Guava leaf tea lowers cholesterol.
No clinical studies have been conducted looking at the effect of guava leaf tea on either cholesterol or lipids in humans.
Numerous blogs and websites such as boldsky.com recommend guava leaf tea to help lower cholesterol. Guava leaf tea is made by boiling guava leaves in some water, straining the water and then adding that strained water to regular tea. The blogosphere also lists many other health benefits of guava leaf tea but provides no references to support the majority of these claims.
Only two clinical trials of guava leaf tea have been conducted in humans and neither looked at cholesterol lowering effects. The first study was done in Mexico and involved the administration of guava leaf extract three times a day for three days in patients with acute symptomatic diarrhea (1). The guava leaf tea reduced the duration of abdominal pain in these patients with diarrhea.
The second study was conducted in 62 infants with rotavirus infection in China (2). Infants who received guava leaf extract had faster clearance of rotavirus from their feces and a shortened duration of diarrhea.
A single study in rats showed that guava leaf extract may be beneficial in the treatment of fatty liver disease (3).
As a relative level of evidence, this is even particularly low compared to other foods, herbs and spices that have been studied for their effect on cholesterol (see Bergamot).
Earlier this year, researchers from Granada, Spain published an extensive overview of the health effects of guava leaf tea in the International Journal of Molecular Science (4). The comprehensive review has 147 references listing all published studies relating to guava leaf tea in the last decade but none relate to cholesterol or lipid lowering effects.
In summary, there is no science to support the claim that guava leaf tea helps lower cholesterol.