The effects of fat on your health

With warmer weather upon us, many become suddenly conscious of the fat stores that seem to magically appear under protective winter covers of down and fleece. We hate how it looks, but we also know carrying excess fat is bad for us. Unfortunately, most of us don’t really understand why. This makes sense - most people view fat cells as just storage for excess calories. The most commonly known negative effect, atherosclerosis, can be simplified as some of that excess fat winding up in your blood and depositing inside your arteries. Over time this blocks the artery, causing a stroke or heart attack.
The reality is much more complex. Excess fat isn’t just a collection of inert tissue, it’s actually an organ in its own right. Fat cells don’t just sit there, they interact with and change levels of many hormones, affecting other cells in distant or seemingly unrelated parts of the body.
One unfortunate hormonal change that occurs in fat is the conversion of testosterone to estrogen. The more fat in our bodies, the lower our testosterone and the higher our estrogen. This is obviously significant for men, but women need testosterone, too. Decreases in the ratio of testosterone to estrogen cause hormonal changes in our body that favor deposition of of more fat. In other words: as we get fat, our bodies decide they want to get even fatter. Testosterone also helps both men and women maintain muscle mass. When muscle mass drops, so does one’s metabolic rate, further contributing to weight gain.
The rise in estrogen resulting from testosterone conversion in fat also decreases the ratio of progesterone to estrogen, again in both men and women. Changes in this ratio can cause undesirable effects like acne, bloating, insomnia, and moodiness.
Excess fat is a major contributor to the onset of diabetes and hypertension. The reasons are not fully understood, but fat cells secrete a large number of chemicals that regulate (or fail to regulate) our metabolism - how hungry we are, what our blood sugar levels are, whether we store extra energy as muscle or fat. These include leptin, resistin, adinopectin, interleukin-6 and tumor necrosis factor alpha. These (primarily leptin) are part of a hormonal cascade that should make us less hungry and therefore return to a lower weight. Unfortunately, something in our environment - either dietary changes or exposure to environmental toxins - is causing this cascade to malfunction, leading to resistance to leptin as our body is overwhelmed by its secretion by more fat tissue. This is felt by many to have a significant role in the marked societal increase in obesity as compared to a few decades ago.
Fat is also the where our bodies collect and store toxic environmental chemicals. Most of the carcinogenic or neurotoxic chemicals we are exposed to are soluble in fat, not water. Think of the chemical sheen of gasoline in a parking lot after a light rain. Any fat soluble toxins you absorb will remain in your fat since the kidneys, which flush toxins from our body into the urine, are much better at removing water soluble chemicals than fat soluble ones. Many of these chemicals are endocrine disruptors, meaning they exert their own deleterious effects on our bodies’ hormonal balance.
Of course, understanding what fat does in our body is only a fraction of the battle.  What we all want to know is how to decrease our fat stores and its health effects. Check back over the next few weeks - we’ll review why our metabolism decides to store energy as fat and hopefully use that understanding to suggest dietary changes with more sense and greater effect than many fad, deprivations diets that rarely result in long-term weight loss.

—Dr. Rebecca Gelber is an Incline Village resident and graduate of The Johns Hopkins School of Medicine. She is an adjunct professor with the UNR School of Medicine and practices locally at Tahoe Medical Spa. Call 775-298-1750, or go totahoemedicalspa.com for additional articles and information.