Sugar Blossom

Biomarkers of Tissue and Organ Aging

Different tissues and organs change over time at varying rates, so enhancing their function by taking the steps in this book will likely slow your rate of biological aging and, in some cases, even reverse it. Some of the more common biomarkers for aging that you can have tested are listed in the following sidebar. Unfortu­nately, most of them you can’t do on your own, but by learning more about them, you will at least know which tests to consider having at some point.

Biomarkers Indicative of Biological Aging

• Cardiovascular function (blood pressure, heart strength)

• Metabolic activity (blood glucose and cholesterol levels)

• Maximal aerobic capacity (exercise stress testing)

• Muscular strength (hand grip strength)

• Breathing capacity (forced vital capacity and expiratory volume)

• Bone mineral density

• Skin elasticity

• Mental function (cognitive abilities, including memory)

• Systemic in?ammation (measured by markers in blood)

• Reaction time (nerve conduction velocity)

Control Your Blood Pressure. An easily measured biomarker of aging is your systolic blood pressure, which is the ?rst number in a blood pressure reading, such as 130 in a reading of 130/85. A normal blood pressure never has a systolic value of more than 120, but elevations in systolic pressure are more common the older you get (more on the effects of high blood pressure and how to control it in Step 6). Systolic pressures re?ect the elasticity of your arteries, or how well they expand when your heart pumps blood into them. The longer your value stays in a normal or near normal range, the younger your vessels are acting. Either have your pressure mea­sured at your next doctor’s visit, or step into the nearest pharmacy

and measure it yourself for free. Although drugstore testing is less accurate, it still gives you a ballpark idea of your systolic reading.

Action Steps for Better Health Tip

Certain biomarkers of biological aging can let you know whether you’re doing better or worse than your chronological age would indicate. Consider having your blood pressure, blood glucose and cholesterol levels, maximal aerobic capacity, breathing capacity, bone mineral density, or any combination of these measured to get a better picture of how young you still are.

Keep Your Blood Glucose and Cholesterol Levels Normal. Sim­ilarly, you can get your fasting blood glucose and cholesterol lev­els measured at the next visit to your doctor’s of?ce. A normal blood glucose reading after fasting overnight (or going at least eight hours without eating) is between 70 mg/dL and 99 mg/dL; if yours is between 100 and 125, you technically have prediabe­tes, and higher than 125 is a diagnosis of diabetes. Having higher than normal elevations in your glucose levels (either fasting or after meals) tends to make your blood vessels age more rapidly for a number of reasons, so staying in a normal range makes them biologically younger. As for blood cholesterol, lower total values generally give you a better chance of avoiding coronary or other blood vessel disease. But to really know your risk, ?nd out the subfractions of the different types of cholesterol (discussed in more detail in Step 6), because some are bene?cial, while others are more harmful.

Improve Your Aerobic Capacity and Muscle Strength. You can get an exercise stress test done that measures your maximal aerobic capacity, known as maximum oxygen consumption testing. This test may be one of the best ways to measure your biological age, as it examines the integrated function of your heart, lungs, blood

vessels, and muscles all in one test. Such testing is usually done either by cardiologists to diagnose heart problems or by exercise physiologists (such as Dr. Sheri) to ?nd out how ?t and young your cardiovascular system is. In general, the higher your maximal aerobic capacity, the younger you are staying. Fortunately, you can improve your aerobic capacity on your own with an exercise training program, as outlined in Step 2.

Along the same vein, you can also get an exercise professional to measure your hand grip strength with a special dynamometer. Declining strength on this test is indicative of a loss of muscle mass throughout your body and a higher biological age. The good news is that an overall resistance training program can improve your grip strength, along with the strength of other muscles throughout your body, thus slowing or preventing biological aging associated with loss of muscle (