Vegan diets are known to help people lose weight.
However, they also offer an array of additional health benefits.
For starters, a vegan diet may help you maintain a healthy heart.
What's more, this diet may offer some protection against type 2 diabetes and certain cancers.
Here are 6 science-based benefits of vegan diets.
If you switch to a vegan diet from a typical Western diet, you'll eliminate meat and animal products.
This will inevitably lead you to rely more heavily on other foods. In the case of a whole-foods vegan diet, replacements take the form of whole grains, fruits, vegetables, beans, peas, nuts and seeds.
Since these foods make up a larger proportion of a vegan diet than a typical Western diet, they can contribute to a higher daily intake of certain beneficial nutrients.
For instance, several studies have reported that vegan diets tend to provide more fiber, antioxidants and beneficial plant compounds. They also appear to be richer in potassium, magnesium, folate and vitamins A, C and E (, , , ).
However, not all vegan diets are created equal.
For instance, poorly planned vegan diets may provide insufficient amounts of essential fatty acids, vitamin B12, iron, calcium, iodine or zinc ().
That's why it's important to stay away from nutrient-poor, fast-food vegan options. Instead, base your diet around nutrient-rich whole plants and fortified foods. You may also want to consider supplements like vitamin B12.
Bottom Line: Whole-food vegan diets are generally higher in certain nutrients. However, make sure you get all the nutrients your body needs.
An increasing number of people are turning to plant-based diets in the hope of shedding excess weight.
This is perhaps for good reason.
Many observational studies show that vegans tend to be thinner and have lower body mass indexes (BMIs) than non-vegans (, ).
In addition, several randomized controlled studies — the gold standard in scientific research — report that vegan diets are more effective for weight loss than the diets they are compared to (, , , , , , , , ).
In one study, a vegan diet helped participants lose 9.3 lbs (4.2 kg) more than a control diet over an 18-week study period ().
Interestingly, participants on the vegan diet lost more weight than those who followed calorie-restricted diets, even when the vegan groups were allowed to eat until they felt full (, ).
What's more, a recent small study comparing the weight loss effects of five different diets concluded that vegetarian and vegan diets were just as well-accepted as semi-vegetarian and standard Western diets ().
Even when they weren't following their diets perfectly, the vegetarian and vegan groups still lost slightly more weight than those on a standard Western diet.
Bottom Line: Vegan diets have a natural tendency to reduce your calorie intake. This makes them effective at promoting weight loss without the need to actively focus on cutting calories.
Going vegan may also have benefits for type 2 diabetes and declining kidney function.
Indeed, vegans tend to have lower blood sugar levels, higher insulin sensitivity and up to a 50–78% lower risk of developing type 2 diabetes (, , , , ).
Studies even report that vegan diets lower blood sugar levels in diabetics more than the diets from the American Diabetes Association (ADA), American Heart Association (AHA) and National Cholesterol Education Program (NCEP) (, , , ).
In one study, 43% of participants following a vegan diet were able to reduce their dosage of blood-sugar-lowering medication, compared to only 26% in the group that followed an ADA-recommended diet ().
Other studies report that diabetics who substitute meat for plant protein may reduce their risk of poor kidney function (, , , , , ).
What's more, several studies report that a vegan diet may be able to provide complete relief of systemic distal polyneuropathy symptoms — a condition in diabetics that causes sharp, burning pain (29, ).
Bottom Line: Vegan diets may reduce the risk of developing type 2 diabetes. They are also particularly effective at reducing blood sugar levels and may help prevent further medical issues from developing.
According to the World Health Organization, about one-third of all cancers can be prevented by factors within your control, including diet.
For instance, eating legumes regularly may reduce your risk of colorectal cancer by about 9–18% ().
Research also suggests that eating at least seven portions of fresh fruits and vegetables per day may lower your risk of dying from cancer by up to 15% ().
Vegans generally eat considerably more legumes, fruit and vegetables than non-vegans. This may explain why a recent review of 96 studies found that vegans may benefit from a 15% lower risk of developing or dying from cancer ().
What's more, vegan diets generally contain more soy products, which may offer some protection against breast cancer (, , ).
Avoiding certain animal products may also help reduce the risk of prostate, breast and colon cancers.
That may be because vegan diets are devoid of smoked or processed meats and meats cooked at high temperatures, which are thought to promote certain types of cancers (, , , ). Vegans also avoid dairy products, which some studies show may slightly increase the risk of prostate cancer ().
On the other hand, there is also evidence that dairy may help reduce the risk of other cancers, such as colorectal cancer. Therefore, it's likely that avoiding dairy is not the factor that lowers vegans' overall risk of cancer ().
It's important to note that these studies are observational in nature. They make it impossible to pinpoint the exact reason why vegans have a lower risk of cancer.
However, until researchers know more, it seems wise to focus on increasing the amount of fresh fruits, vegetables and legumes you eat each day while limiting your consumption of processed, smoked and overcooked meat.
Bottom Line: Certain aspects of the vegan diet may offer protection against prostate, breast and colon cancers.
Eating fresh fruits, vegetables, legumes and fiber is linked to a lower risk of heart disease (, , , , ).
All of these are generally eaten in large amounts in well-planned vegan diets.
Observational studies comparing vegans to vegetarians and the general population report that vegans may benefit from up to a 75% lower risk of developing high blood pressure ().
Vegans may also have up to a 42% lower risk of dying from heart disease ().
What's more, several randomized controlled studies report that vegan diets are much more effective at reducing blood sugar, LDL cholesterol and total cholesterol levels than the diets they are compared to (, , , , ).
This may be particularly beneficial to heart health since reducing high blood pressure, cholesterol and blood sugar levels may reduce the risk of heart disease by as much as 46% ().
Compared to the general population, vegans also tend to consume more whole grains and nuts, both of which are good for your heart (, ).
Bottom Line: Vegan diets may benefit heart health by significantly reducing the risk factors that contribute to heart disease.
A few studies have reported that a vegan diet has positive effects in people with different types of arthritis.
One study randomly assigned 40 arthritic participants to either continue eating their omnivorous diet or switch to a whole-food, plant-based vegan diet for 6 weeks.
Those on the vegan diet reported higher energy levels and better general functioning than those who didn't change their diet ().
Two other studies investigated the effects of a probiotic-rich, raw food vegan diet on symptoms of rheumatoid arthritis.
Both reported that participants in the vegan group experienced a greater improvement in symptoms such as pain, joint swelling and morning stiffness than those who continued their omnivorous diet (, ).
Bottom Line: Vegan diets based on probiotic-rich whole foods can significantly decrease symptoms of osteoarthritis and rheumatoid arthritis.
Vegan diets may provide an array of health benefits.
For the most part, the exact reasons why these benefits occur are not fully known.
That said, until further research emerges, it can only benefit you to increase the amount of nutrient-rich, whole plant foods in your diet.