutrients, such as protein, calcium, vitamin B-12, iron, zinc and iodine, which may lead to poor health outcomes due to from nutritional deficiencies. Given the abundance of foods and supplements available in today’s marketplaces, restaurants, grocery stores and online, vegetarian diets can certainly be structured to meet nutritional needs at every stage of the lifespan. In their statement article, the Academy breaks down the nutrients of concern:
- Protein: Vegetarian and vegan diets typically meet or exceed recommended protein intakes when caloric intake is adequate. Excellent sources of vegetarian protein include legumes and soy products.
- Iron: Vegetarians generally consume as much, if not more iron, than omnivores. However, the iron stores of vegetarians are often lower than those of non vegetarians. Over time, vegetarians are able to adapt to lower iron intakes and their bodies will reduce iron losses. Individuals with low iron stores can also increase their iron absorption by including food items that have high iron bioavailability.
- Zinc: Studies show that dietary zinc intake in vegetarians is relatively similar or lower to omnivores, although zinc deficiency is not evident in Western vegetarians. The best zinc sources include soy products, legumes, grains, cheese, seeds and nuts.
- Iodine: Iodine deficiency is virtually nonexistent in Western nations since the introduction of iodized salt in the 1920s.1
- Calcium: Vegetarians who consume dairy and egg products typically meet or exceed calcium recommendations, although calcium intakes for vegans vary widely and may fall below recommendations. Vegans can increase calcium intake through certain vegetables, namely kale, turnip greens, Chinese cabbage and bok choy. Tofu, soy products and fortified plant milks are also excellent sources of calcium, while white beans, almonds, figs, and oranges are moderate sources of calcium.
- Vitamin B-12: Vitamin B-12 is not present in plant foods and non-meat substitutes cannot be relied upon as practical sources of B-12. Vegans must regularly consume fortified B-12 food or supplements or they risk becoming B-12 deficient. Signs of severe B-12 deficiencies are unusual fatigue, tingling in the fingers and toes, poor cognition, poor digestion and failure to thrive in small children. Long-term B-12 deficiency from low B-12 intake may result in stroke, dementia and poor bone health.
WHY THIS MATTERS
Studies have repeatedly shown that vegetarian diets benefit long-term health. Vegetarian diets are associated with lower body mass index and can be used to achieve and maintain a healthy weight. Additionally, vegetarians have lower incidence of heart disease, diabetes and cancer. Heart disease risk is reduced as vegetarian diets improve several risk factors for heart disease, including abdominal obesity, blood pressure, serum lipid profile, blood glucose, oxidative stress, and atherosclerotic plaque formation. One study found that vegetarians had a 13% and 19% decreased risk of developing cardiovascular disease and ischemic heart disease, respectively. Another study found that vegetarians had a 32% lower risk of hospitalization or death from heart disease. In regards to diabetes, one study found that vegans were 62% less likely to develop diabetes. Overall cancer incidence is also lower in vegetarians, who are 18% less likely to develop cancer.
The Academy statement also includes information on vegetarian diets across the lifespan. The statement includes specifics on each life stage, but reiterates that with necessary modifications, vegetarian diets are safe, healthful and beneficial for individuals of all ages. Pregnant and lactating women in particular may benefit from vegetarian diets, as vegetarians have a lower risk of excessive gestational weight gain and gestational diabetes. The Academy recommends pregnant and lactating women consume iron, zinc and B-12 supplements to ensure adequate intake.
Parents who implement vegetarian diets for their children must be especially mindful to ensure young vegetarian diets include iron, zinc, vitamin B-12, calcium and vitamin D. For infants and children, rich sources of protein, iron and zinc may include hummus, tofu, well-cooked legumes, mashed avocados and full-fat, fortified soy milk or dairy milk. Finally, nutritional status in older vegetarians shows to be similar or better than older nonvegetarians. Older vegetarians should be mindful of protein, calcium and vitamin B-12 intake.
In addition to health benefits, the Academy highlights the environmental benefits of vegetarian diets. Vegetarian diets use less water and fossil fuel resources, lower amounts of pesticides and fertilizers, and fewer antibiotics to prevent and treat animal diseases.
THE BOTTOM LINE
Vegetarian diets benefit human and environmental health. The well-planned vegetarian diet can adequately meet or exceed vitamin and nutrient recommendations for all individuals across the lifespan. Vegetarian diets promote heart and bone health, diminish risk of overweight and obesity, type 2 diabetes and cancer. The benefits of vegetarian diets are derived from high intakes of fibrous fruits and vegetables, legumes, whole grains, legumes, nuts and seeds.
If you’re not ready to pursue an entirely vegetarian lifestyle, you can still reduce your meat intake by skipping it a few designated days per week (Meatless Monday, anyone?) or consuming meat on special occasions or only when going out to eat. Here are some helpful websites to plan a balanced, nutritionally adequate vegetarian diet:1
VegetarianNutrition.net Blog with evidence-based vegetarian nutrition plus resources for consumers.
vrg.org The Vegetarian Resource Group provides nutrition information, recipes, meal plans, and recommended readings for vegetarian nutrition.
PCRM.org The Physicians Committee for Responsible Medicine promotes preventive medicine through innovative programs and offers free patient educational materials.
VeganHealth.org Evidence-based recommendations covering the nutritional features of plant-based diets.
NutritionFacts.org Brief, referenced video clips and articles on numerous aspects of vegetarian nutrition.
VegWeb.com Vegetarian recipes, community, and a blog.
Vegetarian-nutrition.info Provides topical articles, resources, and news.