Are vegan diets nutritionally deficient?
Once upon a time, the word ‘malnutrition’ conjured up a picture of an emaciated child with a bulging belly due to Kwashiorkor malnutrition,
Whilst this is still a sad truth in swathes of the developing world, in Western countries we too are suffering from malnutrition.
Our malnutrition looks different. We too have bulging bellies! But alongside those expanded waistlines we also now expect to spend a good decade or more suffering from cancer, heart disease, dementia or a whole host of unnecessary diseases.
So, is a whole food plant-based diet without animal products too restrictive to provide enough nutrients?
Not enough protein?
The first time I spoke to someone about their Whole Food Plant Based Vegan diet, I asked them the same question that pops up in most peoples’ minds “Where do you get your protein from?”.
It means I can’t cringe when people ask me this now (read on for the answer to this by the way)!
My immediate thought was that a vegan diet is extreme and must be very restrictive.
I did a lot of research before deciding that it was a switch that I needed to make. And yet, though I made some changes, I did not make a total commitment for another 9 months.
I worried about knowing how to cook easy, nutritious and tasty meals without my go-to tasty and filling ingredients like cheese (halloumi salads and wraps, pasta bakes, aubergine parmagianna, paneer tikka masala…the list goes on!) and yogurt.
In some respects my concerns were valid;
Had I continued to eat the exact same diet but remove the dairy (and occasional eggs), my diet would indeed have been restrictive, unsatisfying and nutritionally insufficient.
This is where the important difference lies between studies that look at vegans in western society compared with indigenous cultures who eat little or no animal products; the diets of cultures who eat predominantly plants have evolved to be nutritionally balanced and satisfying so people generation after generation continue to follow their cultural dietary practice.
Rather than dying out from a lack of animal products, they have the lowest rates of heart disease, dementia, stroke, diabetes and cancer.
In fact, the 5 ‘Blue Zones’ in the world (these are pockets of populations that are known to have the highest life expectancy, and more importantly the longest HEALTHY life expectancy with people well into their 80s, 90s and even 100s still in excellent physical health) eat a predominantly plant based diet. One of them (the 7th Day Adventists of Loma Linda, California) are even essentially vegan. The remainder eat only a small portion of meat (the size of a deck of cards) only a handful of times per month.
In other words, we are realising that a shift away from animal products towards primarily plant proteins is more optimal.
My husband was raised an omnivore, but decided in his late teens to adopt a vegetarian diet. He did what a lot of people do — he ate the same meals that his family ate minus the meat.
This amounted to some boiled veg and salad. At university he improved somewhat by throwing fruit and veg with some nuts into a blender and (this being prior to the advent of the NutriBullet), downed the lumpy puree daily in order to mitigate the risk of nutritional deficiencies. He would then spend the rest of the day feeling hungry and eating pizza and donuts. Naturally he lapsed frequently from his intention to become vegetarian because who would choose to eat like this indefinitely?
So really, nutritional deficiencies in a vegan diet will occur if you eat a typical western diet without the animal products.
But in fact, nutritional deficiencies are the problem of the typical Western diet anyway, whether that includes animal proteins or not.
Here is why:
1. The main problem of Western diets is overconsumption rather than underconsumption.
There is no doubt that waistlines are increasing worldwide. And along with these burgeoning waistlines are a growth in serious health problems.
Unprocessed plant foods are the least calorie dense. In fact, some are so low in calories that the effort to digest them is greater than the calories that they themselves possess!
Of the 3 macronutrients (carbohydrate, fat and protein), people worry a lot about consuming enough protein on a diet absent of animal products.
How much protein do we actually need? According to the British Nutrition Foundation:
”The Reference Nutrient Intake (RNI) is set at 0.75g of protein per kilogram bodyweight per day in adults. This equates to approximately 56g/day and 45g/day for men and women aged 19–50 years respectively.”
To put this into context:
It is clear that plant foods also contain protein, and certainly enough to provide the recommended amount if you are eating a varied diet.
Now consider this; that 85g serving of beef would also come with nearly 4g of saturated fat. And whilst the 85g ham would only have 1.2g of saturated fat, it comes with 1125mg of sodium.
The lentils, kale and hempseeds however come with fibre (ONLY found in plant foods, none in animal foods), heart healthy fats and a wealth of antioxidants (again ONLY found in plants) as well as phytonutrients.
In fact, according to the British Nutrition Foundation, the average person in the UK is exceeding this recommended protein intake, with the average UK man consuming 88g/day and the average UK woman consuming 64g/day.
Does it matter? Actually, yes.
Studies now indicate that eating above the recommended amount of protein is harmful to health. It increases the risk of diabetes, kidney disease, impacts bone health and even cancer risk.
Compare this with fibre intake, which should be 30g/day, but in fact the average UK adult consumes a mere 18g/day.
Fibre is a very under-appreciated nutrient because frankly its function is to pass through us unabsorbed. But actually, that’s how it does it’s magic. It is critical to our gut health. It is the wonderfood for our gut bacteria which ferment it to make butyrate. Butyrate in turn feeds the cells lining our gut. A beautiful symbiosis. Keeping the lining of our gut healthy and the balance of gut microbes in balance is critical to our immune system, modulating inflammation and thus protecting us from chronic illness and cancer.
Fibre also expands in our stomach, activating our stomach stretch receptors to signal a feeling of fullness. It is therefore a very important tool in healthy weight management.
2. People don’t eat ‘protein’, ‘vitamins’ or ‘minerals’…..we eat ‘food’
When we cook a meal we don’t (well, not most of us anyway!) think
- ‘have I covered my vitamin A here?’, or
- ‘have I met my iron requirement?’, or
- ‘how much selenium is in this meal?’
What we actually do is eat a general pattern of foods, and this pattern is repeated regularly. For example:
(a) a plate with the main player being the chicken/beef/lamb, plus a certain number of vegetables and perhaps a salad
(b) a plate with the main players being rice/pasta/noodles with beans/lentils/tofu plus vegetables and perhaps a salad
Whether you exclude animal products or not, eating in the pattern of option (b) is much more likely to help you achieve the range of nutrients you need on a regular enough basis to keep you healthy, keep you at an optimum BMI, and prevent you getting a chronic disease including heart disease, dementia and cancer.
We have learned that you can’t really eat fantastic amounts of some nutrients and not others and have optimum health — the goodies in our food are not solo artists, they behave like members of an orchestra playing a symphony and they are more than the sum of their individual parts.
Avoiding red and processed meat is a really positive step, and thinking of meat as a condiment rather than a central part of the meal is key. If you can have meals with no meat on occasion that is fantastic. At first you may think it is going to be difficult but time and time again the feedback we get is that it turned out to be much easier than anticipated and nobody (including the kids!) missed the meat.
Most things seem like a big deal until you do them.
The UK Biobank is a study of half a million people in the UK who were recruited in 2006 from NHS patient registers. A vast volume of information is collected on these volunteers, including diet and lifestyle surveys, various physical and mental assessments, and blood and urine samples were stored from each person. The aim is to see whether after following these people over many years we can figure out what it is that people do that causes illness and death.
In one of their studies taking a cohort of nearly 200,000 people, they found that regular meat eaters consumed 25% of their calories from animal foods. Given how calorific these foods are this meant that the remainder of their plates were not very filled with antioxidant rich foods.
In fact, the vegans in the study consumed 64% more fruit and over 100% more vegetables than the meat eaters.
It is worth considering what you make room in your stomach for!
3. Quality and Quantity has Changed with Time
We are habituated to think that the way our parents raised us is the way they were raised, and that is how their parents were raised. Things turned out more or less fine, and their health was on a par with that of their peers so why venture into the unknown when we have the evidence of our own family history right?
Well, no.
According to ‘Eating-better.org’ “The fat content of chicken increased from 8.6 grams of fat per 100 grams in 1970 to 22.8 grams of fat in 2004. Chicken now offers 69% less iron than in 1940 and five times less omega-3 than in 1970.”
Shirley Cramer, Chief Executive of the Royal Society for Public Health says: ‘We know that for human and planetary health we should all be eating less and better meat and more plants, yet our chicken consumption has been increasing as a substitute for red meat. We need to get the message out that chickens today have over twice the amount of fat of chickens consumed in 1970 and have fewer essential nutrients, they are not the answer.’
So whilst many think that replacing red or processed meat with poultry is a healthy choice the reality is that it isn’t.
Not only are the animal products that peoples‘ parents and grandparents ate are not what is on offer today, but studies demonstrate that health outcomes are not great no matter what the source of animal protein.
and finally….
4. What about the protein question?
Proteins are made up of amino acids. In fact, the whole purpose of eating proteins are so that we can break them back down again into their constituent parts and repurpose them to make the proteins that we need! A little like taking a car apart and making a new car!
In some ways, that analogy works very well. We can make amino acids, but not all of them. The ones we can’t make are called ’essential’ amino acids — we have to get them from our diets. Animal foods contain them in exactly the correct proportions. To stay with the analogy we are trying to make a new car using the components of another car.
Whilst plant proteins don’t have the amino acids in the same exact proportions as we need them (more like making a car from a toaster, a combine harvester and a lorry), EVERY component we need is there. This is particularly the case if you combine wholegrains with legumes. Ancient dietary wisdom found in eg rice and beans, or dhal and rice.
A recent meta-analysis looking at protein from animal and plant sources found there to be a dose-response improvement in cardiovascular and all-cause mortality with higher intake of plant protein but NOT animal protein. They concluded that replacing animal foods with plant foods may be associated wtih longevity.
According to Professor David Sinclair -a world expert in the genetics of ageing at Harvard University, the exact type of protein restriction found in a vegan diet (long chain amino acids and methionine) has been shown in every single species studied to extend healthy life expectancy.
Why?
Because we have evolved-when things are in abundance-to reproduce (or as an organism, to divide our cells). But mild physiological stressors eg intermittent fasting, exercise or even mild protein restriction, cause that cell division to pause and switch to ‘housekeeping’ functions such as DNA repair.
In other words, whilst giving our body what it needs is important, flooding it with animal proteins is to our detriment.
Food for thought.
