Death and taxes are understood to be the only inevitable elements of life. But, there's a third issue that many of us automatically assume is unavoidable as well—getting old.

We chalk our flagging energy levels and stiffening joints up to what Larry Matson, Ed.D, co-author of the book, "Live Young, Think Young, Be Young…at Any Age," calls the, "immutable and mysterious aging process."

But the notion of aging as an uncontrollable, unstoppable force may, in fact, be faulty.

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According to Matson, once a person reaches their physical peak (somewhere between 30 and 35 years old) less than one percent of physical and mental decline each year can be attributed to the aging process alone.

"We think it's normal to be over-weight at 40, have multiple chronic diseases at 60 and be totally dependent at 70," he says. "But age is really a measure of time, not how ‘old' we are."

How to avoid feeling your age

Matson provides a list of the factors that cause people to physically and mentally feel the effects of advancing years—and simple tips for reducing their impact:

  1. Absence of physical activity: Matson points to physical disuse as the number one thing that accelerates age and is associated with the vast majority of chronic diseases. Even if you can't make it to the gym every day, there are still things you can do to stay active. Pay attention to your posture—keep your shoulders back, stand and sit up taller, and don't slouch. Take deeper breaths. Always walk as if you're going to be late for a meeting or an appointment, and look for ways to insert small bouts of physical activity into your day.
  2. Meager mental stimulation: Mental neglect comes in a close second to physical disuse in the rankings of factors that make us feel older. "As we get older, we just don't realize how much less we use our mind," Matson says, "We get zoned into a particular job task and get good at it, but we don't use other parts of our brain." After a long day of caregiving, you may be just wishing for a few minutes to sit and veg out in front of your favorite television show. Instead, try adding one mentally-stimulating activity to your nightly routine. Tackle a Sudoku puzzle, knock out a few chapters of that book club book you promised you'd read, commit to learning a new hobby. Anything that forces your brain to work in a way that it normally wouldn't.
  3. Disastrous dietary decisions: Fruits, veggies, whole grains, lean proteins—you've heard the balanced nutrition spiel before. Another way to optimize your eating plan is to munch more mindfully and slowly. Recognize the rule of halves: half of the pleasure of eating happens in the first bite and is then reduced by half with each subsequent mouthful.
  4. Excessive stress: Chronic stress, an epidemic among caregivers, can cause your cortisol levels to skyrocket, leading to inflammation and metabolic malfunctioning. Identify the things that stress you out, anticipate when they will occur, and take steps to manage your response. Take deep breaths, meditate, participate in a yoga class—whatever helps you feel more calm and centered.
  5. Attitude adjustment: "Most people underestimate the effect of the mind, but research in this area is very powerful," Matson says. Caregivers often feel that they should be able to do everything for their loved one. They adopt a "fix it" mentality that can lead to feelings of guilt and low self-esteem. Try to become more in-tune with the tone of your inner voice and swap negative notions with positive affirmations. Matson also suggests searching for ways to help others—such as offering support and advice to fellow caregivers.
  6. Alcohol in abundance: Research indicates that small amounts of alcohol may provide certain health benefits, but women especially should aim for imbibing no more than two drinks in a single day. Beyond that, the drawbacks of alcohol begin to outweigh the benefits.
  7. Second-hand smoke: Plain and simple—don't put up with secondhand smoke. For non-smokers, long-term exposure to second hand smoke is nearly as bad as puffing on an actual cigarette. Set boundaries. "It is the smoker's responsibility to smoke away from you and others," Matson says.
  8. Chemical contaminants: Since you don't have much control over the environment when you're outside, be sure to minimize your exposure to chemicals while in your own home. Invest in a water filter and cut down on how often you use aerosol cleaning and beauty products.
  9. Pill-popping: Poly-pharmacy is a big problem for many adults, one that only get worse with age. Medications (both prescription and over-the-counter), while helpful for managing certain conditions, may end up doing more harm than good in the long run. "Know what you're taking and why you're taking it," Matson advises. He says that many medications are prescribed for conditions that can be otherwise managed by making lifestyle changes. Ask your doctor if there's any way you can safely reduce your dosage, or go off a prescription all together.
  10. The genetic gamble: You may not be able to alter your genetic code, but you can take steps to reduce the impact of your detrimental genes. Research your family history and make the lifestyle changes necessary to accommodate your unique set of inherited vulnerabilities.

There's no magic cure for aging, but making small, simple lifestyle changes can improve your physical and mental wellbeing.