Some studies in adults suggest that omega-3 fatty acids may be beneficial in the treatment of mild to moderate depression, but more research is needed.

Fish oil is a good source of omega-3 fatty acids, which play an important role in brain function. People with depression may have low blood levels of brain chemicals called eicosapentaenoic (i-koe-suh-pen-tuh-e-NO-ik) acid (EPA) and docosahexaenoic (doe-koe-suh-hek-suh-e-NO-ik) acid (DHA). EPA and DHA can be found in fish oil.

Eating fish a few times a week may provide your body with these healthy oils. Examples of fish high in omega-3s include sardines, salmon, herring, trout and canned white (albacore) tuna. Because some types of fish have higher levels of mercury than others, follow the recommendations of the Food and Drug Administration (fda.gov), especially if you're pregnant or nursing.

While it's generally true that the best way to get nutrients is through healthy foods, this is one example where a supplement may help. Some studies have shown that contaminants such as mercury do not appear to accumulate in fish oil, but remain primarily in the meat of the fish. So if you're concerned about mercury, a high-quality fish oil supplement may help with depression, but ask your doctor for advice.

Although using fish oil is generally safe, taking too much can increase your risk of bleeding and might suppress your immune response, so take fish oil supplements only under a doctor's supervision.

Fish oil isn't considered a replacement for treatment of depression, but it may be helpful as an addition to prescribed medications or other treatment. Although more studies are needed to determine exactly what role omega-3s play in depression, it's possible that fish oil supplements high in omega-3s may help lower the risk of depression — and omega-3 fatty acids help reduce high triglyceride levels and may help protect heart health.

A fitness ball can be a great tool for toning your abdominal muscles (abs), as well as other core muscles.

Fitness balls — also known as stability balls — come in various sizes. Choose a fitness ball that allows your knees to be at a right angle when you sit on the ball with your feet flat on the floor.

To tone your abdominal muscles using a fitness ball, try the abdominal crunch:

• Sit on the fitness ball with your feet resting on the floor, about hip-width apart.
• Keeping your back straight, cross your arms on your chest and tighten your abdominal muscles.
• Lean back until you feel your abdominal muscles further tighten.
• Hold for three deep breaths.
• Return to the starting position and repeat.

Start with up to five repetitions, as long as you're able to maintain good form and technique. Over time, as you strengthen your abs and core muscles, gradually increase to 12 to 15 repetitions on the fitness ball. For most people, a single set of 12 to 15 repetitions can build strength and improve fitness as effectively as can multiple sets of the same exercise. Remember to breathe freely and deeply while using the fitness ball.

The Flat Belly Diet is a weight-loss plan developed at Prevention magazine and featured in print and online versions of the magazine. The diet promises quick weight loss — especially around the middle — in about a month. The creators of the diet encourage exercise to improve results but claim exercise isn't essential.

The Flat Belly Diet has two phases. The first is a four-day, 1,600-calorie daily diet with food intended to limit gas or bloating. Beverages are limited to water infused with natural ingredients. The second phase is a four-week meal plan with 1,600 daily calories for women and 2,000 for men.

Each meal or snack in the Flat Belly Diet has a plant-based food high in monounsaturated fatty acids (MUFAs). Sources of MUFAs in the diet include olives, nuts, seeds, avocados, dark chocolate and oils, such as olive, canola, safflower, flaxseed and others.

Numerous studies have shown that plant-based foods rich in MUFAs, as well as polyunsaturated fats and other nutrients, are beneficial for weight management and cardiovascular health. The Flat Belly Diet itself has not been investigated in large or long-term clinical studies.

You might lose weight on the Flat Belly Diet because it limits total calories and encourages generally healthy eating. The menus are similar to the heart-healthy Mediterranean diet, which includes generous servings of nonstarchy vegetables, fruit and whole grains; cooking with healthy plant-based oils; and modest portions of fish, lean meats, poultry and dairy.

Although quick weight loss may sound appealing, the reality is that successful, long-term weight management requires a lifelong commitment to healthy eating and exercise.

Although you may appear thinner when you wear a girdle, the girdle doesn't strengthen or tone your abdominal muscles. Girdles just temporarily compress and redistribute fat and skin around the abdomen. When it comes to a flat stomach, diet and exercise — not undergarments — are what count.

Dietary changes and aerobic exercise can help you shed unwanted pounds, including those around your middle. Although it takes aerobic activity to burn fat, core exercises can strengthen and tone the underlying muscles.

Core exercises include:

• Abdominal crunches
• Leg lifts
• Plank poses
• Bridge poses

But any exercise that uses the trunk of your body without support counts, including Pilates and fitness ball exercises.

There is limited evidence to support the idea that taking flaxseed might lower your risk of prostate cancer.

Some studies have suggested that flaxseed may have positive effects on the prostate. For instance, one study involving men diagnosed with prostate cancer found that those who took a flaxseed supplement and followed a low-fat diet saw their prostate-specific antigen (PSA) levels decline. PSA can be a measure of how fast prostate cancer is spreading.

Other studies have shown no positive effect of flaxseed — and the alpha-linolenic acid contained in flaxseed — on prostate health.

Overall, it remains unclear whether flaxseed or flaxseed oil has a role in the prevention or treatment of prostate cancer. Controlled clinical trials may help determine whether or not it's useful in the long term.

Most nutrition experts recommend ground over whole flaxseed because the ground form is easier to digest. Whole flaxseed may pass through your intestine undigested, which means you won't get all the benefits.

Flaxseed's health benefits come from the fact that it's high in fiber and omega-3 fatty acids, as well as phytochemicals called lignans. One tablespoon (7 grams) of ground flaxseed contains 2 grams of polyunsaturated fatty acids (includes the omega 3s), 2 grams of dietary fiber and 37 calories.

Flaxseed is commonly used to improve digestive health or relieve constipation. Flaxseed may also help lower total blood cholesterol and low-density lipoprotein (LDL, or "bad") cholesterol levels, which may help reduce the risk of heart disease.

You can buy flaxseed in bulk — whole or ground — at many grocery stores and health food stores. Whole seeds can be ground at home using a coffee grinder or food processor.

Tips for including flaxseed in your diet:

• Add a tablespoon of ground flaxseed to your hot or cold breakfast cereal.
• Add a teaspoon of ground flaxseed to mayonnaise or mustard when making a sandwich.
• Mix a tablespoon of ground flaxseed into an 8-ounce container of yogurt.
• Bake ground flaxseed into cookies, muffins, breads and other baked goods.

Like other sources of fiber, flaxseed should be taken with plenty of water or other fluids. Flaxseed shouldn't be taken at the same time as oral medications. As always, talk with your doctor before trying any dietary supplements.

If you are pregnant or have given birth within the last two weeks and think you have the flu (influenza), call your health care provider right away. It's recommended that you take an antiviral medication, such as oseltamivir (Tamiflu), zanamivir (Relenza) or peramivir (Rapivab), as soon as possible. This type of medication, available by prescription, is most effective when taken within 48 hours of the first symptoms — although benefits are still possible if the medication is taken up to four to five days after symptoms start.

Also, call your doctor if you're pregnant and come into close contact with someone who has the flu. You might be prescribed an antiviral medication to reduce your risk of getting the flu.

The flu is more likely to cause severe illness in pregnant women than in women who aren't pregnant. Taking antiviral medications can prevent serious flu complications, such as pneumonia. Although it's important to be cautious with any medication during pregnancy, research suggests that the benefits outweigh the potential risks of antiviral medications to treat flu during pregnancy. Your health care provider might recommend oral oseltamivir because it has the most studies available to support its safety.

A flu shot is the best way to protect yourself and your baby from the dangers of the flu during pregnancy. The Centers for Disease Control and Prevention recommends a flu shot for anyone who's pregnant during flu season — typically November through January or later — unless you've had a severe reaction to a previous flu vaccination.

When you get your flu vaccine, request the flu shot and not the nasal spray vaccine. The flu shot is made from an inactivated virus, so it's safe for both mother and baby during any stage of pregnancy. The nasal spray vaccine is made from a live virus, and isn't recommended for use during pregnancy.

In some cases, wearing a mask might help protect you from the human influenza A and B viruses — the ones responsible for most seasonal outbreaks of flu (influenza). But the U.S. Centers for Disease Control and Prevention (CDC) generally suggests that only health care workers who are in close contact with people with influenza wear masks. The CDC doesn't recommend that people in public areas wear masks to protect themselves from influenza.

If you have influenza and need to leave your home, such as to go to a doctor's appointment, you can wear a mask, which may help reduce the spread of infection. The CDC also recommends avoiding contact with anyone if you're ill with influenza.

Generally, taking precautions such as washing your hands regularly and avoiding people who are sick is considered the best mode of protection against influenza.

People who live in community housing — such as college dorms, nursing homes or military barracks — are at higher risk of influenza because they're in contact with more potentially infected people.

Influenza A and B viruses travel through the air in droplets when someone with the infection coughs, sneezes or talks. You can inhale the droplets directly, or you can pick up the germs from an object — such as a telephone or computer keyboard — and then transfer them to your eyes, nose or mouth.

For health care workers caring for people with influenza, surgical-type masks may help block respiratory droplets carrying influenza germs and transmission of germs from the hands to the mouth. However, in most cases, the best way to protect yourself from influenza is to follow preventive measures such as washing your hands often and getting your annual influenza vaccination.

Yes, it's safe to get a flu shot during pregnancy. In fact, the Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists recommend that all women who are pregnant during flu season get a flu shot, regardless of their trimester.

A flu shot during pregnancy can help:

• Prevent the flu and maternal complications. The flu is more likely to cause severe illness in pregnant women than in women who are not pregnant. Getting the flu during pregnancy increases your risk of becoming hospitalized. A flu shot decreases your risk of getting the flu during your pregnancy.
• Prevent potential fetal health problems due to the flu. Having a fever caused by the flu early in pregnancy might increase the risk of fetal birth defects.
• Protect your baby after birth. Infants are at increased risk of severe flu symptoms, but childhood flu vaccines can't begin until a baby is 6 months old. If you have a flu shot during pregnancy, the antibodies you develop will pass through the placenta and breast milk, if you're breast-feeding. These antibodies help protect your baby from the flu after birth.

When you get vaccinated, request the flu shot — not the nasal spray vaccine. The flu shot is made from an inactivated virus, so it's safe for both mother and baby during any stage of pregnancy. The nasal spray vaccine isn't recommended for use in pregnant women.

If you have concerns about the flu shot during pregnancy, talk to your doctor.

The flu shot protects against influenza, which isn't the same thing as the stomach flu (gastroenteritis). Gastroenteritis is an infection caused by a variety of viruses, including rotaviruses and noroviruses. Although it is often called the stomach flu, gastroenteritis is not caused by influenza viruses.

Influenza attacks your respiratory system — your nose, throat and lungs. Signs and symptoms of influenza may include:

• Coughing
• Congestion
• Fever
• Muscle aches

Gastroenteritis, on the other hand, attacks your intestines, causing signs and symptoms such as:

• Diarrhea
• Vomiting
• Fever
• Chills
• Headache
• Body aches

You can reduce your risk of influenza and gastroenteritis by washing your hands often with soap and water, as well as disinfecting contaminated and frequently touched surfaces.

The annual flu vaccine is the most effective way to reduce your risk of getting influenza or reducing its severity, if you do. Two oral rotavirus vaccines are available for young infants — RotaTeq and Rotarix, to protect against rotavirus gastroenteritis.