Breaking Down Glucose and Insulin
Breaking Down Glucose and Insulin
Understanding how blood glucose and insulin interact can be the key to unlocking a lifestyle regimen that works for you, no matter what your goals are. For some, it will be managing PCOS and getting ovulation to normalize. For others, it might be to halt weight fluctuations and steady your hormones.
When I first got involved with fertility awareness charting, I found out I had mild to moderate insulin resistance. Worse, I didn't understand these terms, what they meant, or how to begin addressing them. I've created this guide to make it easier for you. Enjoy this look into breaking down glucose and insulin.
What is insulin?
Insulin is a hormone which brings nutrients from the blood stream into the cells. There, they will be used for storage or use.
The basic cycle is this:
You eat some food > blood sugar rises > the pancreas notices blood sugar is elevated and releases insulin > sugar moves from the blood to the cells > blood sugar falls
Your cells must know how to listen to the messages that come from insulin to regulate blood sugar.
What is insulin resistance?
Insulin resistance occurs when your cells don't respond to insulin's messages.
The basic cycle is this:
You eat some food > blood sugar rises > the pancreas notices blood sugar is elevated and releases insulin > the cells do not respond to this message > blood sugar stays high > the pancreas notices blood sugar is still elevated and sends out even more insulin > there is a disproportionate ratio of insulin to blood sugar
Is diabetes different from insulin resistance?
Yes. The pancreas must work extra hard when you have insulin resistance. Over a long period of time, high blood sugar will damage the cells of the pancreas. When the pancreas cells fail, they stop producing insulin altogether, and blood sugar is high, because that sugar is unable to move into the cells without insulin's help.
This is how people with diabetes start off with not too little insulin, but by producing too much. Insulin resistance may go on for years before the pancreas gives up. When it does, this is what we call type 2 diabetes. Sometimes insulin resistance is referred to as being "pre-diabetic."
What is hypoglycemia?
Hypoglycemia is a result of insulin resistance, where blood sugar drops abruptly within a couple hours of eating. If insulin is being regulated properly you don’t have consistently high insulin or high blood sugar. A graph of this process looks like nice calm waves.
But when you are insulin resistant, your cycle of blood sugar & insulin is more like sharp peaks & valleys. Because insulin is being released in greater than normal amounts, the body will eventually respond, pulling sugar out of the blood drastically. The higher the insulin level, the sharper the blood sugar drop.
Hypoglycemia produces what we commonly know as the "sugar crash" or being "hangry"
Other effects of insulin resistance
High insulin results in low glucagon. Glucagon is the hormone that helps us release stored energy. Therefore insulin resistance causes a halt in fat breakdown. This is why it's harder for someone with insulin resistance to lose weight even if they restrict caloriews and exercise regularly.
The stress hormone cortisol also plays a role in regulating blood sugar. Cortisol increases insulin resistance which increases blood glucose levels. This results in a vicious cycle of stress > cortisol > insulin resistance > higher blood glucose > more insulin resistance > less fat breakdown - and so on.
Lastly, insulin resistance causes androgen excess.
How insulin causes androgen excess
Because with insulin resistance, the body does not respond to normal amounts of insulin, and higher amounts must be secreted, this means that there is an overall increase in insulin the bloodstream. This excess insulin instructs the ovaries to make far more testosterone than is necessary. This results in delayed ovulation, because the follicles which mature the next egg are impaired by the production of testosterone. This person will also experience other androgenic symptoms like hirsutism, acne, and hair loss. This is a key way that insulin resistance is a root cause of PCOS, and why there are so many undeveloped follicles seen on an ultrasound.
Confusion about testing for insulin resistance
Because insulin resistance is a pre-condition to diabetes, and not diabetes itself, glucose testing is not a helpful marker of insulin resistance. Blood sugar levels may appear completely normal when tested, even if insulin resistance is developing.
In the HOMA-IR test, the ratio between insulin and glucose is measured after fasting for at least ten hours. Sometimes even this test may come back with a false normal reading.
In the Insulin-Glucose challenge test, the patient drinks glucose and measurements are taken for insulin and glucose 2-4 hours later. This may be a better way to monitor insulin resistance instead of fasting testing like the HOMA-IR test.
In the HBA1C test, blood glucose is monitored for a few months. It can detect pre-diabetes and diabetes.
Glycemic Index
The glycemic index is a system of categorizing how quickly food breaks down into sugar in the bloodstream.
It measures how much a food with 50 grams of carbohydrates raises blood sugar over two hours in comparison to how much a food with 50 grams of glucose raises blood sugar over two hours. The closer the food is to 100 on the glycemic index, the closer it is to a pure sugar.
Glycemic index only measures blood sugar rise when you consume carbohydrates. It does not actually measure how that food effects your insulin levels.
An example of this limitation is that although proteins do not raise blood sugar to the same extent as carbs, they still can cause high insulin response. Glycemic index does not account for this.
It also does not account for the fact that we eat different serving sizes of different foods. When you see a reading for glycemic index, it is measured as if you are eating 50 grams of that food, though your actual portion size may be significantly smaller.
Glycemic Load
You may sometimes see glycemic index (GI) listed next to another marker, glycemic load (GL). Well what is the difference? Just quantity.
Remember glycemic index simply measures how close 50 grams of that food is to pure sugar.
Glycemic load is the amount of food eaten multiplied by the glycemic index of that food.
For example, pumpkin has a glycemic index of 75, but only a glycemic load of 4. You would have to consume a excessive amount of pumpkin in order to raise your blood sugar to a dangerous level. So not all high glycemic index foods are necessarily "bad foods to avoid."
Glycemic load also fails to measure how that food effects your insulin levels.
Food Insulin Index and Food Insulin Demand
The food insulin index is similar to glycemic index, except we are measuring for insulin response instead of blood glucose response. Foods that are high on the glycemic index also tend to be high on the food insulin index, these are mainly carbohydrates and sugars.
Let's talk about the macros --
Carbohydrates and sugar: raises blood sugar, and raises insulin response
Sugar is inflammatory and can cause insulin resistance, even naturally derived sugar is high in fructose, so always eat fresh fruit with all the fiber. Juice and dried fruits are particularly bad for insulin resistance.
Starchy carbohydrates are mostly glucose with little fructose. This means the effects of glucose on insulin sensitivity are less extreme, but always try to pair them with protein, fat, and fiber to slow the absorption of glucose and keep insulin lower. In other words, avoid "naked carbohydrates."
Proteins: does not raise blood sugar, but raises insulin response
Both poultry and red meat keep blood sugar low, but poultry has a significantly lower insulin response
Fish and shellfish tend to have lower insulin responses than other meats
Fats: does not raise blood sugar, and does not raise insulin response
Include fats rich in medium chain and omega-3 fatty acids from coconut oil, avocado, and fish. Avoid vegetable oils high in omega-6.
Food insulin demand is similar to glycemic load. It measures insulin response, but also takes into account how much of that food is typically going to be consumed in a meal.
What sets the FII/FID apart is that they measure all the macronutrients, not just carbohydrates, and they account for insulin response which is particularly useful if you are dealing with insulin resistance, PCOS, or other related issues like weight gain or weight that refuses to come off despite your best efforts.
The goal is not to eliminate good proteins or carbohydrates entirely because they raise insulin, but to choose types of these macros which are lower on the FID.