Yujin Lee

In vitro Production of IL-6 and IFN-γ is Influenced by Dietary Variables and Predicts Upper Respiratory Tract Infection Incidence and Severity Respectively in Young Adults

Assessment of immune responses in healthy adults following dietary or lifestyle interventions is challenging due to significant inter-individual variability. Thus, gaining a better understanding of host factors that contribute to the heterogeneity in immunity is necessary. To address this question, healthy adults [n = 36, 18–40 years old, body mass index (BMI) 20–35 kg/m2] were recruited. Dietary intake was obtained via 3-day dietary recall records, physical activity level was evaluated using the International Physical Activity Questionnaire, and peripheral blood mononuclear cells were isolated from peripheral blood. Expression of activation markers on unstimulated immune subsets was assessed by flow cytometry. T-cell proliferation and cytokine secretion was assessed following in vitro stimulation with anti-CD3 or lipopolysaccharide. Furthermore, the incidence and severity of cold or flu symptoms were obtained from self-reported upper respiratory tract infection (URTI) questionnaires. The relationship between activation marker expression on T cells and T-cell effector functions; and in vitro cytokine secretion and URTI was determined by linear or logistic regression. CD69 and CD25 expression on unstimulated T cells was significantly associated with T-cell proliferation and interleukin-2 secretion. Incidence and severity of cold or flu symptoms was significantly associated with in vitro interleukin-6 and interferon-gamma secretion, respectively. Furthermore, host factors (e.g., age, BMI, physical activity, and diet) contributed significantly to the relationship between activation marker expression and T-cell effector function, and cytokine secretion and cold and flu status. In conclusion, these results suggest that lifestyle and dietary factors are important variables that contribute to immune responses and should be included in human clinical trials that assess immune endpoints.

Consumption of Bifidobacterium animalis subsp. lactis BB‐12 impacts upper respiratory tract infection and the function of NK and T cells in healthy adults

SCOPE Probiotics can modulate immunity and reduce upper respiratory tract infections (URTI) in humans; however few studies have examined both outcomes in the same trial. The goal of the current study was to investigate the effect of Bifidobacterium animalis subsp. lactis BB-12, on natural killer (NK) and T-cell function in conjunction with self-reported cold/flu outcomes in healthy adults. METHODS AND RESULTS In a randomized, partially blinded, four-period crossover study, healthy adults (n = 30) were recruited, and received four treatments for 4 weeks in a random order: (i) yogurt smoothies alone (YS); smoothies with BB-12 added (ii) before (PRE) or (iii) after (POST) yogurt fermentation, or (iv) BB-12 capsule (CAP). NK- and T-cell function was assessed at baseline and after each treatment. Incidence and severity of cold/flu infection was quantified using self-reported URTI questionnaires. Participants on YS, PRE, or CAP treatments had elevated IL-2 secretion and NK-cell cytotoxicity, concurrently with fewer days with URTI. However, the POST treatment did not change immune outcomes or the severity of URTI. CONCLUSION The timing of BB-12 addition to yogurt smoothies in relation to the fermentation process influenced the impact of BB-12 on immune function and cold/flu severity in young healthy adults.

Effects of Dark Chocolate and Almonds on Cardiovascular Risk Factors in Overweight and Obese Individuals: A Randomized Controlled‐Feeding Trial

Background Consumption of almonds or dark chocolate and cocoa has favorable effects on markers of coronary heart disease; however, the combined effects have not been evaluated in a well‐controlled feeding study. The aim of this study was to examine the individual and combined effects of consumption of dark chocolate and cocoa and almonds on markers of coronary heart disease risk. Methods and Results A randomized controlled, 4‐period, crossover, feeding trial was conducted in overweight and obese individuals aged 30 to 70 years. Forty‐eight participants were randomized, and 31 participants completed the entire study. Each diet period was 4 weeks long, followed by a 2‐week compliance break. Participants consumed each of 4 isocaloric, weight maintenance diets: (1) no treatment foods (average American diet), (2) 42.5 g/d of almonds (almond diet [ALD]), (3) 18 g/d of cocoa powder and 43 g/d of dark chocolate (chocolate diet [CHOC]), or (4) all 3 foods (CHOC+ALD). Compared with the average American diet, total cholesterol, non–high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol after the ALD were lower by 4%, 5%, and 7%, respectively (P<0.05). The CHOC+ALD decreased apolipoprotein B by 5% compared with the average American diet. For low‐density lipoprotein subclasses, compared with the average American diet, the ALD showed a greater reduction in large buoyant low‐density lipoprotein particles (−5.7±2.3 versus −0.3±2.3 mg/dL; P=0.04), whereas the CHOC+ALD had a greater decrease in small dense low‐density lipoprotein particles (−12.0±2.8 versus −5.3±2.8 mg/dL; P=0.04). There were no significant differences between diets for measures of vascular health and oxidative stress. Conclusions Our results demonstrate that consumption of almonds alone or combined with dark chocolate under controlled‐feeding conditions improves lipid profiles. Incorporating almonds, dark chocolate, and cocoa into a typical American diet without exceeding energy needs may reduce the risk of coronary heart disease. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT01882881.

Chapter 5:Nutritional and Physiological Aspects of Chocolate

In addition to primary constituents such as proteins, fats and carbohydrates, cacao produces a variety of chemicals that often influence the consumer. Cacao is most well-known for its methylxanthine alkaloids, theobromine and caffeine. These compounds interfere with adenosine receptors, thus having noticeable effects on mood and alertness. Cocoa flavanols are associated not only with their antioxidant potential, but also their ability to lower blood pressure and improve mental processes. Possible synergistic and antagonistic effects among these main phytochemicals and others, such as amines and endocannabinoids, are also discussed.