Benefits of a Plant-Based Diet
By Dr Shireen Kassam, Director of Plant-Based Health Professionals UK
A plant-based diet is one that focuses on the consumption of fruit, vegetables, whole grains, beans, nuts and seeds, whilst minimising or avoiding animal-derived and processed foods. There is no precise medical definition of a ‘plant-based diet’, and it includes vegan (100% plant-based), vegetarian and flexitarian diet patterns. Most people consider a plant-based diet one where at least 85% of calories are derived from plant foods. There are numerous benefits to this way of eating and it is healthy and safe to do so at all stages of life.
So, what are some of the expected benefits?
Maintaining a healthy weight
A healthy diet is the main way to maintain a healthy weight. A plant-based diet consists predominantly of foods which are lower in energy density, yet packed full of essential nutrients. People following a 100% plant-based or vegan diet tend to have an overall lower body mass index when compared to people following non-vegan dietary patterns.
One of the most important nutrients for maintaining a healthy weight is fibre and this is only found in plant foods. Fibre not only keeps you feeling full for longer, but it also promotes a healthy gut microbiome, which in turn positively impacts body weight.
On a plant-based diet, you can usually eat to fullness without overly worrying about portion control or calorie counting. You are also less likely to gain weight over time. This is certainly true when you concentrate on eating minimally processed plant foods, as close to nature as possible.
Reducing the risk of high blood pressure
High blood pressure or hypertension is a leading cause of illness, especially heart disease, a major cause of death in the UK. Yet for most people it is possible to maintain a normal blood pressure throughout life by adopting healthy lifestyle habits. These include regular physical activity, avoiding tobacco smoking and alcohol consumption, sleeping well and managing stress.
When it comes to diet, plant-based diets are best for maintaining a healthy blood pressure and can have a similar blood pressure lowering effect to medications. A vegan diet may have the greatest beneficial impact on blood pressure, in part due to the association with lower body weight.
There are certain foods and nutrients within a plant-based diet that stand out in their ability to reduce blood pressure. These include whole grains, legumes and nuts and seeds. Nitrate-rich vegetables, such as leafy greens and beetroot, including beetroot juice, dilate the blood vessels and reduce blood pressure. Flaxseed and hibiscus tea are also useful additions.
Minimising salt / sodium consumption is essential for maintaining a healthy blood pressure although it is worth noting that most salt in the diet comes from ultra-processed foods rather than the salt used in cooking or for flavouring. Increasing the intake of potassium by eating more fruit and vegetables benefits blood pressure control. For those trying to cut down on salt (sodium chloride), switching to potassium chloride salt, may be beneficial, although caution is required for people with chronic kidney disease and those taking medications that elevate blood potassium levels.
Reducing the risk of high cholesterol
As animal-sourced foods are progressively removed from the diet, blood cholesterol levels fall. People who eat a vegan or 100% plant-based diet, tend to have the lowest cholesterol levels of all diet patterns. This is because a plant-based diet avoids or minimises ‘nutrients’ that increase blood cholesterol, namely saturated fat, and to a lesser extent dietary cholesterol. It also emphasises nutrients that naturally keep blood cholesterol low, such as fibre and unsaturated fatty acids.
Some standout foods for lowering cholesterol that are part of the Portfolio diet are nuts and seeds, plant protein (chickpeas, soya, beans), foods high in viscous fibre, plant sterols and oils high in monounsaturated fatty acids, such as extra virgin olive oil.
Reducing the risk of type 2 diabetes
Type 2 diabetes is driven by insulin resistance, a condition caused by the abnormal accumulation of fat inside the muscle, liver and pancreatic cells. This fat accumulation inhibits the action of insulin and thus leads to elevated blood glucose levels.
Plant-based diets, including vegetarian and vegan diets, are associated with a significantly lower risk of type 2 diabetes, in part, but not exclusively due to the beneficial impact on body weight. Plant-based diets are also central to the treatment of type 2 diabetes, and in some can induce remission.
Reducing the risk of heart disease
The main risk factors for heart disease are being an unhealthy weight, high blood pressure, high cholesterol and type 2 diabetes. Avoiding these conditions significantly reduces the risk of heart disease. So it is not surprising that plant-based diets, including vegetarian and vegan diets, are associated with lower rates of heart disease.
It is worth noting that not all plant-based diets are created equal. To optimise health outcomes, a plant-based diet needs to be composed mainly of minimally processed, whole foods. A plant-based diet that is high in refined grains, free sugar and ultra-processed foods can be as bad as a meat-heavy diet and does not benefit health.
Reducing the risk of cancer
The causes of cancer are varied and complex. Eating a plant-based diet is one of several healthy habits that is associated with a lower risk of cancer. This is because you avoid foods associated with a higher risk of cancer, such as processed and red meat, and instead focus on foods and nutrients that reduce cancer risk. These include fibre, whole grains, fruit and vegetables and soya foods.
In general, meat-free diets, both vegetarian and vegan, have been associated with a lower overall risk of cancer of around 15%. In part, because of the association with a healthier body weight, but also because of the associations with lower inflammation and a healthier gut microbiome.
Surprising benefits
There is a long list of health benefits of plant-based eating that may surprise you. Some are listed below:
- Lower risk of urinary tract infections, as most infections are derived from bacteria carried in meat.
- Improvements in menstrual pain in women.
- Improvements in menopausal symptoms, especially when emphasising soya foods.
- Lower risk of fatty liver disease because it is naturally low in saturated fat and high in fibre-rich foods.
- Lower use of insulin in people with type 1 diabetes.
- Lower in cost by a third, compared to the typical Western diet.
- Lower medical costs and lower use of prescribed medications.
Best for planetary health
Without a healthy planet there are no healthy people.
The climate and ecological crises are now directly affecting human health globally. One of the main drivers is our food system. Animal agriculture is a major cause of greenhouse gas emissions, biodiversity loss, land, water and air pollution, land use change and more. The most impactful action we can take as individuals is to remove animal-sourced foods from the diet and instead eat a plant-based diet. Without exception, the production of all plant foods has significantly less impact on the environment than animal-sourced foods. There is now international consensus that if we want to meet our climate and nature goals, we need a global transition to a plant-based food system.
The Planetary Health Diet, devised by the Eat-Lancet Commission, provides a global framework for a healthy diet that will keep the food system within planetary boundaries. It is a diet that is composed of more than 85% plant-based foods, with animal-sourced foods greatly limited and not considered essential.
Concluding remarks
The positive impacts of a plant-based diet far outweigh any perceived downsides. There are additional huge benefits to our animal kin who find themselves living their entire lives in factory farms. Like with all diet patterns, a plant-based diet needs to be appropriately planned. If adopting a vegetarian or vegan diet, supplementation with vitamin B12 is essential.
Plant-based diets are full of abundance and flavour, can be adapted to all traditional and cultural diet patterns, and are a joy to adopt.