People choose a vegetarian or vegan diet for a number of reasons. Sometimes it's out of concern for the way animals are treated or for the environment. But it's also common to choose a plant-based diet because it's considered healthier.
And that's for good reason. Research over many years has linked plant-based diets to lower rates of heart disease, type 2 diabetes, and some cancers (as compared with diets high in meat and other animal products). Dietary guidelines and recommendations from nutrition experts reflect this, encouraging the adoption of diets (such as the Mediterranean diet and the DASH diet) that are heavy on fruits and vegetables and restrict consumption of red meat.
Popular plant-based diets include
- a vegetarian diet, which includes no meat
- a vegan diet, a type of vegetarian diet that excludes not just meat but also animal products, such as milk or eggs
- a pescatarian diet, which is largely vegetarian but also includes seafood.
Plant-based diets carry some risk of inadequate protein, vitamin, and mineral intake. But these risks are readily overcome by choosing the right vegetarian foods and, when necessary, supplements. For example, soy, quinoa, and nuts are good sources of protein, and tofu, lentils, and spinach are good sources of iron.
But a new study, published in the medical journal The BMJ, raises the possibility that despite the health benefits demonstrated by past research, plant-based diets could come with a previously unrecognized health risk.
Vegetarians and vegans may have an increased risk of stroke
Researchers in the United Kingdom analyzed the risk of stroke and other health problems over two decades among nearly 50,000 people based on the diets they followed. The types of stroke were also analyzed, including bleeding into the brain (hemorrhagic stroke) and nonbleeding stroke (ischemic stroke). Compared with meat eaters:
- rates of heart disease (such as angina or heart attack) were 13% lower in pescatarians
- rates of heart disease were 22% lower in vegetarians
- rates of stroke were 20% higher among vegetarians. However, the overall risk was small, equal to three extra cases per 1,000 people over 10 years.
- the higher stroke risk among vegetarians was mostly due to hemorrhagic stroke
- the higher stroke risk was not observed among pescatarians.
If confirmed, these findings will complicate the way we look at plant-based diets. Are there serious and underappreciated downsides to these diets that should make us think twice about choosing them? Or is the increased risk of stroke heavily outweighed by cardiac and other health benefits?
This study is also a reminder that the health impact of a particular intervention (such as diet) may not be easy to predict or explain. In most cases, the risk of stroke and heart disease tend to rise or fall together, but that wasn't the case in this research.
Beware the study's limitations
This study linking a vegetarian diet with a higher risk of hemorrhagic stroke has a number of important limitations that should temper the concerns of vegetarians.
- The study was observational. That means it simply observed what happened among different people who followed different diets over time, without being able to account for every other relevant factor. For example, if vegetarians chose plant-based diets because of a family history of stroke, it could be their genes driving the higher rates of stroke, not the diet.
- The findings might have been different if the study had included a different study population, such as one with different genetic backgrounds or higher rates of obesity.
- The data regarding diet was self-reported. While the use of dietary surveys is common and necessary in research that requires a large number of study subjects, it isn't always reliable.
- The study was not large enough to reliably sort out differences in the rates of disease between vegans and vegetarians. As a result, it's not clear whether the increased stroke risk applies to all vegetarians, or whether vegans might have a different risk.
- We don't know whether the health outcomes reported in this study might be due to what is included in the diet or what is eliminated. For example, is the lower risk of heart disease among vegetarians due to the plant-based diet, or is it just due to the restriction of animal-based products?
Even so, the results are worthy of our attention — and future study.
The bottom line
If the findings of this new research stand the test of time (and future study), a key question will be: how does a vegetarian diet increase the risk of stroke? Understanding how one's diet impacts the risk of stroke and other disease will be crucial in future dietary recommendations and other preventive measures and treatments.
FAQs
Most adults can benefit from a plant-based diet. Research shows plant-based diets may prevent and treat chronic diseases and reduce dependence on medications. If you suffer from a digestive disease, consult your doctor prior to changing your diet.
Do cardiologists recommend plant-based diet? ›
A whole-food, plant-based diet can be an effective tool for managing heart disease—that's the consensus of the American Heart Association, the American College of Cardiology, and a number of published scientific studies, including a 2023 clinical trial that saw participants lower their cholesterol in a matter of weeks ...
What is the downside of a plant-based diet? ›
Plant-based diets carry some risk of inadequate protein, vitamin, and mineral intake. But these risks are readily overcome by choosing the right vegetarian foods and, when necessary, supplements. For example, soy, quinoa, and nuts are good sources of protein, and tofu, lentils, and spinach are good sources of iron.
Is a vegan diet healthy in Harvard? ›
Plant-based diets offer all the necessary protein, fats, carbohydrates, vitamins, and minerals for optimal health, and are often higher in fiber and phytonutrients. However, some vegans may need to add a supplement (specifically vitamin B12) to ensure they receive all the nutrients required.
Can I eat eggs on a plant-based diet? ›
Eggs can and should be part of a plant-based diet, and these five suggestions showcase how easy it is to incorporate the incredible egg into your plant-forward dishes.
Do you live longer on a plant-based diet? ›
A team of researchers at Loma Linda University in the United States has shown vegetarian men live for an average of 10 years longer than non-vegetarian men — 83 years compared to 73 years. For women, being vegetarian added an extra 6 years to their lives, helping them reach 85 years on average.
Can heart failure be reversed with plant-based diet? ›
Groundbreaking research shows that a plant-based diet doesn't just prevent heart disease but that it can manage and sometimes even reverse it.
Can you eat rice on a plant-based diet? ›
Whole foods are foods in their natural state or foods that have been minimally processed; think canned beans or frozen vegetables. Foods like olive oil, bleached flour, refined sugar and white rice, even though they are plant-based, are all processed foods and are not included in a WFPB diet.
Can you eat bread on a plant-based diet? ›
Multigrain breads, whole grain breads, and breads that use sprouted grains, such as ezekiel bread are packed with health benefits and are great for a plant-based diet. Breads made from refined flours do not contain the fiber and protein that whole grain, multigrain, or sprouted grain breads offer.
What foods should you avoid on a plant-based diet? ›
You'll restrict grains and foods made with them, such as bread and pasta. You also limit starchy vegetables like potatoes and corn, as well as beans and legumes. And you'll cut high-sugar tropical fruits such as pineapple, mango, and bananas, as well as fruit juices and sweets.
The 10 best vegan meat alternatives
- Lupin protein. ...
- Green spelt. ...
- Oat flakes. ...
- Black beans. ...
- Chickpeas. ...
- Pea protein. ...
- The risks of meat consumption. ...
- ProVeg supports the availability of plant-based meat alternatives. ProVeg does not only point out healthy, cruelty-free alternatives but also makes them more readily available.
Plants are high in fiber.
Eating a plant-based diet improves the health of your gut so you are better able to absorb the nutrients from food that support your immune system and reduce inflammation. Fiber can lower cholesterol and stabilize blood sugar and it's great for good bowel management.
Why are people against plant-based diets? ›
Studies elsewhere have found that vegan diets can be deficient in other micronutrients, including vitamin D, iodine, selenium, riboflavin and vitamin B12. The latter can be particularly problematic, since it does not occur in plants, therefore vegans must rely on taking vitamin B12 supplements to acquire enough.
Can you eat cheese on a plant-based diet? ›
Following a plant-based diet means saying goodbye to all animal products — including lean meat and dairy products such as milk, yogurt, cheese and ice cream.
Can you eat pasta on a plant-based diet? ›
Vegans can eat whole grain pasta as long as it does not include egg or other non-vegan ingredients. Whole grain pasta is also plant-based in most cases, but be sure to read the ingredients before purchasing. Whole-grain pasta has the added benefit of extra fiber and is a good addition to any vegan diet.
Is plant-based really better than meat? ›
Vegetarians and vegans typically have lower body mass index, serum low-density lipoprotein (LDL) cholesterol and blood pressure than comparable regular meat-eaters, as well as lower bone mineral density.
How long does it take for your gut to adjust to a plant-based diet? ›
Going from a Meat-Based Diet to a Plant-Based Diet
Our bodies will especially need to adjust to a much higher intake of fiber (a great thing!), but to which our digestive system needs to adapt over the course of the first few weeks or months.
Is being vegan actually healthier? ›
Vegan diets have also been shown to help in the treatment of type 2 diabetes by lowering total and LDL cholesterol and by controlling lipid levels, for example by reducing triglycerides, a type of fat that is also associated with a greater risk of heart disease (Jenkins et al.
Do vegans live longer than meat-eaters? ›
A 2013 study published in the JAMA Internal Medicine journal found that “vegans have a 9% lower risk of death from all causes compared with omnivores”, according to Live Science.
