Background

Dietary strategies that help patients adhere to a weight reduction diet may increase the likelihood of weight loss maintenance and improved long-term health outcomes. Regular nut consumption has been associated with better weight management and less adiposity. The objective of this study was to compare the effects of a walnut-enriched reduced-energy diet to a standard reduced-energy-density diet on weight, cardiovascular disease risk factors, and satiety.

Methods

Overweight and obese men and women (n = 100) were randomly assigned to a standard reduced-energy-density diet or a walnut-enriched (15% of energy) reduced-energy diet in the context of a behavioral weight loss intervention. Measurements were obtained at baseline and 3- and 6-month clinic visits. Participants rated hunger, fullness and anticipated prospective consumption at 3 time points during the intervention. Body measurements, blood pressure, physical activity, lipids, tocopherols and fatty acids were analyzed using repeated measures mixed models.

Results

Both study groups reduced body weight, body mass index and waist circumference (time effect p < 0.001 for each). Change in weight was -9.4 (0.9)% vs. -8.9 (0.7)% (mean [SE]), for the standard vs. walnut-enriched diet groups, respectively. Systolic blood pressure decreased in both groups at 3 months, but only the walnut-enriched diet group maintained a lower systolic blood pressure at 6 months. The walnut-enriched diet group, but not the standard reduced-energy-density diet group, reduced total cholesterol and low-density lipoprotein cholesterol (LDL-C) at 6 months, from 203 to 194 mg/dL and 121 to 112 mg/dL, respectively (p < 0.05). Self-reported satiety was similar in the groups.

Conclusions

These findings provide further evidence that a walnut-enriched reduced-energy diet can promote weight loss that is comparable to a standard reduced-energy-density diet in the context of a behavioral weight loss intervention. Although weight loss in response to both dietary strategies was associated with improvements in cardiovascular disease risk factors, the walnut-enriched diet promoted more favorable effects on LDL-C and systolic blood pressure.

Trial registration

The trial is registered at ( NCT02501889 ).

Purpose

Low physical functioning among breast cancer survivors appears to reduce survival, although the mechanisms underlying these associations are not clear. We examined inflammation as a possible biological mediator of association between low physical functioning and mortality after breast cancer.

Methods

Analysis included 2,892 participants from the Women's Healthy Eating and Living Study. All measures were collected at study baseline. Physical function was assessed by the Short Form 36 (SF-36) Health Survey Physical Function subscale. Low physical function was defined as the bottom tertile of the subscale score. Inflammation was measured as serum concentration of C-reactive protein (CRP). Cox proportional hazards modeled the associations of low physical function and the putative mediator (i.e., CRP) with all-cause and breast cancer-specific mortality.

Results

There were 293 deaths during study follow up, with 243 due to breast cancer. Low physical functioning was associated with a 50 % higher risk of all-cause mortality (HR, 1.49; 95 % CI, 1.2-1.9) and a 40 % higher risk of breast cancer-specific mortality (HR, 1.39; 95 % CI, 1.1-1.8), after adjustment for covariates. The addition of CRP did not markedly change the all-cause mortality hazard ratio attributed to low physical functioning. However, the addition of CRP modestly attenuated the breast cancer-specific mortality hazard ratio such that it was no longer statistically significant.

Conclusions

Interventions to improve physical functioning may prevent early morbidity and mortality among breast cancer survivors.

Implications for cancer survivors

Functional status measure may be a valuable indicator of long-term health outcomes among breast cancer survivors.

To examine associations between decreased emotional eating and weight loss success; and whether participation in a behavioral weight loss intervention was associated with a greater reduction in emotional eating over time compared to usual care. Secondary data analysis of a randomized controlled trial conducted at two university medical centers with 227 overweight adults with diabetes. Logistic and standard regression analyses examined associations between emotional eating change and weight loss success (i.e., weight loss of ≥7 % of body weight and decrease in BMI). After 6 months of intervention, decreased emotional eating was associated with greater odds of weight loss success (p = .05). The odds of weight loss success for subjects with decreased emotional eating at 12 months were 1.70 times higher than for subjects with increased emotional eating. No differences in change in emotional eating were found between subjects in the behavioral weight loss intervention and usual care. Strategies to reduce emotional eating may be useful to promote greater weight loss among overweight adults with diabetes.

Regular nut consumption is associated with lower adiposity and reduced weight gain in adulthood. Walnut feeding studies have observed minimal effect on body weight despite potential additional energy intake. Several mechanisms may explain why consuming nuts promotes weight control, including increased early phase satiety, possibly reflected in postprandial response of gastrointestinal and pancreatic peptides hypothesized to affect appetite. The purpose of this study was to compare postprandial insulin, glucagon and gastrointestinal peptide response and satiety following a meal with ∼54% of energy from walnuts or cream cheese, using a within-subject crossover study design in overweight/obese adults (N = 28). Sixty minutes after the walnut-containing meal, glucagon-like peptide-1 was lower than after the reference meal (p=0.0433), and peptide YY, cholecystokinin and ghrelin did not differ after the two meals. Sixty and 120 min after the walnut-containing meal, pancreatic polypeptide (p = 0.0014 and p = 0.0002) and glucose-dependent insulinotropic peptide (p < 0.0001 and p = 0.0079) were lower than after the reference meal, and 120 min after the walnut-containing meal, glucagon was higher (p=0.0069). Insulin and C-peptide increased at 60 min in response to both meals but were lower at 120 min after the walnut-containing meal (p=0.0349 and 0.0237, respectively). Satiety measures were similar after both meals. These findings fail to support the hypothesis that acute postprandial gastrointestinal peptide response to a walnut-containing meal contributes to increased satiety. However, inclusion of walnuts attenuated the postprandial insulin response, which may contribute to the more favorable lipid profile observed in association with regular walnut consumption.

Breast cancer survivors not only experience distressing physical symptoms associated with treatments, but also are faced with psychosocial challenges. Despite growing scientific evidence that physical activity (PA) may mitigate psychosocial distress experienced by women treated for breast cancer, the literature is equivocal. This study investigated the relationships between cardiorespiratory fitness (CRF), PA, and psychosocial factors in breast cancer survivors. Data involving overweight or obese breast cancer survivors (N = 260) were examined. CRF was determined by a submaximal graded exercise test. PA, depressive symptoms, total fatigue, and global self-esteem were assessed with self-report measures. Pearson's correlations were conducted to determine associations among CRF, PA, depressive symptoms, total fatigue, and global self-esteem. Multiple regression models, with age and body mass index as covariates, were performed using continuous levels for CRF and PA. Bivariate correlations suggested that CRF and PA were unrelated to the psychosocial variables. One of the regression models identified a marginally significant (P = 0.06) inverse association between depressive symptoms and PA. CRF and PA were not associated with psychosocial factors in this sample of breast cancer survivors. However, minimal PA was reported by the majority of participants, so low PA variability likely influenced these findings.

Background

Serum C-reactive protein (CRP) is a marker of acute inflammatory response and has been associated with health outcomes in some studies. Inflammation and immune response may have potential prognostic implications for breast cancer survivors.

Methods

The Women's Healthy Eating and Living Study includes 2,919 early-stage breast cancer survivors with serum collected 2 years postdiagnosis and follow-up for clinical outcomes over approximately 7 years. CRP concentrations were measured using high-sensitivity electrochemiluminescence assay. Outcomes, including all-cause mortality, breast cancer-specific mortality, and additional breast cancer events were oncologist verified from medical records and death certificates. Cox proportional hazards models were conducted with adjustment for potential confounding factors to generate HRs and 95% confidence intervals (CI).

Results

CRP concentrations in women diagnosed with breast cancer were associated with death due to any cause, death due to breast cancer, and additional breast cancer events, after adjustment for sociodemographic and cancer characteristics (lnCRP: P < 0.05 for all three outcomes). The HR for women with (vs. without) acute inflammation suggests a threshold effect on overall survival, rather than a dose-response relationship (≥ 10.0 mg/L vs. <1 mg/L: HR, 1.96; 95% CI, 1.22-3.13). Associations were similar for breast cancer-specific mortality (HR, 1.91; 95% CI, 1.13-3.23) and any additional breast cancer-related event (HR, 1.69; 95% CI, 1.17-2.43).

Conclusions

Acute inflammation status (CRP ≥ 10 mg/L) may be an important independent biomarker for long-term survival in breast cancer survivors.

Impact

Interventions to decrease circulating CRP concentrations in breast cancer survivors with acute inflammation may improve prognosis.

Purpose

To examine whether baseline sleep duration or changes in sleep duration are associated with breast cancer prognosis among early-stage breast cancer survivors in the multi-center Women's Healthy Eating and Living Study.

Methods

Data were collected from 1995 to 2010. Analysis included 3047 women. Sleep duration was self-reported at baseline and follow-up intervals. Cox proportional hazard models were used to investigate whether baseline sleep duration was associated with breast cancer recurrence, breast cancer-specific mortality, and all-cause mortality. Time-varying models investigated whether changes in sleep duration were associated with breast cancer prognosis.

Results

Compared to women who slept 7-8 h/night at baseline, sleeping ≥9 h/night was associated with a 48% increased risk of breast cancer recurrence (Hazard ratio [HR] 1.48, 95% Confidence interval [CI] 1.01, 2.00), a 52% increased risk of breast cancer-specific mortality (HR 1.52, 95% CI 1.09, 2.13), and a 43% greater risk of all-cause mortality (HR 1.43, 95% CI 1.07, 1.92). Time-varying models showed analogous increased risk in those who inconsistently slept ≥9 h/night (all P < 0.05), but not in those who consistently slept ≥9 h/night.

Conclusions

Consistent long or short sleep, which may reflect inter-individual variability in the need for sleep, does not appear to influence prognosis among early-stage breast cancer survivors.

We recently reported that interleukin-6 (IL-6), an inflammatory marker associated with breast pathology and the development of breast cancer, decreases with diet intervention and weight loss in both insulin-sensitive and insulin-resistant obese women. Here, we tested whether an individual's genotype at an IL6 SNP, rs1800795, which has previously been associated with circulating IL-6 levels, contributes to changes in IL-6 levels or modifies the effect of diet composition on IL-6 in these women. We genotyped rs1800795 in overweight/obese women (N = 242) who were randomly assigned to a lower fat (20% energy), higher carbohydrate (65% energy) diet; a lower carbohydrate (45% energy), higher fat (35% energy) diet; or a walnut-rich (18% energy), higher fat (35% energy), lower carbohydrate (45% energy) diet in a 1-year weight loss intervention study of obesity-related biomarkers for breast cancer incidence and mortality. Plasma IL-6 levels were measured at baseline, 6 and 12 months. At baseline, individuals with a CC genotype had significantly lower IL-6 levels than individuals with either a GC or GG genotype (p < 0.03; 2.72 pg/mL vs. 2.04 pg/mL), but this result was not significant when body mass index (BMI) was accounted for; the CC genotype group had lower BMI (p = 0.03; 32.5 kg/m² vs. 33.6 kg/m²). We did not observe a 2-way interaction of time*rs1800795 genotype or diet*rs1800795 genotype. Our findings provide evidence that rs1800795 is associated with IL-6 levels, but do not support a differential interaction effect of rs1800795 and diet composition or time on changes in circulating IL-6 levels. Diet intervention and weight loss are an important strategy for reducing plasma IL-6, a risk factor of breast cancer in women, regardless of their rs1800795 genotype.

Background

Among postmenopausal breast cancer survivors, poor physical health has been associated with higher risks of breast cancer events. Obesity and physical inactivity are known risk factors for poor physical health, while circulating estrogen is an additional potential risk factor. We tested the hypothesis that the relationship between poor physical health and worse breast cancer outcomes is mediated by higher estrogen concentrations associated with body size and physical inactivity.

Methods

We used data from 1030 postmenopausal breast cancer survivors to examine the association between serum estradiol levels, body mass index (BMI), physical activity, and RAND-36-item Health Survey (SF-36) physical health.

Results

In univariate analysis, poor physical health was associated with higher estradiol levels, in addition to obesity and low physical activity. Higher estradiol levels were significantly associated with higher odds of poor physical health (odds ratio, OR, 1.20 [95% confidence interval 1.03-1.39]) in a multivariable model adjusting for age, cancer stage and treatment, alcohol use, and physical activity. However, the relationship between estradiol levels and poor physical health was no longer significant (OR 1.06 [0.91-1.24]) after adding BMI in the model. In multivariate analysis, only poor physical health resulted in higher risks of recurrence (hazard ratio 1.33 [95% CI 1.08-1.64]).

Conclusions

These findings indicate that estradiol is related to poor physical health, but is not an independent risk factor from body size or inactivity. While obesity and physical activity in survivorship are potential targets for improving physical health, other biological processes that impact physical health, e.g. inflammation, remain to be identified.

Background

Obesity is a risk factor for postmenopausal breast cancer incidence and premenopausal and postmenopausal breast cancer mortality, which may be explained by several metabolic and hormonal factors (sex hormones, insulin resistance, and inflammation) that are biologically related. Differential effects of dietary composition on weight loss and these metabolic factors may occur in insulin-sensitive vs. insulin-resistant obese women.

Objective

To examine the effect of diet composition on weight loss and metabolic, hormonal and inflammatory factors in overweight/obese women stratified by insulin resistance status in a 1-year weight loss intervention.

Methods and results

Nondiabetic women who were overweight/obese (n=245) were randomly assigned to a lower fat (20% energy), higher carbohydrate (65% energy) diet; a lower carbohydrate (45% energy), higher fat (35% energy) diet; or a walnut-rich (18% energy), higher fat (35% energy), lower carbohydrate (45% energy) diet. All groups lost weight at follow-up (P<0.0001), with mean (SEM) percent loss of 9.2(1.1)% in lower fat, 6.5(0.9)% in lower carbohydrate, and 8.2(1.0)% in walnut-rich groups at 12months. The diet×time×insulin resistance status interaction was not statistically significant in the model for overall weight loss, although insulin sensitive women at 12months lost more weight in the lower fat vs. lower carbohydrate group (7.5kg vs. 4.3kg, P=0.06), and in the walnut-rich vs. lower carbohydrate group (8.1kg vs. 4.3kg, P=0.04). Sex hormone binding globulin increased within each group except in the lower carbohydrate group at 12months (P<0.01). C-reactive protein and interleukin-6 decreased at follow-up in all groups (P<0.01).

Conclusions

Findings provide some support for differential effects of diet composition on weight loss depending on insulin resistance status. Prescribing walnuts is associated with weight loss comparable to a standard lower fat diet in a behavioral weight loss intervention. Weight loss itself may be the most critical factor for reducing the chronic inflammation associated with increased breast cancer risk and progression.