Time-Restricted Eating: A Novel and Simple Dietary Intervention for Primary and Secondary Prevention of Breast Cancer and Cardiovascular Disease

The Diurnal Transcriptome Reveals the Reprogramming of Lung Adenocarcinoma Cells Under a Time-Restricted Feeding-Mimicking Regimen

BACKGROUND

The processes of tumor growth and circadian rhythm are intimately intertwined; thus, rewiring circadian metabolism by time-restricted feeding (TRF) may contribute to delaying carcinogenesis. However, research on the effect of a TRF cellular regimen on cancer is lacking.

OBJECTIVE

Investigate the circadian signatures of TRF in lung cancer in vitro.

METHODS

We first developed a cellular paradigm mimicking in vivo TRF and collected cells for transcriptome analysis. We further confirmed the effect on tumor cells upon 6-h TRF-mimicking (6-h TRFM) by real-time PCR, Lumicycle experiments, CCK-8, and flow cytometry assays.

RESULTS

We found that A549 lung adenocarcinoma cells treated with 6-h TRFM conditions displayed robust diurnal rhythms of transcriptomes, as well as modulation of the core clock genes relative to other different cellular regimens used in this study, including the fasting-mimicking conditions (ie, short-term starvation) and the serum-free regime. Notably, pathway analysis of oscillating genes exclusively in 6-h TRFM showed that some circadian genes were enriched in tumor-related pathways, such as the oxytocin signaling pathway, HIF-1 signaling pathway, and pentose and glucuronate interconversions. Moreover, in line with the circadian pathway enrichment results, 6-h TRFM robustly inhibited cell proliferation and induced cell apoptosis and cell cycle arrest in lung adenocarcinoma A549 cells, lung adenocarcinoma H460 cells, esophageal carcinoma Eca-109 cells, and breast adenocarcinoma MCF-7 cells.

CONCLUSIONS

Our findings provide the first in vitro mimicking medium for TRF intervention and indicate that 6-h TRFM is sufficient to reprogram the circadian signatures of lung adenocarcinoma cells and inhibit the progression of multiple tumors.

Decanoylcarnitine Inhibits Triple-Negative Breast Cancer Progression via Mmp9 in an Intermittent Fasting Obesity Mouse

Purpose: Treatment of triple-negative breast cancer (TNBC) remains challenging. Intermittent fasting (IF) has emerged as a promising approach to improve metabolic health of various metabolic disorders. Clinical studies indicate IF is essential for TNBC progression. However, the molecular mechanisms underlying metabolic remodeling in regulating IF and TNBC progression are still unclear. Methods: In this study, we utilized a robust mouse model of TNBC and exposed subjects to a high-fat diet (HFD) with IF to explore its impact on the metabolic reprogramming linked to cancer progression. To identify crucial serum metabolites and signaling events, we utilized targeted metabolomics and RNA sequencing (RNA-seq). Furthermore, we conducted immunoblotting, real-time quantitative polymerase chain reaction (RT-qPCR), cell migration assays, lentivirus-mediated Mmp9 overexpression, and Mmp9 inhibitor experiments to elucidate the role of decanoylcarnitine/Mmp9 in TNBC cell migration. Results: Our observations indicate that IF exerts notable inhibitory effects on both the proliferation and cancer metastasis. Utilizing targeted metabolomics and RNA-seq, we initially identified pivotal serum metabolites and signaling events in the progression of TNBC. Among the 349 serum metabolites identified, decanoylcarnitine was picked out to inhibit TNBC cell proliferation and migration. RNA-seq analysis of TNBC cells treated with decanoylcarnitine revealed its suppressive effects on extracellular matrix-related protein components, with a notable reduction observed in Mmp9. Further investigations confirmed that decanoylcarnitine could inhibit Mmp9 expression in TNBC cells, primary tumors, lung, and liver metastasis tissues. Mmp9 overexpression abolished the inhibitory effect of decanoylcarnitine on cell migration. Conclusion: This study pioneers the exploration of IF intervention and the role of decanoylcarnitine/Mmp9 in the progression of TNBC in obese mice, enhancing our comprehension of the potential roles of various dietary patterns in the process of cancer treatment.

Time-restricted eating with calorie restriction on weight loss and cardiometabolic risk: a systematic review and meta-analysis

The effect of time-restricted eating (TRE) has been summarized in previous studies, but its benefits in combination with calorie restriction (CR) still need to be determined. The present meta-analysis aimed to evaluate the efficacy of TRE with CR on weight loss and cardiometabolic risk. PubMed, Embase, Cochrane Library, and gray literature databases were searched from inception to October 18, 2022, for potential randomized controlled trial (RCT) studies based on predefined inclusion and exclusion criteria. Body weight and other cardiometabolic risk factors were described as weighted mean difference (WMD) with a 95% confidence interval (CI). Eight RCTs involving 579 participants were enrolled in the present analysis. The pooled results showed that TRE with CR reduced the body weight, fat mass, and waist circumference significantly (WMD: -1.40, 95% CI: -1.81 to -1.00, and I2: 0%; WMD: -0.73, 95% CI: -1.39 to -0.07, and I2: 0%; WMD: -1.87, 95% CI: -3.47 to -0.26, and I2: 67.25%, respectively). However, compared with CR alone, TRE plus CR exhibited no significant benefit on the blood pressure, glucose profile, and lipid profile. Subgroup analysis suggested that early TRE is more effective in weight loss (WMD: -1.42, 95% CI: -1.84 to -1.01, and I2: 0%) and improving fat mass (WMD: -1.06, 95% CI: -1.91 to -0.22, and I2: 0%) than delayed or broader TRE when combined with CR. Although the combination of TRE and CR can effectively decrease body weight, fat mass, and waist circumference, the long-term effects, particularly those on cardiometabolic risk in participants with chronic cardiovascular disease and diabetes, remain to be explored.

Effects of time-restricted eating with different eating windows on human metabolic health: pooled analysis of existing cohorts

BACKGROUND

Time-restricted eating (TRE), a feasible form of intermittent fasting, has been proven to benefit metabolic health in animal models and humans. To our knowledge, specific guidance on the appropriate period for eating during TRE has not yet been promoted. Therefore, to compare and assess the relative effectiveness estimates and rankings of TRE with different eating windows on human metabolic health, we conducted a systematic review and network meta-analysis (NMA).

METHOD

PubMed, EMBASE and the Cochrane Library were searched for randomized controlled trials that compared different eating windows on human metabolic health for adults. A Bayesian NMA was used to compare direct and indirect effects to determine the best different eating windows, and scientific evidence using GRADE.

RESULTS

Twenty-seven RCTs comparing TRE with different eating windows on human metabolic health were reviewed, and all were included in the NMA. Compared with the normal diet group (non-TRE), the TRE group has certain benefits in reducing weight and fasting insulin. In terms of reducing fasting insulin, the 18:6 group (eating time = 6 h) was better than the 14:10 group (eating time = 10 h) and 16:8 group (eating time = 8 h) (P < 0.05); The < 6 group (eating time < 6 h) was better than the 14:10 group (P < 0.05). In terms of reducing fasting glucose, the < 6 group was better than the 14:10 group (P < 0.05). There were no statistical variations in weight, HDL, TG, and LDL across the different modes of TRE (P > 0.05).

CONCLUSIONS

Our research showed that no particular metabolic advantages of various eating windows were found. Therefore, our results suggested that different eating windows could promote similar benefits for metabolic parameters.

Effects of time-restricted eating with different eating duration on anthropometrics and cardiometabolic health: A systematic review and meta-analysis

BACKGROUND

Time-restricted eating (TRE) is a dietary approach that limits eating to a set number of hours per day. Human studies on the effects of TRE intervention on cardiometabolic health have been contradictory. Heterogeneity in subjects and TRE interventions have led to inconsistency in results. Furthermore, the impact of the duration of eating/fasting in the TRE approach has yet to be fully explored.

AIM

To analyze the existing literature on the effects of TRE with different eating durations on anthropometrics and cardiometabolic health markers in adults with excessive weight and obesity-related metabolic diseases.

METHODS

We reviewed a series of prominent scientific databases, including Medline, Scopus, Web of Science, Academic Search Complete, and Cochrane Library articles to identify published clinical trials on daily TRE in adults with excessive weight and obesity-related metabolic diseases. Randomized controlled trials were assessed for methodological rigor and risk of bias using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB-2). Outcomes of interest include body weight, waist circumference, fat mass, lean body mass, fasting glucose, insulin, HbA1c, homeostasis model assessment for insulin resistance (HOMA-IR), lipid profiles, C-reactive protein, blood pressure, and heart rate.

RESULTS

Fifteen studies were included in our systematic review. TRE significantly reduces body weight, waist circumference, fat mass, lean body mass, blood glucose, insulin, and triglyceride. However, no significant changes were observed in HbA1c, HOMA-IR, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, heart rate, systolic and diastolic blood pressure. Furthermore, subgroup analyses based on the duration of the eating window revealed significant variation in the effects of TRE intervention depending on the length of the eating window.

CONCLUSION

TRE is a promising chrononutrition-based dietary approach for improving anthropometric and cardiometabolic health. However, further clinical trials are needed to determine the optimal eating duration in TRE intervention for cardiovascular disease prevention.

Intermittent fasting protects against food allergy in a murine model via regulating gut microbiota

Background

The prevalence of food allergy (FA) is increasing. Decreases in the diversity of gut microbiota may contribute to the pathogenesis of FA by regulating IgE production of B cells. Intermittent fasting (IF) is a popular diet with the potential to regulate glucose metabolism, boosting immune memory and optimizing gut microbiota. The potential effect of long-term IF on the prevention and treatment of FA is still unknown.

Methods

Two IF protocols (16 h fasting/8 h feeding and 24 h fasting/24 h feeding) were conducted on mice for 56 days, while the control mice were free to intake food (free diet group, FrD). To construct the FA model, all mice were sensitized and intragastrical challenged with ovalbumin (OVA) during the second half of IF (day 28 to day 56). Rectal temperature reduction and diarrhea were recorded to evaluate the symptoms of FA. Levels of serum IgE, IgG1, Th1/Th2 cytokines, mRNA expression of spleen T cell related transcriptional factors, and cytokines were examined. H&E, immunofluorescence, and toluidine blue staining were used to assess the structural changes of ileum villi. The composition and abundance of gut microbiota were analyzed by 16srRNA sequencing in cecum feces.

Results

The diarrhea score and rectal temperature reduction were lower in the two fasting groups compared to the FrD groups. Fasting was associated with lower levels of serum OVA-sIgE, OVA-sIgG1, interleukin (IL)-4 and IL-5, and mRNA expression of IL-4, IL-5, and IL-10 in the spleen. While no significant association was observed in interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-6, IL-2 levels. Less mast cell infiltration in ileum was observed in the 16h/8h fasting group compared to the FrD group. ZO-1 expression in the ileum of the two fasting groups was higher in IF mice. The 24h/24h fasting reshaped the gut microbiota, with a higher abundance of Alistipes and Rikenellaceae strains compared to the other groups.

Conclusion

In an OVA-induced mice FA model, long-term IF may attenuate FA by reducing Th2 inflammation, maintaining the integrity of the intestinal epithelial barrier, and preventing gut dysbiosis.

Intermittent fasting interventions to leverage metabolic and circadian mechanisms for cancer treatment and supportive care outcomes

Intermittent fasting entails restricting food intake during specific times of day, days of the week, religious practice, or surrounding clinically important events. Herein, the metabolic and circadian rhythm mechanisms underlying the proposed benefits of intermittent fasting for the cancer population are described. We summarize epidemiological, preclinical, and clinical studies in cancer published between January 2020 and August 2022 and propose avenues for future research. An outstanding concern regarding the use of intermittent fasting among cancer patients is that fasting often results in caloric restriction, which can put patients already prone to malnutrition, cachexia, or sarcopenia at risk. Although clinical trials do not yet provide sufficient data to support the general use of intermittent fasting in clinical practice, this summary may be useful for patients, caregivers, and clinicians who are exploring intermittent fasting as part of their cancer journey for clinical outcomes and symptom management.

Early time-restricted eating may favorably impact cognitive acuity in university students: a randomized pilot study

Cognitive acuity is important for academic success. The preliminary efficacy of early time-restricted eating (eTRE) on cognitive acuity was examined in a sample of university students attending a large southwestern university. It was hypothesized that adherence to eTRE would result in improved cognitive acuity as assessed by the Trail Making Tests (i.e., TMT-A and TMT-B) and the Stroop Color and Word Test. Participants were randomized to an intervention group (eTRE) with a daily 6-hour eating window or a control group (CON) with a daily 16-hour eating window; 24 participants initiated the study (13 eTRE and 11 CON). Blood ketones (i.e., β-hydroxybutyrate [BHB]) and brain-derived neurotrophic factor were also assessed. The 8-week intervention was forestalled by COVID-19 laboratory closures beginning in March 2020, and only data obtained at week 0 (baseline) and week 4 were viable for statistical analyses. Study attrition was high (50% for eTRE and 23% for CON). At week 4, there was a 27% and 6% decrease in TMT-B response time for the eTRE and CON groups, respectively (P = .02). TMT-B response time was inversely correlated to plasma BHB among participants (r = -0.633; P = .008). Considering the inverse relationship between TMT-B response time and plasma BHB, these preliminary data suggest that eTRE may improve some aspects of cognitive acuity in this population. Future investigations are needed to confirm these findings and should accommodate individual preferences regarding the initiation time of the eating window while also considering the impact on social influences and exercise engagement.

Association of hormone receptor status with cardiovascular disease mortality in 399,209 patients with stage I to III breast cancer: A population-based study

Adjuvant endocrine therapy (AET) is known to reduce the risk of hormone receptor-positive (HR+) breast cancer (BC) recurrence and mortality rates, but its impact on cardiovascular disease (CVD) events is unclear. The primary objective of this study was to analyze the association of HR status with CVD mortality in patients with stage I to III BC. A retrospective study of patients with stage I to III BC was conducted using the 2004 to 2016 Surveillance, Epidemiology, and End Results (SEER) database, and patients were grouped according to their HR status. Propensity score matching (PSM) was used to adjust for heterogeneity between the groups. The cumulative incidence rate of CVD mortality was evaluated via a cumulative incidence curve. Univariate and multivariate Fine and Gray's competing risk regression models were used to identify risk factors associated with CVD mortality. In total, 399,209 patients with BC were included in this study, and 329,958 patients (82.65%) were HR-positive. The cumulative incidence of CVD death was 8.28% in stage I to III BC patients. In the constituent ratio analysis, primary BC was the leading cause of death (45.29%, N = 31,465), followed by heart disease (16.07%, N = 11,166). Compared to the second year following BC diagnosis, the risk of CVD-specific death gradually increased. After PSM, 65,952 pairs of patients were matched, which led to the equilibrium of all variables between the HR-negative cohort and HR+ cohort. Multivariate analysis indicated that HR status was not significantly associated with the risk of CVD mortality, with a hazard ratio of 1.01 (P = .895). This study highlights the importance of understanding the associations between risk factors and CVD for BC patients. HR status was not associated with the risk of CVD mortality in this study.

The Role of Intermittent Fasting in the Management of Nonalcoholic Fatty Liver Disease: A Narrative Review

Intermittent fasting is a non-pharmacological dietary approach to management of obesity and metabolic syndrome, involving periodic intervals of complete or near-complete abstinence from food and energy-containing fluids. This dietary strategy has recently gained significant popularity in mainstream culture and has been shown to induce weight loss in humans, reduce gut and systemic inflammation, and improve gut microbial diversity and dysbiosis (largely in animal models). It has been hypothesized that intermittent fasting could be beneficial in the management of nonalcoholic fatty liver disease, given the condition's association with obesity. This review summarizes protocols, potential mechanisms of action, and evidence for intermittent fasting in nonalcoholic fatty liver disease. It also highlights practical considerations for implementing intermittent fasting in clinical practice. A search of the literature for English-language articles related to intermittent fasting or time-restricted feeding and liver disease was completed in PubMed and Google Scholar. Potential mechanisms of action for effects of intermittent fasting included modulation of circadian rhythm, adipose tissue and adipokines, gut microbiome, and autophagy. Preclinical, epidemiological, and clinical trial data suggested clinical benefits of intermittent fasting on metabolic and inflammatory markers in humans. However, there was a paucity of evidence of its effects in patients with nonalcoholic fatty liver disease. More clinical studies are needed to determine mechanisms of action and to evaluate safety and efficacy of intermittent fasting in this population.

Obesity, cancer risk, and time-restricted eating

Obesity and the associated metabolic syndrome is considered a pandemic whose prevalence is steadily increasing in many countries worldwide. It is a complex, dynamic, and multifactorial disorder that presages the development of several metabolic, cardiovascular, and neurodegenerative diseases, and increases the risk of cancer. In patients with newly diagnosed cancer, obesity worsens prognosis, increasing the risk of recurrence and decreasing survival. The multiple negative effects of obesity on cancer outcomes are substantial, and of great clinical importance. Strategies for weight control have potential utility for both prevention efforts and enhancing cancer outcomes. Presently, time-restricted eating (TRE) is a popular dietary intervention that involves limiting the consumption of calories to a specific window of time without any proscribed caloric restriction or alteration in dietary composition. As such, TRE is a sustainable long-term behavioral modification, when compared to other dietary interventions, and has shown many health benefits in animals and humans. The preliminary data regarding the effects of time-restricted feeding on cancer development and growth in animal models are promising but studies in humans are lacking. Interestingly, several short-term randomized clinical trials of TRE have shown favorable effects to reduce cancer risk factors; however, long-term trials of TRE have yet to investigate reductions in cancer incidence or outcomes in the general population. Few studies have been conducted in cancer populations, but a number are underway to examine the effect of TRE on cancer biology and recurrence. Given the simplicity, feasibility, and favorable metabolic improvements elicited by TRE in obese men and women, TRE may be useful in obese cancer patients and cancer survivors; however, the clinical implementation of TRE in the cancer setting will require greater in-depth investigation.

Time-restricted Eating to Address Cancer-related Fatigue among Cancer Survivors: A Single-arm Pilot Study

Purpose

Cancer-related fatigue is a prevalent, debilitating condition that can persist for months or years after treatment. In a single-arm clinical trial, the feasibility and safety of a time-restricted eating (TRE) intervention were evaluated among cancer survivors, and initial estimates of within-person change in cancer-related fatigue were obtained.

Methods

Participants were 4-60 months post-cancer treatment, were experiencing fatigue (≥ 3 on a scale 0-10), and were not following TRE. TRE entailed limiting all food and beverages to a self-selected 10-h window for 14 days. Participants reported their eating window in a daily diary and completed the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Brief Fatigue Inventory (BFI), and symptom inventory pre- and post-intervention. This study was pre-registered at clinicaltrials.gov in January 2020 (NCT04243512).

Results

Participants (n=39) were 61.5 ± 12.4 years old and 1.8 ± 1.3 years post-treatment; 89.7% had had breast cancer. The intervention was feasible in that 36/39 (92.3%) of participants completed all questionnaires and daily diaries. It was also safe with no severe adverse events or rapid weight loss (average loss of 1.1 ± 2.3 pounds, p=0.008). Most adhered to TRE; 86.1% ate within a 10-h window at least 80% of the days, and the average eating window was 9.33 ± 1.05 h. Fatigue scores improved 5.3 ± 8.1 points on the FACIT-F fatigue subscale (p<0.001, effect size [ES]=0.55), 30.6 ± 35.9 points for the FACIT-F total score (p<0.001, ES=0.50), and -1.0 ± 1.7 points on the BFI (p<0.001, ES=-0.58).

Conclusion

A 10-h TRE intervention was feasible and safe among survivors, and fatigue improved with a moderate effect size after two weeks.

Limitations

This was a single-arm study, so it is possible that expectation effects were present for fatigue outcomes, independent of effects of TRE per se. However, this feasibility trial supports evaluation of TRE in randomized controlled trials to address persistent cancer-related fatigue.