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Health Benefits of a Vegetarian Diet – A Thorough Discussion

Jennifer Hanes MS, RDN, LD

We become vegetarians for various reasons. Some of us were raised on a vegetarian diet. Others switch because they are concerned with ethics and animal welfare.  More recently, people are omitting meat due to concerns for the environment or world hunger.

Finally, there are some of us who switch to a vegetarian diet for health benefits.

For those of you who switched for reasons other than health, did you expect your health to improve, or were you worried that you may experience protein and various vitamin and mineral deficiencies?

You probably heard both viewpoints as you made the switch.

In my post about unhealthy vegetarians,  we discussed the various pitfalls and problems that can happen if your vegetarian diet is not well-planned.

Here, I will delve deeper into the health benefits of following a vegetarian diet.

What is a Vegetarian diet?

A vegetarian diet is a pattern of food intake that omits animal products to varying degrees. The vegan diet is the most strict vegetarian, and a semi-vegetarian (or flexitarian) diet is the most flexible.

Each individual vegetarian has their own “line in the sand,” so to speak, and you’ll find different people omit or include different foods based on a variety of factors.

Nutritional Components of a Vegetarian Diet

Depending on the pattern, a vegetarian diet is generally higher in fiber and carbohydrates than an omnivorous diet. 

A vegan likely eats less protein and fat than an omnivorous eater or even a less restrictive vegetarian but still gets adequate amounts of each.   Protein can come from whole grains, nuts, seeds, soy, seitan, and more.

Vegan fat sources typically include nuts, seeds, avocados, olives, and cooking oils. 

Interestingly, lacto-ovo-vegetarians have similar fat and protein intakes as those who eat meat.

Vegetarian diets also tend to have higher intakes of polyunsaturated fats, folate, magnesium, and vitamins C and E. 

Intakes of calcium, iron, zinc, iodine, and calcium varied among vegans, vegetarians, and meat eaters, with vegans having the lowest amount, which resulted in lower bone density overall.

A vegan diet does not include vitamin B12, which must be supplemented. A lacto-ovo-vegetarian should get plenty.

Heart Health

Vegetarians typically have a lower risk of heart disease. I discussed this in a previous post.

We typically see lower levels of total cholesterol, LDL (bad) cholesterol, blood pressure, and certain inflammatory markers linked to heart disease when a person eats a diet that is high in fruits, vegetables, and whole grains. 

While blood markers are great, does that actually translate to better outcomes? Meaning do vegetarians have less heart disease?


Vegetarians tend to have approximately 25% less risk of heart disease than omnivores in observational studies.

Furthermore, vegetarians with heart disease are hospitalized less frequently and for shorter time periods than omnivores with heart disease.

Lower cancer risk

The World Health Organization has categorized red meat (group 2) and processed meat (group 1) as carcinogens. This means that they are pretty sure that red meat causes colon cancer, and they know that processed meat does. 

Confusion arises when people notice that processed meat is in the same category as asbestos and cigarette smoke.

These groupings do not indicate the potency of the carcinogen but rather the level of research behind the claim that a substance causes cancer.

We know with the same level of certainty that processed meat causes colon cancer as asbestos and smoking cause lung cancer.

This does not mean that everyone who eats bacon and sausage will get colon cancer, just like every smoker doesn’t get lung cancer. Typically, these substances’ propensity for causing cancer depends on the amount, frequency, and duration of exposure.

Additionally, protective environmental factors could reduce the risk.

Beyond just the exclusion of red and processed meats, vegetarians seem to have a lower risk of colorectal cancer than omnivores.

However, pescatarians seem to have the lowest (43% lower than omnivores, compared to lacto-ovo vegetarians, 18%, and vegans, 16%).

This study focused only on risk and did not provide a reason why including fish in the diet would further reduce the risk of colon cancer. My speculation is that the EPA/DHA content of fish is responsible. That’s some good stuff.

Vegetarians also have a lower risk of breast cancer, possibly due to the higher intake of soy isoflavone than the general population. So cook up that tofu!

Most studies on vegetarianism and cancer focus on colorectal cancer, and the link is pretty clear. However, the jury is still out on a vegetarian diet and the risk of all cancers.

A meta-analysis showed an 8% reduction in the total incidence of cancer, which may be significant for those who didn’t get cancer but is not enough to recommend that everyone should drop meat to slash cancer risk.

Lower risk of type 2 diabetes

Vegans and vegetarians have a lower risk of developing diabetes, regardless of weight. This indicates some other protective benefits of the diet and reduces our reliance on using weight as a risk factor for disease.

This study also adjusted for other factors such as sleep habits, education, income, television habits, physical activity, race, and age.

They calculated a 50% (!) reduction in the risk of diabetes when meat is excluded from the diet. Pescatarians (33%) and flexitarians (25%) also had a lower risk of diabetes than omnivores but to a lesser extent.

Again, the reduction in oxidative stress from high intakes of fruits, vegetables, and whole grains seems to be the biggest protective factor.  Vegetarians in larger bodies still had a lower rate of diabetes than omnivores.

But what if you already have type 2 diabetes?

One study showed that vegan and vegetarian diets improved blood sugar control in patients with diabetes more than the ADA guidelines for dietary management of diabetes! 

A second similar study compared a low-fat vegan diet to the ADA diet. 43% of vegans reduced their glucose-lowering medications with an average A1c reduction of 0.96%.  

Of those who followed the ADA diet, only 26% were able to decrease their medication, and the average A1c fell by 0.56%. 

Patients with diabetic neuropathy (a complication that causes severe pain in the feet) saw a reduction in symptoms when adopting a vegetarian diet, compared to a control group that did not.

Both the exclusion of red meat and the inclusion of soy protein seem to improve kidney function in patients with type 2 diabetes.

Considering the implications of diabetes on kidney function and the later need for dialysis or kidney transplant, this is an important area of research to pursue further!

Improved Digestive Health

Essentially, because a vegetarian diet increases an individual’s intake of fiber, their digestive health tends to improve. There are many reasons for this.

Adequate fiber intake provides bulk to the stool, which can alleviate diarrhea and pulls water into the colon, which can alleviate constipation.

Fiber is also excellent for our gut microbiome, which in turn does a lot of good for the rest of us, including our immune system (which resides largely in the gut) and our mental health.

A variety of fibers is an important component of the improvement of gut health for most people, and vegetarians tend to have a greater variety of fiber sources than those who eat meat.

It is possible to have too much of a good thing, though.  Eating fiber in amounts that far exceed the recommendations (~25-30g per day) can cause nutrient deficiencies due to binding in the gut. 

Additionally, some people will experience an exacerbation of GI distress when fiber intake is too high. Fiber from raw vegetables seems particularly offensive for those with irritable bowel syndrome.

Longer life expectancy

Vegetarians appear to have a longer life expectancy. This requires more research to be definitive and likely depends on a lot of factors. However, eating meat less than once a week appears to lengthen life expectancy in people.

Lower risk of cataracts?

This was a little surprise that showed up when I was researching. I guess it makes sense since diabetes is a major cause of cataracts. A lower risk of diabetes could lead to a lower risk of cataracts, right? 

A large study on self-reported “health conscious” Brits showed that vegetarians have a lower risk of developing cataracts compared to meat eaters.

The risk of cataract development appeared to decrease as meat intake decreased. This is one of the few studies that looked at overall diet patterns rather than individual nutrients in relation to cataract development.

It is important to note that this study only looks at correlation. There is no evidence provided that eating meat causes cataracts or that any particular food prevents them.


One study showed a decreased risk of cognitive decline, osteoporosis, diverticular disease, gallstones, and rheumatoid arthritis. 

Better cooking skills

I’ll be the first to say that my cooking improved dramatically after I stopped eating meat.

I learned new techniques and figured out flavor combinations and complements. I was a passable cook before. And now, I’m pretty dang good. I’ve met other ve*gans who have said the same thing.

More diverse diet

Our diet is also far more diverse now. My family eats more and a greater variety of vegetables. We snack on different fruits. We seek out new cuisines to try (and have learned a lot about other cultures as a result).  

As good as it is to eat your veggies, eating the same three over and over and over isn’t necessarily healthy. Variety in a diet is consistently shown to improve health.

So pick up that weird-looking fruit on the end cap. Go to the farmer’s market and pick out a vegetable you’ve never tried before. Start asking your neighbors and co-workers about their traditional family meals or their favorite ingredients.

Learn from those around you.

Tips for a Balanced Vegetarian Diet

Research showing the health benefits of a vegetarian diet is very clear in specifying that a well-balanced vegetarian diet is health-promoting.

If we choose to simply stop eating meat without getting the nutrients in meat elsewhere, we run the risk of nutrient deficiency and worsening physical and mental health.

It’s a bit more nuanced, but the main nutrients a veg*n can miss out on are protein, vitamin B12, and iron. 

Make sure to include a source of protein every time you eat. Vegetarian sources of protein include whole grains, nuts, seeds, soy, beans, quinoa, dairy, and eggs.  

Vegetarian sources of iron include beans, nuts, seeds, leafy greens, and dark chocolate. This is especially important for people who are menstruating, as monthly blood loss depletes our iron.

Vitamin B12 is only found naturally in animal foods. A lacto-ovo-vegetarian likely gets enough from dairy and eggs. However, a vegan will need to supplement or include B12-fortified foods.

In addition to specific nutrients, having a wide variety of foods is important to health. 

While any increase in fruits and vegetables is likely a good thing, overreliance on 2-3 faves makes you miss out on the different phytochemicals, nutrient composition, and fibers of the foods you aren’t eating.

I’m not saying you have to choke down foods you hate in order to eat more variety. However, remind yourself to branch out every once in a while. Try foods cooked in different ways or foods you’ve never had before or haven’t had in a while.

Potential Challenges and Solutions

There are a few challenges that a person may face if starting a vegetarian diet. Below are just a few, along with potential solutions.

Problem: Not sure what to eat, as all meals used to center around meat.

Solution: Once you identify sources of protein and understand that you need to eat a variety of fruits and vegetables, this gets much easier. It honestly just takes some practice and experimenting.

Use Google or Pinterest to search for vegetarian versions of your favorite foods, or simply do a search for “easy vegetarian dinners.”

Facebook also has groups that focus on vegetarian or vegan recipe sharing.

Problem: Grocery stores and restaurants near me carry very few vegetarian options.

Solution: Unfortunately, if you live in a more rural area, this may be the case for you.  However, even in rural areas, you can usually still find tofu and a wide variety of beans, nuts, and seeds.

I’ve noticed that mock meats are increasingly more available in grocery stores in the few rural areas I’ve visited.

Luckily, there are plenty of delivery options available now, including Whole Foods (through Amazon) and Thrive Market. 

This greatly increases your ability to regularly source other vegetarian items such as seitan, tempeh, and other tofus, such as the super-firm (aka high-protein) variety.

Problem: People are offended or confused about my decision to stop eating meat.

Solution: This firmly falls in the category of “their” problem. For the most part, this will blow over. The people you care about will get used to your new dietary patterns, and the strangers who make rude comments don’t matter anyway.

Just don’t go around trying to force your ideals onto other people!

Is it all diet?

We honestly don’t know. The benefits of a vegetarian diet could be due to the exclusion of meat, or it could be due to higher intakes of fruits, vegetables, legumes, nuts and seeds, and whole grains.

Additionally, according to Harvard University, vegetarians are more likely not to smoke, not drink alcohol excessively, and get adequate exercise. (Makes us sound kind of boring, doesn’t it? lol)

It’s likely a combination of all of the above. Less meat, more plants, not smoking, limiting alcohol intake, and exercising are recommended to everyone to improve their health, all for their own reasons.

It seems illogical to take one health behavior and apply it to all aspects of our health. Most likely, each healthy behavior compounds the other. Additionally, we have to take in our differences.

I feel great on a vegetarian diet. Others may feel tired or bored. Just like I don’t like to eat a big breakfast, and others love it. Some of us exercise to keep our weight down, and others to keep it up.   

We have to remember that when we talk about the health benefits of any diet pattern. Whether it is vegan, vegetarian, flexitarian, or we follow the Mediterranean or Nordic diet pattern.

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