By Ronald Klatz, MD, DO, and Robert Goldman, MD, DO, PhD
On a cellular scale, metabolism is the breakdown of fats, proteins or carbohydrates and how our cells, organs, and tissues process these fuels. On a broader scale, metabolism is not merely the process of burning up the calories we consume from food, but rather how the various nutrients from that food help us maintain a healthy body.
Metabolism slows with age, thereby contributing to weight gain in our older years. After age 45, the average individual loses around 10 percent of their muscle mass per decade. This equates to losing about one-third to one-half a pound of muscle each year and also gaining that much in body fat.
A comprehensive study funded by the Agricultural Research Service suggests metabolism may slow with age because of a gradual loss of body cells, especially high-energy-consuming muscle cells. As a result, people burn fewer calories while at rest when they're older, which often leads to weight gain over time. This study, a statistical analysis conducted by researchers at the Human Nutrition Research Center on Aging at Tufts University in Boston, showed a direct association between metabolic rate and cell mass, also known as lean- or fat-free mass.
Proper nutrition can play a key role in getting your body to work for you. People who are physically fit, eat a healthy, balanced diet, and take nutritional supplements can measure out to be up to 20 years biologically younger than their chronological age. Let's take a look at what the science is saying about the link between nutrition and metabolism.
Metabolic Syndrome: Metabolism Gone Bad
Metabolic syndrome, also known as Syndrome X or insulin-resistance syndrome, affects an estimated 50 million Americans. According to the American Heart Association (AHA), this syndrome, which significantly increases the risk of coronary heart disease, stroke, type 2 diabetes and other significant health problems (particularly those related to plaque buildup on artery walls) , is actually a constellation of six metabolic factors gone bad:
- Abdominal obesity (excessive fat tissue in and around the abdomen).
- Blood fat disorders: low HDL ("good") cholesterol, high LDL ("bad") cholesterol high triglycerides, which promotes plaque buildups on artery walls.
- Elevated blood pressure.
- Insulin resistance or glucose intolerance (the body can't properly use insulin or blood sugar).
- Prothrombotic state (which elevates the risk of blood clot formation).
- Pro-inflammatory state (e.g., elevated C-reactive protein in the blood; linked to numerous diseases).
The AHA suggests primary interventions to manage or reduce the risk of metabolic syndrome include weight loss (goal is to attain a body mass index of less than 25 kg/m2); increasing physical activity (goal of 30 minutes or more of moderate-intensity activity on most days of the week; and adopting health eating habits, including reducing intake of saturated fat, trans fat and cholesterol. |
Chromium
Chromium is an essential trace mineral that helps the body to make glucose available for energy and to maintain normal blood sugar levels. It is also important for the metabolism of amino acids and fats. People ages 55 and older who exercise regularly are at risk of deficiency and therefore may benefit from taking supplementary chromium.
Chromium is widely believed to be useful in the treatment of diabetes. Chromium may lower the risk of heart disease. People with higher blood levels of chromium are at lower risk of developing heart disease, and chromium may also lower total cholesterol, LDL cholesterol, and triglyceride levels, while also raising levels of HDL cholesterol.
Green tea
Unlike black and oolong tea, green tea (Camellia sinensis) is not fermented; therefore, the active ingredients remain unaltered in the herb. Green tea increases fat metabolism and helps to regulate blood sugar and insulin levels. A study of overweight and obese people found that drinking a beverage containing 625 mg of green tea catechins enhanced exercise-induced weight loss - particularly in the abdominal area - and reduced fasting serum triglyceride levels. A study of green tea and weight loss in obese Thai men found the compound increases energy expenditure and fat oxidation.
Green tea is also thought to prevent cardiovascular disease by lowering cholesterol levels, inhibiting LDL cholesterol oxidation, and reducing the tendency of blood platelets to stick together. It also is a potent antioxidant. Green tea compounds not only directly scavenge free radicals, but also enhance the effectiveness of the body's natural antioxidant systems.
Magnesium
Magnesium is essential for life, as it plays a major role in the metabolism of glucose. It is also used in the production of cellular energy and to create protein. In addition, magnesium may help to protect against cardiovascular disease. Epidemiological studies have found that eating a diet low in minerals, specifically calcium, potassium, and magnesium, is associated with hypertension (high blood pressure). Studies have also shown that people with diabetes tend to have low magnesium levels. In one study, middle-aged people with the lowest serum magnesium levels were twice as likely as those with the highest to develop type 2 diabetes.
Potassium
Potassium is important for intracellular chemical reactions and regulates the transfer of nutrients to the cells. Potassium is required for proper carbohydrate metabolism. Severe potassium deficiency can lead to heart attack. Studies have found that potassium can reduce high blood pressure and help to prevent heart attacks. Additionally, potassium supplementation may help to prevent type 2 diabetes in people taking thiazide diuretics. Research published last year suggests depleted blood potassium levels may explain why people prescribed diuretics for the treatment of high blood pressure run an increased risk of developing type 2 diabetes.
Drs. Ronald Klatz and Robert Goldman are the president and chairman, respectively, of the American Academy of Anti-Aging (www.worldhealth.net), a nonprofit organization dedicated to the prevention, detection and treatment of aging-related disease.