Vegan diet and diabetes: A science-backed approach to type 2 diabetes management

Our experts explain how a healthy plant-based vegan diet can positively impact those suffering from type 2 diabetes.

Diabetes affects one in 15 people in the UK – five million have been diagnosed with the disease and a further million or more have it, but don’t realise it.

Diabetes is a serious health threat and one of the main diseases of affluence – along with heart disease, obesity, gout and some cancers. They are all on the rise.

In this article, we’re talking about type 2 diabetes, which usually develops later in life – but now, due to unhealthy lifestyles, teenagers are increasingly at risk.

Type 2 is by far the most common and affects around 90 per cent of those with diabetes. Gestational diabetes affects some women during pregnancy and there are other rarer types of diabetes too.

According to the NHS, once you have type 2 diabetes, your risk of heart and kidney disease, nerve and eyesight damage all increase while your quality of life decreases.

Can you prevent type 2 diabetes?

The good news is, type 2 diabetes is preventable and for those who are already affected, it can be managed and even reversed through changes in your diet and lifestyle.

More and more health professionals now recommend a healthy plant-based diet and, as a result, many people with type 2 diabetes have been able to reduce their medication or come off it entirely¹.

The hormone insulin is made by your pancreas and it allows glucose in your blood to enter your body’s cells to provide energy. When functioning properly, it should act as a key that opens the cell door to allow in glucose, but with diabetes, the lock is jammed.

In all types of diabetes, glucose can’t get into your cells efficiently and consequently builds up in your blood to a point where it can damage your heart, eyes, feet and kidneys.

According to biologist and health researcher Veronika Charvatova, when treating type 2 diabetes diet is the key. More and more health professionals now recommend a substantial diet change and many type 2 diabetic patients are successfully reversing their condition². 

The big issue in diabetes is high blood sugar, a result of the body’s sugar metabolism – governed by the hormone insulin – working incorrectly.

This has a knock-on effect on other systems in the body, increasing blood cholesterol and fat levels, damaging the eyes, kidneys and nerve endings and can lead to insensitivity in hands and feet.

Is type 2 diabetes caused by sugar or fat?

Despite popular belief, sugar isn’t the villain. Type 2 diabetes is usually, but not always, linked to increased body weight as when your diet contains too much fat, tiny droplets of it are stored under the skin and in muscle and liver cells. When the amount of stored fat reaches a certain level, it reduces the cells’ ability to react to insulin.

This is called insulin resistance – your body produces insulin, but your cells cannot react to it. Studies have shown that insulin resistance in muscles and liver is strongly linked to the amount of fat they store.

If you’re obese, it’s more likely your muscle and liver cells will store fat, but you don’t have to be overweight for this to happen and, unfortunately, the problem doesn’t always show.

Western diets that are high in meat, dairy, fatty and processed foods, can cause the buildup of fat droplets within your cells.

On the other hand, wholefood, plant-based diets protect against this – which is why vegans are 50 percent less likely to develop type 2 diabetes, have more efficient blood sugar control, as well as higher insulin sensitivity than any other dietary group.

It follows that a wholesome, low-fat vegan diet is the best way of preventing and reversing type 2 diabetes. It helps to reduce fat stores in the cells, improves blood sugar control, reduces blood cholesterol, helps to induce weight loss without restricting portion sizes, prevents kidney and nerve damage and helps to lower blood pressure.

In several clinical trials³, people with type 2 diabetes were prescribed a combination of diet change and mild exercise and, as a result, most were able to reduce or discontinue entirely their medication in as little as three weeks.

Plant-based wholefoods tend to contain considerably less fat than animal products – saturated fat in particular. They also contain far more fibre, which helps to regulate blood sugar, as well as many beneficial phytochemicals and complex carbohydrates, which induce positive and long-lasting metabolic changes – which are very much to your benefit.

Much of the fat in animal products is saturated and there is no requirement for any of this kind of fat in your diet. By avoiding all animal products, your fat intake will naturally drop and your cholesterol intake will be zero.

Yes, plant fats are healthier than animal fats, but it’s still important to keep them to a minimum to reduce fat stores inside your cells. What we do need is some omega-3 fats, which are essential to health.

The best sources are ground flaxseeds, chia seeds and hemp seeds (1-2 tablespoons) or walnuts (about 10 halves). So don’t avoid nuts completely, but be aware of how many you eat.

Protecting your kidneys is a key issue for anyone with diabetes and animal protein from meat, fish, dairy and eggs, can place an additional strain on the kidneys and may worsen any damage that has already been caused.

Animal products contain no fibre or healthy carbohydrates, while plant foods, supplemented with vitamin B12, contain all the nutrients you need.

Basic principles of a vegan diet for type 2 diabetes

Type 2 diabetes is usually (but not always) linked to increased body weight and especially to abdominal obesity.

When the body’s metabolism can’t keep up with the amount and type of food eaten, droplets of fat are stored under the skin, but also in muscle and liver cells. Where and how you store fat is largely genetic.

When the amount of fat in the cells reaches a certain level, it reduces the cells’ ability to react to insulin correctly, leading to insulin resistance. Studies show the resistance in muscles and the liver is strongly linked to fat storage in these tissues⁴.

By eating a vegan diet filled with wholefoods, you can not only prevent yourself from developing type 2 diabetes, but also treat the condition if you already have it.

Studies where type 2 diabetics were prescribed a combination of diet change and mild exercise resulted in them being able to discontinue or significantly reduce medicating, in as little as three weeks, explains Veronika.

To prevent or reverse type 2 diabetes, follow these basic principles:

1^st principle – No animal products

By eliminating all animal products you avoid eating substantial amounts of fat and your cholesterol intake will be zero.

Most of the fat found in animal products is saturated and there’s absolutely no requirement for saturated fat in our diet.

Another good reason for avoiding all animal products is because animal protein from meat, fish, dairy and eggs places an additional strain on the kidneys and can increase the damage already caused by diabetes. Protecting kidneys is a key issue for diabetics.

All foods should be of plant origin and unrefined wherever possible, which means they will be naturally high in fibre and complex carbohydrates.

Animal products contain no fibre or healthy carbohydrates, while plant foods (supplemented with vitamin B12) contain all the essential nutrients we need.

2^nd principle – low-fat

Even though plant fats are healthier, it is important to keep them to a minimum. In order to reverse or improve diabetes, it is essential to reduce fat stores inside the cells and this can only happen if you avoid excessive fat consumption.

The amount of fat per serving should be three grams maximum (just 10 percent of calories should come from fat).

Apart from added oils, you might need to curb the amount of nuts and seeds you eat.

Within the low-fat rule, the best sources of healthy, omega-3 fats are flaxseed, hempseed and walnuts (for snacking or adding to dishes) and rapeseed oil for cooking.

3^rd principle – low glycemic index (GI)

Glycemic index (GI) is a measure of how carbohydrates in food affect your blood sugar. Carbohydrates that are digested fast and rapidly release glucose into the blood and have a high GI.

Carbohydrates that break down slowly, releasing glucose gradually into the bloodstream, have a low GI.

To help the body use energy effectively and prevent sugar highs and lows, it’s important to focus on slow-releasing, low-GI foods.

But bear in mind that it’s the overall GI that counts, so you can combine low and medium GI foods to achieve the desired lower GI effect.

• Low GI foods include: most fruits and vegetables, pulses (beans, soya, peas, lentils, chickpeas), barley, buckwheat, hummus, pasta, nuts and seeds, sweet potatoes, dried apricots and prunes, rolled oats, all-bran cereals, wholegrain pumpernickel bread, soya yoghurt.
• Medium GI foods include: wholemeal and rye bread, crispbread, brown rice, basmati rice, corn, porridge oats, shredded wheat, pineapple, cantaloupe melon, figs, raisins and beans in tomato sauce.
• High GI foods (to avoid) include: potatoes, rice cakes, watermelon, pumpkin, white bread, white rice, cornflakes, sweet cereal, dates and sugary foods.

A vegan diet based on these principles is the healthiest possible, but it is advised you take a vitamin B12 supplement or eat enough B12 enriched foods.

Vitamin B12 requirements may be higher in diabetics taking the drug Metformin as it can reduce B12 absorption.

Whether you’re at risk of or have type 2 diabetes, your diet should be based on wholegrains, pulses, soya, vegetables, fruit and nuts and seeds. This limits the types of food you can eat, but not the amount.

Being high in fibre and digested gradually, it makes you feel full sooner and for longer and the calorie intake is reduced by the minimal amount of fat it contains. Research shows that diabetics who follow this type of vegan diet get better results than any single drug can produce.

Ready to kickstart your journey to health? Learn how to eat a balanced vegan diet with this seven-day healthy wholefood vegan meal plan.

References

1. McMacken M, Shah S. A plant-based diet for the prevention and treatment of type 2 diabetes. J Geriatr Cardiol. 2017 May;14(5):342-354. doi: 10.11909/j.issn.1671-5411.2017.05.009. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5466941/
2. Jardine MA, Kahleova H, Levin SM, Ali Z, Trapp CB, Barnard ND. Perspective: Plant-Based Eating Pattern for Type 2 Diabetes Prevention and Treatment: Efficacy, Mechanisms, and Practical Considerations. Adv Nutr. 2021 Dec 1;12(6):2045-2055. doi: 10.1093/advances/nmab063. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5466941/
3. Schlesinger S. Diet and Diabetes Prevention: Is a Plant-Based Diet the Solution? Diabetes Care. 2023 Jan 1;46(1):6-8. doi: 10.2337/dci22-0041. Available at: https://pubmed.ncbi.nlm.nih.gov/36548706/
4. Kahn BB, Flier JS. (2000) Obesity and insulin resistance. J Clin Invest. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC380258/