The world loves meat: the global meat market is expected to increase by over 4% by the year 2026. Yet, the popularity of vegetarian diets is also on the rise, and they are valued much more widely than they used to be. Nevertheless, the age-old argument remains: are vegetarians actually healthier than everyone else, like many claim? In this article, we'll dive into the benefits of being a vegetarian, and see if might be right for you.

Scientists have long been seeking an answer to this question, and have even used twins — with their identical DNA assumed to remove genetic impacts on health differences — as study subjects, in the hope of providing solid evidence that will finally answer this question once and for all. What scientists have concluded may surprise you. Read on to learn about the health benefits — and potential risks — of vegetarian diets, and “food for thought” concerning whether you should kick meat out of your life.

What is a vegetarian diet?

The definition of “vegetarian” isn’t black and white — which, as we’ll see later in this article, is probably part of the reason why so much conflicting “evidence” exists regarding the healthfulness of vegetarian diets compared to diets that include meat. There are several different types of vegetarians, classified according to the types of animal-based products that are avoided:

• Lacto-vegetarians do not eat meat, fish, poultry, eggs, or foods that contain these products. They do, however, eat dairy products such as milk, cheese, yogurt and butter.
  
• Ovo-vegetarians do not eat meat, fish, poultry, or dairy products — but they do eat eggs.
  
• Lacto-ovo vegetarians do not eat meat, fish, or poultry — but they do consume dairy products and eggs.
  
• Vegans avoid all foods containing animal products, including meat, fish, poultry, dairy, and eggs.
  
• Pescatarians are often included in the list of vegetarians because they do not consume meat or poultry. However, since people adhering to a pescatarian diet eat fish, this diet technically isn’t vegetarian. Therefore, for the purposes of this article, we do not consider a pescatarian to be a vegetarian.

There is another group of people that adhere to a “flexitarian diet” — a diet that is vegetarian most of the time, but includes animal products on occasion. We’ll discuss this group in a later section.

What are the health benefits of being a vegetarian?

Despite the varied opinions and evidence contained in the hundreds if not thousands of scientific studies on this topic, there is one fact that has emerged, crystal-clear, in the vast majority of them: vegetarian diets do have several important health benefits.

• Reduced risk of cancer. Multiple meta-analyses have demonstrated that vegetarian diets are associated with a reduced risk of developing cancer broadly, and that risk level drops even more with vegan diets. Whether or not vegetarian diets can impact different types of cancer remains controversial, with some studies demonstrating no significant associations between vegetarian diet and cancer type, and others demonstrating associations between vegetarianism and reduced risk for GI tract cancers and female-specific cancers, such as female breast, endometrial, uterine, and ovarian cancers. Conflicting results could be due to the grouping of vegetarian diet subtypes into a single group; for example, one meta-analysis revealed that the reduced risk of female-specific cancers was observed among vegans, while the reduced risk for GI tract cancers was observed with lacto-ovo vegetarians. Combining these diet subtypes into a single “vegetarian diet” group can mask such associations.
  
• Reduced risk of type 2 diabetes (T2D). A 2018 review summarized the well-recognized benefits of vegetarian diets on reduced risk for T2D. Similar to observations for cancer, different levels of beneficial effects have been observed across vegetarian diet subtypes.
  
• Reduced risk of ischemic heart disease. Studies have shown that vegetarian diets effectively reduce the risk of ischemic heart disease (narrowing of the arteries; also known as coronary artery disease). However, the impact of vegetarian diets on the broader category of cardiovascular disease is inconsistent across scientific studies.

These are just a few examples of the scientifically proven benefits of vegetarian diets. Some studies have also suggested that vegetarian diets have positive beneficial impacts on cholesterol, heart disease, and metabolic syndrome — but results are either conflicting, inconclusive, or include data from people consuming plant-based diets rather than strictly vegetarian diets. 

Most scientists attribute the health benefits of vegetarian diets to the polyphenols, antioxidants, vitamins and minerals, and fiber found in plants. But health benefits can also result from the avoidance of certain compounds, such as unhealthy fats and cholesterols, which are more plentiful in animal products. People who follow a vegetarian diet are also more likely to avoid other unhealthy habits, such as smoking and drinking large amounts of alcohol, and they also may be more conscious about exercising regularly — all factors which positively impact cardiovascular and metabolic health regardless of whether meat is consumed or not.

Can vegetarians be unhealthy?

With all of these health benefits associated with vegetarian diets, why then do so many people think that vegetarian diets “aren’t as good” as we’re now told they are? 

One of the biggest arguments against vegetarian diets is that they make it difficult for people to get enough protein, particularly for groups with higher protein needs than others (children, athletes, post-menopausal women, and the elderly). This argument isn’t necessarily valid, however: lacto-ovo vegetarians, for example, typically don’t have any problem getting the protein they need because they eat dairy and eggs. But other vegetarians that avoid one of these food groups, or both (as in the case of vegans), might indeed have trouble meeting either recommended protein and/or specific vitamin/mineral intake levels; (see the table, below, for additional information). Accordingly, various vegetarian groups may need to supplement their diets to prevent deficiencies. For example, according to a NIH Fact Sheet, vegans who consume no animal products and vegetarians who consume some animal products (e.g., dairy products, eggs, or both), but not meat, have a higher risk of developing vitamin B12 deficiency because natural food sources of vitamin B12 are limited to animal foods. Consumption of foods fortified with vitamin B12 (such as fortified nutritional yeasts) as well as vitamin B12 supplements can substantially reduce the risk of deficiency

These issues, however, are not necessarily reasons to decide not to be vegetarian. You’ll simply need to ensure, with a few directives in mind, that you get the nutrition you need if you do decide to go vegetarian — and especially if you become vegan. In fact, according to the Academy of Nutrition and Dietetics, “appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases.” 

You can use the table below as a general guide for getting enough nutrients on a vegetarian diet. You can (and should) also work with your healthcare provider, who can take regular blood tests to monitor your vitamin and mineral levels and create a customized supplementation plan for you to ensure you get the nutrition you need.

‍Note: The list below is appropriate for most adults. Pregnant or breastfeeding women as well as children may need additional guidance from healthcare professionals to ensure they get the nutrients they need to support the health of the developing fetus, the baby after birth, and the development of the child throughout their younger years.

Protein

• Eggs and/or dairy (lacto/ovo/lacto-ovo vegetarians only)
• Nuts, nut butters, seeds, beans, legumes (i.e., lentils, legumes), soy, and cereals

Vitamin D

• Fortified milk (lacto/lacto-ovo vegetarians only), cereals, and soy products
• Supplements (under supervision of a healthcare provider)

Vitamin B12

• Yeast
• Fortified dairy products (lacto/lacto-ovo vegetarians only)
• Fortified soy milk
• Fortified cereals
• Supplements (under supervision of a healthcare provider)

Calcium

• Dairy products (lacto/lacto-ovo vegetarians only)
• Tofu
• Fortified orange juice
• Kale, turnip greens, and broccoli
• Supplements (under supervision of a healthcare provider)

Iron

• Beans
• Legumes
• Spinach,green peas
• Cashews
• Supplements (under supervision of a healthcare provider)
• Iron should always be consumed with adequate amounts of Vitamin C, which is necessary for the body to absorb iron

Zinc

• Dairy products (lacto/lacto-ovo vegetarians only)
• Dried beans
• Nuts
• Soy
• Fortified cereals
• Supplements (under supervision of a healthcare provider)

Iodine

• Dairy products (lacto/lacto-ovo vegetarians only)
• Enriched bread
• Enriched macaroni products
• Seaweed, lima beans, green peas
• Apple juice, prunes, bananas

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Beware of processed foods – whether vegetarian or not

Another issue with vegetarian diets is that their health benefits only occur when people consume real, whole foods. Many people opt for processed foods — such as chips, cookies, and meatless burgers — to replace the foods they’re used to eating once they go vegetarian. Processed foods contain added sugar, refined carbs, and unhealthy fats — which have been associated with a variety of medical problems, including cardiovascular disease, obesity, diabetes, and certain cancers. If going vegetarian simply means consuming more sugary, fatty foods, then going vegetarian isn’t the healthier option, period. 

Often, people replace animal products with unhealthy alternatives because they simply don’t know where to begin. The 2015–2020 Dietary Guidelines for Americans provides easy-to-understand advice on what types and quantities of whole foods to eat on a vegetarian diet. Your healthcare provider is another great resource with expertise in how you, as an individual with a unique health profile and demographic, can adopt and enjoy a healthy vegetarian diet.

What if you’re not ready to go completely meatless?

There are many reasons a person might decide to eliminate meat or all animal products from their diet: animal welfare and environmental consciousness are two of the biggest reasons. But what if you just want to improve your health, yet aren’t ready to go completely meatless? Can you still reap the health benefits of a vegetarian diet?

Scientific research suggests that, yes, you can. A simple search on Pubmed (the National Institutes of Health repository for scientific publications) reveals that many of the studies, meta-analyses, and reviews on the beneficial impacts of vegetarian diets also include “plant-based” diets: diets that emphasize whole, plant-based foods, but don’t necessarily eliminate all animal products. Furthermore, many of these studies show no difference between vegetarian diets and the comparison group, whether that be other healthy diets (such as the Mediterranean diet) or simply omnivorous food consumption. There are decades of studies demonstrating the many health benefits of these diets, especially the Mediterranean diet, because they are rich in whole grains, fruits and vegetables, legumes, and nuts.

You can also make healthier meat choices. Studies show that grass-fed beef has an anti-inflammatory omega fatty acid profile as opposed to the pro-inflammatory profile associated with conventional beef. Grass-fed beef also contains more antioxidants than conventional beef. 

The New Zealand Heart Foundation suggests that a flexitarian diet, one that reduces but doesn’t completely eliminate the consumption of animal products and emphasizes consumption of whole, plant-based foods, ”may be the most realistic and sustainable way for many of us to adopt a plant-based diet.” 

Of course, certain health conditions might warrant a full switch to vegetarianism. In these cases, the best thing to do is to work with your healthcare provider to determine the best diet for you, together with ways to supplement your regimen in order to better manage any particular medical condition you may have. 

Key takeaways

When it comes to the health benefits of being a vegetarian, many people continue to insist that either a vegetarian or non-vegetarian diet is superior to the other; however, the science shows that either one can be worse than the other — depending on the specific foods consumed. Remember, chips and cookies are vegetarian — but that doesn’t make them healthy! Although vegetarian and vegan diets high in whole foods do have several beneficial impacts on health and may be appropriate for individuals with certain diseases, many of these benefits can be realized simply by increasing your consumption of fruits, vegetables, legumes, and whole grains rather than by eliminating meat altogether. If you’re interested in going meatless for health or ethical reasons, the best thing to do is to work with your healthcare provider to ensure you’re getting all the nutrients you need (which may require supplementation, especially if you go vegan). And, if you’re not quite ready to go meatless yet, you don’t have to feel guilty: just work on eating more fruits, vegetables, legumes, and whole grains and you’ll still reap significant health benefits.