Consumption of cranberry polyphenols enhances human γδ-T cell proliferation and reduces the number of symptoms associated with colds and influenza: a randomized, placebo-controlled intervention study.

BACKGROUND: Our main objective was to evaluate the ability of cranberry phytochemicals to modify immunity, specifically γδ-T cell proliferation, after daily consumption of a cranberry beverage, and its effect on health outcomes related to cold and influenza symptoms. METHODS: The study was a randomized, double-blind, placebo-controlled, parallel intervention. Subjects drank a low calorie cranberry beverage (450 ml) made with a juice-derived, powdered cranberry fraction (n = 22) or a placebo beverage (n = 23), daily, for 10 wk. PBMC were cultured for six days with autologous serum and PHA-L stimulation. Cold and influenza symptoms were self-reported. RESULTS: The proliferation index of γδ-T cells in culture was almost five times higher after 10 wk of cranberry beverage consumption (p <0.001). In the cranberry beverage group, the incidence of illness was not reduced, however significantly fewer symptoms of illness were reported (p = 0.031). CONCLUSIONS: Consumption of the cranberry beverage modified the ex vivo proliferation of γδ-T cells. As these cells are located in the epithelium and serve as a first line of defense, improving their function may be related to reducing the number of symptoms associated with a cold and flu.

Supplementation with aged garlic extract improves both NK and γδ-T cell function and reduces the severity of cold and flu symptoms: a randomized, double-blind, placebo-controlled nutrition intervention.

BACKGROUND & AIMS: Earlier studies show that dietary bioactive compounds can modify proliferation of γδ-T cells. Garlic contains numerous compounds that have this potential and, in addition, has been shown to influence NK cell function. Our primary aim was to demonstrate that aged garlic extract could modify these immune cells. METHODS: A randomized, double-blind, placebo-controlled parallel intervention study recruited 120 healthy subjects (60 per group) to determine the effect of aged garlic extract supplementation (2.56 g/d) on immune cell proliferation and cold and flu symptoms. RESULTS: After 45 d of consuming an encapsulated aged garlic extract, γδ-T cells (p = 0.039, n = 56) and NK cells (p = 0.043, n = 56) were shown to proliferate better compared to placebo. After 90 d of supplementation, illness diary entries showed that the incidence of colds and flu, a secondary outcome, were not statistically different; however, the group consuming the aged garlic extract appeared to have reduced severity as noted by a reduction in the number of symptoms reported (21% fewer, p < 0.001, z-test of proportions), a reduction in the number of days (61% fewer, p < 0.001, z-test) and incidences (58% fewer p < 0.001, z-test) where the subjects functioned sub-optimally and the number of work/school days missed due to illness (58% fewer, p = 0.035, z-test). CONCLUSIONS: These results suggest that supplementation of the diet with aged garlic extract may enhance immune cell function and that this may be responsible, in part, for reduced severity of colds and flu.

Regular consumption of concord grape juice benefits human immunity.

γδ T cells are important immune surveillance cells residing in epithelial layers lining the intestine, lung, and reproductive tract. The main objective of this study was to test the hypothesis that consumption of dietary compounds from grapes would modify γδ T-cell function. Other factors related to immune function after grape juice consumption were also tested. A randomized, double-blind, placebo-controlled, parallel intervention was conducted: 100% grape juice made from Concord grapes or a placebo beverage was consumed by 85 individuals daily for 9 weeks. Subjects were asked not to consume other red, blue, and purple fruits during the study. Blood samples, taken at the beginning and the end, were analyzed for γδ T-cell numbers and proliferation, vitamin C, antioxidant capacity, and the ability to protect DNA from strand breaks. Those consuming the grape juice had significantly greater numbers of circulating γδ T cells and higher serum vitamin C levels compared to the placebo by two-way repeated-measure analysis of variance (P < .05). Individuals consuming the placebo had lower serum antioxidant activity, less γδ T-cell proliferation, and increased DNA strand breaks when challenged with H(2)O(2). Analysis of the data by structural equation modeling confirmed that 61% of the variance in biological functions at 9 weeks was due to grape juice consumption. Based on conventional statistical analyses, as well as on sophisticated modeling techniques, regular consumption of purple grape juice in the absence of other red, blue, or purple fruits benefited immunity in healthy, middle-aged human subjects.

Standardized capsule of Camellia sinensis lowers cardiovascular risk factors in a randomized, double-blind, placebo-controlled study.

OBJECTIVE: Previous studies examining the effect of tea drinking on cardiovascular health have produced mixed results due to their observational nature and qualitatively and quantitatively imprecise definitions of active tea components. The objective of this study was to determine if a standardized and defined decaffeinated green tea (Camellia sinensis) product lowers blood pressure, serum lipids, oxidative stress, and markers of chronic inflammation. METHODS: A randomized, double-blind, placebo-controlled, parallel study on 111 healthy adult volunteers 21-70 y old was performed. We administered a standardized capsule of Camellia sinensis compounds (CSC) twice a day. Before and after 3 wk, blood pressure, serum lipids, serum amyloid-alpha (a marker of chronic inflammation), and serum malondialdehyde (a marker of oxidative stress) were measured. RESULTS: After 3 wk, CSC lowered systolic and diastolic blood pressures by 5 and 4 mmHg, respectively. After 3 mo, systolic blood pressure remained significantly lower. CSC lowered serum amyloid-alpha by 42% and lowered malondialdehyde by 11.9%. In men, there were 10- and 9-mg/dL reductions in total and low-density lipoprotein (LDL) cholesterol, respectively. In all subjects with a baseline LDL cholesterol level >99 mg/dL, there was 9 mg/dL lowering of total and LDL cholesterol. Adverse effects were mild and few and not different from placebo. CONCLUSION: CSC was effective for decreasing, in as quickly as 3 wk, blood pressure, LDL cholesterol, oxidative stress, and a marker of chronic inflammation, all independent cardiovascular risk factors.

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 DESIGN: Randomized, double-blind, placebo-controlled study. SUBJECTS: Healthy adults 18-70 years old. INTERVENTION: Proprietary formulation of Camellia sinensis (green tea) capsules, or a placebo, twice a day, for 3 months. MEASURES OF OUTCOME: 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.

Immunity and antioxidant capacity in humans is enhanced by consumption of a dried, encapsulated fruit and vegetable juice concentrate.

The daily consumption of fruits and vegetables is a common dietary recommendation to support good health. We hypothesized that a commercially available encapsulated fruit and vegetable juice powder concentrate (FVJC) could support functional indices of health due to increased intake of various phytonutrients. This was a double-blind, randomized, placebo-controlled investigation of 59 healthy law students who consumed either FVJC or placebo capsules for 77 d. Blood was collected on d 1, 35, and 77 to examine the number of circulating alphabeta- and gammadelta-T cells, cytokine production, lymphocyte DNA damage, antioxidant status, and levels of carotenoids and vitamin C. A log of illnesses and symptoms was also kept. The FVJC group tended to have fewer total symptoms than the placebo group (P < 0.076). By d 77 there was a 30% increase in circulating gammadelta-T cells and a 40% reduction in DNA damage in lymphocytes in the FVJC group relative to the placebo group. Plasma levels of vitamin C and of beta-carotene, lycopene, and lutein increased significantly from baseline in the FVJC group as did plasma oxygen radical absorptive capacity (50%). Interferon-gamma produced by phorbol-stimulated lymphocytes was reduced 70% in the FVJC group, whereas other cytokines (IL-4, IL-6, transforming growth factor beta) were unchanged relative to treatment or time. FVJC consumption during this study period resulted in increased plasma nutrients and antioxidant capacity, reduction in DNA strand breaks, and an increase in circulating gammadelta-T cells.

Inhibition of neoplastic transformation of benzo[alpha]pyrene-treated BALB/c 3T3 murine cells by a phytochemical extract of passionfruit juice.

The phytochemical composition of passionfruit juice (PFJ) was hypothesized to have valuable anti-cancer activity, and this was tested in a BALB/c 3T3 neoplastic transformation model. A higher concentration of PFJ compared with a lower concentration was effective in reducing the number, size, and invasiveness of transformed foci. When incubated with another mammalian cell line, the MOLT-4, PFJ was unable to alter the cell cycle kinetics while at the same time was successful in inducing the activity of caspase-3, an enzyme that commits the cell to apoptosis. This suggests that phytochemicals found in PFJ were able to produce the changes in transformed foci due to apoptotic mechanisms rather than by a reduction in cell proliferation. These beneficial results were achieved at levels that could theoretically be attained in the plasma after consumption of the juice.