Are Plant-Based Diets Better for Blood Sugar Control?

March 7, 2021

by Cathe Friedrich

Having blood sugar in a healthy range is vital for good health. Cells rely on glucose for energy, but to supply that energy, glucose must get into cells. Insulin opens the channels that send glucose from the bloodstream into cells. Healthy people produce the right amount of insulin and their cells respond well to it, making the system work well when it works. Yet that’s not always the case.

Around one in ten people has diabetes, most of whom have type 2 diabetes where their blood sugars are too high. About one in three people has prediabetes, a condition where blood sugar levels are too high but not yet in the diabetic range. People with prediabetes have insulin resistance, where their cells don’t respond well to insulin and their fasting blood sugar level is higher than normal.

Without a change in lifestyle, a high percentage of people with prediabetes will progress to type 2 diabetes. Why does this matter? Along with the short-term effects of high blood sugar, diabetes can damage every organ in the human body and even lead to blindness or limb amputations. That’s why lifestyle change to bring blood sugars down is so important.

Lifestyle and Diet for Blood Sugar Control

Diet matters when you have unhealthy blood sugar. Eating the wrong diet worsens blood glucose control and leads to weight gain, a risk factor for type 2 diabetes. Therefore, it’s not surprising that research has looked at various diets and their effect on markers of blood sugar control. Some sources believe that a plant-based diet is the best eating plan for controlling type 2 diabetes, but is there science to support this?

According to Harvard Health, eating a plant-based diet is a smart strategy for blood glucose control. A meta-analysis of nine studies published in JAMA Internal Medicine found that people who ate a plant-based diet enjoyed a 23% reduction in their risk of developing type 2 diabetes, but diet quality counts. A poorly planned plant-based diet could include junk food, like processed vegan fare, unhealthy vegan snacks, starchy vegetables, foods made with white flour, and processed breakfast cereals. Research shows these foods cause blood sugar spikes. In fact, the same study found that people who ate an unprocessed plant-based diet benefited from a 30% drop in the risk of type 2 diabetes.

How Do Plant-Based Diets Help with Blood Glucose Control?

One reason a plant-based diet helps with blood glucose control is the effect it has on body weight. Whole, plant-based foods are naturally high in fiber, a dietary component that increases satiety. Studies show people in Western countries only get half the amount of fiber experts recommend for good health, 25 grams per day for women and 37 grams for men. Foods that are high in fiber and protein reduce appetite more than refined carbohydrates. So, fiber-rich, high-protein foods, like beans, lentils, and whole grains are excellent choices.

Plant-based foods also contain phytonutrients that reduce inflammation and improve insulin sensitivity. Better insulin sensitivity helps with blood sugar and weight control. However, the biggest benefit of a plant-based diet may be the effect it has on body weight. Weight loss is the best prescription for improving insulin sensitivity and lowering the risk of type 2 diabetes. In fact, losing a modest amount of weight can have a big impact. According to David Marrero, Ph.D., president of health care and education for the American Diabetes Association, losing only 7% of body weight reduces the risk of developing type 2 diabetes by 60%. Plant-based foods can help you do that.

The Adventist Health Study 2 looked at the risk of type 2 diabetes among 61,000 people. The study showed those who ate a plant-based diet enjoyed a lower risk of type 2 diabetes. When you break it down, those who ate an omnivorous diet with plants and meat had a 7.6% risk of developing type 2 diabetes, while partial vegetarians had a 6.1% risk of becoming a type 2 diabetic. Those who ate plant-based foods and fish had a risk of 4.8% and vegetarians who ate eggs and dairy products 3.2%. The lowest risk was in vegans, where the risk was 2.9%. Based on these findings, there are benefits to eating plants if you’re concerned about developing type 2 diabetes.

Plant-Based Foods May Reduce the Long-Term Impact of Diabetes on Health

In people who already have diabetes, eating a plant-based diet, with its abundance of antioxidants, may lower the risk of diabetic complications in men and women who are already diabetic. The leading cause of death in people with diabetes is cardiovascular disease. A plant-based diet may reduce the risk of heart disease and stroke in diabetics by improving blood lipids and by reducing inflammation.

Whole food, plant-based diets also contain a variety of antioxidants, including beta-carotene, that play a role in heart health and may protect the retina of the eye against damage from diabetes.

Diet Quality Still Matters

Not eating meat or dairy isn’t enough to make a diet healthy or prevent prediabetes or type 2 diabetes. Many people eat a processed vegan diet that includes vegan packaged foods and snacks high in refined carbohydrates and sugar. Such a dietary strategy won’t help with blood sugar control and will likely worsen it.

Fortunately, there are plenty of unprocessed, plant-based foods you can enjoy in abundance if you have prediabetes or type 2 diabetes. Lentils, beans, nuts, seeds, non-starchy vegetables, and berries have minimal impact on blood glucose and supply lots of nutrients and macronutrients for sustained energy and good health. The key is to choose more unprocessed plant-based foods.

The Bottom Line

Whole-food, plant-based eating helps with weight and blood sugar control and that can lower the risk of type 2 diabetes. Combine a diet rich in plants with regular physical activity and you have a winning formula for better blood sugar control and health, but make sure you’re eating a balanced diet that contains all the nutrients your body needs for good health.

References:

WebMD.com. “Plant-Based Diet Helps Keep Diabetes at Bay”
Harvard Gazette. “Growing support for plant-based diet”
Qian F, Liu G, Hu FB, Bhupathiraju SN, Sun Q. Association Between Plant-Based Dietary Patterns and Risk of Type 2 Diabetes: A Systematic Review and Meta-analysis. JAMA Intern Med. 2019;179(10):1335–1344. doi:10.1001/jamainternmed.2019.2195.
“Weight and Diabetes: Lose Pounds to Lower Your Risk”
McMacken M, Shah S. A plant-based diet for the prevention and treatment of type 2 diabetes. J Geriatr Cardiol. 2017;14(5):342-354. doi:10.11909/j.issn.1671-5411.2017.05.009.
Diabetes Spectrum 2017 May; 30(2): 82-88.https://doi.org/10.2337/ds16-0057.
Toumpanakis A. 2018. Effectiveness of plant-based diets in promoting well-being in the management of type 2 diabetes: a systematic review. BMJ Open Diabetes Research and Care. https://drc.bmj.com/content/6/1/e000534.
Brazionis L, Rowley K, Itsiopoulos C, O’Dea K. Plasma carotenoids and diabetic retinopathy. Br J Nutr. 2009 Jan;101(2):270-7. doi: 10.1017/S0007114508006545. Epub 2008 Jun 13. PMID: 18554424.