You can make a significant, positive difference in your well-being. Find out what to do in each decade of your life to fend off cancer, heart disease, osteoporosis, and more with advice from top integrative doctors.

20s and 30s 
You're young and busy, and illnesses such as heart disease, cancer, and osteoporosis don't cross your mind. But experts agree: This is the time to put disease-fighting strategies in place. Start with an anti-inflammatory, Mediterranean diet that includes plenty of fruits and vegetables, whole grains and legumes, and healthy omega-3 (wild salmon, walnuts, flax) and monounsaturated (olive oil) fats. 

Limit or eliminate processed foods and sugar, and don't eat red meat more than twice a week (when you do, choose lean cuts). Rack up 30 to 40 minutes of exercise most days of the week and develop a regular stress-relieving practice, such as meditation or yoga. Also, learn the details of your family's medical history to get a clearer picture of your health risks.

Build Bone, Pronto 
What's Important Now 
At this age, most of us take our skeletons for granted -- but that's a big mistake. "You can improve bone density until around 30," says Sharon Plank, M.D., "but that's your last chance." From that point, we tend to lose more bone than our bodies can build. Conscious efforts now can lower your risk of fractures as you age. 

What You Should Be Doing 
Exercise is essential, says Birgit Rakel, M.D. Resistance training and weight-bearing exercise (running and jumping, not biking or swimming) stimulate bone growth, so include them several times a week. Calcium and vitamin D are also critical for sturdy bones. Aim for 1,000 milligrams of calcium daily from a combination of foods such as low-fat dairy and leafy greens and supplements (calcium citrate is easiest to absorb). To get enough D, take a supplement that contains 1,000 IU of vitamin D3, and spend 15 minutes outside (no sunscreen) daily during summer months.

Consider This 
Scientists recently gave twenty-somethings a daily dose of 1,000 IU of vitamin D during the winter months; by winter's end, 100 percent of the women still had insufficient levels of vitamin D.

Sexual Health
What's Important Now 
An estimated one in four women between 14 and 59 are infected with human papillomavirus (HPV), a mostly symptomless sexually transmitted disease. HPV causes cervical dysplasia, which is characterized by precancerous cell changes that can progress to cervical cancer. "But if you catch it early, you can prevent it from moving forward," says Marcia Prenguber, a naturopathic physician who specializes in cancer care. 

What You Should Be Doing 
While they help, condoms provide only partial protection; HPV can spread through contact with skin near the genitals. Get an annual Pap smear, and talk to your doctor about an HPV-specific test. "HPV is relatively common in younger women, and many times it goes away," says Tieraona Low Dog, M.D. So some doctors run the test in twenty-something women only if a pap smear shows abnormal cells. However, after a woman turns 30, most doctors run the test routinely. "Women over 30 have likely had HPV longer and are at greater risk for developing cervical cancer," explains Low Dog. Since studies suggest that cigarette smoke interacts with HPV to increase cervical cancer risk, limit your exposure to secondhand smoke, and if you smoke, quit.

A diet packed with colorful produce, which offers beneficial nutrients such as carotenoids and folic acid, may help reverse mild cervical dysplasia, Prenguber says. She also recommends a multivitamin or B-complex that provides 400 to 800 mcg of folic acid, especially if you take oral contraceptives. Some studies have shown a relationship between the pill and diminished folate levels, which may leave you more vulnerable to cervical dysplasia. 

Consider This 
At some point in their lives, at least 50 percent of sexually active women become infected with HPV.

Thwart the "Big Two" 
What's Important Now 
Heart disease and cancer rank as the top two killers of women. The habits you form now will help cut your risk for both diseases in the future. 

What You Should Be Doing 
Cancer specialist Keith Block, M.D., and cardiologist Mimi Guarneri, M.D., agree: Adopt an anti-inflammatory diet, because abnormal inflammation can spark both diseases. Broccoli, leafy greens, and cabbage are especially important cancer foes, Block says; they convert procancer estrogens in your body to more protective forms of these hormones. What you drink matters, too. It's a good time to rethink your cocktail consumption if you drink alcohol regularly. Researchers recently found that even one drink a day can slightly increase a woman's risk for certain cancers. Although red wine has a heart-protective reputation, Guarneri warns against drinking more than four to five ounces (a small glass) daily. Not only does it fuel inflammation, but it's also "too much sugar, so it's fattening," she says. Any excess weight puts you at greater risk for both of the big two. 

Consider This 
An assessment of 12 studies showed that sticking to a Mediterranean diet can decrease the risk of dying from cardiovascular disease by nine percent and from cancer by six percent.

Beat IBS 
What's Important Now 
If you regularly experience symptoms such as crampy abdominal pain, bloating, constipation, and diarrhea, you've got company. Irritable bowel syndrome (IBS) is shockingly common; nearly a quarter of women in the United States suffer from this digestive disorder. The average age of onset: 29. 

What You Should Be Doing 
Confirm the diagnosis with a physician, says Rakel. Other diseases -- ulcerative colitis and celiac disease, for example -- have similar symptoms but require different treatments. Try an elimination diet to identify irritants, suggests Rakel, who cites dairy and gluten as two common culprits. 

Keep a food diary for clues to what bothers you, then remove suspect foods one at a time for a week to see if your symptoms improve. She recommends taking a daily probiotic to repopulate your bowels with beneficial bacteria (buy a supplement with at least a billion of a variety of organisms), and she also suggests stirring a tablespoon or two of ground flaxseeds into your cereal or smoothie each day. These tiny seeds contain soluble fiber, which, in time, eases both constipation and diarrhea. Enteric-coated peppermint oil may help as well; take one or two capsules containing 0.2 milliliters of peppermint oil three times a day between meals.

Additionally, chill out with mind-body practices; scientists continue to discover strong links between stress and digestion. Plank recommends this calming breath anytime you feel tense: Breathe in through your nose for four counts, and then exhale for six. Repeat six times. Consider this IBS is the second most common reason Americans miss work, after the common cold.

Key Tests 
Make these tests a must, and discuss them with your doctor, who may recommend additional screenings depending on your individual risk factors. 

Dental cleaning and exam: Every six months 
Eye exam: Annually 
Pelvic exam and Pap smear: Annually for pelvic; every one to three years for Pap; more after an abnormal Pap  
HPV test: Every three years beginning at 30 
STD test: After sexually active; frequency according to risk 
Clinical breast exam: Every three years 
Self breast exam: Monthly 
Cholesterol test*: Every five years starting at 20 
Blood pressure: Annually 
Self skin exam to check for changing moles or freckles: Monthly 
Clinical skin exam: Annually (as part of a regular checkup) 
Thyroid test: Every five years beginning at 35 
Vitamin D: Every one to three years 
*Total cholesterol, LDLs and HDLs, and triglycerides