The Power of Lifestyle Modification and Metabolic Reserves
by Thomas Guilliams, PhD
From The Role of Stress and the HPA Axis in Chronic Disease Management
The concept is straightforward: The body has an amazing ability to heal itself (return to homeostasis) when the appropriate signals are provided or removed. When harmful signals are removed and the right signals are enhanced, cells and organs are capable of self-regulating and creating optimal health. That’s why lifestyle modification is so incredibly powerful and should form the core of most treatment plans. Laboratory testing, when paired with thoughtful patient interaction, provides the insight necessary to identify the harmful signals that are keeping the body from achieving ideal wellness.
While the names given to various diseases are based on the part or system of the body involved, such as osteoporosis, diabetes or cancer, the chronic dysfunction involved in each is ultimately caused by the presence of harmful signals that eventually overwhelm the body’s ability to self-regulate and heal.
This is defined as the ability for each cell or organ to withstand changes that take place every day and are necessary for the body to function properly. This includes things like the arteries’ ability to dilate when blood flow increases, the ability to clear excess glucose after a meal, or the ability for cortisol to rise and fall when faced with a stressful situation that is later resolved.
Think of each system as a group of coiled springs or rubber bands, capable of being stretched but then ready to snap back to their original shape. Sometimes this can happen instantly, like in the case of nerve endings. At other times it can take hours, like in the case of glucose clearance. Some follow a circadian rhythm like the HPA axis, and others are set monthly like the menstrual cycle.
When systems are overwhelmed by harmful signals it can be thought of like a rubber band being stretched too far and unable to return to its original shape. Sometimes this can take months or years, like in the case of insulin resistance and diabetes; at other times it can happen much quicker, as in the case of Ebola exposure and kidney failure.
If physiological resilience (PR) is the capacity of cells and organs to respond to physiological need, then Metabolic Reserves (MR) can be thought of as the ability of the same cells and organs to withstand REPEATED (chronic) changes to physiological needs. In other words, PR is like the ability of a rubber band to stretch around a water bottle and MR is the number of times it can be stretched around that water bottle and return to its original size before becoming permanently elongated.
For example, related to the physiological resilience that permits glucose disposal is the long-term metabolic reserve in the pancreatic beta cell function. By the time a person is diagnosed with type 2 diabetes, up to half the pancreatic beta cell function is already depleted. Insulin sensitivity and beta cell function are critical long-term metabolic reserve functions that influence meal to meal physiological function.
Although the body is well designed to handle life-threatening or immediate stressors, it is less well equipped (or at least prioritizes as less important) to handle stressors that are chronic in nature. This is because the same cells and organs that are needed to manage a stressful event are the same ones that are needed to maintain “normal” physiological function.
Even at the cost of long-term survival, the body prioritizes resources and changing metabolic function to enable immediate survival. Often this priority to “survive now” erodes the capacity to buffer against long-term metabolic dysfunction. For example, the stress response to releasing glucose from stored tissue – so that it can be available now – is that fat cells become less sensitive to insulin. This is thought to be a major link between insulin-related metabolic disorders, and goes to reinforce the notion that the body doesn’t care about tomorrow nearly as much as it does today.