Discover the health benefits of black tea, oolong tea and other types of tea.

Green tea is a super-healthy beverage, linked to a lower risk of cancer and diabetes, and chamomile tea has long been used to soothe unsettled stomachs, but they're not the only brews with a healthy upside. Here are 4 more to try.

-Lisa Valente, M.S., R.D., Digital Nutrition & News Editor

1. Black Tea

People who drank 20 ounces of plain black tea daily over 15 weeks improved markers of heart health and decreased their fasting blood glucose, lowering their risk of type 2 diabetes, according to a study published in Preventive Medicine in May 2012. Researchers think the catechins in black tea help keep your heart healthy by lowering triglycerides (fatty compounds found in your blood) and arming your body with antioxidants (which fight cell-damaging free radicals). With more caffeine than other teas, black tea may also help keep you on your toes. In another study, people given a cup of black tea were more focused and accurate at detailed tasks.

2. Passionflower Tea

Losing sleep during the hectic holiday season? Passionflower tea may help. A study published in the August 2011 issue of Phytotherapy Research found people who drank a cup of passionflower tea about an hour before bed reported a better night's sleep than those who drank a placebo beverage.

3. Oolong Tea

Drinking just 1 to 2 cups of oolong daily was linked to a lower stroke risk compared to nontea drinkers (it took more than 6 cups of green tea to see the same protective effects). And even just ½ cup per day may lower your risk of high blood pressure, reported a review study in the August 2011 issue of Pharmacological Research.

4. Rooibos Tea

Made from the leaves of the rooibos bush, this red-colored herbal tea may be a heart protector. People at risk of developing heart disease (read: high cholesterol, blood pressure and/or body mass index) significantly lowered their triglycerides and "bad" LDL cholesterol and raised their "good" HDL cholesterol by drinking 6 cups of the tea daily over six weeks, says research published in the Journal of Ethnopharmacology.