Effects of Flavonoid Foods on Carbonyl Stress

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. 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). We 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

Inclusion criteria

• 1. Age 25-70 years 2. BMI between 18 and 30 3. Have no known allergy to test food 4. have no known allergies to green tea, apples, blueberries, soy milk, and pineapples 5. Be not engaging in high-intensity exercise 6. Having blood and urine clinical tests in the normal range. 7. Be not taking antibiotics for six months 8. Be not currently taking medication

• No taking any prescription drugs
• If supplements were taken, flavonoid-enriched supplements (see list below) should be avoided.

Major brands Notes Soy Isoflavones All flavonoid-enriched supplements should be avoided. Lipo-Flavonoid Citrus Bioflavonoids Complex Super Flavonoids Super Antioxidants Quercetin Supplement Essential-C and flavonoids Milk Thistle Other flavonoids supplements, including but not limited: Luteolin, Rutin, etc

• No any drugs or supplements within three weeks of the experiment 9. Be nonsmoking 10. Have no alcoholic intoxication

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• No alcoholic addiction
• < 3-4 drinks per week (less than 2 glasses (300 mL) per drink)
• No alcohol within 3 three weeks of the experiment 11. Have no extended exposure to industrial wastes

Exclusion criteria

• 1. Disease: gout, heart disease, peripheral vascular disease, degenerative kidney, degenerative liver, diabetes, GI disorders, or endocrine disorders 2. Cancer patients

• Currently diagnosed cancer patients will be excluded.
• Medication free for >2 years could be considered.