Sara E. Mahoney

Physical Activity and Dietary Behavior in US Adults and Their Combined Influence on Health

OBJECTIVE To examine the association between objectively measured physical activity and dietary behavior and their combined effect on health. PATIENTS AND METHODS Data for this study were obtained from the 2003-2006 National Health and Nutrition Examination Survey cycles. The data were evaluated between September 9, 2012, and August 14, 2013. As part of the national survey, participants wore an accelerometer for 4 or more days to assess physical activity, blood samples were obtained to assess various biological markers, and interviews were conducted to assess dietary behavior. We selected a sample of 5211 participants and categorized them into 4 groups: (1) healthy diet and active, (2) unhealthy diet and active, (3) healthy diet and inactive, and (4) unhealthy diet and inactive. RESULTS A total of 16.5% of participants (weighted proportions) were classified as consuming a healthy diet and being sufficiently active. After adjustments, participants were 32% more likely to consume a healthy diet if they met physical activity guidelines. For nearly all biomarkers, those who consumed a healthy diet and were sufficiently active had the most favorable biomarker levels. Compared with those who consumed a healthy diet and were active, participants who consumed an unhealthy diet and were inactive were 2.4 times more likely to have metabolic syndrome. CONCLUSION Our findings indicate a relationship between objectively measured physical activity and dietary behavior and that participating in regular physical activity and eating a healthy diet are associated with better health outcomes when compared with diet or physical activity alone.

Influence of flavonoid-rich fruit and vegetable intake on diabetic retinopathy and diabetes-related biomarkers.

OBJECTIVE (1) Determine the relationship between dietary flavonoid-rich fruit and vegetable consumption on diabetes-related biomarkers (e.g., HgbA1c) and diabetic retinopathy. METHODS Data from 381 participants with diabetes from the NHANES 2003-2006 were analyzed. Blood samples were taken to measure C-reactive protein (CRP), HgbA1C, and fasting glucose and insulin. Diabetic retinopathy was assessed from a retinal imaging exam. A high-flavonoid fruit and vegetable consumption (HFVC) index variable was created from a food frequency questionnaire (FFQ). RESULTS After adjustments, greater HFVC was associated (p<0.05) with lower levels of CRP (β=-0.005), HgbA1C (β=-0.005) and glucose (β=-0.59), with greater HFVC reducing the odds of having diabetic retinopathy by 30%. CONCLUSION Adults with diabetes consuming more flavonoid-rich fruits and vegetables had lower degrees of inflammation, better glycemic control, and reduced odds of diabetic retinopathy.

Concurrent occurrence of multiple positive lifestyle behaviors and depression among adults in the United States.

BACKGROUND To our knowledge, no studies have examined the dose-response association between concurrent occurrence of multiple positive health behaviors and depression. As a result, the purpose of this study was to examine the dose-response association between concurrent occurrence of lifestyle behaviors (i.e., diet, physical activity, and smoking) on depression symptoms among a national sample of U.S. adults (20-85 yr). METHODS Using data from the 2005-2006 NHANES (n=2574), diet was assessed from the healthy eating index variable; physical activity was assessed via accelerometry; smoking was assessed from cotinine levels; and depression was assessed from the Patient Health Questionnaire 9 (PHQ-9). RESULTS Each lifestyle behavior was independently associated with depression in the expected direction, and there was also evidence of a dose-response relationship. Compared to those having 0 positive lifestyle factors, those with 1, 2, and 3 positive lifestyle factors, respectively, were 15% (p=0.38), 67% (p=0.001), and 82% (p=0.01) less likely to be classifed as having moderate or greater depression symptoms (PHQ-9 ≥10). LIMITATIONS The main limitation of this study was the cross-sectional design. CONCLUSION there is a dose-response relationship between concurrent occurrence of positive lifestyle behaviors and depression symptoms.

Development of a Conceptual Model for Smoking Cessation: Physical Activity, Neurocognition, and Executive Functioning

Purpose: Considerable research has shown adverse neurobiological effects of chronic alcohol use, including long-term and potentially permanent changes in the structure and function of the brain; however, much less is known about the neurobiological consequences of chronic smoking, as it has largely been ignored until recently. In this article, we present a conceptual model proposing the effects of smoking on neurocognition and the role that physical activity may play in this relationship as well as its role in smoking cessation. Methods: Pertinent published peer-reviewed articles deposited in PubMed delineating the pathways in the proposed model were reviewed. Results: The proposed model, which is supported by emerging research, demonstrates a bidirectional relationship between smoking and executive functioning. In support of our conceptual model, physical activity may moderate this relationship and indirectly influence smoking behavior through physical activity-induced changes in executive functioning. Conclusions: Our model may have implications for aiding smoking cessation efforts through the promotion of physical activity as a mechanism for preventing smoking-induced deficits in neurocognition and executive function.

Effects of 5-fluorouracil chemotherapy on fatigue: Role of MCP-1

Chemotherapy has been known to cause severe side effects, including fatigue. While the mechanisms for chemotherapy induced fatigue (CIF) are likely to be multi-factorial in origin, it is thought that inflammation and anemia may play a role. The purpose of this study was to examine the effect of chemotherapy on fatigue in mice, and further, to begin to determine if inflammation and anemia may contribute to this response. For experiment 1, C57BL/6 mice were assigned to: vehicle (PBS), low (20 mg/kg), medium (40 mg/kg), or high (60 mg/kg) doses of 5-fluorouracil (5-FU). Voluntary physical activity (PA) was measured throughout the treatment period (day 1-5) as well as during the recovery period (day 6-14). In experiment 2, we examined the effects of 5-FU (60 mg/kg) on the inflammatory mediator MCP-1 and on markers of anemia (RBC, Hct and Hb). Finally, using MCP-1(-/-) mice we examined the role of MCP-1 on CIF (experiment 3). 5-FU reduced voluntary PA in a dose response manner (p<0.05). Plasma MCP-1 was increased following 5-FU treatment on both days 5 (p=0.10) and 14 (p<0.05). In addition, RBCs, Hct and Hb were reduced with 5-FU on days 5 and 14 (p<0.05). Both C57BL/6 and MCP-1(-/-) mice saw similar decrements in PA through the duration of the treatment period (days 1-5), however the MCP-1(-/-) mice recovered much earlier than wildtype mice. This study provides evidence of the dose response effect of a standard chemotherapy agent on fatigue and demonstrates a potential role of MCP-1 and presumably inflammation, and anemia.

Association between flavonoid-rich fruit and vegetable consumption and total serum bilirubin.

Emerging work demonstrates that serum bilirubin is a novel biomarker implicated in cardiovascular and metabolic diseases. However, we have a limited understanding of the influence of flavonoid-rich fruit and vegetable consumption on bilirubin levels, which was the purpose of this study. Data from the 2003 to 2006 National Health and Nutrition Examination survey were used (n = 1783; 18-85 years of age), with analyses performed in 2014. Total serum bilirubin was measured from a blood sample. Using a food frequency questionnaire (FFQ), a flavonoid index variable was created summing the frequency of consumption of flavonoid-rich foods. After adjustments, greater consumption of flavonoid-rich fruits and vegetables was positively associated with bilirubin levels. Our findings suggest an association between flavonoid-rich fruit and vegetable consumption and bilirubin levels. If confirmed by prospective and experimental studies, then regular consumption of flavonoid-rich fruits and vegetables should be promoted to increase levels of bilirubin.

Dietary quercetin reduces chemotherapy-induced fatigue in mice.

Purpose. While fatigue is the most commonly reported symptom of chemotherapy, there are currently no effective treatments for chemotherapy-induced fatigue (CIF). We used a mouse model to examine the benefits of quercetin on CIF as measured by voluntary wheel running activity and sought to determine whether quercetin may be associated with a decrease in inflammation and/or anemia. Methods. Mice were assigned to 1 of 4 groups: placebo-vehicle (Plac-PBS), placebo-5-fluorouracil (Plac-5FU), quercetin-vehicle (Quer-PBS), or quercetin-5-fluorouracil (Quer-5FU). All mice were given a daily injection of either 60 mg/kg of 5-FU or phosphate buffered saline (PBS) for 5 days. Quercetin (0.02%) treatment was administered in the food 3 days prior to 5-FU administration and for the duration of the experiment (ie, days −2 to 14). A second group of mice was sacrificed at 5 and 14 days post initial injection for assessment of monocyte chemoattractant protein-1 (MCP-1) and anemia. Results. Voluntary wheel running was reduced in both the Plac-5FU and Quer-5FU groups following 5-FU injection (P < .05). However, the Quer-5FU group recovered to baseline levels by approximately day 7, whereas the Plac-5FU group remained suppressed. MCP-1 was significantly elevated at 14 days in Plac-5FU (P < .001), but no changes were seen with Quer-5FU. Treatment with 5-FU resulted in anemia at both 5 days and 14 days; however, quercetin blocked this effect at 14 days (P < .001). Conclusion. These results demonstrate the beneficial effect of quercetin on improving recovery of voluntary physical activity following 5-FU treatment, which may be linked to a decrease in inflammation and anemia.

Physical activity and nicotine dependence among a national sample of young U.S. adults who smoke daily: evaluation of cross-sectional and longitudinal associations to determine which behavior drives this relationship.

The association between nicotine dependence and physical activity (PA) is relatively unknown. No study has concurrently examined the cross-sectional and longitudinal associations between PA and nicotine dependence, which was the primary purpose of this study. A secondary purpose was to examine how well nicotine dependence and PA behavior track over a two-year period. Data from the 2003-2005 National Youth Smoking Cessation Survey (NYSCS) were used, with young adults (18-24 yrs; n=1168) being followed over a two-year period. Physical activity was assessed using a questionnaire and nicotine dependence was assessed using the modified Fagerstrom Test for Nicotine Dependence scale. This study identified three notable findings: 1) baseline PA and nicotine dependence demonstrated a bidirectional, cross-sectional association (e.g., β=-0.23; 95% CI: -0.44 to -0.02; p=0.02); 2) when examined longitudinally, nicotine dependence influenced PA (OR=0.90; 95% CI: 0.82-0.99; p=0.04), but there was no evidence of the reverse pathway (i.e., PA influencing 2-year follow-up smoking status [OR=0.95; 95% CI: 0.66-1.39; p=0.82) or nicotine dependence (β=0.05; 95% CI: -0.14 to 0.24, p=0.61]); and 3) both PA (OR=3.52, 95% CI: 2.68-4.69; p<0.001) and nicotine dependence (β=0.52; 95% CI: 0.46-0.58, p<0.001) tracked relatively well over a two-year period during early adulthood. These findings suggest that both behaviors (physical activity and nicotine dependence) track over time, but nicotine dependence appears to be driving the cross-sectional relationship between nicotine dependence and physical activity, as opposed to the reverse pathway.

Polarized vs. High Intensity Multimodal Training in Recreational Runners

PURPOSE This study longitudinally compared changes in running performance (5-km TT) and fitness (VO2max, body composition) between polarized training and CrossFit Endurance© in recreational runners. METHODS Participants (N=21) completed 12 weeks of CrossFit Endurance (CFE) or polarized endurance training (POL). Both groups trained 5 d·wk-1. POL ran 5 d·wk-1 while CFE ran 3 d·wk-1 and performed CrossFit© 3 d·wk-1 (run + CF 1 d·wk-1). Intensity was classified as low, moderate, or high (Zone 1, 2, or 3) according to ventilatory thresholds. POL was prescribed greater volume (295±67 min·wk-1), distributed as 85/5/10% in Z1/Z2/Z3. CFE emphasized a lower volume (110±18 min·wk-1) distribution of 48/8/44%. RESULTS POL ran 283±75.9 min·wk-1 and 47.3±11.6 km·wk-1, both exceeding the 117±32.2 min·wk-1 and 19.3±7.17 km·wk-1 in CFE (p<0.001). The POL distribution (74/11/15%) had greater total and percent Z1 (p<0.001) than CFE (46/15/39%), which featured higher percent Z3 (p<0.001). TT improved -93.8±40.4s (-6.21±2.16%) in POL (p<0.001) and -84.2±65.7s (-5.49±3.56%) in CFE (p=0.001). Body composition improved by -2.45±2.59 %fat in POL (p=0.02) and -2.62±2.53% CFE (p=0.04). The magnitude of improvement was not different between groups for TT (p=0.79) or BC (p=0.88). Both groups increased VO2 max (p≤0.01), but with larger magnitude (p=0.04, d=0.85) in POL (4.3±3.6 ml·kg·min-1) than CFE (1.78±1.9 ml·kg·min-1). CONCLUSIONS Recreational runners achieved similar improvement in 5-km performance and body composition through polarized training or CFE, but POL yielded a greater increase in VO2 max. Extrapolation to longer distances requires additional research.