Just like a car, the human body shows its age and how it's been used, part by part. Brakes and tires wear out, and so do joints and cartilage. Upholstery splits, frays and fades; skin wrinkles, sags and discolors from the sun. Electrical systems fail; brains don't remember, concentrate or learn as they once did. Latches suddenly stop locking; eyes can't focus on near objects. • As the 30s become the 40s and beyond, a night out with friends finds everyone at the table needing glasses to see the menu, comparing cholesterol, back pain and prescriptions and sporting at least a few extra pounds. Most secretly hope it'll be an early evening and they can be in bed by 10 p.m. • But just as proper care, operation and maintenance can keep a good car going for decades, there's a lot you can do to minimize and cope with the effects of time.
• SKIN, HAIR, TEETH
Dermatologists mostly agree that nothing shows your age quite like your skin.
Timetable: Subtle changes start to show up in your 20s if you're a sun worshipper. Add smoking and/or excessive alcohol, and you'll look far older than your years.
The first signs of aging skin usually come in fine lines around the eyes, followed by deepening creases around the mouth, on the forehead and between the eyebrows. You might experience tiny red blood vessels on the cheeks or nose, dryness, dark patches or brown spots. Particularly if you're thin, bones and veins look more pronounced.
"Skin gets thinner, it seems to be shrinking, there's a loss of elasticity in the skin. It becomes like a rubber band that has lost its snap," says Tampa dermatologist Seth Forman.
Action plan: "Sunscreen, sunscreen and sunscreen,'' says Dr. Mary Lien, a dermatologist at USF Health in Tampa. "Start early and use it every day." Plus, Forman says, wear a wide-brimmed hat and sunglasses outside. Lien also suggests taking vitamin C, at least 1,000 milligrams a day, plus eating lots of omega-3-rich fish. And use a good moisturizer.
Professional measures: Lasers can zap red blood vessels, Botox can relax frown and mouth lines, fillers can restore structure to sinking areas, chemical peels can smooth out texture. Prescription-strength Retin-A ointment and laser treatments together can lighten age spots and smooth fine lines. "Now we're seeing women in their late 20s and 30s starting these treatments," Lien says. "They want a consistent look that is seamless from one decade to the next, so they seem to be aging gracefully."
Your crowning glory
Timetable: Most everyone's hair thins with age. But 90 percent of hair loss in men is inherited and can start in the 20s. Men and women can also have baldness caused by an immune system disorder. An easily treated thyroid disorder may also be to blame. So see your doctor if you suddenly start losing your hair.
Crash diets, too much sun and overuse of chemicals can all cause abnormal thinning. As for graying, it's inevitable, but when it happens before age 40, it's probably genetic.
Action plan: Drugs like Rogaine and Propecia can slow hair loss for some people. As for the general condition of the hair you do have, follow a balanced diet, especially Omega-3s, vitamin A and zinc. Don't overuse chemical dyes, perms and relaxers. And treat hair gently. Excessive flat ironing and blow drying can damage hair. Forget that 100 brushstrokes a night. Tight pulling, braiding, teasing and weaving can cause permanent hair loss. Some trend watchers say gray is stylish, but if it's not quite working for you, find a colorist who'll help you achieve a natural look appropriate to your age.
Take a bite out of aging
More of us are keeping our natural teeth longer than ever thanks to better oral hygiene and medical advances. Still, mouth pain, tooth loss or the inability to chew can be devastating at any age, compromising nutrition and social connections and contributing to depression. Gum disease has even been connected with heart disease.
Timetable: With age, and especially with poor dental hygiene, teeth can become crowded and crooked; saliva production drops; gums recede; teeth may become decayed, loose, temperature-sensitive, discolored.
Action plan: Keep up with the basics: brushing and flossing, regular professional cleanings and at least an annual dental checkup, including oral cancer screening. For whiter teeth, don't use tobacco, and limit or at least brush well after having cola, coffee, tea, red wine and intensely colored foods like berries and spaghetti sauce.
Over-the-counter whitening products, used as directed, work well, but they take longer than professional whitening. For straightening, braces are an option at any age and can be far more attractive than the ones your friends sported when you were kids.
• DIET AND EXERCISE
One in three adult Americans is obese, and many more are overweight. Genetics may set you up to be heavy, but lifestyle choices close the deal.
Timetable: Metabolism naturally slows down beginning in your late 20s to 30s.
"That's why many of us gain weight as we get older," says Dr. Denise Edwards, a weight management specialist at USF Health. "Plus, we tend to become less active as we get older, but our eating habits don't change."
Four main factors influence weight gain: food, activity, sleep and stress. "All four must be in balance to maintain a healthy weight," says Edwards.
If you're 40 and still eating like a 20-year-old without seriously increasing activity, you're going to gain weight. Chronic stress tells the body to hang on to calories. Crash diets and not getting enough sleep put stress on the body. Inactivity can lead to weakness, falling and fractures.
Action plan: At every age, eat a balanced diet low in saturated fat. If you're overweight, keep a food journal (don't forget to include alcohol and other caloric beverages) and measure portions and calories so you can't fool yourself.
Get moving at least 30 minutes a day most days of the week. Don't hurt yourself, but do make it challenging. You need activity that offers cardio (such as walking), strength (calisthenics and weight training), flexibility and balance (yoga and tai chi provide both).
Find a good outlet for stress. Exercise is a great one. So are prayer and meditation. Get to bed early and do it consistently.
• TAKE THIS TO HEART
Your heart may be the hardest-working muscle in the body, but take it for granted and you risk your life. Heart disease is the No. 1 killer in America.
Timetable: As you age, fatty deposits build up in the arteries, blood vessels become less flexible, the heart muscle thickens and blood pressure rises as the heart works harder to keep blood flowing. The heart can't respond as quickly to changes in activity, so we become short of breath and can't exercise as long or as intensely.
When all this happens depends greatly on genetics and lifestyle. A smoker in his 40s, with a family history of early heart disease who doesn't exercise and lives on fast food, is a heart attack waiting to happen.
For many Americans, heart disease actually starts in their 20s — and in this age of childhood obesity, even earlier.
Action plan: "I can't emphasize enough how much you have to watch what you eat. Eat less and exercise more. If you do that, half the battle is won," says Dr. Peter Wassmer, cardiologist and medical director of the Tampa Bay Heart Institute at Northside Hospital.
• Emphasize fruits, vegetables and fish, maintain a normal body weight, count calories rather than going on fad diets, and reduce salt intake, he tells his patients.
• Above all, don't smoke.
• See your doctor at least once a year to check your blood pressure, cholesterol and blood sugar. Ask if you need an EKG, a stress test and/or a carotid artery ultrasound.
• LET'S TALK SEX
You want it most and are best equipped for it (at least physically) in your teens and 20s. But with age comes experience and emotional maturity — plus less risk of pregnancy. All of which means sex can be great at any age, but it won't be the same.
Timetable: It's no accident that sexual interest is highest in the young; after about age 28, it becomes increasingly more difficult to become pregnant because fewer eggs are produced and they tend to be of poorer quality; also, the older a woman is, the greater the risk for birth defects.
Sex hormones peak in your 20s and decline slowly until about the 40s. Then comes a more dramatic drop in estrogen for women and a less dramatic decline in testosterone for men. Women may develop hot flashes, mood swings and pain during sex. Most men won't even notice their loss of testosterone, but about a third experience lower sex drive, erectile dysfunction, mood problems, fatigue and sleep disturbances.
"We don't usually check testosterone until the 40s and older, but I see men in their 30s with low testosterone," says Dr. Jose Santana, a geriatric medicine specialist with Morton Plant Mease Primary Care.
"The drop can have a profound impact on energy level, mood, the ability to enjoy life, libido. You see it every single day in a primary care office," he says.
Action plan: Men and women can get hormone replacement therapy, but it comes with some health risks, so do your homework and discuss it fully with your doctor. Otherwise, if you want to remain sexually active throughout your life, maintain a normal body weight and blood pressure, keep your cholesterol in check, prevent diabetes, don't smoke, don't drink too much, avoid stress and get plenty of sleep.
For many men, erectile dysfunction is a sign of heart disease, so don't just march into the doctor demanding Viagra without doing your part for heart health.
Medical science hasn't yet come up with a pill to inspire female arousal, but don't just assume this problem comes with age. Talk to your doctor.
• HEAD ON STRAIGHT
The brain is the most important organ in the body, and possibly the least understood. But at every age, protecting the brain should be a top priority.
Timetable: Age-related changes in the brain begin at the cellular level as early as the 30s, but they may not get your attention until your 50s, when you can never seem to remember where you put your car keys.
Relax: It's only a serious problem if you can't remember what the keys do. Forgetfulness is a normal part of aging, says Dr. Amanda Smith, medical director of the USF Health Alzheimer's Center.
"Older people can still learn, it just takes longer," she says.
Alzheimer's is perhaps the biggest fear of old age, and it does become more common after age 85, but it's not the only cause of forgetfulness or even dementia.
Action plan: Talk to your doctor if you suspect a serious problem with mental function. Depression is a common, treatable cause of dementia; certain medications can cause mental confusion; so can chronic pain, stress and lack of sleep.
There's no proof yet that lifestyle measures can prevent Alzheimer's, but Smith says you may be able to preserve brain power with the same lifestyle habits that protect your heart.
Plus, challenge yourself by learning new things throughout life; be social; find meaning through volunteer work; nurture your faith. Do your best to maintain a positive attitude, and surround yourself with people who are generally optimistic.
• SENSORY (UNDER)LOAD
Timetable: Early in life, it takes just a slight odor to wrinkle your nose, just a little heat to burn your tongue. But over time, all of our senses become less sharp and need more stimulation to tell the brain what's going on.
One of the first sensory changes you're likely to notice is vision, which can begin declining in your 30s or 40s. The major causes of age-related vision loss, cataracts and macular degeneration, usually crop up in the 60s or later.
Hearing starts to decline about age 50 (unless, of course, you've been cranking up the volume from an early age).
The sense of taste usually isn't affected until after age 60, with salty and sweet going first. The sense of smell begins its decline after age 70. Touch also seems to decline with age, but it can be affected earlier by injuries, surgeries, chronic diseases like diabetes and poor blood circulation. But, after age 50, most of us become less sensitive to pain, which can be a good and bad thing.
"The loss of senses isolates people and can lead to a loss of independence," says Morton Plant's Santana. People avoid social situations because they can't hear conversations or see well enough to leave home. If you can't feel pain, you may not know you have an injury or infection. Loss of taste or smell can lead to consuming spoiled food, or leaving something to burn on the stove. In seniors, sensory loss increases the risk of falling.
Action plan: Start by protecting your hearing, Santana says. Turn down the volume on music, TV and video games. Wear earplugs when around loud machinery.
Sometimes the fix is simple. "A blockage of earwax can cause hearing problems. Removing that can be life changing. I see it all the time," Santana says.
For more serious hearing loss, get a hearing aid. It may be hard to get used to it, but it could be key to your overall well-being.
Get your eyes checked annually so small problems don't get out of hand.
"The eyeglasses that may have worked for you at 50 may not work at 55 or 60. Get new glasses every two years," Santana says.
Preserve your senses of taste and smell by not smoking. If you have difficulty sensing temperature or pain, rely on thermostats and thermometers and inspect your skin for injuries. If balance is a problem, check the home, yard and workplace for tripping and falling hazards.