It’s no secret that type 2 diabetes is spreading faster than California’s wildfires. Well, not exactly faster, but you get the gist. Fueled by widespread obesity, fed by chronic stress, bad eating habits and increasing sitting time, diabetes affects 30.3 million Americans – about 9.4% or 1 in 4 of the US adult population. A further 84.1 million Americans have prediabetes – which could become full-blown diabetes within five years – and most of them don’t even know it.
The costs of diabetes are staggering:
- $306 billion in direct medical cost
- $13, 700 in medical expenditures per patient
- $69 billion in loss of productivity at work or at home and premature death.
Needless to say, we need an answer. NOW. And unbeknownst to many, that answer could be right under our noses.
What is a plant-based diet?
A plant-based diet is a diet regimen that emphasizes nutrient-dense plant foods while eliminating foods from animal sources (meat, eggs, cheeses and milk), processed foods and fats.
Plant food sources high in fiber, vitamins, antioxidants, omega-3 fats and proteins like vegetables, fruits, beans, peas, lentils, seeds and nuts are highly encouraged. However, proponents have varying opinions as to what comprises the optimal plant-based diet.
Radical experts like Esselstyn, the director of the cardiovascular disease prevention and reversal at the Cleveland Clinic, recommends the complete elimination of animal food sources and fat, as well as soybeans and nuts. On the other hand, Dr. Dean Ornish’s regimen allows a bit of egg whites and skim milk.
Benefits for diabetes?
Interest in plant-based diet in the prevention of chronic disease began in the late 50’s with the Adventist Mortality Study. The study followed 22, 940 adult members of the Seventh-day Adventist Church (a Christian denomination that encourages a plant-based lifestyle) of California for a total of 30 years starting in 1958. The results of the study indicated that Adventists have a lower risk for cancer, heart disease and diabetes and live 7.3 years longer than the general population.
Coming after the Adventist Mortality Study, David Snowdon’s team studied exactly 25, 698 adult Seventh Day Adventists for 21 years. During the follow-up period, the team found that Seventh Day Adventists who followed a vegan diet had half the rates of diabetes of those who ate meat once or more times per week. In fact, the frequency of meat-eating was directly proportional to the risk of diabetes in a clear stepwise fashion, as seen in the table below.
In 2002, the even bigger Adventist-2 study followed 89, 000 people. In the chart below, you will see a drop in diabetes rates in direct proportion to the frequency of plant-based eating. Subjects who were strictly vegan had a 78% lower risk for diabetes and 75% lower risk for high blood pressure than non-vegans.
Weight loss
Obesity, especially central obesity, is the number one cause of type 2 diabetes, accounting for 90% of all cases. But if you look at the Adventist-2 table, not only do vegans have lower rates of diabetes and high blood pressure, they have lower levels of obesity as well.
Susan Berkow and Neal Barnard found similar results in their own study.
In their study published in Nutrition Reviews, Berkow and Barnard found that vegans had significantly lower body weight than meat eaters. Similarly, the authors found that heart disease, high blood pressure, diabetes and obesity are lower in vegan populations. And interestingly, the study suggests that a vegan diet promotes weight loss even without exercise, at a rate of about 1 pound per week, in part by boosting the metabolic rate instead of getting stored as fat.
Another study by Barnard published in 2006 found that a vegan diet was so effective at improving blood sugar levels that 43% of the subjects on the diet were able to reduce their medications, compared with only 26% of those not on the diet.
The BROAD study, a randomized controlled trial that used plant-based diet approach to manage obesity and heart disease, found basically similar results: Weight reduction was greater in subjects who consumed a vegan diet even without caloric restriction. Cholesterol reduction was also greater with the low-fat vegan diet. The results are shown below.
The table below includes data from three studies. You will see the direct relationship between vegan diet and low body weight across the study samples.
Improves insulin resistance
Low-fat, meatless plant-based diets are rich sources of antioxidants, fiber and minerals, all of which have been proven to increase insulin sensitivity. Antioxidants like plant polyphenols could decrease carb absorption, increase insulin release, reduce glucose production by the liver and enhance glucose absorption into the cell. Antioxidants have also been shown to be effective at decreasing inflammation.
Fiber, which is found in fruits, vegetables and grains, is important for the health of gut bacteria, improves insulin signaling and insulin sensitivity and promotes weight loss. Plant-based diets are low in saturated fat, which could reduce abdominal fat and improve inflammation.
Improves diabetic neuropathy
In one study, a 25-day lifestyle program that emphasizes plant-based diets improved neuropathic pain in 81% of the participants. Participants who adhered to the diet after the study experienced ongoing improvement in neuropathic pain.
Improves heart health
The end-goal of diabetes treatment is to protect the blood vessels of the heart, eyes and kidneys from microvascular damage. In some studies, plant-based diets reduced the rates of heart disease and early death by as much as 32% compared to omnivorous diets.
In the Lifestyle Heart Trial, 82% of cardiac patients demonstrated a reversal of atherosclerosis (thickening of arteries). After a 5-year follow-up, levels of bad cholesterol decreased by 20%.