The benefits of vegetarianism for health have been particularly discussed lately.
There seems to be a clear trend: the more humanity exists, the more the question of the health benefits of a plant-based diet becomes relevant. This is also confirmed by Google search query statistics:
Main thoughts:
In the army of supporters and evangelists of the green diet, alongside scientists and doctors, famous actors, athletes, and public figures join in. A striking example is the recently controversial “Game Changer” or “Turning Point,” as it has been dubbed in Russian.
It is said that vegetarianism is good for cardiovascular health, protects against cancer, diabetes, dementia, kidney diseases, and that one can even lose weight on it.
Well, let’s dig into this trend. Below we will examine the main health benefits of vegetarianism/veganism that have scientific backing.
1 A vegetarian diet is rich in health-promoting micronutrients
Typically, vegetarianism begins with a complete/partial rejection of meat and other animal products (dairy, eggs, fish, etc.) and an increase in the proportion of plant-based foods (vegetables, fruits, legumes, nuts, and seeds).
At least, that’s how it should be.
Plant-based foods are nature’s intended sources of health-promoting substances: vitamins and minerals, antioxidants, and fiber. The more of them in the diet, the better.
Scientific studies confirm that vegetarians/vegans, on average, consume significantly more fiber, antioxidants, and biologically active plant compounds, as well as potassium, magnesium, folate (vitamin B9), vitamins A, C, and E, and significantly less saturated fat and cholesterol 1, which are considered harmful to health.
At the same time, not all vegetarian diets are created equal. Numerous studies note a high prevalence of deficiencies in essential fatty acids omega-3, protein, vitamin B12, vitamin D, iron, calcium, iodine, and zinc among vegetarians, along with significantly higher carbohydrate intake.
Facts about deficiencies are shown in a large study of over 65,000 residents of the United Kingdom, both those consuming animal products and those adhering to various forms of vegetarianism (lacto-, ovo-, pesco, strict vegetarianism) 1, as well as in a number of smaller studies 2, 3, 4.
The risk of developing various types of deficiencies is the main downside of vegetarianism, which is most often pointed out by its opponents. And it is somewhat justified.
Why? There can be many reasons.
I will name just one of them. I won’t be far off if I call it one of the most common.
Very often, the space freed from animal products in the diets of vegetarians is occupied by refined products: pasta, baked goods, various sweets – simple carbohydrates that carry an excess of calories and are very poor in the beneficial nutrients listed at the beginning.
This does not prevent such vegetarians from being called “vegetarians” in the strict sense.
What is healthier/more harmful in this case – “such pseudovegetarianism” or meat-eating – is a big question.
But an unhealthy complexion, illness, poor test results, chronic and frequent seasonal diseases, along with an increase in body fat percentage in this case should not surprise anyone.
The American Dietetic Association provides the following comment regarding this “downside of vegetarianism”:
“A well-planned vegetarian diet is appropriate for individuals of all ages, including pregnant women and lactating mothers, infants, children, adolescents, and athletes, and can provide all the necessary micronutrients and macronutrients in the right amounts.” 5
The deficiency of micronutrients and macronutrients is primarily characteristic of cases of poor dietary planning or severe calorie restriction, for example, during weight loss.
In many scientific experiments that note the risk of developing deficiencies in vegetarians and vegans, the subjects are usually on calorie-restricted diets.
Remember a simple rule: when you are on a diet and eat less, along with calorie restriction, you also limit the amount of macronutrients and micronutrients entering the body.
To avoid this, you need to be a “proper vegetarian”: build your diet primarily using whole natural foods rich in micronutrients.
One of the main advantages of vegetarianism is that plant-based foods are rich in health-promoting substances: vitamins, minerals, antioxidants, and fiber.
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2 You can lose weight on a vegetarian diet
One of the reasons for frequently turning to vegetarianism is the desire to lose weight.
Statistical data shows that vegetarians, compared to non-vegetarians, on average have a lower body mass index (percentage of body fat) 6, 7, 52, 53.
30% of Adventist vegetarians have a low body mass index, and the percentage of body fat significantly correlates with the frequency of meat consumption among both men and women 29.
In a large statistical study of over 37,800 adults following different dietary styles, it was shown that meat-eaters have the highest body mass index (percentage of fat), vegans have the lowest, and vegetarians (various types) have an average value 30.
In a 5-year study of over 22,000 healthy individuals examining the impact of various diets on long-term weight maintenance, it was shown that those participants who switched to a diet low in animal products gained less body fat over the 5 years 31.
Adults who become vegetarians in adulthood eventually reach a body mass index typical of lifelong vegetarians 32.
Those who have followed a vegetarian diet for a long time generally have a lower body mass index than those who have only recently changed their eating habits.
Among Adventists on the island of Barbados, the number of vegetarians with obesity was 70% lower among those who had been vegetarians for more than 5 years compared to those who had recently become vegetarians (less than 5 years) 33.
What does this indicate?
It indicates that the process of losing weight on a vegetarian diet is not quick. But it cannot be quick by definition.
Numerous scientific studies confirm that vegetarianism/veganism is more effective for weight loss than many other traditional diets 8, 9, 10.
Interestingly, this effectiveness is often demonstrated in experiments where participants are allowed to eat plant-based foods in unlimited quantities (as much as they want) or when participants are not consistent in following it – an undeniable advantage over diets that require constant self-restraint 56.
This distinguishes vegetarianism from other diets for weight loss, as the most effective diet for a specific person is one that they can adhere to for a long time.
One explanation for the benefits of veganism/vegetarianism for weight loss is as follows.
Plant-based foods have a lower energy density (calories per unit of volume or mass) due to their lower fat content and higher fiber content 54.
Therefore, even when consumed in relatively large quantities, they do not carry excess calories and, at the same time, provide good satiety, as the degree of satiety is proportional to the degree of stomach fullness.
Scientific studies confirm the effectiveness of vegetarianism/veganism for weight loss, even in cases where participants are allowed to eat food without restrictions, until satiation.
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3 Benefits of veganism in diabetes and from diabetes
Adventist vegetarians are less likely to suffer from diabetes than non-vegetarian Adventists 34.
According to some reports, within this organization, the risk of developing diabetes is twice as high among those who consume meat and other animal products 35.
Contrary to the widely held belief that the main cause of diabetes is the excessive consumption of simple carbohydrates and sugar in particular, scientists also identify the consumption of meat and, in particular, processed meat products 36, 37.
One report indicates a significantly higher risk of diabetes among those who regularly consume bacon and hot dogs 37.
On the other hand, increased consumption of vegetables, whole grains, legumes, and nuts is associated with a significantly lower risk of type 2 diabetes, better blood sugar control, and improved insulin sensitivity, both in healthy individuals and those with type 2 diabetes 38, 39, 40, 41.
Consuming 3 servings of whole grains throughout the day reduces the risk of developing type 2 diabetes by 20-30% 42.
Note this not-so-obvious paradox: increased carbohydrate intake is a proven factor in reducing the risk of diabetes.
The popular belief is that carbohydrates are the number 1 enemy for diabetics and those predisposed to this disease.
The key question is: which carbohydrates?
According to a non-strict, familiar classification, they can be simple and complex.
Simple or fast carbohydrates are dangerous in terms of diabetes, while complex carbohydrates are beneficial.
A large statistical study of Chinese women showed that those who consume a relatively large amount of legumes, peanuts, and soybeans have a 38-47% lower incidence of diabetes 41.
Other studies have shown an inverse relationship between vegetable consumption, but not fruit 40 and not fruit juices 55, and the risk of diabetes.
Regarding diabetic patients, a 5-month clinical study demonstrated that a low-fat vegan diet significantly improves blood sugar control: 43% of participants significantly reduced their medication dosage by the end of the experiment 44.
A large-scale study of the Adventist population (~100,000 people) confirms these findings: lacto-ovo vegetarians are 38-61% less likely to develop type 2 diabetes, while vegans are 47-78% less likely than non-vegetarians.
Such wide ranges in this and other studies are explained by the great diversity of dietary patterns even within a specific branch of vegetarianism, as well as the presence of other risk factors.
As described above, in the strict sense, a vegan is someone who completely excludes animal products, as well as someone who consumes large amounts of sweets. Naturally, the latter has a higher risk of diabetes.
Among the advantages of vegetarianism/veganism is a reduced risk of developing diabetes. However, this is only true for those vegetarians who do not abuse simple carbohydrates.
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4 Vegetarianism and Cancer
It is commonly believed that cancer is a genetic disease. And if it is written in your genes, then it is almost impossible to avoid your fate.
The author of the well-known and once controversial China Study, Colin Campbell, offers a different assessment: “no more than 2-3% of cancer cases are purely genetic in nature; all others are the consequences of diet and other lifestyle factors.”
In his book, Colin Campbell shows through numerous examples that it is the food we eat that determines our health and can both kill and heal.
A large meta-analysis of the causes of colorectal cancer involving approximately 2 million patients indicates that regular consumption of legumes reduces the risk of colorectal cancer by 9-18% 14,
A study of the lifestyle and diet of over 65,000 residents of the UK allowed scientists to conclude that “consuming 7 or more servings of fruits and vegetables a day reduces the risk of death from cancer by 25%; with vegetables being more significant” 15.
The results of another review indicate that a vegetarian diet reduces the risk of death from all types of cancer by 8%, while a vegan diet reduces it by 15% 7.
What is this related to?
There are many possible explanations.
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Red meat, smoked and grilled, and… cancer
The consumption of meat and animal protein in general is referred to by the author of the China Study as one of the main causes of cancer.
Red meat, in particular, especially processed meat (smoked, exposed to high temperatures) has well-known carcinogenic properties 16, 17, 18.
Based on an analysis of over 16,000 cases of gallbladder cancer among a population of more than 1.5 million people, scientists concluded that the risk of gallbladder cancer is 15% higher among those who regularly consume red meat and 22% higher with the consumption of processed meat products 16.
Meat cooked at high temperatures (on a grill or barbecue) contains carcinogens (polycyclic aromatic hydrocarbons and heterocyclic amines) on its surface.
Regular consumption of it may double the risk of developing breast cancer in women 17.
An analysis of over 26,000 deaths among Europeans showed a significant correlation between the consumption of red meat, particularly processed, and mortality from all causes (cancer, cardiovascular diseases, etc.) 18.
The health benefits of vegetarianism are manifested in a reduced risk of cancer, which significantly increases with the consumption of red meat, especially smoked and grilled.
Dairy products and cancer
Vegans and some vegetarians also do not consume dairy products.
High consumption of dairy products is associated with a higher risk of prostate cancer in men. A similar association has been found for calcium from dairy products, but not from supplements and other natural sources 19.
At the same time, there is evidence that the consumption of dairy products may reduce the risk of developing colorectal cancer 20.
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Some types of cancer are more common among vegans and vegetarians…
A study of Adventists (~100,000 people) showed that the risk of all types of cancer among vegans is 14% lower, while the risk for lacto-ovo-pesco vegetarians is not different from that of non-vegetarians 13.
At the same time, it is curious that lacto-ovo-pesco vegetarians are less likely to suffer from gastrointestinal cancer, while vegans are almost as likely as non-vegetarians.
Vegans have a 73% higher risk of urinary tract cancer compared to non-vegetarians.
Neither vegans nor lacto-ovo-pesco vegetarians show a lower risk of respiratory system cancer.
In a large study of UK residents (over 65,000 people), in addition to the aforementioned benefits of vegetarianism in reducing cancer risk, it is noted that vegetarians are more likely to suffer from colorectal cancer than non-vegetarians 45.
What is the reason for such contradictions?
This fact may again be indirect evidence that vegetarianism varies greatly 13, 46, 47.
Scientists explain this contradiction by suggesting that other factors not accounted for in the analysis may influence the risk of various diseases.
It is also important to understand that all the studies mentioned above are statistical: they reflect what scientists see when analyzing certain populations, most often based on surveys.
In such studies, it is unclear what exactly the respondents eat, even if they are asked relevant questions; the answers do not always reflect reality.
To establish the true causes of cancer development, strict controlled scientific experiments are required, which for ethical reasons is not possible.
Vegetarianism/veganism may reduce the risk of cancer, including prostate cancer in men, breast cancer in women, and colorectal cancer. At the same time, individual studies show a higher risk of certain types of cancer among vegetarians and vegans.
5 Vegetarianism and Cardiovascular Diseases
One of the most frequently cited benefits of veganism by proponents of plant-based diets is the reduced risk of heart and vascular diseases, which is also supported by numerous studies.
In particular, the consumption of vegetables and fruits (more so vegetables) 15, fiber 21, 22, and legumes 23, 24 is associated with a lower risk of disease and death from cardiovascular diseases (stroke, ischemic heart disease (arterial blockage), heart attack, etc.).
A large study of vegetarians (with a total of ~100,000 people) showed that abstaining from meat reduces the risk of mortality from cardiovascular diseases by 26-68% 13.
For lacto-ovo-pesco vegetarians, the risk of developing hypertension (high blood pressure) is 55% lower, and for vegans, it is 75% lower compared to non-vegetarians.
The risk of mortality from cardiovascular diseases is 23% lower for lacto-ovo-pesco vegetarians and 42% lower for vegans.
This positive effect of a plant-based diet on cardiovascular health may be explained by the reduction in blood sugar, cholesterol levels, and blood pressure—known factors that increase the risk of diseases in this group 25.
On the other hand, vegetarians tend to consume more grains and nuts, which are beneficial for heart health.
According to scientific data, the risk of blockage in the vessels supplying the heart is 37% lower for those who include nuts in their diet more than 4 times a week compared to those who never do or do so sporadically 26.
Those who consume 2-3 servings of whole grains per week have a 21% lower risk of cardiovascular diseases. However, refined grains in the form of breakfast cereals, products made from white refined flour, or rice do not have this effect 27.
A vegetarian diet rich in whole grains, legumes, vegetables, and fruits significantly reduces the risk of cardiovascular diseases and death from these causes.
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6 Vegetarianism is beneficial for joint health
Another advantage of vegetarianism is its positive impact on joint health.
Prescribing a plant-based diet based on whole foods to individuals with joint diseases (osteoarthritis) for 6 weeks led to significant improvements in their condition (physical activity, pain perception, inflammation in the joints) compared to the control group 28.
Similar results were obtained in other similar studies 49, 50, 51.
This positive effect of a plant-based diet is explained by the fact that the standard Western diet is saturated with animal proteins in various forms, which stimulate the production of arachidonic acids in the body – precursors of inflammatory processes.
A whole plant-based diet does not contain these acids in large amounts and suppresses inflammatory processes, alleviating arthritis symptoms 48.
The author of the aforementioned China Study – a book that can be considered a scientific justification for the benefits of vegetarianism – points out that a plant-based diet can be beneficial and may even be the only means of treating such a serious autoimmune joint disease as rheumatoid arthritis, one of the probable causes of which is the consumption of animal proteins, primarily in the form of milk and dairy products.
Incomplete breakdown of protein molecules into amino acids during digestion leads to an autoimmune reaction, resulting in immune cells beginning to destroy joint cartilage.
A vegetarian diet is beneficial for joint health and improves symptoms of joint diseases (osteoarthritis and rheumatoid arthritis).
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Conclusion
Numerous studies confirm the health benefits of vegetarianism/veganism. This is hard to dispute.
Yes, most of these studies are statistical and do not explain the exact mechanism of action of a plant-based diet, but for us, ordinary people, this is precisely what we need: not scientific calculations, but practical results.
Based on the studies reviewed and many others, we can draw the following conclusion: the consumption of plant-based foods is critically important for health.
In the common sense, vegetarianism, unlike veganism, implies not a complete rejection of animal food.
Therefore, in the context of discussions about the health benefits of vegetarianism, a logical question arises: does it matter whether there is a complete exclusion of animal food or a change in the ratio between animal and plant foods in favor of plant foods?
There are various opinions on this matter.
Colin Campbell, the author of the China Study, believes that “moderation kills“, recommending a complete elimination of animal products.
The compilers of the Encyclopedia of Sports Nutrition, when considering the benefits of vegetarianism in sports, point out that it is unclear whether some advantages of vegetarianism mentioned in several studies are related to a complete rejection of meat or to an increase in the proportion of plant foods in the diet.
However, it can be confidently said: for anyone who cares about their health, it is important, if not to completely eliminate animal products, at least to strive to saturate their daily diet with whole, natural plant foods: vegetables, fruits, nuts, legumes, and grains.
