Specific formulation of Camellia sinensis prevents cold and flu symptoms and enhances gamma,delta T cell function: a randomized, double-blind, placebo-controlled study.
OBJECTIVE
Determine if a specific formulation of Camellia sinensis (CSF) can prevent illness and symptoms due to cold and flu, and enhance gammadelta T cell function


METHODS



METHODS
Randomized, double-blind, placebo-controlled study.


METHODS
Healthy adults 18-70 years old.


METHODS
Proprietary formulation of Camellia sinensis (green tea) capsules, or a placebo, twice a day, for 3 months.


METHODS
As assessed by daily symptom logs, percentage of subjects experiencing cold and flu symptoms, number of days subjects experienced symptoms, and percentage of subjects seeking medical treatment. Mean in vivo and ex vivo proliferative and interferon gamma responses of subjects' peripheral blood mononuclear cells to gammadelta T cell antigen stimulation.


RESULTS
Among subjects taking CSF there were 32.1% fewer subjects with symptoms (P = 0.035), 22.9% fewer overall illnesses of at least 2 days duration (P = 0.092), and 35.6% fewer symptom days (P < 0.002), compared to subjects taking placebo. gammadelta T cells from subjects taking CSF proliferated 28% more (P = 0.017) and secreted 26% more IFN-gamma (P = 0.046) in response to gammadelta T cell antigens, as compared to gammadelta T cells from subjects taking placebo. CSF was well-tolerated.


CONCLUSIONS
This proprietary formulation of CSF is a safe and effective dietary supplement for preventing cold and flu symptoms, and for enhancing gammadelta T cell function.
Rowe
Cheryl A
CA
Food Science and Human Nutrition Department, University of Florida, Gainesville, Florida 32611, USA.
Nantz
Meri P
MP
Bukowski
Jack F
JF
Percival
Susan S
SS
D000328:Adult; D000368:Aged; D028241:Camellia sinensis / Q000737:chemistry*; D003139:Common Cold / Q000276:immunology / Q000473:pathology* / Q000517:prevention & control; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects* / Q000502:physiology; D007251:Influenza, Human / Q000276:immunology / Q000473:pathology* / Q000517:prevention & control; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D012720:Severity of Illness Index; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors; D016896:Treatment Outcome
D007371:Interferon-gamma