Ask Dr. Etingin

Ask Dr. Etingin

Orli R. Etingin

My doctor advised me to drink tonic water containing quinine for nighttime leg cramps. What is quinine and how does it work?

Quinine, a substance found in the bark of the cinchona tree in South America, is primarily used to treat malaria. Quinine was discovered to have a secondary medical use in preventing leg cramps, but the exact mechanism of how and why it works is unknown. (Quinine is now manufactured synthetically to protect cinchona trees.)

Until recently, quinine was sometimes prescribed for prevention of leg cramps. However, in December 2006, the FDA banned the use of quinine for leg cramps due to severe and sometimes fatal side effects (irregular heartbeat, hemorrhage, serious allergic reactions, birth defects, and miscarriages in pregnant women) that occurred with its use.

The amount of quinine in tonic water is far lower than the amount in prescription quinine but is often enough to relieve leg cramps. The FDA restricts the amount of quinine in tonic water to 83 mg per liter (about 20 mg per eight-ounce serving). Never take quinine in pill or supplement form unless it has been prescribed by your doctor.

If your calves cramp, doing calf stretches before bedtime and/or placing a heating pad on the cramp area may help prevent night cramps.

Inform your doctor if you have severe, recurrent leg cramps at night, as they may be symptomatic of a pinched nerve, impaired blood flow, or an imbalance of minerals or hormones in your body.

Which fruits and vegetables contain the highest levels of pesticides?

According to the Environmental Working Group (EWG), a non-profit research organization, produce with the highest levels of pesticides include peaches, apples, sweet bell peppers, celery, nectarines, strawberries, cherries, lettuce, imported grapes, pears, spinach, and potatoes.

The EWG suggests choosing organic varieties of the worst offenders whenever possible. The bright side? Onions, avocados, pineapples, mangos, asparagus, kiwi, bananas, cabbage, broccoli, and eggplant all ranked low in pesticides. The EWG also points out that washing and rinsing produce may reduce pesticides but does not eliminate them completely. In fact, the majority of the test data–from more than 40,000 pesticide tests collected by the U.S. Department of Agriculture (USDA) and the U.S. Food and Drug Administration (FDA)–were collected after foods were washed and rinsed or prepared (e.g., peeling a banana) as you would at home. And while some fruits, such as apples, peaches, and pears, have edible skins that can be peeled to further reduce pesticides, this often decreases the nutrients you’re getting.


Lack of vitamin D may increase your risk of heart disease

Vitamin D, touted primarily as an important nutrient to prevent osteoporosis, may also protect against heart disease, according to a study in the January issue of Circulation, the journal of the American Heart Association. Vitamin D appears to protect vascular smooth muscle and the endothelium, or inner lining, of the body’s blood vessels.

In the study, 1,739 people with an average age of 59 were followed for an average of 5.4 years; those with low blood levels of vitamin D (below 15 nanograms per milliliter, or ng/mL) had twice the risk of a heart attack, heart failure, or stroke within five years compared to people who had normal or higher levels of vitamin D. A normal blood level of vitamin D is 25 to 50 ng/mL.

During the study, 120 participants developed a first cardiovascular event such as non-hemorrhagic stroke, which occurred in 28 participants. Another 19 were diagnosed with heart failure. And eight participants developed “claudication,” which is a type of fatigue during activity that is caused by poor circulation in the legs.

The researchers report that low levels of vitamin D are “highly prevalent” in the United States. Lack of sun exposure and inadequate dietary intake of vitamin D-enriched foods such as fatty fish, milk, and cereal leads to a deficiency of the nutrient.

The researchers advocate getting adequate vitamin D through foods and supplements. The recommended daily allowance for vitamin D is 400 international units (IU) per day for men and women ages 51-70, and 600 IU for men and women over age 71.

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