The Master Hormone
Insulin is a storage hormone secreted from the pancreas in response to increasing blood sugar levels. Its main role is to keep this blood sugar level within a certain range. Blood sugar is raised primarily in response to eating carbohydrates. The higher the glycemic load of a carb, the more insulin needed to stabilize the blood sugar. Upon eating a meal with a lot of carbohydrates (bread, pasta, rice, corn, sugar) the blood is quickly flooded with sugar, stimulating the pancreas to release an appropriate amount of insulin to deal with the sugar rush. Insulin acts like an enforcer to do any of these three things: put the sugar into the cells to be used as immediate energy, put it into the liver as stored energy (glycogen), or stored in fat cells for later use. Without insulin, we would quickly become hyperglycemic (high blood sugar – which is very toxic) and die.
The problem: insulin is chronically high because of our modern diet. We consume over 152 lbs of sugar per person each year in America. Also, we consume an overly abundant amount of carbohydrates (bread, cereals, beverages, bagels, pastas, pies, pancakes, bars, etc.). I know the 152 lbs of sugar sounds really bad (it is), but the refined carb load via bread, French fries, pasta, etc. is certainly no better. And “whole grains” are even higher in carbs than their castigated cousins.
With chronically high carb loads leading to chronically high insulin levels, we are forced to deal with insulin’s secondary role: fat storage regulation. Once the system has stocked its available storage sites for carbs (which doesn’t take that much), insulin starts pumping that blood sugar into fat cells. Contributing to this accumulation of fat, insulin stimulates an enzyme called lipoprotein lipase (LPL) which acts to pull fat from the bloodstream into fat cells. Because LPL activity is in higher concentrations around the midsection (men & women), hips (women), and thighs (women), insulin is likely your worst nightmare. If you ever wondered why you seem to have “nice” arms but a flabby gut and chunky thighs…LPL activity (stimulated by insulin) is the reason. Estrogen plays a role here too but we’ll cover that later. Conversely, insulin also acts to inhibit hormone sensitive lipase (HSL), whose function is to release fat from fat cells into the blood to be used as energy. So, we see that a high level of insulin in the blood is a perfect recipe for excess fat accumulation.
Excess insulin also stimulates the cells lining the arteries and blood vessels to grow, thickening the arterial walls. This causes the diameter of the vessel to decrease while also decreasing its elasticity. Narrower and stiffer blood vessels cause a spike in blood pressure which puts one at risk of heart disease. To compound this issue, insulin causes the kidneys to retain salt and fluid, which adds to the blood volume increasing the pressure even more. Since there are no drugs that directly decrease the amount and need for insulin, dietary changes and exercise are the only effective strategies to controlling this master hormone.
Thanks for listening & I hope you enjoyed,