What better place to channel our passion for the second permaculture ethic than into finding a permaculture solution to the ultimate disease of civilization – metabolic syndrome? Also known as “syndrome X” or “insulin resistance syndrome,” metabolic syndrome consists of a number of metabolic abnormalities that result in an apple-shaped body type and increase a person’s risk of developing cardiovascular disease and diabetes (Cefalu et al., 2008).
Three organizations have put forth diagnostic criteria to define the syndrome – the World Health Organization, the Adult Treatment Panel III, and the International Diabetes Foundation. While there are minor variations among the specific numbers, they all basically agree that the syndrome is present with three or more of the following – obesity, hypertension (high blood pressure), dyslipidemia (cholesterol abnormalities), and glucose intolerance or diabetes (Fitzgerald, 2010).
Etiology and Pathophysiology
The exact causes of the syndrome has not been isolated, but the most universally agreed upon theory about the pathophysiology of the syndrome is that the core defect is insulin resistance (IR). IR is not completely understood, but seems to occur when, for whatever reason, there is reduced sensitivity to insulin – a hormone secreted by the beta cells of the pancreas. Normally insulin is secreted primarily in response to increase levels of glucose in the blood. Once in the bloodstream it has a variety of effects on a variety of tissues, but most importantly it binds to receptors in skeletal muscle and fat tissue. Once bound, it initiates a cascade of reactions, the most pertinent of which being the activation of the PI-3-kinase pathway, which causes a glucose transporter to translocate to the surface of the cell and to facilitate the uptake of glucose from the blood into skeletal muscle (Powers, 2012).
Again, for reasons that are not entirely clear, this doesn’t happen the way it was designed to in metabolic syndrome. However, it is known that a major player in the malfunction of this system is an overabundance of free fatty acids (FFAs) being released from adipose (fat) tissue. These FFAs cause the liver to produce more glucose and triglycerides and to secrete very low density lipoproteins (VLDLs). In addition to reducing high-density lipoproteins (HDL or “good” cholesterol), and increasing low-density lipoproteins (LDL or “bad” cholesterol), FFAs inhibit the process of insulin mediated glucose uptake as described above. Less glucose is divided up and stored as glycogen and there is an increase in circulating triglyceries and glucose. These increases stimulate and increased secretion of insulin from the pancreas, which can result in increased sodium reabsorption from the kidneys, and increased stimulation of the sympathetic nervous system – the division of the autonomic nervous system that is responsible for the “fight-or-flight” phenomenon. These effects of insulin contribute to the development of hypertension or chronic high-blood pressure. All of this adds up to a pro-inflammatory state, which forms somewhat of a positive feedback loop in reinforcing the insulin resistance caused by the FFAs.
As if that wasn’t enough, adipocytes (fat cells) are metabolically active and secrete a variety of inflammatory substances, also contributing to the feedback loop. These inflammatory substances also break down the fat cells, which release more triglycerides and FFAs into the blood stream, worsening the insulin resistance. They cause the fat cells to release plasminogen activator inhibitor 1, which inhibits the release of this substance that protects us from abnormal clot formation. They cause the liver to produce more glucose, VLDL, and fibrinogen, the latter of which contributes to clot formation. Not only is the whole body now in a persistent inflammatory state, but also in a pro-thrombotic state – which makes it more likely that abnormal clots will form. And the production of adiponectin, an endogenous anti-inflammatory and insulin-sensitizing substance, is reduced (Eckel, 2012).
I’ll bet you never knew that those few extra pounds around your waist, creating more of an apple-shaped figure, could be so dangerous! And it is especially that abdominal fat that is so metabolically active. Even more frightening is that there are really no symptoms to speak of until the syndrome is advanced and the person finally shows up at their doctors office with signs and symptoms of full-blown cardiovascular disease (e.g., hypertension, which has a prolonged asymptomatic period), or diabetes (the 3 polys – polyphagia, polydipsia, and polyuria, i.e., being hungry and thirsty all the time and peeing a lot), or even worse, the end-organ damage caused by both of these diseases – kidney failure, heart failure, nerve damage, blindness, etc. And the list of associated conditions goes on and on – polycystic ovarian syndrome, sleep apnea, fatty liver disease, and more.
Next time we’ll compare the diagnosis and management of metabolic syndrome from a permaculture perspective…