Today is World Vegan Day and I wanted to consider whether a vegan diet is healthy or not. I find, of all the online groups and forums I take part in, what people eat can become very dogmatic and cause arguments and raised tempers! Even environmentally aware people have an opinion on veganism now, with some suggesting that eating a plant based diet is the only way we’ll be able to feed our growing population in the future and address climate change.
For the purpose of this blog post, we’re looking at four aspects of the vegan diet – not the full lifestyle implications. (Although, as a health and wellness website, it’s interesting to note that all medicine in the UK must be tested on animals before it is deemed safe for human use, and of course, some supplements and medicines contain animals products such as lactose or gelatine. Likewise some vaccinations contain animal-based ingredients or use ingredients that are grown on eggs. Or they include an adjuvant such as fish-derived squalene) You can see how much of a minefield this is already! [Source]
This is a huge topic, which deserves a book of its own, so we’ll be focusing on four aspects of the vegan diet – whether meat is carcinogenic or not, whether cholesterol is bad for us, whether veganism is the healthiest type of diet we can eat and what humans are designed to eat. Pull up a chair, and let’s get stuck in!
What is veganism?
Put simply, veganism is a way of living which seeks to exclude all forms of exploitation of, and cruelty to, animals. Diet-wise, this means vegans eat a plant based diet which excludes all meat, fish, as well as dairy, eggs and honey.
Does that sound limiting or healthy? Let’s take a look at what people are saying:
Meat is carcinogenic
In their report “vegan diets support excellent health”, [download a copy here] the vegan society state that “Choosing a vegan diet gives more room for health-promoting plant foods while cutting out carcinogens from meat…”.
The World Health Organization classified red meat as Group 2A (probably carcinogenic to humans). And they classified processed meat as Group 1 (carcinogenic to humans). But they did not evaluate poultry.
In the case of red meat, the classification is based on limited evidence from epidemiological studies showing positive associations between eating red meat and developing colorectal cancer as well as strong mechanistic evidence. Limited evidence means that a positive association has been observed between exposure to the agent and cancer but that other explanations for the observations (technically termed chance, bias, or confounding) could not be ruled out. [source]
The World Cancer Research Fund have this to say about eating red meat and processed meat: “If you eat red meat, limit consumption to no more than about three portions per week. Three portions is equivalent to about 350–500g (about 12–18oz) cooked weight. Consume very little, if any, processed meat.”
They also point out “This Recommendation is not to completely avoid eating meat. Red meat is a good source of protein, iron and other micronutrients. For those who consume it, lean rather than fatty cuts are preferred. Poultry and fish are valuable substitutes for red meat. Eggs and dairy are also valuable sources of protein and micronutrients.” [Source]
There have been suggestions that charring meat, such as barbecuing it until the meat is blackened increases the risk of cancer. PAHs (polycyclic aromatic hydrocarbons) are formed when meat fat drips onto the flames and HCAs (heterocyclic amines) are generated from reactions between molecules including amino acids and sugars. According to Dr Simon Cotton, senior lecturer in chemistry at Birmingham University, “Animal testing has shown exposure to high levels of chemicals such as these is linked with cancer, but these are levels of exposure much higher than humans would get from eating meat. Some studies do appear to have shown that meat that has been burned, fried or barbecued is associated with higher possibilities of certain cancers, but these links are hard to prove for certain.” [Source]
Conclusion – is meat carcinogenic?
It would appear that it’s better to avoid processed meat and reduce your intake of red meat (and when you do cook it, don’t over cook or char it) to decrease possible carcinogens. But to date there is no evidence that poultry and fish are carcinogenic, so they can be enjoyed as part of a balanced, healthy diet.
Cholesterol is bad for you (or is it?)
In the report “vegan diets support excellent health”, the vegan society said “Choosing a vegan diet [cuts out] saturated fat and cholesterol“.
Viva Health state that humans don’t need saturated fat, animal protein or cholesterol. They go on to say “Eggs contain high levels of cholesterol, for which we have no nutritional need. A strong body of scientific evidence shows that high cholesterol levels in our blood increases our risk of heart disease. People who eat a lot of eggs have a higher risk of dying earlier than those who don’t – especially if they have diabetes – and those who eat lots of eggs are more likely to develop diabetes.” [Edited 23rd Sept 2021 – please note, the page I took that quotation from (vivahealth.org.uk/going-vegan/why-vegan-best) has now been removed from their site. Their most up to date information says “there is no dietary need for cholesterol at all” [source])
In the past it was suggested that we only eat three or four eggs per week, but that advice has been changed. The misconceptions around eggs and cholesterol largely stemmed from incorrect conclusions drawn from early research that dietary cholesterol contributed to raised blood cholesterol levels.
Current advice from the NHS is that there is no recommended limit on the amount of eggs we should eat per day. They go on to say “Having high cholesterol levels in our blood increases our risk of heart disease. Although eggs contain some cholesterol, the amount of saturated fat we eat has more of an effect on the amount of cholesterol in our blood than the cholesterol we get from eating eggs.” The British Heart Foundation add “Current research shows that for most healthy people, cholesterol in food, such as eggs, has a much smaller effect on blood levels of total cholesterol and harmful LDL cholesterol…”
While cholesterol is often seen as the bad guy, it actually plays a very important function in your body. It’s a structural molecule that is essential to every cell membrane. And our bodies have a pretty neat way of regulating it! If you’re not getting enough cholesterol from your diet (yes, you read that right), your liver will produce it. Conversely, when you eat a lot of cholesterol-rich foods, your your liver produces less to keep cholesterol levels from becoming excessively high. [Source].
There are two main types of cholesterol – LDL or Low-density lipoprotein cholesterol which contributes to plaque accumulation on the walls of your arteries and is called ‘bad’ cholesterol. HDL or High-density lipoprotein cholesterol discourages plaque buildup and is referred to as ‘good’ cholesterol. Cholesterol is necessary to make certain hormones, plus it’s involved in making vitamin D, which helps the body absorb calcium.
Whilst high levels of “bad” cholesterol in the blood are still a concern for heart disease, many researchers and physicians now believe that eating cholesterol-rich foods such as eggs may not affect the cholesterol that is in your blood. Not only that, but research is beginning to show that your genetic makeup – not diet – is the driving force behind cholesterol levels. [Source] So vegan diets may well be lower in cholesterol, but it’s not necessarily a beneficial thing. Some studies have shown that those with low cholesterol were more likely to have symptoms of depression and anxiety. A 2012 study presented at the American College of Cardiology Scientific Sessions found a possible relationship between low cholesterol and cancer risk. Another concern about low cholesterol involves women who may become pregnant. If you’re pregnant and you have low cholesterol, you face a higher risk of delivering your baby prematurely or having a baby who has a low birth weight. [Source]
Conclusion – is cholesterol bad for you?
Cholesterol is essential for humans. Current research shows while high levels of ‘bad’ cholesterol are still a concern for heart disease, the amount of cholesterol we eat has little effect on blood levels and that people with low cholesterol may also be at risk from certain health conditions.
A vegan diet is the healthiest diet
According to Dr Marco Springmann of the Oxford Martin Programme on the Future of Food, “Imbalanced diets, such as diets low in fruits and vegetables, and high in red and processed meat, are responsible for the greatest health burden globally and in most regions.”
Springmann discovered that a global vegan diet would result in 8.1 million fewer deaths per year. Approximately half of the avoided deaths were due to reduction of red meat consumption, with the other half due to a combination of increased fruit and vegetable intake and a reduction in calories, leading to fewer people being overweight or obese. [Source]
On their website, The Vegan Society say “Well-planned vegan diets follow healthy eating guidelines, and contain all the nutrients that our bodies need. Both the British Dietetic Association and the American Academy of Nutrition and Dietetics recognise that they are suitable for every age and stage of life.”
It would appear that the phrase ‘well planned’ is key!
While vegan diets are generally rich in fibre, vitamin C and folate; thanks to all that fruit and veg, the diet can be lacking in other vitamins and minerals. Vitamin B12 is a good example. Vitamin B12 is used for the regulation of the nervous system and in the formation of red blood cells, which carry oxygen to every part of the body. A person deficient in this vital vitamin can suffer from neurological decline, fatigue or even pernicious anemia.
Well-absorbed forms of vitamin B12 are readily available in animal-based foods such as meat, fish, eggs and dairy. Vitamin B12 is not available in plants (however, soil can contain it, so perhaps don’t wash your home grown carrots!) Fortified foods such as cereals, spreads, nutritional yeast and plant-based milks, are the only reliable food sources for vegans. Otherwise supplements are needed. The Vegan Society recommend that you should eat a food fortified with B12 at each meal, or take a supplement that contains at least 10 micrograms of B12 each day in order to stay healthy.
Vitamin D is another example. Vitamin D is needed for the formation of strong bones and teeth. A lack of this vitamin can cause bones to become soft and weak, which can result in children developing rickets or adults developing osteomalacia; where bone pain and muscle weakness are symptoms.
In the UK, most people can make enough vitamin D between March and September by exposing their skin for short periods (such as the hands and forearms or lower legs) to the sun – without sunscreen – between 11am and 3pm. There’s no formula for how long you need to expose yourself, but you want to ensure you do not burn.
Between October and early March, however, UK sunlight doesn’t contain enough UVB radiation, so need to get vitamin D from other sources. Food based sources include oily fish – such as salmon, sardines and mackerel, as well as red meat and eggs. Which means vegans are at a disadvantage. So once again, vegans need to rely on fortified foods such as breakfast cereals, fat spread and non-dairy milks or supplements.
Research over many years has linked plant-based diets to lower rates of heart disease, type 2 diabetes, and some cancers. But a new study carried out over two decades among nearly 50,000 people, raises the possibility that despite the health benefits demonstrated by past research, vegans may have an increased risk of stroke. [Related BMJ article] If we think back to cholesterol, High levels of HDL have also been shown to protect against stroke and heart attack, while low HDL has been shown to increase those risks. [Source]. Maybe there’s a link?
However, if you take any type of diet, such as the Mediterranean diet or Paleo Diet, you will find evidence both for and against them being healthy. The Mediterranean Diet has been under the spotlight for many years and while it too reduces red meat intake, it recommends fish and dairy as part of its regime.
The Paleo Diet, which relies heavily on pasture fed meat, also makes some impressive health claims.
Conclusion – is the vegan diet the healthiest?
There is some impressive evidence that a well balanced vegan diet is beneficial to health. But is it the healthiest diet for all humans? It’s questionable whether a diet that requires supplementation is healthy. However, many people now say we should all take supplements because even the healthiest diet (whatever that is!!) cannot provide all the nutrients we need due to pollution and depleted soils.
Human – omnivore, carnivore or herbivore?
Depending on where you look, you’ll find heated debates on what a human is naturally designed to eat! There is an ongoing debate within the scientific community to determine whether humans are naturally herbivores, carnivores or omnivores.
According to PETA, the natural human diet is vegan.
They compare our fingernails to claws, short canine teeth to long teeth used for ripping meat, low stomach acid, movement of our jaw and length of intestine as evidence for us being anatomically herbivorous. [Source]
Likewise in the video below, Dr William C Roberts has been reported to say “Although most of us conduct our lives as omnivores – in that we eat flesh as well as vegetables and fruits – human beings have the characteristics of herbivores, not carnivores. The appendages of carnivores are claws, those of herbivores are hands or hooves. The teeth of carnivores are sharp; those of herbivores are mainly flat (for grinding). The intestinal tract of carnivores is short (3 times body length); that of herbivores is long (12 times body length). And so it goes on through the ways we cool our bodies, drink, the shape of jaw, digestive enzymes or whether we can produce our own vitamin C.
The conclusion from Roberts is that although we behave as omnivores, we are biologically herbivores. A herbivore, such as the chimpanzee, will eat around 2-3 % meat, in the form of insects
Zoologist, Matan Shelomi says that humans are definitely omnivores and meat-eating is in our history as well as our DNA and physiology. This conclusion is based on humans having both incisors for tearing meat and molars for grinding. Shelomi also says that we lack cellulases that herbivores have, have lots of proteases inline with carnivores and that we can digest fruit too. [Source]. Samantha Hopkins, an assistant professor of geology at the University of Oregon, agrees that humans are omnivores. She too, bases her evidence on our teeth and digestive tract. [Source].
Nora Gedgaudas, a keto and ancestral nutrition specialist, believes humans are carnivores. She says “The digestive systems of pure herbivores are simply different from ours,” “We instead rely on the extraction of nutrients from the animals we consume.” She goes on to say “Our human digestive system much more closely resembles that of a carnivore than any herbivore,” “Our very physiological design clearly indicates that animal products are an integral part of human health.” and goes so far to say that humans have evolved by not relying on plant-based foods. She emphasized that “our species was never, ever even close to being vegetarian, much less vegan.” [Edit 11th Aug 2020 – These were quoted from an article on MSN which is no longer live online.]
Conclusion – what are humans really designed to eat?
What we are designed to eat is still up for debate. But one thing is for sure, with the wide range of foods available to us, we don’t need to eat meat or animal products to survive. It’s clear it’s a personal choice. While some people eat meat and animal products multiple times a day, others feel better on a plant based diet. There are some basic common sense rules we can apply such as avoiding junk food and enjoying things in moderation.
If you’re struggling to know what to eat, why not book in for a food intolerance test? By using kinesiology we can ask YOUR body what it likes to eat – giving you the perfect diet for you!