Clinical trial NCT00360919: Assessing the Presence of Casomorphins in Human Plasma After Dairy Ingestion
Official title: Assessing the Presence of Casomorphins in Human Plasma After Dairy Ingestion
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: EARLY_PHASE1
Conditions: Food Habits
Keywords: casomorphin
cheese
craving
casein
milk
Lead sponsor: Physicians Committee for Responsible Medicine
Sponsor class: OTHER
First posted: 2006-08-07
Enrollment: 28
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: DIAGNOSTIC

Brief summary: This purpose of this study is to perform a pilot investigation to determine if opioid peptides such as casomorphin can be detected in human plasma after cheese ingestion.

Detailed description: Cheese is one of the most commonly craved foods, suggesting the possibility of opiate activity, as has been demonstrated with other craved foods, particularly chocolate. Like other dairy products, cheese contains casein, which is the major protein in cow's milk. This is unlike human milk, in which the primary protein is whey. Casein includes αs1-, αs2-, β- , and κ-casein, with αs1 and β forms predominating. Human and bovine casein molecules are cleaved during digestion to release opioid peptides that are believed to have biological properties relevant to infant physiology and behavior. Specifically, β-casein is cleaved to form β-casomorphins. Like other opiate agonists, β-casomorphins prolong gastrointestinal transit time and have an antidiarrheal effect.

Casomorphin receptor binding has been demonstrated in opiate receptor assays and bioassays. Duodenal aspirates from human volunteers given cow's milk have demonstrated the presence of several casomorphins, particularly β-casomorphin-7. Few studies have assessed the presence or action of casomorphins in humans. The ability of casein-derived opioid peptides to pass into the bloodstream is not well characterized, and is the subject of the present study.

Eligibility criteria: Inclusion Criteria:

* Age greater than 18 years
* Male or female
* Either self-described as having a strong liking for cheese, or have been following a vegan diet for a least the previous six months.

Exclusion Criteria:

* Unstable medical status
* Physical condition affecting eating behavior, digestion, or intestinal absorption
* Dairy allergy or lactose intolerance
* Pregnancy
* History of severe mental illness
* Smoking during the past six months
* Alcohol consumption of more than two drinks per day
* History of substance abuse or dependency followed by any current use
* Inordinate fear of blood draws

Primary outcomes:
measure: casomorphin quantification
timeFrame: Measurements will be collected on designated studys within 12-hour time frame
Secondary outcomes:
Other outcomes:
Locations:
city: Washington, DC
country: United States
facility: Physicians Committee for Responsible Medicine
state: District of Columbia
Study officials:
affiliation: Physicians Committee for Responsible Medicine
name: Neal Barnard, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Washington Center for Clinical Research
name: Hope R Ferdowsian, MD, MPH
role: STUDY_DIRECTOR
References:
citation: Shah NP. Effects of milk-derived bioactives: an overview. Br J Nutr. 2000 Nov;84 Suppl 1:S3-10. doi: 10.1017/s000711450000218x.
citation: Meisel H, FitzGerald RJ. Opioid peptides encrypted in intact milk protein sequences. Br J Nutr. 2000 Nov;84 Suppl 1:S27-31. doi: 10.1017/s000711450000221x.
citation: Brantl V, Teschemacher H, Blasig J, Henschen A, Lottspeich F. Opioid activities of beta-casomorphins. Life Sci. 1981 Apr 27;28(17):1903-9. doi: 10.1016/0024-3205(81)90297-6. No abstract available.
citation: Svedberg J, de Haas J, Leimenstoll G, Paul F, Teschemacher H. Demonstration of beta-casomorphin immunoreactive materials in in vitro digests of bovine milk and in small intestine contents after bovine milk ingestion in adult humans. Peptides. 1985 Sep-Oct;6(5):825-30. doi: 10.1016/0196-9781(85)90308-0.
citation: Drewnowski A, Krahn DD, Demitrack MA, Nairn K, Gosnell BA. Taste responses and preferences for sweet high-fat foods: evidence for opioid involvement. Physiol Behav. 1992 Feb;51(2):371-9. doi: 10.1016/0031-9384(92)90155-u.