Diabetes, fiber and the micro biome

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November 14, 2019

One of the talks at the conference was “Beyond Carb Counting: Why Plant-Based Nutrition is Sweet Medicine for Insulin Resistance”. It was delivered by Dr. Michelle McMacken, a board-certified internal medicine physician and an assistant professor of medicine at NYU School of Medicine. She is vegan and is deeply involved with encouraging her patients to adopt plant-based nutrition as a way to improve overall health, lose weight and possibly decrease medications.

Some of this information can be found in Dr. McMacken’s articles on the Forks over Knives website. She notes that the American Association of Clinical Endocrinologists recommends a plant-based diet for all type 2 diabetics. Type 2 diabetics are usually adults, although the onset is getting younger as the general population suffers more from obesity.

I’ll interject here what I heard about “The new biology of type 2 diabetes (DM)” from Dr. Gerald Shulman from Yale at the International Conference on Nutrition in Medicine held this summer in DC. The initial step in diabetes development is fat collection in muscle cells, making them more resistant to the action of insulin and thus to the uptake of sugar. Eventually there is fat accumulation in liver cells, and they too become insulin resistant. The pancreas can compensate initially by producing more insulin, but eventually glucose wins that game and sugars rise, giving way to a diagnosis of diabetes.

Dr. McMacken notes that all animal protein consumption increases the risk of diabetes. Processed meats such as cold cuts and sausage impose the highest risk.   

Along with protein, animal products are high in saturated fats. Solid fats such as coconut oil also are high in saturated fats. An acute saturated fat load (think cheeseburger and fries or chicken parmesan), can cause increased fat in liver cells, and insulin resistance, temporarily short circuiting the process mentioned above. 

On the other hand, plant-derived polyUNsaturated fatty acids (PUFAs) actually decrease insulin resistance and delay the onset of diabetes. In particular, Dr. McMacken advocated having a serving of avocado, nuts or seeds one to three times per day. Whole grains provide the best protection against diabetes.   Contrary to popular belief, fruits don’t cause diabetes.  Once you have diabetes, you should check your blood sugar to see how it is affected by fruit intake.  However, on balance, fruit is a healthy component of nutrition, in reasonable quantities.

In addition to containing healthy fats, an additional benefit of a plant-based diet is the high fiber content. Dr. McMacken recommends 20 grams of fiber per 1000 calories eaten. The diverse fiber associated with many different beans, seeds, legumes etc, helps to change the gut bacteria – the microbiome that we’re constantly hearing about. There’s much we do not know about the microbiome and how to change it to our advantage. It’s not clear which of the over-the-counter probiotics might help, if any, but a diverse fiber intake IS felt to be beneficial.

Improved fiber intake has also been shown to decrease the pain of peripheral neuropathy compared to a conventional diet. It improves beta cell function in the pancreas – the cells that release insulin – and so gets at the root cause of DM. And it is the component that we think helps decrease the risk of cancer in people on plant-based diets. The rate of colon cancer in young people has risen enough that the recommendations for first screening colonoscopy has been dropped to 45 years old instead of 50. That alone may be enough to make you want to increase your fiber intake. Increased fiber intake is also associated with a decrease in depression symptoms, weight, cholesterol level and long-term sugar level, as well as an increase in quality of life. In contrast to plant options, animal products are devoid of fiber.

As I mentioned last week, even a plant based diet can be unhealthy – if it includes potatoes fried in palm oil, juices and sodas. To optimize the benefits of a plant-based diet, Dr. McMacken advocates for a Power Plate approach, based on Physicians Committee for Responsible Medicine recommendation. Have 1/2 the plate filled with non-starchy vegetables, 1/4 legumes (peas, beans), and 1/4 whole grains, preferably intact, not flours.

If you like to cook, get inspiration from online recipes at www.cookieandkate.com, some from our own recipe section, or search your favorite books or websites for vegetarian recipes. But if you’d like to take a quick approach to meals, you can get plenty of plant-based foods without much food prep. A colorful salad topped with nuts, seeds, and berries with a healthy dressing, or non-dairy yogurt and milk blended with banana, peanut butter and chocolate can be very filling.

Make a lunch of lentil soup, or apple slices with peanut butter, with or without whole grain bread. For simple cooking, chickpea or spinach pasta with veggies topped with a store-bought tomato sauce (Rao’s brand is my favorite) is simple and healthy.

I’d love to say that I cook at home the same amazing food we had at the conferences I mentioned. Last week, we had overnight oats with pumpkin spice, sweet potato black bean burritos, chickpea and spinach stew, roasted colorful veggies and many more selections. It’s easy to stay plant-based when those options are presented.  Most of us are not that fortunate.

But as I mentioned in last week’s post, celebrate any move you make in the direction of having more plant-based foods. You’ll help yourself while you’re helping the planet. Take some time to scroll through the forks over knives website to get inspired! I suggest subscribing to Nutrition Action Health Letter to get scientifically reliable information about nutrition and a few simple recipes each month.