The overall objective was to design and implement an intervention program to promote changes in diet and physical activity that promotes, through the focus of the motivational interview, the increase in the consumption of fruits and vegetables, the decrease in the consumption of fats and the increase in physical activity, to achieve an impact in the reduction of weight and body fat, the improvement in the biomarkers of the disease and in the quality of life in women survivors of BC.
Specific objectives
1. Determine the adherence of participants to a healthy lifestyle intervention by analyzing biological markers of dietary intake (alpha and beta carotene, as well as lipid profile) at the beginning of the study and at 4 and 8 months after initiation of the intervention.
2. Investigate the impact of the intervention on changes in weight, body mass index, body fat, muscle mass and bone mineral density of women by measuring these variables at the beginning of the study and at 4 and 8 months after intervention.
3. Examine the effect of the intervention on biomarkers of the disease: mammographic density, telomere length and telomerase activity, VEGF, DNA methylation and CPTP at baseline and 8 months.
4. To evaluate the impact of the intervention program on inflammatory markers: leptin and adiponectin, IL6, IL8, CRP and TNF-α at the beginning, 4 and 8 months after the intervention started.
5. Analyze the effect of the intervention on the alterations in sleep quality and quality of life of the women survivors of breast cancer at the beginning, 4 and 8 months after the intervention.
Study Design and Participants
This was a randomized controlled clinical trial with two groups of breast cancer survivors. In the intervention group, we used the strategy of Motivational Interviewing to promote changes in diet and physical activity; the comparison group received an orientation with a traditional educational approach. The intervention program lasted eight months. A total of 60 women from Sonora, Mexico, participated in the study. The women were selected from the State Oncology Center and through social networks. The research protocol was sent to the ethics committee of the Center for Research in Food and Development, A.C. and women signed an informed consent letter to participate in the study.
Visits and monitoring
After the recruitment, application of questionnaires and blood sampling at the first visit (baseline), the participants were randomly assigned to the intervention (n = 30) or the comparison group (n = 30). The orientation was similar in both groups and was carried out in two modalities: in person at the participant's house and by telephone. The first orientation was made within the first 15 days after the first visit (baseline) and was at the participant's home. Within a week of the first initial orientation, the participants were called by phone to continue the monitoring and orientation process. During the first four months, the orientation was every fifteen days, and combined the visits to the participant's house with phone calls. During the next four months, the orientation took place once a month and at the participant's house.
Intervention program for changes in lifestyle
Guidance on lifestyle changes in the intervention group was carried out using the motivational interviewing approach and was conducted by trained personnel for that purpose. The dietary intervention was designed to promote the increase in plasma carotene levels, due to the increase in the consumption of fruits and vegetables. The intervention also promoted the improvement of the lipid profile (due to the decrease in fat consumption) and the control or reduction of body weight.
The diet and physical activity components of the lifestyle change program were progressive, and we managed individualized interventions. Both the diet and the physical activity regimen could be adjusted to any unexpected situation (e.g., Decrease in the number of steps due to stomach problems or ankle sprains) during the entire participation period.
The dietary goals contemplated to reach a consumption of 20% of the total energy coming from fats, the consumption of 6 or more servings of fruits / vegetables a day and the promotion of a healthy body weight, to increase fiber consumption to a greater than 30 grams daily, decrease the consumption of sugary drinks and increase the consumption of protein. The emphasis on dietary fat restriction helped to achieve other dietary goals, such as increased consumption of vegetables and fruits, increased fiber consumption, and mild to moderate body weight loss. To reach the goal of having a fat intake in the diet of 20% of the total energy consumed, a goal of grams of fat was established for each participant.
The component of physical activity consisted of a moderately low aerobic regime with the aim of gradually increasing the number of steps per week, in order to be able to walk at least 4000 steps (in addition to those that are already routine) per day or 28,000 steps per week. In addition, participants were encouraged to reduce sedentary time, by performing simple exercises while sitting and stretching exercises, among others.
The educational materials covered different topics such as knowing how to read and interpret the labels on food, recommendations for buying food, recommendations for eating out and others. The visits and orientation calls included a brief assessment of the food consumed and the physical activity performed the previous day, as well as a review of the list of weekly behavior goals and lifestyle journals, which helped the counselor to assess adherence to lifestyle goals and provide specific encouragement and feedback to the participant. Lifestyle journals were used to assess the intake of fat grams as well as daily steps to assess adherence and identify specific barriers to compliance with behavioral goals.
Comparison group
This group received a notebook that included general health information. As with the intervention group, they were provided with a pedometer and common literature on recommendations to stay physically active. Participants in this group were not asked to record their diet or physical activity, and guidance was provided monthly during the 8-month intervention.
Collection of information
The collection of the information was carried out in the two groups. The sociodemographic and health data of the participants were obtained in the first visit. The anthropometric and body composition measurements, as well as the application of questionnaires on sleep quality and quality of life were carried out at the first visit (day 1), 4 and 8 months after the intervention as well the dietary evaluation. The blood samples for the analysis of carotenoids, lipid profile, , VEGF, DNA methylation, and proinflammatory markers were taken on the first day, at 4 and 8 months. The mammographic density analysis, telomere length, and telomerase activity were carried out at the beginning of the study and at 8 months.
