NCT05321277

Response of Cardiometabolic Biomarkers and Gut Microbiota to Walnut Consumption

• Status: Active Not Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (actual)
• Sponsor: University of California, Davis · Academic / Other
• Sex: All
• Age: 45 Years – 70 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this research is to test if eating walnuts will cause any changes in blood lipids (like good and bad cholesterol, for example) and levels of inflammation in the blood, as well as changes in the bacteria living in the gut.

Detailed description

The purpose of this research is to test if eating walnuts will cause any changes in blood lipids (like good and bad cholesterol, for example) and levels of inflammation in the blood, as well as changes in the bacteria living in the gut. Overweight/obese adults between the ages of 45 and 70 yo with elevated LDL-C levels are eligible to participate. The study involves 5 visits (1 initial screening and 4 study visits) and will last about 10 weeks. There is a 1-week run-in period before starting the study, followed by two diet intervention periods each lasting 3 weeks, separated by a 3-week washout period. Participation in this study will involve an initial 1-week run in period to become accustomed to the study diet. After this 1 week period, participants will be randomly selected to start either a walnut or a no-nut diet. During each phase of the study, participants will be asked to come to the University of California, Davis campus after a 10-12 hour overnight fast. At each visit, body measurements will be taken; blood, urine and fecal samples will be collected. During the 10 weeks of the study, all nuts and nut-derived products will need to be avoided. The study will provide walnuts to be eaten at home for each intervention phase. Additionally, the investigators will ask that ellagitannin-rich foods, high-fiber and fermented foods be avoided in the diet. Detailed food diaries will be filled out and brought to study visits.

Conditions

• Cardiovascular Diseases

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Walnuts	Participants will consume 56 g of walnuts daily for 3 weeks. Participants will also follow a diet devoid of ellagitannin-rich, high fiber, and fermented foods.
DIETARY_SUPPLEMENT	No-nut diet	Participants will exclude all nuts and nut-derived products; high-fiber, fermented and ellagitannin-rich foods will also be excluded.

Timeline

• Start date: 2022-04-19
• Primary completion: 2024-06-11
• Completion: 2026-08-01
• First posted: 2022-04-11
• Last updated: 2026-02-10

Locations

1 site across 1 country: United States