Apple cider vinegar isn't likely to be effective for weight loss.

Proponents of apple cider vinegar claim that it has numerous health benefits and that drinking a small amount or taking a supplement before meals helps curb appetite and burn fat.

However, there's little scientific support for these claims. Studies of apple cider vinegar for weight loss have not consistently shown significant and sustainable weight loss across diverse groups of people.

Although occasional use of apple cider vinegar is safe for most people, it does carry some risks. For example:

• Apple cider vinegar is highly acidic. It may irritate your throat if you drink it often or in large amounts.
• Apple cider vinegar may interact with certain supplements or drugs, including diuretics and insulin. This may contribute to low potassium levels.

Remember, there's no magic bullet for weight loss. Be skeptical of any approach that claims you can lose weight without decreasing calories or increasing physical activity.

Arcus senilis is a gray or white arc visible above and below the outer part of the cornea — the clear, domelike covering over the front of the eye. Eventually, the arc may become a complete ring around the colored portion (iris) of your eye.

Arcus senilis is common in older adults. It's caused by fat (lipid) deposits deep in the edge of the cornea. Arcus senilis doesn't affect vision, nor does it require treatment.

When arcus senilis occurs in older adults, it isn't related to high cholesterol. However, an arc or ring around the iris sometimes occurs in younger people who have severe cases of high cholesterol and high triglycerides passed down through families (familial hyperlipidemia). In people with familial hyperlipidemia, this arc or ring typically occurs before age 45 and is associated with an increased risk of heart disease.

Research on the effectiveness of aromatherapy — the therapeutic use of essential oils extracted from plants — is limited.

However, some studies have shown that aromatherapy might have health benefits, including:

• Relief from anxiety and depression
• Improved quality of life, particularly for people with chronic health conditions
• Improved sleep

Smaller studies suggest that aromatherapy with lavender oil may help:

• Reduce pain for people with osteoarthritis of the knee
• Improve quality of life for people with dementia
• Reduce pain for people with kidney stones

Essential oils used in aromatherapy are typically extracted from various parts of plants and then distilled. The highly concentrated oils may be inhaled directly or indirectly or applied to the skin through massage, lotions or bath salts. Some essential oil manufacturers have oils that can be taken internally, but research on the safety and efficacy of this method is extremely limited.

Aromatherapy is thought to work by stimulating smell receptors in the nose, which then send messages through the nervous system to the limbic system — the part of the brain that controls emotions.

Many essential oils have been shown to be safe when used as directed. However, essential oils used in aromatherapy aren't regulated by the Food and Drug Administration.

When oils are applied to the skin, side effects may include allergic reactions, skin irritation and sun sensitivity. In addition, further research is needed to determine how essential oils might affect children and how the oils might affect women who are pregnant or breast-feeding, as well as how the oils might interact with medications and other treatments.

If you're considering aromatherapy, consult your doctor and a trained aromatherapist about the possible risks and benefits.

Artificial nails, a nail enhancement that can be made from a variety of materials, aren't likely to harm healthy natural nails. However, artificial nails can sometimes cause problems, such as an infection.

Popular types of artificial nails include acrylic and gel nails. Both are made with types of acrylic, but gel nails require "curing" with ultraviolet light. If an artificial nail is damaged or as your natural nails grow, a gap can develop between the artificial nail and your natural nail. This gap provides a moist, warm environment in which a nail infection can flourish. A nail infection might also occur if artificial nails are too long or rigid, or the nails are applied with unsanitary tools. It's also possible to have an allergic reaction to components of artificial nails or their adhesives. Signs of a nail infection include redness, swelling and pus.

If you choose to have artificial nails applied in a salon, take steps to minimize the risks:

• Stick to salons that display a current state license, and work only with technicians also licensed by the state board.
• Make sure your nail technician properly sterilizes all tools used during your treatment and washes his or her hands between customers.
• Request a new nail file — or consider bringing your own — since nail files can't be sterilized.
• Return to the salon every two to three weeks for maintenance.

If you apply artificial nails at home, follow the safety precautions on the package. Work in a well-ventilated area, and protect the skin around your nails from the chemicals used during the application process.

Consider removing your artificial nails and letting your natural nails breathe every two to three months. If you suspect a nail infection, consult a dermatologist for an evaluation.

You can use most sugar substitutes if you have diabetes, including:

• Saccharin (Sweet'N Low)
• Aspartame (NutraSweet, Equal)
• Acesulfame potassium (Sunett)
• Sucralose (Splenda)
• Stevia (Pure Via, Truvia)

Artificial sweeteners, also called sugar substitutes, low-calorie sweeteners or nonnutritive sweeteners, offer the sweetness of sugar without the calories. Artificial sweeteners are many times sweeter than sugar, so it takes a smaller amount to sweeten foods. This is why foods made with artificial sweeteners may have fewer calories than those made with sugar.

Sugar substitutes don't affect your blood sugar level. In fact, most artificial sweeteners are considered "free foods" — foods containing less than 20 calories and 5 grams or less of carbohydrates — because they don't count as calories or carbohydrates on a diabetes exchange. Remember, however, that other ingredients in foods containing artificial sweeteners can still affect your blood sugar level.

More research is needed, but some studies have found that the benefits of substituting sugar-sweetened food and beverages with those that have been sweetened artificially may not be as clear as once thought. This may be especially true when artificial sweeteners are consumed in large amounts. One reason may be a "rebound" effect, in which some people end up consuming more of an unhealthy type of food because of the misperception that it's healthy because it's sugar-free.

Also, be cautious with sugar alcohols — including mannitol, sorbitol and xylitol. Sugar alcohols can increase your blood sugar level. And for some people, sugar alcohols may cause diarrhea.

Artificial tears are eyedrops used to lubricate dry eyes and help maintain moisture on the outer surface of your eyes. Such eyedrops may be used to treat dry eyes that result from aging, certain medications, a medical condition, eye surgery or environmental factors, such as smoky or windy conditions.

Artificial tears are available without a prescription. No single brand works best for every form of dry eyes. You may need to try several different brands before you find one that works best for you.

Besides lubricating your eyes, some artificial tears also promote healing of the eyes and others work to decrease tear evaporation. Artificial tears may also contain thickening agents, which keep the solution on the surface of your eyes longer.

There are two categories of artificial tears:

• Eyedrops with preservatives. This type often comes in multidose bottles and contains chemicals (preservatives) that discourage growth of bacteria once the bottle has been opened. The preservatives may irritate your eyes, especially if you have moderate or severe dry eyes.
• Preservative-free eyedrops. This type has fewer additives and is generally recommended if you apply artificial tears more than four times a day, or if you have moderate or severe dry eyes. Preservative-free eyedrops may come in single-dose vials.

Artificial tears are also available as nonprescription gels and gel inserts. These may cause temporary blurred vision.

If you still don't have relief after trying various products, the next step might be to try one or more artificial tear ointments. These can temporarily cause blurred vision, so you might prefer to apply the ointment just before bedtime.

If you haven't experienced some relief with these efforts, make an appointment with an eye doctor (ophthalmologist or optometrist), who can suggest other treatments.

Reactions to aspirin are common. If you have an aspirin allergy or sensitivity, you may also have a reaction to nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve).

Aspirin allergy symptoms

An aspirin allergy or sensitivity, or a reaction to NSAIDs, can cause symptoms that range from mild to severe. Reactions occur within minutes to hours of taking the medication. They may include:

• Hives
• Itchy skin
• Runny nose
• Red eyes
• Swelling of the lips, tongue or face
• Coughing, wheezing or shortness of breath
• Anaphylaxis — a rare, life-threatening allergic reaction

If you have asthma, nasal polyps, chronic sinusitis or chronic hives (urticaria), you're more likely to have a reaction to aspirin or NSAIDs. When a reaction occurs, it can worsen symptoms of these conditions.

What you can do

Having asthma or another of these conditions doesn't guarantee you'll have a reaction, or that you should avoid aspirin and other NSAIDs. However, if you've ever had a severe reaction to an NSAID or you're uncertain about your reaction, it's best to avoid all NSAIDs until you've had an evaluation by your doctor — whether you have one of these conditions or not.

Keep in mind that aspirin and other NSAIDs are found in many over-the-counter medications — so check labels carefully. If you aren't sure if your medication contains an NSAID, ask your doctor or pharmacist. It may be OK for you to use acetaminophen (Tylenol, others) instead, but check with your doctor first to make sure it's safe for you.

Always tell your doctor if you have any medication reaction, particularly if it's severe. For a serious reaction, you may need to see a doctor who specializes in diagnosing and treating this type of reaction (allergist/immunologist).

Generally, aspirin isn't recommended during pregnancy unless you have certain medical conditions.

Low-dose aspirin — 60 to 100 milligrams (mg) daily — is sometimes recommended for pregnant women with recurrent pregnancy loss, clotting disorders and preeclampsia.

However, use of higher doses of aspirin poses various risks depending on the stage of pregnancy. During the first trimester, use of higher doses of aspirin poses a concern for pregnancy loss and congenital defects. Taking higher doses of aspirin during the third trimester increases the risk of the premature closure of a vessel in the fetus's heart. Use of high-dose aspirin for long periods in pregnancy also increases the risk of bleeding in the brain of premature infants.

If you need to take aspirin during your third trimester of pregnancy, your health care provider will likely closely monitor you and your baby.

The typical over-the-counter, low-dose aspirin is 81 mg (previously referred to as baby aspirin). If you need to take a pain reliever during pregnancy, talk to your health care provider about the options. He or she might suggest occasional use of acetaminophen (Tylenol, others) instead of aspirin.

Asthma and acid reflux often occur together. It isn't clear why, or whether one causes the other. But we do know that acid reflux can worsen asthma and asthma can worsen acid reflux — especially severe acid reflux, a condition known as gastroesophageal reflux disease (GERD).

Asthma and acid reflux can occur together in children as well as in adults. In fact, about half the children with asthma also have GERD.

When asthma and acid reflux do occur together medications may not work as well to control signs and symptoms of either condition, such as coughing, shortness of breath, wheezing and chest pain.

Treating acid reflux may help ease symptoms. You may be able to control acid reflux with over-the-counter medications — for example, a proton pump inhibitor, such as omeprazole (Prilosec OTC). Avoiding reflux triggers, such as fatty foods, alcohol and tobacco, also may help. If that's not enough, prescription medications may be needed. If you have asthma and think you might have acid reflux, talk to your doctor about the best treatments.

In some cases, asthma medications can worsen acid reflux. This is particularly true of theophylline (Elixophyllin, Theo-24, Theocron). But don't quit taking or change any asthma medications without getting your doctor's OK first.

There's no asthma diet that will eliminate your symptoms. But these steps may help:

• Eat to maintain a healthy weight. Being overweight can worsen asthma. Even losing a little weight can improve your symptoms. Learn how to eat right to maintain a healthy weight over the long term.
• Eat plenty of fruits and vegetables. They're a good source of antioxidants such as beta carotene and vitamins C and E, which may help reduce lung swelling and irritation (inflammation) caused by cell-damaging chemicals known as free radicals.
• Avoid allergy-triggering foods. Allergic food reactions can cause asthma symptoms. In some people, exercising after eating an allergy-causing food leads to asthma symptoms.
• Take in vitamin D. People with more-severe asthma may have low vitamin D levels. Milk, eggs and fish such as salmon all contain vitamin D. Even spending a few minutes outdoors in the sun can increase vitamin D levels.
• Avoid sulfites. Sulfites can trigger asthma symptoms in some people. Used as a preservative, sulfites can be found in wine, dried fruits, pickles, fresh and frozen shrimp, and some other foods.

It's also possible that eating less salt (sodium) or eating foods rich in oils found in cold-water fish and some nuts and seeds (omega-3 fatty acids) may reduce asthma symptoms. But more research is needed to verify this.

Making informed choices about what foods to eat and what foods to avoid won't cure asthma. But eating a balanced diet and avoiding known trigger foods may improve your symptoms and your overall health.