Design of the Building Research in CRC prevention (BRIDGE-CRC) trial: a 6-month, parallel group Mediterranean diet and weight loss randomized controlled lifestyle intervention targeting the bile acid-gut microbiome axis to reduce colorectal cancer risk among African American/Black adults with obesity.

BACKGROUND: Among all racial/ethnic groups, people who identify as African American/Blacks have the second highest colorectal cancer (CRC) incidence in the USA. This disparity may exist because African American/Blacks, compared to other racial/ethnic groups, have a higher prevalence of risk factors for CRC, including obesity, low fiber consumption, and higher intakes of fat and animal protein. One unexplored, underlying mechanism of this relationship is the bile acid-gut microbiome axis. High saturated fat, low fiber diets, and obesity lead to increases in tumor promoting secondary bile acids. Diets high in fiber, such as a Mediterranean diet, and intentional weight loss may reduce CRC risk by modulating the bile acid-gut microbiome axis. The purpose of this study is to test the impact of a Mediterranean diet alone, weight loss alone, or both, compared to typical diet controls on the bile acid-gut microbiome axis and CRC risk factors among African American/Blacks with obesity. Because weight loss or a Mediterranean diet alone can reduce CRC risk, we hypothesize that weight loss plus a Mediterranean diet will reduce CRC risk the most. METHODS: This randomized controlled lifestyle intervention will randomize 192 African American/Blacks with obesity, aged 45-75 years to one of four arms: Mediterranean diet, weight loss, weight loss plus Mediterranean diet, or typical diet controls, for 6 months (48 per arm). Data will be collected at baseline, mid-study, and study end. Primary outcomes include total circulating and fecal bile acids, taurine-conjugated bile acids, and deoxycholic acid. Secondary outcomes include body weight, body composition, dietary change, physical activity, metabolic risk, circulating cytokines, gut microbial community structure and composition, fecal short-chain fatty acids, and expression levels of genes from exfoliated intestinal cells linked to carcinogenesis. DISCUSSION: This study will be the first randomized controlled trial to examine the effects of a Mediterranean diet, weight loss, or both on bile acid metabolism, the gut microbiome, and intestinal epithelial genes associated with carcinogenesis. This approach to CRC risk reduction may be especially important among African American/Blacks given their higher risk factor profile and increased CRC incidence. TRIAL REGISTRATION: ClinicalTrials.gov NCT04753359 . Registered on 15 February 2021.

Effect of Mediterranean diet and Mediterranean diet plus calorie restriction on cognition, lifestyle, and cardiometabolic health: A randomized clinical trial.

A Mediterranean diet and intentional weight loss each positively affect cognitive functioning. Combining both could produce synergistic effects on cognition. The purpose of this study is to compare a Mediterranean diet lifestyle intervention with and without caloric restriction versus control on cognition, lifestyle, and cardiometabolic disease. In a three-arm trial conducted between 2017 and 2020 in Chicago, one hundred and eight-five, 55-85-year-old, predominately non-Hispanic black females with obesity were randomized (2:2:1) to an 8-month Mediterranean diet plus caloric restriction intervention, Mediterranean diet alone, or control. The primary outcome was change from baseline to post-intervention in cognitive composite scores: attention, information & processing; executive function; and learning, memory, & recognition. Secondary outcomes were weight, lifestyle and cardiometabolic markers. The 8-month Mediterranean diet interventions did not significantly affect cognition. Adherence to a Mediterranean diet improved more in the Mediterranean diet plus caloric restriction arm (mean [SE] score change, +6.3 [0.7] points) and Mediterranean diet alone arm (+4.8 [0.7] points) relative to controls (+0.6 [0.9] points). Mean weight loss was greater among the Mediterranean diet plus caloric restriction arm (-4.6 [0.6] kg) compared to the Mediterranean diet alone (-2.6 [0.6] kg) and control arms (-0.6 [0.7] kg). The interventions did not affect activity or cardiometabolic risk markers; although, fasting insulin did decline in the Mediterranean diet plus caloric restriction arm relative to the Mediterranean diet alone and control arms. A Mediterranean diet lifestyle intervention with and without caloric restriction did not significantly affect cognitive function compared to controls. The Mediterranean diet interventions, however, significantly affected diet quality and body weight.

Adapting to the COVID-19 pandemic on Building Research in Diet and Cognition (BRIDGE) trial.

BACKGROUND: The COVID-19 pandemic has altered the research landscape for clinical trials, requiring thoughtful consideration regarding how to handle the risks and benefits of continuing them. DESIGN: This brief report describes the experience of adapting the Building Research in Diet and Cognition (BRIDGE) study, a randomized clinical trial examining the effects of the Mediterranean diet, with and without weight loss, on cognitive functioning in 185 older obese African American adults during the COVID-19 pandemic. MEASUREMENT: The University of Illinois at Chicago (UIC) developed an expedited amendment process for research shifting to remote data collection. We conducted the study in three consecutive groups. For group 3, 14-month data collection period, we adapted our protocol to allow data collection via telephone and e-mail. We were unable to collect certain measures that required face-to-face contact. RESULTS: For measures that could be collected remotely, 14-month retention was similar for group 3 compared to groups 1 and 2: data were collected for 86.9% of group 3 (remote) and 87.9% of groups 1 and 2 (face to face), p = .84. CONCLUSIONS: In order to preserve the integrity of our clinical trial and ensure the safety of our participants and staff during the COVID-19 pandemic, we had to carefully and efficiently adapt our data collection procedures. The procedures put in place allowed us to collect our primary outcomes and the majority of our secondary outcomes and will enable us to examine the role of dietary intake, with and without weight loss, on cognitive functioning in a vulnerable and high-risk population. TRIAL REGISTRATION: ClinicalTrials.gov NCT3129048. Registration Date: 4/17/2017.

Adapting to the impact of the COVID-19 pandemic on a randomized controlled trial examining lifestyle behaviors on cognitive functioning in obese African American adults: Building Research in Diet and Cognition (BRIDGE).

Background . The COVID-19 pandemic has significantly altered the research landscape for clinical trials, requiring thoughtful consideration regarding how to handle the risks and benefits of continuing them. Design . This brief report describes the experience of adapting the Building Research in Diet and Cognition (BRIDGE) study, a randomized clinical trial examining the effects of the Mediterranean Diet, with and without weight loss, on cognitive functioning in 185 older obese African American adults during the COVID-19 pandemic. Measurement . The University of Illinois at Chicago (UIC) developed an expedited amendment process for research shifting to remote data collection. For the Cohort 3, 14-month data collection period, we adapted our protocol to allow data collection via telephone and e-mail. We were unable to collect certain measures that required face-to face contact. Results . For measures that could be collected remotely, 14-month retention was similar for Cohort 3 and earlier cohorts: data were collected for 86.9% of cohort 3 (remote) and 87.9% of cohorts 1 and2 (face to face), p = .84. Conclusions . In order to preserve the integrity of our clinical trial and ensure the safety of our participants and staff during the COVID-19 pandemic, we had to carefully and efficiently adapt our data collection procedures. The procedures put in place allowed us to collect our primary outcomes and the majority of our secondary outcomes and will enable us to examine the role of dietary intake, with and without weight loss, on cognitive functioning in a vulnerable and high-risk population. ClinicalTrials.gov NCT03129048.

Building research in diet and cognition (BRIDGE): Baseline characteristics of older obese African American adults in a randomized controlled trial to examine the effect of the Mediterranean diet with and without weight loss on cognitive functioning.

In the United States, >5.4 million people age 65 and older are affected by cognitive impairment and dementia, including Alzheimer's disease. African Americans are more likely than non-Hispanic whites to suffer from these disorders. Obesity is linked to accelerated age-related cognitive decline, and weight loss through caloric restriction is a potential strategy to prevent this cognitive impairment. Adherence to a healthful dietary pattern, such as the Mediterranean Diet (MedDiet), has also shown positive effects on reducing risk for dementia. African Americans are disproportionately affected by obesity and have less healthful diets than non-Hispanic whites. We present baseline characteristics from a three-arm randomized controlled trial that randomized 185 obese (BMI ≥ 30 kg/m2 and ≤ 50 kg/m2) healthy older adults (55-85 years of age) to: 1) Typical Diet Control (TDC); 2) MedDiet alone (MedDiet-A) intervention; or 3) MedDiet caloric restricted intervention to promote weight loss (MedDiet-WL). The majority of the sample was African American (91.4%) and female (85.9%). The two active interventions (MedDiet-A and MedDiet-WL) met once weekly for 8 months, and the TDC received weekly general health newsletters. Baseline data were collected between January 2017 and July 2019 in Chicago, IL. In our sample, closer adherence to a MedDiet pattern was associated with higher attention and information processing (AIP) and higher executive functioning (EF). Consistent with the literature, we saw that older participants performed more poorly on the cognitive assessments than younger participants, and women outperformed men across verbally mediated tasks, especially ones related to learning and memory.

Relationship Between Grocery Shopping Frequency and Home- and Individual-Level Diet Quality Among Low-Income Racial or Ethnic Minority Households With Preschool-Aged Children.

BACKGROUND: The home food environment can shape the diets of young children. However, little is known about modifiable factors that influence home food availability and dietary intake. OBJECTIVE: The purpose of this study was to examine the relationship between grocery shopping frequency with home- and individual-level diet quality. DESIGN: This was a secondary, cross-sectional analyses of data from the Study on Children's Home Food Availability Using TechNology. Data were collected in the homes of participants from November 2014 through March 2016. PARTICIPANTS/SETTINGS: A purposive sample of 97 low-income African American and Hispanic or Latinx parent-child dyads residing in Chicago, IL, enrolled in the study. MAIN OUTCOME MEASURES: The main outcomes were home- and individual-level diet quality. Healthy Eating Index-2010 (HEI-2010) scores were calculated from home food inventory data collected in participants' homes to assess home-level diet quality. To assess individual-level diet quality, HEI-2010 scores were based on multiple 24-hour diet recalls from parent-child dyads. STATISTICAL ANALYSES: Grocery shopping frequency was examined in relation to diet quality at the home and individual levels. Grocery shopping frequency was defined as the number of times households shopped on a monthly basis (ie, once a month, twice a month, 3 times a month, or 4 times or more a month). Multivariable linear regression analysis, controlling for covariates, tested the relationships between grocery shopping frequency and HEI-2010 total and component scores at the home and individual levels. RESULTS: Grocery shopping frequency was positively associated with home-level HEI-2010 scores for total diet, whole grains, and empty calories (higher scores reflect better diet quality) and with individual-level HEI-2010 scores for total and whole fruit (parents only), vegetables (children only), and sodium (children only). CONCLUSIONS: Grocery shopping frequency was associated with multiple dimensions of diet quality at the home and individual levels. These results offer a potential strategy to intervene on home food availability and individual dietary intake.

The relationship between home- and individual-level diet quality among African American and Hispanic/Latino households with young children.

BACKGROUND: The quality of most Americans' diets is far from optimal. Given that many Americans consume a significant portion of calories in the home, intervening in this setting could be beneficial. However, the relationship between the home food environment and diet quality is not well understood. This study examined the relationship between diet quality at the individual level with home-level diet quality using an index that measures compliance with federal dietary guidance. METHODS: This was a cross sectional study that enrolled 97 African American and Hispanic/Latino low-income parent-child dyads. Diet quality at the individual level was assessed through two 24-h dietary recalls collected for parents and children, respectively. Diet quality at the home level was assessed with two home food inventories conducted in participants' homes. Diet quality scores at the home and individual levels were computed by applying the Healthy Eating Index-2010 (HEI-2010) to these data. Linear models adjusted for potential confounding factors were used to examine the relationship between diet quality at the home and individual levels. RESULTS: Total HEI-2010 scores from parents and children's diets were positively associated with HEI-2010 scores based on home food inventories (parent diet: ß: 0.36, 95% CI: 012-0.60; child diet: 0.38 95% CI: 013-0.62). Positive associations were also observed between individual level and home level subcomponent HEI-2010 scores for total fruit (parent: 0.55 95% CI: 0.16-0.94; child: 0.49 95% CI: 0.03-0.94), whole fruit (parent only: 0.41 95% CI: 0.07-0.74), greens and beans (parent only: 0.39 95% CI: 0.05-0.74), and whole grain (children only: 0.33 95% CI: 0.04-0.63). CONCLUSION: This study demonstrated that individual level diet quality was positively associated with home-level diet quality. Findings from this study can help us to address modifiable targets of intervention in the home to improve diet quality.