We absolutely need and rely on the hormone insulin, but only when it stays in its sweet spot: just enough, not too much. Too much insulin has a direct adverse effect (obesity, type 2 diabetes) and many far-reaching effects, including an increased risk of cancer, Alzheimer’s Disease and more. News out just this week of a study by Melissa Schilling of NYU suggests that insulin may be harmful to our brains. Excess insulin in our brain competes with amyloid-beta for clean up priority. If you have a lot of insulin, the brain’s enzymes break down insulin first, and may allow amyloid-beta to accumulate, a risk factor for Alzheimers disease. (Previous work suggests that the reverse mechanism can also exist: Alzheimer’s Disease can raise the likelihood of developing diabetes. Either way you look at it, we must all have resources to prevent the development of diabetes and Alzheimer's.)
Back to Basics
So what is insulin? Insulin is a small protein, a hormone released by the pancreas in response to expectations of food, to sweet taste, and to elevations of blood sugar. From the point of view of diabetics, insulin is used to prevent blood sugar from going too high: insulin stimulates cellular insulin receptors and enables them to take glucose into the cell from the blood. Within the cell the glucose is either burned for fuel, or stored as either glycogen (carbohydrate, limited storage capacity), increased muscle mass, or fat (unfortunately more capacious storage available.) But the first thing that insulin does, thank you Tommy Wood, is to prevent various tissues from breaking down to be used for fuel. It blocks breakdown of glycogen as well as fat. High levels of insulin prevent you from burning body stores of fat from fuel.
Insulin’s effects are opposite to those of glucagon: glucagon arises when blood sugar is low, when we are fasting, and encourages the breakdown of either stored fat, stored carbohydrate (glycogen) or muscle tissue, to be used as fuel or energy.
Why Do I Care?
Most commonly in my practice I encounter patients with reason to worry that their insulin is too high. Type 2 diabetics, or pre-diabetics, and those with stubborn obesity, or early Alzheimer’s: all may be in the situation of having insulin levels that are too high.
Insulin can be measured by a simple blood test at a lab; there is not yet an easy way to check your insulin at home. We typically measure insulin in the fasted state, first thing in the morning when we also check glucose. Although typical laboratory values allow an insulin up to 25 mIU/L, I consider those numbers far too high! Any value over 10 likely prevents your body from burning fat, which you absolutely want to do 8-12 hours from your last meal!
When I want to identify or rule out type 2 diabetes, or pre-diabetes, I look at several values and consider normal to be:
Fasting 2 hours after 75 grams glucose
Glucose, mg/dL <100 <120 or < 140, opinions vary
Insulin, mIU/L <10 <130
Values above this range suggest early or outright type 2 diabetes. Such an outcome can be very useful information to someone frustrated with trying to lose extra weight: you can’t lose weight if your insulin constantly hovers in the range at which its first effect is to store rather than break down for fuel. The low carb, high fat approach to weight loss is inspired by this insight: lower carbs eaten, you will lower blood sugar (glucose) levels.
So What’s New?
The buzz in the insulin/obesity/diabetes world these days,on the nutritional side of things, that is, is fasting. Dr. Jason Fung writes about his experience with recommending fasting to his patients in his new book The Obesity Code.
His book is very readable, even funny—and provides those helpful meal plans so valuable to those making practical real-life plans. Dr. Fung suggests we explore the world of fasting.
Those who might be particularly interested are those who have trouble losing weight, those with pre-diabetes or type 2 diabetes, or those with other syndromes of insulin resistance, such as fatty liver, erectile dysfunction, or polycystic ovarian syndrome. If you fall into any of these categories, cutting a few calories is unlikely to provide any real benefit, nor will a few extra minutes on the treadmill. But I don’t need to tell you that: if you’ve ever had a weight problem, you already know that to be true!
Dr. Fung suggests a 10-day fast for those with serious metabolic derangement, as perhaps the only and certainly the most efficient, way to bring down sky-high insulin levels. I have walked several patients through such a fast: they have all done well, some amazingly well, and I am inspired that his recommendation is not that wild an idea! He also explores the possibility of alternate fasting schedules: 24-hour fasts (dinner to dinner) and 36-hour fasts (skipping food for a day) are both options that can be introduced one to several times a week.
Here’s what’s key: the staple of any successful fast is adequately salted bone broth! The salt helps stave off headaches, light-headedness, and possibly even the “adrenal stress” that many people experience when they drastically reduce either just carbs or all food intake. He also allows some coffee or tea, even with a bit of crea.
Dr. Fung busts several myths of dieting and fasting:
- You don’t burn up your muscles when you fast. That would, evolutionarily speaking, be a bad idea: how good would it be to feel weak when you need to find food. Your muscles are largely preserved and your brain is sharply focused.
- Non-caloric sweeteners, even stevia, aren’t such a good idea: just the taste of sweetness can fool your body that sugar is in the neighborhood and cause it to produce insulin. For many people, a fatty food (butter coffee, an avocado) can stave off a sweet craving.
There are certain cautions, of course, while doing anything differently.
- Diabetics on medication must know how to check their own blood sugar and regulate their medication accordingly.
- Those taking medications for high blood pressure would be wise to do the same: fasting or intermittent fasting can lower elevated blood pressure readings and might require medication adjustment.
- Pregnant women should not take on fasting!
- Muscle cramps or constipation can be managed with magnesium supplementation, or by increasing fiber on the days one is eating.
And After The Fast
What should one eat when one is not fasting? You might read any of many articles on this website for guidance that is not at odds with any of Dr. Fung’s suggestions. Start with Low Carb Eating or the Paleo Diet and consider the Elimination Diet or Autoimmune disease recommendations if you have other challenges. And in the midst of eating again, think about fasting one or two days a week!