Can a Plant-Based Diet Help Control Type 2 Diabetes?

Medics give us their opinions about whether or not a plant-based diet controls type 2 diabetes

Fatigue, blurred vision and skin disorders are just three possible side effects of type two diabetes-an illness that affects 3.15 million people in the UK. “Type two diabetes is the result of the body’s inability to produce enough insulin or use it properly. Insulin is needed to keep blood sugars stable,” explains East Anglia-based vegan medic Dr Hannah Short. “The illness is primarily as a result of being overweight or obese due to poor diet choices and physical inactivity. However, genetics, age, certain medications and ethnicity also play a part-people of south Asian, Chinese, African-Caribbean and black African descent have a much higher risk of developing the condition at much earlier age.”

Dr Neal Barnard is an American writer, physician, and founding president of the Physicians Committee for Responsible Medicine [PCRM], an international network of doctors, scientists, and laypeople. He is the author of 21-Day Kickstart and Power Foods for the Brain as well as USA Today bestselling-book Dr. Barnard’s Program for Reversing Diabetes. He works closely with nurse practitioner Emily Kasmar, M.S., A.G.P.C.N.P.-B.C. who specializes in type 2 diabetes treatment. She told Vegan Life: “Over 22 million Americans are diagnosed with this illness, and one in three adults has prediabetes. When left untreated, prediabetes often develops into type 2 diabetes.  Many people aren’t aware that they are at risk. Other terms for prediabetes include impaired glucose tolerance (IGT) or impaired fasting glucose (IFG).

“The price of type 2 diabetes is staggering. The average person who has diabetes spends about $85,000 over their lifetime on diabetes treatment and medication, which doesn’t include complications such as amputation, kidney failure, or vision loss. This is why prevention is so important, especially at a young age.”

But what preventative measures can be taken? Obviously nothing can be done about the unmodifiable factors-family history of diabetes, age, and race. But modifiable cause- lifestyle factors such as body weight, physical activity level, and diet-are all, to some extent, controllable.

Looking at different food types, one stands out as hitting recent headlines for all the wrong reasons. Red meat has recently been identified by the World Health Organisation as carcinogenic. As a food source that’s high in both calories and saturated fat, is it a factor in the disease?

Dr Hannah Short and Emily Kasner both think so. Emily says: “Meat consumption doubles the risk for type 2 diabetes. Red meat is void of fibre, high in fat, and increases inflammation inside the body. Here’s what we’ve found: meat products are high in fat but contain zero fibre. Fibre provides a feeling of satiety, or fullness. Participants who consume high-calorie or high-fat foods without feeling completely satiated are at risk for overeating and becoming overweight or obese, which triples the risk for type 2 diabetes.

“High fat intake inhibits insulin from doing its job, which is to facilitate glucose into the cells. People who consume meat may absorb more iron than necessary. Excess iron can damage tissues and creates further insulin resistance, and consumers of processed meat ingest nitrites, which increases risk for type 2 diabetes.

“Western dietary patterns—rich in meats, processed foods, and oils—increase inflammation and create insulin resistance.

“Our research shows that people who follow a plant-based diet weigh 10 pounds less, on average, than their meat-eating peers. This lowers at least one risk factor for type 2 diabetes: body weight. A high-fiber diet fills you up with fewer calories, which makes it easier to lose weight and keep it off for good. Extra fat inside the body creates extra insulin resistance. By keeping fat intake low, you’ll start to decrease the fat in your cells. This elimination of extra fat makes it easy for insulin to do its job, which creates an efficient operating system.”

Dr Short adds: “I am aware of some studies suggesting red meat can be an issue. From what I understand, there is not one identifiable link but – according to a 2012 study by the Harvard School of Public Health – three components of red meat are likely to be involved: (heme) iron, nitrites and sodium. In concentrated amounts, in susceptible people, these compounds are theorised to lead to chronic systemic inflammation, impair the function of the pancreatic beta-cells (which produce insulin) and lead to insulin resistance. In this study, the researchers found that a daily serving of red meat no larger than a deck of cards increased the risk of adult-onset diabetes by 19 per cent, with processed red meat being the worst offender.”

Viva! Health is a vegan organisation. It recently released a 56 page Health Report which analysed a number of scientific papers from peer-reviewed journals. The report also suggests meat reduction can play a part in the control of type 2 diabetes, saying: “Research suggests that eating just one serving of meat per week significantly increases the risk of diabetes. A study looked at the link between meat intake and the occurrence of diabetes in 8,000 adult Seventh Day Adventists, all of whom were non-diabetic at the start of the study. Those who followed a ‘low-meat’ diet over the 17 years of this long-term study had a staggering 74 per cent increase in their risk of developing type 2 diabetes compared to participants who followed a meat-free diet for the same period. Part of this difference was attributable to obesity and/or weight gain but even after allowances were made for this, meat intake remained an important risk factor.”

Dr Michael Greger-physician and author of How not to Die-goes even further. He writes: “Type 2 diabetes can be prevented, arrested, and even reversed with a healthy-enough diet. Unfortunately doctors don’t tend to educate their patients about diabetes prevention. Only about one in three pre-diabetic patients reports ever being told by their doctors to exercise or to improve their diets.”

There can be issues in recommending a plant-based diet in practice though: Dr Hannah Short says: “I don’t generally talk about vegan diets per se as I am concerned I would be seen as ‘pushing my agenda’ (my colleagues are aware that I follow a vegan diet and lifestyle for ethical reasons and, as a medical professional, I have to keep these opinions and feelings out of my work). In addition, for most of my patients the idea of following a fully vegan diet is currently inconceivable. I have to try and promote and encourage what I feel to be achievable aims – and eating more fruit and veg is something everyone can do. Weight loss is well understood as one of the main ways of achieving diabetes control. Plant-based diets are high in fibre and tend to be low GI (which keeps blood sugars more stable). A well-planned vegan diet is an excellent and healthy way to lose weight.”

As of 2016, the NHS says there is no special diet for people with diabetes. It does offer some guidelines, recommending a diet that is low in fat, sugar and salt and contains a high level of fresh fruit and vegetables. In general, the organisation is more sceptical about the ability of a plant-based diet to control diabetes.

In 2014, the NHS reported on some research carried out by Keio University in Japan and The George Washington University School of Medicine in the US-Dr Barnard was a co-author of this study, and declared a non-financial conflict of interest. The study was a systematic review and meta-analysis combining the results of controlled trials that examined the effects of vegetarian diets on blood sugar control in type 2 diabetes. Previous research had suggested a link between a vegetarian diet and improved blood sugar control.

According to the NHS news report: “[The study] found the vegetarian or vegan diet gave significant improvement in one measure of blood sugar control (HbA1c), but not in another (fasting blood glucose). However, there are some important limitations to consider before we can categorically conclude that people with type 2 diabetes should switch to a meat and fish-free diet.

“Provided you do your homework, it is possible to eat healthily on a vegetarian or vegan diet. But if you do have type 2 diabetes, we recommend that you talk to the doctor in charge of your care be-fore making any radical changes to your diet.”

Viva! health, which reviewed a number of investigations led by Dr Barnard in its health report-covered the story with a far more positive outlook than the NHS. Describing a 1994 study by Bar-nard, Viva! claimed: “In one of the ground-breaking studies that followed, researchers employed a combination of diet change and exercise. The subjects were 197 men with type 2 diabetes and after just three weeks of a low-fat plant-based diet, 140 of them were able to discontinue their medication.”

In light of these reviews, nurse practitioner Emily Kasnar often recommends a plant-based diet to her patients with the illness, saying: “Those who follow a low-fat vegan diet often reverse type 2 diabetes. By eating a diet rich in four food groups, vegetables, fruits, whole grains, and legumes, our study participants and patients experience a metabolic boost, increase their fibre intake, gain energy, improve insulin function and start to experience other positive health outcomes, including improvements in blood pressure and cholesterol.  It’s a new way of eating and a new way of living. We encourage everyone to try this approach for 21 days, which is a timeframe that is short enough to be manageable and long enough to see results. There is a good chance that after three weeks people won’t go back to eating the foods that are keeping them from achieving a clean bill of health.”

Dr Short adds: “I encourage most of my patients to include more fruit, vegetables and legumes in their diet, as there is almost always an overwhelming medical reason for doing so-be it to treat constipation, high blood pressure or diabetes, amongst other things.

“I have only ever, knowingly, seen one vegan patient in my clinical practice-but I do see a lot of type two diabetic patients! However, it is widely acknowledged that vegans, as a rule, have lower BMIs than their meat and dairy-eating counterparts. Reduced body-weight/BMI is associated with a much lower risk of developing type two diabetes, and it is also possible to lower your blood sug-ars/‘reverse’ type two diabetes with a healthy diet and weight loss to within the normal range i.e. BMI 19-24.”


A bit more about type 2 diabetes

Diabetes is a condition caused by the pancreas failing to produce the hormone insulin or producing insufficient quantities. Another cause is insulin resistance – the body cells’ inability to react to insulin. Insulin is a hormone produced by the pancreas and acts as a key, allowing glucose into the body’s cells.

Glucose is a vital source of energy for cells and is the main fuel for the brain and body’s processes. In diabetics, blood sugar levels rise too high and this can damage blood vessels and cause nerve damage but it also has a negative effect on health overall, increasing cholesterol levels and the risk of heart disease.

In type 2 diabetes, the body can still make some insulin but not enough or it fails to react to insulin as it should (insulin resistance). Lifestyle and environmental factors play an enormous role in type 2 diabetes. Therefore, even individuals with susceptible genes, or people who have already developed type 2 diabetes, don’t necessarily have to live with the condition for the rest of their lives.

Taken from Viva!’s Incredible Health Report 2016


Symptoms of type 2 diabetes

  • Feeling tired during the day, particularly after meals (fatigue)
  • Often feeling hungry, particularly if you feel hungry shortly after eating (polyphagia)
  • Urinating more often than normal, particular needing to do so during the night (polyuria)
  • Feeling abnormally thirsty (polydipsia)
  • Blurred vision
  • Itching of the skin, particularly itchiness around the genitals (genital itchiness)
  • Slow healing of cuts or wounds
  • Having regular yeast infections (thrush)
  • Having a skin disorder such as psoriasis or acanthosis nigricans
  • Sudden weight loss or loss of muscle mass

Note: The information in this article is not a substitute for advice from your doctor. If you have any concerns about your health, you should always visit your GP, who will provide personal medical advice.


The lifestyle magazine written by vegans for vegans.