It's a national epidemic of fatigue: About 60 percent of Americans report that most of the time, they don't get a good night's sleep. A survey by the National Sleep Foundation of more than 1,000 people between ages 25 and 60 found that the average American gets between six and seven hours of sleep on weeknights, leaving them feeling chronically tired. "Most people require seven to nine hours of sleep to feel rested," Thomas J. Balkin, chairman of the foundation, told CNN.com. "Sleepiness impacts every aspect of our lives."

One in four people surveyed said they'd missed work or a family event because they'd been too tired to function; one in four said they were too exhausted most nights to have sex. The cause in most cases, researchers said, was poor "sleep hygiene." Sleep can be disturbed by such practices as making big changes in bedtimes and waking times, which confuses the body's internal clock; excessive worry and anxiety; and being too busy right up to bedtime, instead of spending the last hour of the day winding down.

The survey found that 75 percent of African-Americans and 64 percent of whites routinely watch TV right up to bedtime, with another 20 percent going online - activities that experts say may be too stimulating. The benefits of changing these bad habits and thus getting better rest, Balkin says, include clearer thinking during the day, more energy, and "a better quality of life."

If you've never used maitake (my-TAH-key) mushrooms (Grifola frondosa) in cooking, you're in for a treat. They're tasty, they're one of only a few items available in the produce section that contain vitamin D, and they enhance immune function, helping the body defend against a range of illnesses, including cancer.

The maitake activates several components of the immune system. It increases the activity of T-cells (natural killer cells), and germ devouring macrophages. It boosts production of interleukin-1, which plays an important role in the inflammatory response to infection. The fungus is also rich in beta- glucan, a compound that supports the body's defenses against cancer. Finally, it increases synthesis of cytokines, which help the various components of the immune system coordinate.

In a recent study published in the Journal of Cancer Research and Clinical Oncology, researchers at Memorial Sloan-Kettering Cancer Center in New York City gave maitake mushrooms (various doses) to 34 women, median age 55, who had just completed a treatment for breast cancer that suppresses immune function. With the help of maitake, the women's immune systems returned to normal more quickly, and as dosage increased, so did their immune function.

Maitake mushrooms are available at health food stores that sell exotic mushrooms or at Asian markets. Prepare them the same way you would with white button mushrooms.

The taste of a warm, juicy strawberry on a hot summer day is a delight to the mouth. Even in February when southern California strawberries appear at the northern California farmer's markets, the sight of the red fruit is a joy as they promise that better weather and a variety of berries will soon appear.

Strawberries are a rich source of flavonoids, iron, folate, potassium, vitamins B, C and E, and phenols. In the strawberry, these phenols are led by anthocyanins and ellagitannins. The anthocyanins not only provide the strawberry's red color, but they also supply antioxidants. Strawberries' unique phenol content gives them heart-protective, anti-cancer, and anti-inflammatory abilities. Strawberries also have blood-purifying, astringent, diuretic, and liver-tonic properties. Medicinally, the fruit has been used to treat anemia, constipation, fevers, hangover, high blood pressure, gout, and rheumatism. Cut strawberries have even been used to whiten teeth and are said not to damage the enamel. In a recent study (see HC 110195-396), freeze-dried strawberries were found to lower cardiovascular disease risk factors in women with metabolic syndrome.

According to the Environmental Working Group's 2009 report "Shopper's Guide to Pesticides," strawberries are among the most common fruits with pesticide residuals. Therefore, purchasing organic strawberries is worth the effort and expense.

While strawberries are often thought of as a sweet snack or used in desserts and jams, the sliced fruit is also a great addition to a summer salad. With the addition of chopped nuts and cheese drizzled with lemon and olive oil, a strawberry and greens salad can be a tasty, as well as healthy, meal.