You can dry and steep the red, fleshy part of a hibiscus flower where the petals meet the stem to make hibiscus tea, which some people call sour tea because of its tart flavor. While some studies provide evidence for a cholesterol-lowering effect of hibiscus tea in animals and people with diabetes, no strong evidence suggests that hibiscus tea lowers cholesterol in otherwise healthy adults.
Your body contains two types of cholesterol: HDL and LDL. While high levels of HDL cholesterol benefit your health, high levels of LDL cholesterol can lead to serious health problems over time. The New York Times Health Guide warns that high levels of LDL lead to hardening of your arteries, or atherosclerosis. Atherosclerosis damages your heart by limiting blood flow. Small build-ups of LDL on your artery walls can also cause blood clots which block blood flow.
Animals studies suggest that hibiscus tea can lower LDL cholesterol and guard against its damaging effects. In a July 2003 study in the "Journal of Agricultural and Food Chemistry," Chang-Che Chen and colleagues showed that giving rabbits regular doses of extracts from hibiscus plants reduces their levels of LDL. Chen and colleagues also suggest that the antioxidants in hibiscus extract reduced the damage that cholesterol inflicted on the rabbits' arteries. While the findings of Chen and colleagues suggest that hibiscus tea can lower cholesterol, they do not prove that hibiscus tea will lower cholesterol levels in humans.
Diabetes and Cholesterol
Hibiscus tea may help improve cholesterol levels in people with type II diabetes. In a 2009 study published in the “Journal of Alternative and Complementary Medicine,” H. Mozaffari-Khosravi and colleagues studied diabetes patients who consumed either hibiscus or black tea twice a day for one month. The people who drank hibiscus tea ended up with higher levels of HDL cholesterol and lower levels of LDL cholesterol. The researchers noted that the people who drank black tea also had higher levels of HDL cholesterol at the end of the study, but their LDL levels did not change.
Rebecca Kuriyan and colleagues did not find any LDL cholesterol-lowering effects of hibiscus extracts in a June 2010 study published in the journal “BMC Complementary and Alternative Medicine.” People who took a daily 1 gram dose of hibiscus extract for 90 days did end up with lower levels of LDL cholesterol, but a control group that took a placebo for 90 days also had lower levels of LDL cholesterol at the end of the study. Kuriyan's study suggests that changing your eating and exercise habits can have a better effect on cholesterol levels than hibiscus extracts or teas.
Hibiscus tea may be unsafe for pregnant woman. In a March 2002 article in the obstetrics and gynaecology journal “BJOG,” E. Ernst wrote that hibiscus may have emmenagogue effects. Emmenagogue herbs stimulate menstrual bleeding and can cause problems in the early stages of pregnancy. Ernst notes that researchers have not yet established a direct link between hibiscus tea and complications in pregnancy, although it is best for pregnant women to avoid drinking the tea.