Xanthohumol and Prevention of DNA Damage

The purpose of this research study is to learn if and in what amount a compound from hops, called xanthohumol (ZAN-tho-HUE-mol), prevents damage to DNA and oxidative stress. The human body is constantly exposed to oxidative stress from environmental compounds (e.g. air pollution) which may cause damage to DNA. The human body can repair some DNA damage, but too much DNA damage is harmful and may lead to cancer. Research done at OSU and around the world has shown that xanthohumol can stop or slow processes that lead to cancer.

Participants will consume a non-alcoholic beverage containing xanthohumol with breakfast, lunch and dinner for 3 weeks. Then they will go through a washout period of 3 weeks. And then they will consume the same beverage without the xanthohumol compound (placebo) for another 3 weeks. Participants will be randomly assigned into groups and will vary whether they will consume the xanthohumol product during the first or second 3-week period. Xanthohumol doses will be 0, 6, 12 or 24 mg/day.

The study includes donation of blood and urine samples and one-month food frequency questionnaires.

Inclusion criteria

• Non-smokers or no other tobacco use in the past 3 months.
• Willing to stop taking regular supplements including anti-oxidants for 2 weeks prior to study entry through conclusion of study.
• Willing to stop consumption of high levels of flavonoids and xanthohumol in the normal diet (onions, teas including green/black tea and microbrew beers) for 2 weeks prior to study entry through conclusion of study.
• Must be able to give written informed consent.
• Blood screen tests (Comprehensive metabolic profile [CMP] and lipid profile) within normal limits.

Exclusion criteria

• Body Mass Index (BMI) less than 18.5 (underweight) or greater than 30 (obese)
• Have a significant acute or chronic coexisting illness such as cardiovascular disease, chronic kidney or liver disease, gastrointestinal disorder, endocrinological disorder, immunological disorder, metabolic disease, cancer, history of chemotherapy, celiac disease or gluten/wheat intolerance*, diabetes, thyroid problems, or any condition which contraindicates, in the investigators judgement, entry into the study.
• Currently taking prescription drugs except oral contraceptives.
• Consumption of more than the recommended alcohol guidelines i.e. >2 drinks/day.
• Consumption of high levels of flavonoids and xanthohumol in the normal diet (onions, teas including green/black tea and microbrew beers).
• Pregnancy (as confirmed by urine pregnancy test), breastfeeding, or planning to become pregnant before completing the study.
• Undergoing UV therapy (e.g. treatment for skin conditions such as psoriasis), using UV tanning beds, or unprotected sun exposure greater than 1 hour per day.
• Engaging in vigorous exercise more than 6 hours per week.
• Participation in another dietary study in the past 3 months.
• Had surgery in the last 3 months.
• Post-menopausal status

(*Note: Beverage is formulated with a barley extract. Barley contains gluten.)