Metabolic dysfunctions are fast becoming major risk factors for cardiovascular incidents ie. myocardial infarction, stroke, and non-ischemic cardiovascular disease. The constellation symptoms indicative of metabolic dysfunction include: central obesity (apple body types), glucose intolerance and insulin resistance (eg. non-insulin-dependent diabetes mellitus), hypertension, dyslipidemia, high markers of inflammation, and poor clotting (hyperfibrinolysis). Given the wide array of symptoms metabolic syndrome was often overlooked, though the current criteria have been established, with three of the five required for diagnosis: Criteria Defining Value 1. Abdominal obesity Waist circumference: Women >88 cm men >102 cmWaist to hip ratio: women >0.85 and men > 1.0
When we think about hormones and aging, many of us focus on estrogen, progesterone and testosterone, and the changes that occur as we move into middle age. However, these are just three of many hormones metabolized by our bodies; hormones which also change as we age. Hormones are natural chemicals produced in one location, released into the bloodstream, and used by other target organs and systems.
In fact, aging is comprised of a whole variety of “symptoms”, functional signs and body composition changes that occur over time. Let’s review a few of them to determine what happens to our metabolism as we age and whether there is anything we can do to slow the process.
Metabolism and Hormones
The word metabolism comes from the Greek word meaning “to change”. Metabolism isn’t just how fast or slow we burn calories; it includes all the ways that our bodies store and use energy from food. It turns proteins, carbs and fats into compounds that grow and maintain cells, muscle and adipose tissue. To keep your body’s systems working healthily, a whole series of hormones must be in balance. Too much or too little of any hormone can impact not only your weight but many aspects of your overall health. The metabolic pathways impacted during aging affect insulin resistance, body composition, a decline in growth hormone and sex steroids. As we age, changes occur to the way our body systems are controlled, and in general, the body metabolizes hormones more slowly.
The Endocrine System
The endocrine system is made up of organs and tissues that produce hormones. The hormones it produces target organs. Some organs have their own internal control systems, and other hormones control many of the organs that produce hormones. In other words, it’s complicated! Aging changes this complex process. For example, the hypothalamus produces hormones that control the endocrine system and the pituitary gland. The thyroid, which releases hormones that regulate metabolism, is one of the organs that can change with age. As metabolism slows, thyroid hormones may rise, leading to increased cardiovascular risk. Parathyroid hormones can impact calcium and phosphate levels, which in turn impact bone strength. The adrenal glands produce other hormones that decrease with age, including aldosterone, which can lead to blood pressure changes.
One relatively recent discovery is how important adipose tissue (or fat) is to the endocrine system – it is, in fact, part of it. Fat cells play an essential role in the storage and release of energy throughout the body, but that’s not all they do. Adipose tissue contains other types of cells that produce hormones in response to signals from the rest of the body. These fat cell hormones play an important role in regulating glucose and cholesterol, amongst other functions.
Aging, Hormones and Weight
Weight management is a common concern for women and men of all ages. Changes in estrogen and progesterone, which are produced by the ovaries, occur in middle age. Menopause is often the time when women find that they develop fat around the middle. It happens because these hormones regulate where fat sits in the body, as well as determining whether your metabolism will burn sugar or fat. Abdominal obesity, in either men or women, can predispose you to any number of health risks, even if you have a normal BMI (body mass index). Many additional hormones also contribute to weight, however.
Insulin – the main fat storage hormone in the body, it allows your cells to take in blood sugar for energy or storage, depending on what is needed. It also tells fat cells to store fat or prevents stored fat from being broken down. Insulin resistance occurs when cells in your muscles, body fat and liver start resisting or ignoring the signal that insulin is trying to send out—which is to grab glucose out of the bloodstream and put it into our cells. When cells are insulin resistant, both blood sugar and insulin levels go up significantly. The average fasting glucose level increases after age 50, becoming less sensitive to the effects of insulin. If not actively managed, insulin resistance can lead to diabetes.
Leptin – a satiety hormone, it communicates with the brain to tell it to tell you that you feel full. Unfortunately, this hormone can get out of balance as we age if we don’t have a healthy lifestyle, leading to feelings of hunger and subsequent overeating.
Cortisol – known as the stress hormone, chronically elevated levels of it can lead to overeating, as many of us can attest. Nighttime stress in particular, which can lead to insomnia, can cause cortisol and blood sugar levels to rise, prompting your body to produce fat cells. It’s one of the many reasons why it’s important to get a good night’s sleep. Cortisol may drop with age, but usually remains stable in the bloodstream, so it’s vital to minimize unhealthy stress in every stage of life.
Aging and Inflammation
A related factor that can exacerbate age-related conditions is an increase in inflammatory cytokines as we get older. An inflammatory cytokine is a type of signalling molecule produced by immune and certain other cell types that promote inflammation. They can interfere with insulin regulation and are also associated with age-related visceral fat. It’s important, therefore, to do everything we can to dial back inflammation, through a healthy diet and other natural solutions.
Slowing the Hands of Time – Aging and Caloric Restriction
One of the most notable findings in the research on aging has been the ability of caloric restriction (CR) to, if not prevent, then significantly delay some of the age-related processes that we have been discussing here. We know that it modulates many of these complex metabolic systems, although we do not have a handle on exactly how it impacts all of them yet. Although experts say extreme caloric restriction may be the best anti-aging strategy we have, it’s not for everyone in terms of quality of life. In certain cases, it can lead to side effects like lowering of bone density and muscle mass. However, choosing moderate caloric restriction and an exercise regimen, as well as supplementing with a natural supplement that mimics the effects of CR, is an alternative most of us can achieve. By committing to healthy strategies, it is possible to tweak our metabolism and enjoy better health, for longer.