Older women with overweight who received cardiotoxic treatment for breast cancer saw a 15% relative CVD risk reduction after following an 8-week time-restricted eating plan, according to research published in JACC: CardioOncology.
In a single-arm, feasibility study, researchers also found that older breast cancer survivors who followed a time-restricted eating plan reduced caloric intake without fat-free mass loss and also experienced a decrease in visceral adipose tissue, which can predict CV events.
“Time-restricted eating is an easy-to-prescribe and follow intervention that may reduce body fat and CV risk,” Amy Kirkham, PhD, assistant professor at the University of Toronto and affiliate scientist at the Toronto Rehabilitation Institute, told Healio. “It requires further study to confirm these effects in randomized controlled trials, but this study demonstrates that time-restricted eating is feasible and associated with low symptom burden for older, overweight or obese breast cancer survivors.”
Breast cancer survivors at CVD risk
Kirkham and colleagues analyzed data from 22 women aged at least 60 years who were breast cancer survivors with overweight (BMI 25 kg/m2) and risk factors for CVD mortality, who completed cardiotoxic treatment (anthracyclines within 1 to 6 years). Researchers asked participants to eat ad libitum between noon and 8 p.m. weekdays and any time of day on weekends but consume only water, black coffee or black tea outside of those hours for 8 weeks. No other dietary or physical activity instructions were given. Women received behavioral support that included a phone call from a registered dietitian before the intervention, check-in calls from study staff at 1, 3 and 6 weeks and twice-daily automated text messages inquiring about eating times. Adherence was determined by text messages; caloric intake was assessed via a 3-day average of 24-hour diet records taken during the first and last weeks of the intervention.
The mean age of women was 67 years; median time since anthracycline treatment was 3 years and 50% received left-sided radiation; 91% of women were taking tamoxifen and/or an aromatase inhibitor during the study. At baseline, 68% of women were classified as “cardiometabolically unhealthy,” defined as meeting criteria for metabolic syndrome or for treatment with statins.
During the intervention, fat-free mass did not change (mean, –0.1 kg; P = .76) and caloric intake changed by a median of –450 kcal, representing a 22% relative reduction (P < .001).
The median Framingham CVD risk decreased for women from 10.9% to 8.6%, a –15% relative change (P = .037). However, modifiable Framingham components such as total cholesterol, HDL and systolic BP did not change overall, indicating interindividual differences in each of these measures.
At 8 weeks, 53% of the women no longer met the criteria for pharmacological treatment of CVD risk or metabolic syndrome and were reclassified as low Framingham CVD risk (< 10%).
Participants reported minor and transient symptoms during the time-restricted eating intervention of headache and irritability.
Potential risk reduction strategy
The researchers noted breast cancer survivors at low Framingham CVD risk experience 38% fewer cardiac events than those at intermediate risk, adding that a long-term reclassification to low Framingham CVD risk or the reversal of metabolic syndrome could reduce health care costs and improve outcomes.
“If these results can be replicated in a randomized controlled trial, time-restricted eating may be used as a simple, cost-effective and safe therapy that can be prescribed in-office as an alternative to pharmacological CV risk reduction therapies,” Kirkland told Healio. “This study was a single-arm feasibility trial, which means it did not have a control group. In order to confirm the study results that suggest a positive impact on visceral fat and CV, a randomized controlled trial will be the next step.”
For more information:
Amy Kirkham, PhD, can be reached at [email protected]; Twitter: @amyakirkham.