Veganism is perhaps one of the most controversial diets out there. For some, being vegan is the new black. It’s more than just a diet for them; it’s a lifestyle and they embrace It wholeheartedly. They say that going vegan is the single biggest way to reduce your environmental impact on the planet. Others however, say it is simply not sustainable and leads to deficiencies of many nutrients. Although many claim to be vegan, it is still a diet that is scorned and misunderstood by many.
But what does the science say? What health benefits does a vegan diet offer? Is it really worth giving up that steak for the lettuce? Before we look at the health benefits of going vegan, let’s define what exactly a vegan diet entails.
What is a Vegan Diet?
A vegan diet is an eating pattern that encourages consumption of unrefined plant foods and discourages meats, dairy products, eggs and processed foods. It is one step further from vegetarianism as it avoids dairy and eggs and for some, honey too.
For some, shunning dairy, meat and other animal products may seem like an extreme sacrifice. For others, the personal and environmental benefits make the choice a no-brainer. For example, many vegans are concerned about the welfare of animals but for many, the health benefits of a plant-based diet alone are enough to prompt many to give up that steak.
The evidence suggesting eating a vegan diet has positive health benefits is not hard to come across, even in the contentious field of nutritional science. In fact, studies show that whole food plant-based vegan diets are preventative against 8 of the top 10 leading causes of death (the others being non-diet related i.e. accidents).
But like all diets, there is such a thing as a good vegan and a bad vegan. You could be vegan and avoid all animal products but still be unhealthy if you’re consuming lots of processed vegan food and sugar. But if your diet is appropriately planned, veganism can be very healthful, nutritionally dense and may provide health benefits in the prevention and treatment of many diseases.
So what are some of the main health benefits of going vegan?
Health Benefits of a Plant-based Diet
Better heart health
Vegan diets have been shown to have up to 42% lower risk of dying from heart disease. In one study, researchers studied lapsed vegetarians to see what impact meat consumption has on disease rates. People who once ate vegetarian diets but then started to eat meat at least once a week experienced a 146% increase in odds of heart disease, a 152% increase in stroke, a 166% increase in diabetes, and 231% increase in odds for weight gain. During the twelve years after the transition from vegetarian to omnivore, meat-eating was associated with a 3.6 year decrease in life expectancy.
Some studies show that vegans report less hypertension than the general population and in fact, benefit from up to a 75% lower risk of developing high blood pressure. Several randomised 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 blood pressure, cholesterol and blood sugar levels may reduce the risk of heart disease by as much as 46%. Vegans also tend to consume more fruits, vegetables, whole grains and nuts which are important for heart health due to their high fibre content.
Lower cancer risk
Vegan diets are associated with a 15% lower incidence of developing or dying from cancer. They tend to regularly consume legumes which can reduce their risk of colorectal cancer by abut 9-18% and plenty of fresh fruits and vegetables which lowers the risk of dying from cancer by up to 15% due to the higher levels of health-promoting substances (such as ascorbic acid, carotenoids, and flavonoids). Also, plant-foods contain a lower level of some carcinogenic components than animal products such as dioxins. Avoiding certain animal products such as smoked or processed meats, meats cooked at high temperatures and dairy have also been associated with a reduced risk of prostate, breast and colon cancer.
In a 2014 study of 61,647 British people who were followed up for almost 15 years, the researchers found that for the 2,246 vegans, the incidence of cancer was 19% lower than the omnivorous group. Another study that has looked at vegans as a separate group is the AHS-2 study, which has reported a 16% reduction of risk of cancer amongst vegan Adventists compared to omnivorous Adventists. Comparing the diets of 100 women with breast cancer to 175 healthy women, researchers concluded that scoring higher on the whole plant food diet index (greater than about thirty compared to less than about eighteen) may reduce the odds of breast cancer more than 90%. This may be attributed to the fact that vegan diets tend to generally consume more soy products which may offer some protection against breast cancer.
A number of chemotherapy drugs have been developed to restore our body’s natural defences, but their use has been limited due to their high toxicity. There are however, a number of compounds distributed widely throughout the plant kingdom- including beans, greens and berries- that appear to have the same effect naturally. For example, dripping green tea on colon, oesophageal or prostate cancer cells has been shown to reactivate genes silenced by cancer that can stop the cancer in its tracks. Also, three hours after eating 50g of broccoli sprouts, the enzyme that cancers use to help silence our defences is suppressed in your bloodstream to an extent equal to or greater than the chemotherapy agent specifically designed for that purpose without the toxic side effects.
People on a vegan diet tend to be thinner and have lower body mass indexes (BMIs) than non-vegans. Also, one 2015 study found that vegan diets were more effective for weight loss than other diets and was actually better for providing macronutrients! Many animal foods are high in saturated fat and calories whereas plant-based foods like fruits and vegetables tend to be less calorie-dense and can help people manage their weight more effectively.
Lower risk of type 2 diabetes
Being vegan may also have benefits for the prevention of type 2 diabetes. According to a 2009 study, vegans tend to have lower blood sugar levels, higher insulin sensitivity and up to a 50-78% lower risk of developing type 2 diabetes. In a systematic review and meta-analysis on prospective observational studies assessing the association between plant-based dietary patterns and risk of type 2 diabetes among adults, greater adherence to plant-based dietary patterns, especially those rich in healthful plant-based foods, is associated with a lower risk of type 2 diabetes.
Can reduce pain from arthritis
Vegan diets based on probiotic-rich, anti-inflammatory whole foods can significantly decrease symptoms of osteoarthritis and rheumatoid arthritis. A 6-week, prospective randomized trial designed to assess the effectiveness of a whole-food, plant-based diet on the reduction of osteoarthritis symptoms when compared with an ordinary Western diet, found that those on the vegan diet experienced a significant improvement in self-assessed measures of functional status and higher energy. Two other studies investigated the effects of a probiotic-rich, raw food vegan diet on symptoms of rheumatoid arthritis. Both concluded that the two vegan groups experienced a greater improvement in symptoms such as pain, joint swelling and morning stiffness.
Improved bone health
Contrary to popular belief, studies have shown that despite lower calcium consumption amongst vegans, they still tend to have improved bone health.
One study compared the rate of bone mineral density loss and fractures of 88 vegan and 90 omnivorous women over the age of 50, two years after the baseline measurement. At baseline, the vegans had significantly lower dietary intakes of calcium and vitamin D as well as total protein and fats. In spite of this, the study found that there was no difference in fracture rates between vegans and omnivores, but that higher intakes of animal protein and fat was associated with greater bone loss.
This may be due to the increased consumption of fruits and vegetables, vegans tend to have a lower renal acid load, which reduces urinary calcium excretion and bone resorption. Furthermore, vegans do not consume preformed vitamin A, which is known to cause a reduction in bone mineral density if it is consumed in large amounts.
Lower risk of other diseases (Parkinson’s, Diverticular)
Vegan diets on a whole have been associated with a reduced risk of many chronic diseases. For example, in one large Oxford study, a sub-cohort of 15,459 participants combining vegetarians and vegans, was found to have a 30% reduced risk of diverticular disease compared with a sub-cohort of 31,574 omnivores. Just taking the vegans into account, the researchers found a 72% lower risk when compared to the omnivores. Whilst researchers have typically associated this lower risk with the tendency of vegans to consume more fibre, a higher and long-term consumption of flesh and milk products has also been correlated with a higher incidence of diverticular disease.
Vegan diets have also been theorised to be protective and even therapeutically beneficial in Parkinson’s disease due to its health benefits on vascular health and blood transport of L-dopa. The calories restriction was also found to be protective of the central nervous system of mice. There is also evidence that dairy product consumption increases risk. Whilst the rationale is promising, the research is inconclusive and more needs to be done in this area.
The issues with dairy
We have been told many a time that milk and other forms of dairy products are an essential component to a balanced diet and if you don’t consume them, this will lead to deficiencies such as calcium. However, farming methods have changed dramatically in the last one hundred years and modern dairy products are highly processed foods. The process of obtaining milk from a cow to being available in our supermarkets is damaging to the nutrient composition and destroys a number of enzymes. Hormones and antibiotics are also finding their way into our milk which causes further damage to our health. All of these changes reduce the ability of the body to absorb and utilise nutrients such as calcium and vitamin A, C, E and K.
Furthermore, dairy is considered to be a rising issue for many people. Lactose intolerance is a condition in which people are not able to breakdown and digest lactose which is the sugar found in milk. The enzyme responsible for breaking down lactose is lactase and as we get older, we produce less of this enzyme. Some people experience a deficiency of this enzyme anyway and if they are unable to breakdown the lactose properly, this can lead to symptoms such as bloating, abdominal pain, gas, cramping, diarrhoea and constipation.
Another component of dairy that a number of people react to is casein, the protein component of dairy products. However the protein structure differs from animal to animal, the A1 beta-casein protein found in most dairy cow milk products is often the issue for many individuals whereas the A2 beta-casein protein found in alternate cow’s milk; such as jersey products, goat, sheep and buffalo are often more tolerated. If someone reacts to casein, symptoms they may experience include eczema, dermatitis, fatigue, frequent ear infections, bloating, diarrhoea and nausea.
A vegan diet is richer in certain nutrients
This is a bit of a controversial point. Vegan diets, if not appropriately planned, often provide insufficient amounts of certain nutrients such as essential fatty acids, vitamin B12, iron, iodine and zinc.
However, what opponents of the vegan diet often forget, is that the vegan diet is often richer in other nutrients. For example, eliminating meat and animal products, means that vegans inevitably rely more heavily on other foods such as whole grains, fruits, vegetables, legumes, nuts and seeds- foods that are nutrient dense. Several studies have reported that vegan diets tend to provide more fibre, antioxidants, and beneficial plant compounds. They’re also richer in potassium, magnesium, folate, and vitamins A, C and E.