Type 2 Diabetes and a Vegan Diet
Vegan diets are becoming a more popular approach for preventing and managing type 2 diabetes. However, there is confusion about the benefits of a vegan or plant-based diet for type 2 diabetes. Many people do not understand how a plant-based diet could impact prevention or management of type 2 diabetes.
This page covers:
- What is Type 2 Diabetes?
- Why is Type 2 Diabetes a Problem?
- What Diet Increases Risk of Type 2 Diabetes?
- What Diet Decreases Risk of Type 2 Diabetes?
- Preventing Type 2 Diabetes: Which Diet is Best?
- Foods that Can Lower the Risk of Type 2 Diabetes
- Lifestyle Changes vs Medication for Type 2 Diabetes
- Recipes for Type 2 Diabetes from Lettuce Veg Out
Please note: This is a broad overview of the topic and the details about physiology/ pathophysiology have been simplified for easy reading and understanding. Always speak to a doctor before making any changes to your diet and/ or medications.
What is Type 2 Diabetes?
There are currently 3 different types of diabetes that are diagnosed: type 1, type 2 and gestational.
Type 1 diabetes is an autoimmune condition where the body attacks the cells that produce insulin. Someone with type 1 diabetes cannot produce insulin and therefore must inject themselves with insulin multiple times each day of their life.
Type 2 diabetes is a condition classified as resistance to insulin, with or without the need for insulin injections. Someone with type 2 diabetes could still produce insulin, but it isn’t being used correctly. This results in a need for more insulin to be produced. With time, the cells that make insulin start to fail and insulin injections may be required.
Gestational diabetes occurs during pregnancy.
This article only focuses on type 2 diabetes which accounts for the majority of cases.
Why is Type 2 Diabetes a Problem?
The hallmark sign of type 2 diabetes is elevated blood sugars. With time, excess sugar in the blood can cause problems such as kidney disease, eye disease, nerve disease and also increases risk of heart disease including heart attacks and stroke.
The next 2 sections cover how people may end up with elevated blood sugars.
The Process of Getting Sugars into the Blood and Into Cells
Insulin is a hormone that many different cells in the body need to absorb sugar from blood. Insulin is often described as a key that unlocks cells. Typically, cells in the body are locked, and are not open to (i.e. not able to absorb) sugar from the blood.
After people eat food, the body breaks down the carbohydrates in that food into sugar. This sugar goes into the blood stream so it can be transported to cells. To get sugar from blood into the cells (where it’s needed to create energy), insulin is required. Insulin attaches to cells and unlocks them. Now that the cell is unlocked, it can absorb sugar that’s in the blood stream.
What is Insulin Resistance?
Someone with type 2 diabetes is said to be resistant to insulin. This means that even though there’s insulin in the body, and it’s attaching to cells, it can’t unlock the cell. Therefore, it can’t allow sugars from the blood into the cell.
With insulin resistance, larger amounts of insulin are often needed to unlock a cell. For example, let’s say in a healthy person one molecule of insulin is needed to unlock a cell. Someone who is resistant to insulin may need two, three or more molecules of insulin to do the same job.
When someone is resistant to insulin, insulin-producing cells have to work overtime, making extra insulin to get the job done.
Eventually this resistance to the effects of insulin makes insulin-producing cells tired. The insulin producing cells start making less insulin or simply cannot keep up with increasing demand. At this point, blood sugar levels stay too high after a meal. This is when type 2 diabetes may be diagnosed.
What Diet Increases Risk of Type 2 Diabetes?
As you will learn below, there are many dietary patterns and foods that are found to help prevent type 2 diabetes. But there are also some foods that could increase the risk of developing type 2 diabetes.
Processed and Red Meats Increase Risk of Developing Type 2 Diabetes
Consumption of processed meat (any meat that has been cured, smoked, dried, canned and salted including bacon, ham, sausage, hot dogs, deli meats, salami, jerky etc.) is associated with many negative health outcomes including increased risk of type 2 diabetes 1.
Red meat consumption is also typically associated with increased risk of developing type 2 diabetes, although some research suggests this association is null (not present) after adjusting for the body weight of participants 1, 2, 3.
Sugar-sweetened Beverages Increase Risk of Developing Type 2 Diabetes
Sugar intake is often touted as the cause of diabetes. While this is not true (there are many factors that play a role in development of diabetes and sugar intake is only one possibility), limiting intake of added sugars is often found to be health-promoting.
Sugar sweetened beverages in particular may increase the risk of type 2 diabetes 4. Limiting consumption of these high sugar drinks could be one goal towards a balanced diet that reduces diabetes risk.
Does this mean you can never enjoy a sweet drink again? Not necessarily. It’s important to find an eating pattern that works for you in the long-term. Completely cutting out foods or beverages you truly enjoy may not be the best way to sustain a healthy lifestyle long term.
What Diet Decreases Risk of Type 2 Diabetes?
There’s significant research that identifies dietary patterns that appear to greatly reduce the risk of developing diabetes.
One of those dietary patterns is a plant-based diet. There are many definitions of plant-based diets, but it appears that the more plant-based foods a person eats, the better their chances are of not developing diabetes 5.
The Mediterranean Diet and Prevention of Type 2 Diabetes
The Mediterranean diet is often considered to have the strongest evidence for prevention of type 2 diabetes 6. The research on the Mediterranean diet is considered strong due to the design of the study as well as the large sample size.
The Mediterranean diet is often considered a type of plant-based diet because there is focus on consuming lots of vegetables, fruits, whole grains, nuts and legumes. However, the Mediterranean diet is not a vegan or fully plant-based diet as it also includes fairly high intake of fish and seafood as well as moderate intake of poultry, dairy and eggs. The Mediterranean diet also incorporates olive oil and red wine while focusing on limiting intake of red meat, processed meat and sweets.
Are Vegetarian Diets Beneficial for Prevention of Type 2 Diabetes?
Vegetarian dietary patterns, including vegan diets, are associated with lower risk of developing type 2 diabetes 5, 7. This information, along with research showing beneficial effects of Mediterranean dietary patterns (which are largely plant-based) suggest that a diet focused around eating whole plant-based foods is ideal for diabetes prevention 6, 7, 8.
Is a Low Carbohydrate Diet Beneficial to Prevent Type 2 Diabetes?
One major criticism of promoting vegan or plant-based diets for diabetes prevention or management is the carbohydrate content of plant-based foods. Plant-based and vegan diets tend to be fairly high in carbohydrates as all whole plant foods, and many processed plant foods, contain carbohydrates.
Luckily the types of carbohydrates in whole plant foods seem to benefit prevention of type 2 diabetes 7, 9, 10. This may be due to fibre or additional compounds in plant-based foods that help with controlling blood sugar levels 10.
Furthermore, there’s no consensus on the efficacy of using low carbohydrate diets (or any one dietary pattern) to prevent or manage type 2 diabetes 6. There may be long-term risks of consuming low carbohydrate diets, especially if those diets eliminate or severely restrict health promoting foods such as whole grains, legumes and fruits 11.
Quality of Carbohydrates is Also a Key Consideration
The type of carbohydrates a person consumes is also a key factor in risk of diseases such as type 2 diabetes 6. Refined grains do not show as favourable a result as whole grains for prevention of diabetes 12, 13. Furthermore, sugar consumption from sweetened beverages does not show the favourable effect that whole fruits have on prevention of diabetes 4, 9, 14, 15.
Preventing Type 2 Diabetes: Which Diet is Best?
There is research supporting many different dietary patterns as being beneficial for prevention of type 2 diabetes 6.
Mediterranean, plant-based and low carbohydrate diets are all supported by research. Is there a clear winner?
I personally don’t think there is enough evidence to support a low carbohydrate diet over one that is based around whole plant foods. However, some people prefer to eat fewer carbohydrates and if that is something that works for them, for the long term, it’s completely ok (as long as nutrient needs are being met and the person enjoys their overall lifestyle and can happily maintain it). There are ways to lower the carbohydrate content of a vegan or plant-based diet, if that is of interest to someone.
The important thing is to make dietary and lifestyle changes that work for you and that you can truly maintain long term. Many people cannot sustain lower carbohydrate diets long term. Other people may not be able to sustain drastic dietary changes long term. Most people cannot sustain the complete elimination of foods from the diet.
Working with a Registered Dietitian can be an excellent step towards making lasting changes to diet and lifestyle for prevention or management of type 2 diabetes.
Foods that Can Lower the Risk of Type 2 Diabetes
Overall, a plant-based dietary pattern is shown to help prevent type 2 diabetes 5, 7, 8. However, there are some food groups that are part of a healthy plant-based diet which are sometimes questioned in relation to type 2 diabetes. Fruit and whole grains are often claimed to be unhealthy. People making these claims usually cite these foods are too high in carbohydrates to be beneficial for prevention of type 2 diabetes or for someone with type 2 diabetes.
As noted above, there are a variety of dietary patterns shown to be beneficial for diabetes. Lower carbohydrate diets don’t appear to hold any special benefit over a well-planned plant-based diet 11.
In fact, fruits and whole grains (along with other higher carbohydrate foods including legumes and vegetables) tend to show great benefit for prevention of diabetes, far from increasing risk 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17.
Lifestyle Changes vs Medication for Type 2 Diabetes
A healthy diet and adequate physical activity are the two best approaches to preventing type 2 diabetes 6.
However, after being diagnosed with type 2 diabetes (or in some cases, pre-diabetes), doctors will most likely prescribe medications. Sometimes, depending on how high blood sugar levels are, doctors may offer a trial period of lifestyle changes before prescribing medication but this is often not the case.
I always recommend listening to your doctor and having a conversation about what care plan works best for you. Diabetes medications are indicated in most cases. Never stop taking your medication without consulting your doctor.
Additionally, if you are interested in making lifestyle changes, it’s best to do so under the supervision of a doctor or health care provider qualified in diabetes (ex. certified diabetes educator). Therefore, before making any dietary or lifestyle changes, speak with your doctor to come up with a plan that works for you.
Adding a Registered Dietitian to your care team (if there isn’t one already) can be a fantastic step to help make realistic and long term lifestyle and dietary changes to help manage type 2 diabetes.
Recipes for Type 2 Diabetes from Lettuce Veg Out
Recipes that include lots of whole plant-based ingredients could be health promoting (always speak to a doctor before making changes to your diet).
Some of my favourite recipes from Lettuce Veg Out include:
Summary: Type 2 Diabetes and a Vegan Diet
Type 2 diabetes is a condition where the body becomes resistant to insulin, which eventually leads to blood sugar levels remaining elevated after a meal. Elevated blood sugar levels can cause a host of problems.
Many dietary and lifestyle factors are associated with decreased risk of developing type 2 diabetes. There is no one diet that is consistently shown to be superior to for prevention and management of diabetes as research on the subject is quite mixed. However, research does indicate a diet based around whole plant foods could help prevent and be appropriate for management of type 2 diabetes (under the supervision of a doctor and dietitian).
The best dietary pattern is one that a person can follow, and be happy with for the long term. Extreme, restrictive diets are not likely to last in the majority of people.
While lifestyle changes can be a great tool in diabetes prevention and management, working with a full care team including a doctor and dietitian is helpful. Never make lifestyle changes, or changes to medications, without first speaking to a doctor.
- Red meat consumption and type 2 diabetes mellitus risk A systematic review of the evidence
- Meat Consumption as a Risk Factor for Type 2 Diabetes
- Meat Consumption, Diabetes, and Its Complications
- Consumption of sugar sweetened beverages, artificially sweetened beverages, and fruit juice and incidence of type 2 diabetes: systematic review, meta-analysis, and estimation of population attributable fraction
- Vegetarian diets and incidence of diabetes in the Adventist Health Study
- Reducing the Risk of Developing Diabetes
- Plant-Based Dietary Patterns and Incidence of Type 2 Diabetes in US Men and Women: Results from Three Prospective Cohort Studies
- An update of the evidence relating to plant-based diets and cardiovascular disease, type 2 diabetes and overweight
- Higher intake of fruits, vegetables or their fiber reduces the risk of type 2 diabetes: A meta-analysis
- Consumption of cereal fiber, mixtures of whole grains and bran, and whole grains and risk reduction in type 2 diabetes, obesity, and cardiovascular disease
- Overweight and diabetes prevention: is a low-carbohydrate–high-fat diet recommendable?
- Whole grain and refined grain consumption and the risk of type 2 diabetes: systematic review and dose–response meta-analysis of cohort studies
- Greater Whole-Grain Intake Is Associated with Lower Risk of Type 2 Diabetes, Cardiovascular Disease, and Weight Gain
- Fruit consumption and risk of type 2 diabetes: results from three prospective longitudinal cohort studies
- Fresh fruit consumption in relation to incident diabetes and diabetic vascular complications: A 7-y prospective study of 0.5 million Chinese adults
- Systematic Review and Meta-Analysis of Human Studies to Support a Quantitative Recommendation for Whole Grain Intake in Relation to Type 2 Diabetes
- Effect of fruit restriction on glycemic control in patients with type 2 diabetes – a randomized trial
Please note that this is a curated list of references for the topics above and is not intended to be comprehensive.
Disclaimer: it is always advised for you to speak with your doctor before making any changes to your diet; please read our full website disclaimer.