Tea Flavonoids May Not Lead to Cholesterol Reduction

January 13/Cardiovascular Device Liability Week -- Fresh data on life sciences are presented in the report "Purified black tea theaflavins and theaflavins/catechin supplements did not affect serum lipids in healthy individuals with mildly to moderately elevated cholesterol concentrations." According to recent research from Vlaardingen, Netherlands, "Ingestion of tea flavonoids found in both green and black tea is linked to cardiovascular health benefits such as lowering serum lipids. Evidence for a cholesterol-lowering benefit of green or black tea consumption from human intervention studies is; however, conflicting and active components responsible for the effect have not yet been clearly identified."

"In a randomized, double-blind, placebo-controlled, parallel design study the effects of ingesting a purified black tea theaflavins (TFs) powder alone or in combination with catechin (TFs/catechins) on lowering serum total (TC) and LDL-cholesterol (LDL-c) were assessed. In total, 102 mildly to moderately hypercholesterolemic (TC and LDL-c: 5.70 ±0.74 and 3.97 ±0.61 mmol/L, respectively) subjects (67 men and 35 women) were randomly assigned to consume once daily one capsule of one of the three treatments: TFs (providing 77.5mg), TFs/catechins (providing 75.0mg TFs plus 150.0mg catechins and 195.0mg of other polyphenols), or placebo (cellulose). Serum TC and LDL-c concentrations did not differ significantly among the three treatments as assessed at four, eight, and 11 weeks using analysis of covariance (p=0.1187 and p=0.1063, respectively). Although changes over time from baseline to week 11 were significant for TC and LDL-c (p=0.0311 and p=0.0269, respectively), this decrease over time was seen in the TFs and placebo groups. In this human intervention study, no statistically significant LDL-c lowering effect was seen with either TFs alone or the TFs/catechins combination as compared to placebo," wrote E.A. Trautwein and colleagues.

The researchers concluded, "Based on these findings, it cannot be concluded that tea flavonoids such as theaflavins and catechins are responsible for a putative cholesterol-lowering effect of black tea, at least not with the daily dose applied in the present study."

Trautwein and colleagues published their study in European Journal of Nutrition ("Purified Black Tea Theaflavins and Theaflavins/Catechin Supplements Did Not Affect Serum Lipids in Healthy Individuals with Mildly to Moderately Elevated Cholesterol Concentrations." European Journal of Nutrition, 2010;49(1):27-35).

For additional information, contact E.A. Trautwein, Unilever Research and Development, Vlaardingen, Netherlands.

From the January 18, 2010, Prepared Foods E-dition