Effects of Flavonoid Foods on Carbonyl Stress

Purpose

This randomized crossover study will compare low- and high-flavonoid diets in healthy adults to identify flavonoid-derived biomarkers in urine and plasma. Using targeted liquid chromatography-mass spectrometry (LC-MS) metabolomics, researchers will measure known and novel flavonoid metabolites and evaluate whether a higher flavonoid intake reduces carbonyl stress markers, including reactive carbonyl species (RCS) and advanced glycation end products (AGEs).

Conditions

  • Human Health
  • Flavonoids
  • Carbonyl Stress

Eligibility

Eligible Ages
Between 25 Years and 70 Years
Eligible Sex
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • Age 25-70 years - BMI between 18 and 30 - Have no known allergy to test food - Have no known allergies to green tea, apples, blueberries, soy milk, or pineapples - Be not engaging in high-intensity exercise - Having blood and urine clinical tests in the normal range. - Be not taking antibiotics for six months - Be not currently taking medication - No taking any prescription drugs - All flavonoid-enriched supplements should be avoided. The flavonoid-enriched supplements list includes soy isoflavones, Lipo-Flavonoid, Citrus Bioflavonoids Complex, Super Flavonoids, Super Antioxidants, Quercetin Supplement, Essential-C, flavonoids, and milk thistle. Also other flavonoid supplements, including but not limited to luteolin, Rutin, etc. - No drugs or supplements within three weeks of the experiment - Be nonsmoking - Have no alcoholic intoxication - No alcoholic addiction - < 3-4 drinks per week (less than 2 glasses (300 mL) per drink) - No alcohol within three weeks of the experiment - Have no extended exposure to industrial wastes

Exclusion Criteria

  • Disease: gout, heart disease, peripheral vascular disease, degenerative kidney, degenerative liver, diabetes, GI disorders, or endocrine disorders - Cancer patients - Currently diagnosed cancer patients will be excluded. - Medication-free for >2 years could be considered.

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
High-Flavonoid Diet, Then Low-Flavonoid Diet 		All participants will first complete a 2-week low-flavonoid wash-in period. Participants in this sequence will then consume the high-flavonoid diet for 3 weeks, complete a 3-week low-flavonoid washout period, and then consume the low-flavonoid diet for 3 weeks.
  • Dietary Supplement: High-Flavonoid Diet
    Participants will consume the high-flavonoid diet daily for 3 weeks. The diet includes 1 Red Delicious apple (approximately 160 g), freeze-dried whole blueberry powder (25 g), soy milk (240 mL), and decaffeinated Lipton green tea ( 2 g tea leaves), providing approximately 420 mg flavonoids per day.
  • Dietary Supplement: Low-Flavonoid Diet
    Participants will consume the low-flavonoid diet daily for 3 weeks. The diet includes 1/3 of Red Delicious, 107 g of pineapple; 8.3 g of blueberry powder plus 16.7 g of blueberry placebo powder; 80 mL of soy milk plus 160 mL of 2% low-fat milk; and 0.67 g tea leaves, providing approximately 140 mg flavonoids per day.
Experimental
Low-Flavonoid Diet Followed by High-Flavonoid Diet 		All participants will first complete a 2-week low-flavonoid wash-in period. Participants in this sequence will then consume the low-flavonoid diet for 3 weeks, complete a 3-week low-flavonoid washout period, and then consume the high-flavonoid diet for 3 weeks.
  • Dietary Supplement: High-Flavonoid Diet
    Participants will consume the high-flavonoid diet daily for 3 weeks. The diet includes 1 Red Delicious apple (approximately 160 g), freeze-dried whole blueberry powder (25 g), soy milk (240 mL), and decaffeinated Lipton green tea ( 2 g tea leaves), providing approximately 420 mg flavonoids per day.
  • Dietary Supplement: Low-Flavonoid Diet
    Participants will consume the low-flavonoid diet daily for 3 weeks. The diet includes 1/3 of Red Delicious, 107 g of pineapple; 8.3 g of blueberry powder plus 16.7 g of blueberry placebo powder; 80 mL of soy milk plus 160 mL of 2% low-fat milk; and 0.67 g tea leaves, providing approximately 140 mg flavonoids per day.

Recruiting Locations

North Carolina Agriculture and Technical State University/ NRI Building
Kannapolis, North Carolina 28081
Contact:
Samantha Caroll
7047013024
samantha_carroll@unc.edu

More Details

Status
Recruiting
Sponsor
North Carolina Agriculture & Technical State University

Study Contact

Shengmin Sang
704-250-5710
ssang@ncat.edu

Detailed Description

Biomarkers of flavonoids and flavonoid-rich foods are needed to monitor diets. Monitoring diets and associating dietary patterns with health risks and outcomes is an essential step in the research process. The goal of this study is to determine the time- and dose-dependent formation of novel flavonoid metabolites in urine and plasma samples by conducting a randomized crossover trial of two dietary interventions with low (~140 mg flavonoids/day) and high (~420 mg flavonoids/day) flavonoid diets among healthy individuals. Foods with high or low flavonoid content will be incorporated into participants' usual diets. Liquid chromatography-mass spectrometry (LCMS)-based targeted metabolomics will be used to assess flavonoid metabolites, including novel RCS-conjugated and oxidized flavonoid metabolites, and to determine whether consuming a flavonoid-rich diet will lead to a decrease in carbonyl stress as measured by RCS and related advanced glycation end products (AGEs). Investigators will determine the changes in the major RCS and related AGEs after each intervention period using LCMS and examine the relationship between changes in RCS and AGEs and the formation of flavonoid RCS conjugates