Effects of Black Tea Intake on Serum Lipids

Effects of Black Tea Intake on Serum Lipids in Mildly Hypercholesterolemic Adults A Randomized Diet-controlled Crossover Trial

A diet-controlled clinical trial which attempts to provide estimates of the effect of black tea consumption on serum lipids under tightly controlled conditions, including a controlled diet. Mildly hypercholesterolemic individuals (total cholesterol levels between 4.9 and 6.7 mmol/L, 190 and 260 mg/dl), non-smoking, chronic disease-free individuals were enrolled in a 15-week, double blind, randomized crossover trial, during which they consumed a controlled low-flavonoid diet plus 5 cups of black tea or a tea-like placebo over two 4-week treatment periods.

Study Overview

• Status: Completed
• Conditions: Hypercholesterolemia
• Intervention / Treatment: Dietary supplement: Placebo; Dietary supplement: Tea Treatment Group

• Study Type: Interventional
• Enrollment (Actual): 57
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Minneapolis, Minnesota, United States, 55454
      • General Clinical Research Center, University of Minnesota

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 45 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• between 45-65 years old
• mildly hypercholesterolemic (total cholesterol levels between 4.9 and 6.7 mmol/L, 190 and 260 mg/dl)
• high-density lipoprotein cholesterol (HDL-C) between 0.9 and 1.6 mmol/L (35 and 65 mg/dl)
• triglyceride (TG) concentrations below 6.8 mmol/L (600 mg/dl)
• habitually consumed a typical American diet with low dietary flavonoid intake (<4 one-half cup servings of fruits and vegetables/day) and low intake (<1 serving/day) of soy-rich foods, nuts, herbs, and spices (besides salt and pepper)
• aspartate aminotransferase (AST) between 0 and 55 mg/L
• creatinine between 70.7 and 150.3 mmol/L (0.8 and 1.7 mg/dl)
• glucose between 3.3 and 6.4 mmol/L (60 and 115 mg/dl)

Exclusion Criteria:

• current smoker
• usage of high amounts of antioxidant vitamin supplements (>3 times the Recommended Dietary Allowance (RDA) of vitamins E, C, and selenium, or >10 mg/day of beta carotene)
• had been diagnosed with diabetes, coagulation disorders, chronic pulmonary disease, current active malignancy, renal disease requiring dialysis, malabsorption, or gastrointestinal disorders, or had a history of cardiovascular disease.
• antihypertensive, immunosuppressive, cholesterol lowering, or anticoagulant medications
• consuming >3 servings of alcohol daily
• Pre-menopausal (women)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Tea Treatment Group; 5 cups brewed tea beverage per day for 28 days, brewed from 700 mg of black tea solids per cup	Dietary supplement: Tea Treatment Group; This intervention was a crossover trial, during which each patient experienced both placebo and tea treatment arms; Other Names: Brewed black tea beverage
Placebo Comparator: Placebo Group; 5 cups tea-like placebo per day for 28 days. Placebo was exactly matched to tea except for flavonoid composition. Placebo was flavonoid-free.	Dietary supplement: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serum lipid levels	Serum lipid levels (total cholesterol, LDL-C, HDL-C, triglycerides, LDL-C+HDL-C fraction, LDL-C/HDL-C ratio) were assessed at the end of a 28-day treatment period	4 weeks

Collaborators and Investigators

• Sponsor: University of Minnesota
• Collaborators: National Center for Research Resources (NCRR)
• Investigators: Principal Investigator: Myron Gross, PhD, University of Minnesota

Publications and helpful links

General Publications

• Troup R, Hayes JH, Raatz SK, Thyagarajan B, Khaliq W, Jacobs DR Jr, Key NS, Morawski BM, Kaiser D, Bank AJ, Gross M. Effect of black tea intake on blood cholesterol concentrations in individuals with mild hypercholesterolemia: a diet-controlled randomized trial. J Acad Nutr Diet. 2015 Feb;115(2):264-271.e2. doi: 10.1016/j.jand.2014.07.021. Epub 2014 Sep 27.

Study record dates

Study Major Dates

• Study Start: April 1, 2002
• Primary Completion (Actual): April 1, 2004
• Study Completion (Actual): April 1, 2004

Study Registration Dates

• First Submitted: June 17, 2013
• First Submitted That Met QC Criteria: June 17, 2013
• First Posted (Estimate): June 20, 2013

Study Record Updates

• Last Update Posted (Actual): May 7, 2019
• Last Update Submitted That Met QC Criteria: May 3, 2019
• Last Verified: May 1, 2019

More Information

Terms related to this study

• Keywords: flavonoids; randomized control trial; cholesterol; serum lipids; serum cholesterol; crossover trial; black tea; diet controlled
• Additional Relevant MeSH Terms: Metabolic Diseases; Lipid Metabolism Disorders; Hyperlipidemias; Dyslipidemias; Hypercholesterolemia
• Other Study ID Numbers: 10205345-A2; M01RR000400 (U.S. NIH Grant/Contract)