Postdiagnostic Dietary Glycemic Index, Glycemic Load, Dietary Insulin Index, and Insulin Load and Breast Cancer Survival

The association between dietary insulin index and dietary insulin load with rheumatoid arthritis

This study was designed to assess the relationship between dietary insulin index (DII) and dietary insulin load (DIL) and rheumatoid arthritis (RA) risk in a case-control study. This study enrolled ninety-five newly diagnosed RA patients and 200 age- and sex-matched healthy controls. Dietary intakes were assessed using a validated 168-item semi-quantitative FFQ. DII and DIL were calculated using food insulin index values from previously published data. In the unadjusted model, individuals in the highest DIL tertile had the significantly higher odds of RA than those in the lowest tertile of the DIL scores (OR = 1·32, 95 % CI (1·15, 1·78), Pfor trend = 0·009). After adjusting for confounders, the risk of RA was 2·73 times higher for participants in the highest tertile of DIL than for those in the lowest tertile (OR = 2·73, 95 % CI (1·22, 3·95), Pfor trend < 0·001). In addition, patients in the highest DII tertile had higher risk of RA than those in the first tertile (OR = 2·22, 95 % CI (1·48, 3·95), Pfor trend = 0·008). This association persisted after adjusting for potential confounders (OR = 3·75, 95 % CI (3·18, 6·78), Pfor trend = 0·002). Our findings suggest that diets high in DII and DIL may increase the risk of developing RA, independent of other potential confounders. These findings can be verified by more research, particularly with a prospective design.

Association between dietary insulin index and load with cardiometabolic risk factors and risk of metabolic syndrome among the patients with type 2 diabetes: a cross-sectional study

BACKGROUND

This study aims to investigate the association between dietary insulin index (DII) and load (DIL) with cardiometabolic risk factors and the risk of developing metabolic syndrome (MetS) among patients with type 2 diabetes (T2DM).

METHODS

A cross-sectional study was conducted among 500 T2DM patients. Dietary intake was assessed using a validated food frequency questionnaire, and DII and DIL were calculated based on insulin response and energy content. Logistic regression analyses were performed to determine the odds ratios (ORs) for MetS.

RESULTS

Participants in the highest quartile of DIL had significantly higher odds of MetS (OR: 2.16; 95% CI: 1.02-4.25, P = 0.039) and hyperglycemia (OR: 1.69; 95% CI: 1.08-4.96, P = 0.032). We also discovered that patients in the highest quartile of DII had higher odds of MetS (OR: 1.69; 95% CI: 1.08-4.96, P = 0.034) and hyperglycemia (OR: 1.39; 95% CI: 1.04-4.12, P = 0.019). Furthermore, participants in the highest quartile of DIL (OR: 1.64; 95% CI: 1.00-2.59, P = 0.03) and DII (OR: 1.42; 95% CI: 1.05-1.95, P = 0.026) had higher odds of high waist circumference. When it came to hypertriglyceridemia, we found a significant association between DII and DIL only in the crude model, not the fully adjusted model. However, we didn't observe any significant association between DII and DIL with hypercholesteremia, Low HDL, and high blood pressure (P > 0.05).

CONCLUSION

Our study provides evidence suggesting that a higher DII and DIL may be associated with an increased risk of cardiometabolic risk factors and MetS in patients with T2DM.

Prediagnosis ultra-processed food consumption and prognosis of patients with colorectal, lung, prostate, or breast cancer: a large prospective multicenter study

Background and aims

Whether ultra-processed food consumption is associated with cancer prognosis remains unknown. We aimed to test whether prediagnosis ultra-processed food consumption is positively associated with all-cause and cancer-specific mortality in patients with colorectal, lung, prostate, or breast cancer.

Methods

This study included 1,100 colorectal cancer patients, 1750 lung cancer patients, 4,336 prostate cancer patients, and 2,443 breast cancer patients. Ultra-processed foods were assessed using the NOVA classification before the diagnosis of the first cancer. Multivariable Cox regression was used to calculate hazard ratio (HR) and 95% confidence interval (CI) for all-cause and cancer-specific mortality.

Results

High ultra-processed food consumption before cancer diagnosis was significantly associated with an increased risk of all-cause mortality in lung (HRquartile 4 vs. 1: 1.18; 95% CI: 0.98, 1.40; Ptrend = 0.021) and prostate (HRquartile 4 vs. 1: 1.18; 95% CI: 1.00, 1.39; Ptrend = 0.017) cancer patients in a nonlinear dose-response manner (all Pnonlinearity < 0.05), whereas no significant results were found for other associations of interest. Subgroup analyses additionally revealed a significantly positive association with colorectal cancer-specific mortality among colorectal cancer patients in stages I and II but not among those in stages III and IV (Pinteraction = 0.006), and with prostate cancer-specific mortality among prostate cancer patients with body mass index <25 but not among those with body mass index ≥25 (Pinteraction = 0.001).

Conclusion

Our study suggests that reducing ultra-processed food consumption before cancer diagnosis may improve the overall survival of patients with lung or prostate cancer, and the cancer-specific survival of certain subgroups of patients with colorectal or prostate cancer.

Dietary Approach of Patients with Hormone-Related Cancer Based on the Glycemic Index and Glycemic Load Estimates

Hormone-related cancers, namely breast, endometrial, cervical, prostate, testicular, and thyroid, constitute a specific group of cancers dependent on hormone levels that play an essential role in cancer growth. In addition to the traditional risk factors, diet seems to be an important environmental factor that partially explains the steadily increased prevalence of this group of cancer. The composition of food, the dietary patterns, the endocrine-disrupting chemicals, and the way of food processing and preparation related to dietary advanced glycation end-product formation are all related to cancer. However, it remains unclear which specific dietary components mediate this relationship. Carbohydrates seem to be a risk factor for cancer in general and hormone-related cancers, in particular, with a difference between simple and complex carbohydrates. Glycemic index and glycemic load estimates reflect the effect of dietary carbohydrates on postprandial glucose concentrations. Several studies have investigated the relationship between the dietary glycemic index and glycemic load estimates with the natural course of cancer and, more specifically, hormone-related cancers. High glycemic index and glycemic load diets are associated with cancer development and worse prognosis, partially explained by the adverse effects on insulin metabolism, causing hyperinsulinemia and insulin resistance, and also by inflammation and oxidative stress induction. Herein, we review the existing data on the effect of diets focusing on the glycemic index and glycemic load estimates on hormone-related cancers.

Assessing the Link between Diabetic Metabolic Dysregulation and Breast Cancer Progression

Diabetes mellitus is a burdensome disease that affects various cellular functions through altered glucose metabolism. Several reports have linked diabetes to cancer development; however, the exact molecular mechanism of how diabetes-related traits contribute to cancer progression is not fully understood. The current study aimed to explore the molecular mechanism underlying the potential effect of hyperglycemia combined with hyperinsulinemia on the progression of breast cancer cells. To this end, gene dysregulation induced by the exposure of MCF7 breast cancer cells to hyperglycemia (HG), or a combination of hyperglycemia and hyperinsulinemia (HGI), was analyzed using a microarray gene expression assay. Hyperglycemia combined with hyperinsulinemia induced differential expression of 45 genes (greater than or equal to two-fold), which were not shared by other treatments. On the other hand, in silico analysis performed using a publicly available dataset (GEO: GSE150586) revealed differential upregulation of 15 genes in the breast tumor tissues of diabetic patients with breast cancer when compared with breast cancer patients with no diabetes. SLC26A11, ALDH1A3, MED20, PABPC4 and SCP2 were among the top upregulated genes in both microarray data and the in silico analysis. In conclusion, hyperglycemia combined with hyperinsulinemia caused a likely unique signature that contributes to acquiring more carcinogenic traits. Indeed, these findings might potentially add emphasis on how monitoring diabetes-related metabolic alteration as an adjunct to diabetes therapy is important in improving breast cancer outcomes. However, further detailed studies are required to decipher the role of the highlighted genes, in this study, in the pathogenesis of breast cancer in patients with a different glycemic index.

Dietary patterns related to biological mechanisms and survival after breast cancer diagnosis: results from a cohort study

BACKGROUND

Inflammatory, insulin and oestrogenic pathways have been linked to breast cancer (BC). We aimed to examine the relationship between pre-diagnostic dietary patterns related to these mechanisms and BC survival.

METHODS

The diabetes risk reduction diet (DRRD), inflammatory score of diet (ISD) and oestrogen-related dietary pattern (ERDP) were calculated using dietary data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Cox proportional hazards models were used to assess associations between dietary patterns and overall mortality and competing risk models for associations with BC-specific mortality.

RESULTS

We included 13,270 BC cases with a mean follow-up after diagnosis of 8.6 years, representing 2340 total deaths, including 1475 BC deaths. Higher adherence to the DRRD score was associated with lower overall mortality (HR1-SD 0.92; 95%CI 0.87-0.96). Greater adherence to pro-inflammatory diets was borderline associated with 6% higher mortality HR1-SD 1.06; 95%CI 1.00-1.12. No significant association with the oestrogen-related dietary pattern was observed. None of the dietary patterns were associated with BC-specific mortality.

CONCLUSIONS

Greater adherence to an anti-diabetic and anti-inflammatory diet prior to diagnosis is associated with lower overall mortality among BC survivors. Long-term adherence to these dietary patterns could be a means to improve the prognosis of BC survivors.

Postdiagnosis dietary factors, supplement use and breast cancer prognosis: Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

Little is known about how diet might influence breast cancer prognosis. The current systematic reviews and meta-analyses summarise the evidence on postdiagnosis dietary factors and breast cancer outcomes from randomised controlled trials and longitudinal observational studies. PubMed and Embase were searched through 31st October 2021. Random-effects linear dose-response meta-analysis was conducted when at least three studies with sufficient information were available. The quality of the evidence was evaluated by an independent Expert Panel. We identified 108 publications. No meta-analysis was conducted for dietary patterns, vegetables, wholegrains, fish, meat, and supplements due to few studies, often with insufficient data. Meta-analysis was only possible for all-cause mortality with dairy, isoflavone, carbohydrate, dietary fibre, alcohol intake and serum 25-hydroxyvitamin D (25(OH)D), and for breast cancer-specific mortality with fruit, dairy, carbohydrate, protein, dietary fat, fibre, alcohol intake and serum 25(OH)D. The results, with few exceptions, were generally null. There was limited-suggestive evidence that predefined dietary patterns may reduce the risk of all-cause and other causes of death; that isoflavone intake reduces the risk of all-cause mortality (relative risk (RR) per 2 mg/day: 0.96, 95% confidence interval (CI): 0.92-1.02), breast cancer-specific mortality (RR for high vs low: 0.83, 95% CI: 0.64-1.07), and recurrence (RR for high vs low: 0.75, 95% CI: 0.61-0.92); that dietary fibre intake decreases all-cause mortality (RR per 10 g/day: 0.87, 95% CI: 0.80-0.94); and that serum 25(OH)D is inversely associated with all-cause and breast cancer-specific mortality (RR per 10 nmol/L: 0.93, 95% CI: 0.89-0.97 and 0.94, 95% CI: 0.90-0.99, respectively). The remaining associations were graded as limited-no conclusion.

One-year nutrition counselling in the context of a Mediterranean diet reduced the dietary inflammatory index in women with breast cancer: a role for the dietary glycemic index

Background: the Mediterranean diet, the low dietary glycemic index (GI) and the dietary inflammation index (DII®) have been associated with lower risk of breast cancer (BC) incidence and mortality. Objective: to investigate whether one-year nutrition counselling in the context of a Mediterranean diet, with or without low-GI carbohydrates counselling, may influence the DII in women with BC. Methods: data were obtained from participants of DEDiCa trial randomized to a Mediterranean diet (MD, n = 112) or a Mediterranean diet with low-GI carbohydrates (MDLGI, n = 111). The diet-derived DII and GI were calculated from 7-day food records while Mediterranean diet adherence from PREDIMED questionnaire. Differences between study arms were evaluated through Fisher's exact test or Mann-Whitney test and associations with multivariable regression analyses. Results: Mediterranean diet adherence significantly increased by 15% in MD and 20% in MDLGI with no difference between arms (p < 0.326). Dietary GI significantly decreased from 55.5 to 52.4 in MD and 55.1 to 47.6 in MDLGI with significant difference between arms (p < 0.001). DII significantly decreased by 28% in MD and 49% in MDLGI with no difference between arms (p < 0.360). Adjusting for energy intake (E-DII) did not change the results. Higher Mediterranean diet adherence and lower dietary GI independently contributed to DII lowering (β-coefficient -0.203, p < 0.001; 0.046, p = 0.003, respectively). Conclusions: DII and E-DII scores decreased significantly after one-year with 4 nutrition counselling sessions on the Mediterranean diet and low GI. Increased adherence to the Mediterranean diet and low GI independently contributed to the DII changes. These results are relevant given that lowering the inflammatory potential of the diet may have implications in cancer prognosis and overall survival.

Prospective Cohort of Pre- and Post-Diagnosis Diet with Survival Outcomes: an Alberta Endometrial Cancer Cohort Study

BACKGROUND

The prognostic relationship between diet and endometrial cancer survival remains largely unknown. We sought to determine pre- and post-diagnosis dietary composition, glycemic load (GL), inflammatory potential (dietary inflammatory index) and quality [Canadian Healthy Eating Index (C-HEI) 2005] associations with disease-free (DFS) and overall survival (OS) among endometrial cancer survivors. In addition, we assessed associations between dietary changes with OS and explored obesity/physical activity effect modification.

METHODS

Survivors, diagnosed in Alberta, Canada between 2002 and 2006, completed past-year, food-frequency questionnaires at-diagnosis (n = 503) and 3-year follow-up (n = 395). Participants were followed to death or January 2022. Cox proportional regression estimated HR [95% confidence intervals (CI)] for dietary survival associations.

RESULTS

During 16.9 median years of follow-up, 138 participants had a DFS event and 120 died. Lower pre-diagnosis GL (HRT1vsT3, 0.49; 95% CI, 0.25-0.97) and greater post-diagnosis energy intakes (EI) from total- and monounsaturated-fat (HRT3vsT1, 0.48; 95% CI, 0.26-0.87) were associated with better OS. Higher pre-diagnosis C-HEI, less inflammatory diets and lower added sugar intakes were nonlinearly associated with better DFS. Consistently low pre- to post-diagnosis EI from carbohydrates and total-fats were associated with better (HR, 0.36; 95% CI, 0.18-0.72) and worse (HR, 2.26; 95% CI, 1.21-4.20) OS, respectively. Decreased pre- to post-diagnosis C-HEI was associated with worse OS. In stratified analysis, healthy diets were most beneficial for survivors with obesity and physical inactivity.

CONCLUSIONS

Adherence to higher quality dietary patterns were associated with better survival.

IMPACT

Our study provides novel evidence that both pre- and post-diagnosis diet are important prognostic factors for endometrial cancer survivors. Post-diagnosis survival associations with diet composition and quality highlight the potential for future interventions.

Plant-Based Diets and Cancer Prognosis: a Review of Recent Research

PURPOSE OF REVIEW

Although plant-based diets are recommended for cancer prevention, their role in cancer survival is still uncertain. The purpose of this systematic review is to summarize the association between postdiagnosis plant-based diets and prognosis in cancer survivors.

RECENT FINDINGS

There is indication that higher intake of plant-based foods was associated with improved prognosis in cancer survivors. For colorectal cancer survival, a better prognosis was observed for a high intake of whole grains and fibre. For breast cancer survival, a higher intake of fruit, vegetable and fibre and a moderate intake of soy/isoflavone were associated with beneficial outcomes. A higher vegetable fat intake was related to improved prognosis in prostate cancer survivors. Emerging evidence suggests benefits of postdiagnosis plant-based diets on prognosis in cancer survivors. However, given the high heterogeneity between studies, further research in cancer survivors, considering clinical factors (e.g. treatment, stage) and methodological aspects (e.g. timing of dietary assessment), is needed.

The association between dietary glycemic index and cardio-metabolic risk factors in obese individuals

Background:

The dietary glycemic index (GI) has been introduced as a novel index to elucidate the potential of foods to increase postprandial glucose. According to the limited available data about the association of GI with cardio-metabolic risk factors such as lipid profile, blood glucose markers, and blood pressure in developing countries, the current study was conducted to investigate this association in apparently obese individuals.

Method and material:

Three hundred forty-seven obese adults were recruited in the present cross-sectional study. A validated 147-food item semi-quantitative food frequency questionnaire (FFQ) was used to evaluate the usual dietary intake of study participants. Dietary GI was calculated using the international GI database. Fatty acid desaturase (FADs)2 gene variants were determined according to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). ANOVA was used to compare study variables across different tertile of GI.

Results:

We found significant differences in terms of anthropometric parameters [weight (P = 0.038), waist circumference (WC) (P = 0.023), weight to hip ratio (WHR) (P = 0.007), and fat-free mass (FFM) (P < 0.001)] between different tertiles of GI. Similarly, energy and macronutrient intakes had a significant difference across dietary GI, and subjects with a higher dietary intake of energy and macronutrients (carbohydrate, protein, and total fat) were assigned to the third tertile of dietary GI (P < 0.001). While there was no significant difference in terms of cardio-metabolic risk factors in different dietary GI tertiles. Moreover, the total GI score was non-significantly higher in the TT genotype of FADS2 gene polymorphism compared with other genotypes. While no significant difference was observed between FADS2 genotype frequencies in different GI tertiles.

Conclusion:

Calculated dietary GI was associated with several cardio-metabolic risk factors in obese individuals. However, further prospective studies and clinical trials are needed to confirm our findings.

Association of Healthy Diet and Physical Activity With Breast Cancer: Lifestyle Interventions and Oncology Education

Global cancer statistics suggest that breast cancer (BC) is the most diagnosed cancer in women, with an estimated 2. 3 million new cases reported in 2020. Observational evidence shows a clear link between prevention and development of invasive BC and lifestyle-based interventions such as a healthy diet and physical activity. The recent findings reveal that even minimal amounts of daily exercise and a healthy diet reduced the risk of BC, mitigated the side effects of cancer treatment, and stopped the recurrence of cancer in the survivors. Despite the myriad benefits, the implementation of these lifestyle interventions in at-risk and survivor populations has been limited to date. Given the need to disseminate information about the role of physical activity and nutrition in BC reduction, the review aimed to present the recent scientific outreach and update on associations between the lifestyle interventions and BC outcomes to narrow the gap and strengthen the understanding more clearly. This review covers more direct, detailed, and updated scientific literature to respond to frequently asked questions related to the daily lifestyle-based interventions and their impact on BC risk and survivors. This review also highlights the importance of the oncology provider's job and how oncology education can reduce the BC burden.

The association of dietary insulin load and index with the risk of cancer and cancer mortality: a systematic review and meta-analysis

Purpose

Insulin levels play an important role in cancer development. However, the link between an insulinogenic diet and cancer is still unclear. Therefore, we performed a systematic review with meta-analysis to investigate the association between dietary insulin index (II) and load (IL) with cancer risk and mortality.

Methods

A comprehensive search between electronic databases (Web of Science, PubMed/Medline, Scopus, and Google Scholar) was conducted to identify relevant studies up to January 2022. The relative risks (RR) and Odds ratios (OR) were extracted from eligible studies, and meta-analysis was performed to calculate the pooled effect size.

Result

12 papers including 14 studies (10 cohorts and 4 case-control) were included for the meta-analysis. Among them, 10 studies reported effect size for the risk of cancer, and 4 studies reported effect size for cancer mortality. We observed no significant association between II and IL with cancer overall (RR_II: 1.03, 95%CI: 0.91-1.17, RR_IL: 1.16, 95%CI: 0.94-1.42) and in cohort studies, however, in case-control studies was related with higher odds of cancer (OR_II: 2.30, 95%CI: 1.21-4.38, OR_IL: 2.57, 95%CI: 1.64-4.02). Higher II and IL scores were associated with the increased risk of total (RR_II: 1.29, 95%CI: 1.02-1.63) and (RR_IL: 1.39, 95%CI: 1.06-1.83) and colorectal cancer mortality (RR_II: 1.29, 95%CI: 1.13-1.48) and (RR_IL: 1.37, 95%CI: 1.18-1.60).

Conclusion

Higher dietary II and IL were not associated with cancer risk in overall and cohort studies, whereas related with a higher risk of cancer in case-control studies. We observed a significant positive relation of II and IL with cancer mortality, especially CRC mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01013-3.

Types of carbohydrate intake and breast cancer survival

OBJECTIVE

To investigate the associations of different types of carbohydrate intake after breast cancer diagnosis with breast cancer-specific and all-cause mortality.

METHODS

We prospectively assessed post-diagnostic intake of total sugar, added sugar, and natural sugar as well as carbohydrate from different sources, among 8932 women with stage I-III breast cancer that were identified in the Nurses' Health Study from 1980 to 2010 and Nurses' Health Study II from 1991 to 2011. Participants completed a validated food frequency questionnaire every four years after diagnosis and were followed up for death.

RESULTS

We prospectively documented 1071 deaths due to breast cancer and 2532 all-cause deaths, over a mean of 11.5 years of follow-up. After adjustment for confounding variables, greater post-diagnostic total sugar intake was suggestively associated with greater risk of breast cancer-specific mortality [hazard ratio (HR)_Q5vsQ1 = 1.16, 95% confidence interval (CI ) = 0.95-1.41; P_trend = 0.02] and significantly associated with greater risk of all-cause mortality (HR_Q5vsQ1 = 1.23, 95% CI = 1.08-1.41; P_trend = 0.0001). Greater post-diagnostic added sugar intake was significantly associated with greater risk of all-cause mortality (HR_Q5vsQ1 = 1.20, 95% CI = 1.06-1.36; P_trend = 0.001). Post-diagnostic natural sugar (occurring in foods and not added as an ingredient) intake was not associated with mortality risk. Greater post-diagnostic fructose intake was significantly associated with greater risk of breast cancer-specific mortality (HR_Q5vsQ1 = 1.34, 95% CI = 1.10-1.64; P_trend = 0.005) and all-cause mortality (HR_Q5vsQ1 = 1.16, 95% CI = 1.02-1.32; P_trend = 0.01). High post-diagnostic intake of sucrose was associated with higher risk of breast cancer-specific and all-cause mortality. Increased post-diagnostic intake of carbohydrate from fruit juice was significantly associated with higher risk of breast cancer-specific and all-cause mortality and carbohydrate from vegetables was significantly associated with lower risk of all-cause mortality. High post-diagnostic intake of carbohydrate from potatoes was suggestively associated with higher risk of breast cancer-specific mortality and carbohydrate from refined grains was suggestively associated with higher risk of all-cause mortality.

CONCLUSIONS

We found that higher total sugar intake, especially added sugar, sucrose, and fructose, as well as carbohydrate from fruit juice after a breast cancer diagnosis were associated with poorer prognosis. High post-diagnostic intake of carbohydrate from vegetables was associated with reduced risk of mortality.

Diabetes Risk Reduction Diet and Survival after Breast Cancer Diagnosis

Type II diabetes is associated with poor breast cancer prognosis. To study the association between a diabetes risk reduction diet (DRRD) and survival following breast cancer, we followed 8,482 women with breast cancer from two large cohort studies. Information on diet and other factors was repeatedly measured in validated questionnaires every two to four years. The DRRD includes 9 components: higher intakes of cereal fiber, coffee, nuts, whole fruits and polyunsaturated/saturated fat ratio; and lower glycemic index, trans fat, sugar-sweetened beverages, and red meat. Cumulative average DRRD score was calculated using repeated measures of postdiagnostic diet. Deaths were assessed by family members or via National Death Index. Multivariable-adjusted HRs and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. During a median of 14 years of follow-up since diagnosis, 2,600 deaths occurred among participants, 1,042 of which were due to breast cancer. Women with higher postdiagnostic DRRD score had a 20% lower risk of breast cancer-specific mortality (top vs. bottom quintile HR = 0.80; 95% CI = 0.65-0.97; P _trend = 0.02) and 34% lower risk of all-cause mortality (HR = 0.66; 95% CI = 0.58-0.76; P _trend < 0.0001). Compared with women who consistently had lower score (≤median) before and after diagnosis, those whose score improved from low to high had a lower risk of breast cancer-specific mortality (HR = 0.77; 95% CI = 0.62-0.95) and overall mortality (HR = 0.85; 95% CI = 0.74-0.97). These findings demonstrate that greater adherence to DRRD was associated with better survival, suggesting postdiagnosis dietary modification consistent with type II diabetes prevention may be important for breast cancer survivors. SIGNIFICANCE: This study suggests that greater adherence to the diabetes risk reduction diet after diagnosis associates with improved survival outcomes among a large number of breast cancer survivors.

Consumption of sugar-sweetened and artificially sweetened beverages and breast cancer survival

BACKGROUND

The activation of insulin pathways is hypothesized to promote tumor growth and worsen breast cancer survival. Sugar-sweetened beverages (SSBs) can lead to a higher risk of insulin resistance and may affect survival. The authors prospectively evaluated the relation of postdiagnostic SSB and artificially sweetened beverage (ASB) consumption with mortality among women with breast cancer.

METHODS

In total, 8863 women with stage I through III breast cancer were identified during follow-up of the Nurses' Health Study (NHS; 1980-2010) and Nurses' Health Study II (NHSII; 1991-2011). Women completed a validated food frequency questionnaire every 4 years after diagnosis and were followed until death or the end of follow-up (2014 for the NHS and 2015 for the NHSII). Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer-specific and all-cause mortality after adjusting for measures of adiposity and other potential predictors of cancer survival.

RESULTS

With a median follow-up of 11.5 years, 2482 deaths were prospectively documented, including 1050 deaths from breast cancer. Compared with women who had no consumption, women who had SSB consumption after diagnosis had higher breast cancer-specific mortality (>1 to 3 servings per week: HR, 1.31 [95% CI, 1.09-1.58]; >3 servings per week: HR, 1.35 [95% CI, 1.12-1.62]; P_trend = .001) and all-cause mortality (>1 to 3 servings per week: HR, 1.21 [95% CI, 1.07-1.37]; >3 servings per week: HR, 1.28 [95% CI, 1.13-1.45]; P_trend = .0001). In contrast, ASB consumption was not associated with higher breast cancer-specific or all-cause mortality. Furthermore, replacing 1 serving per day of SSB consumption with 1 serving per day of ASB consumption was not associated with a lower risk of mortality.

CONCLUSIONS

Higher postdiagnostic SSB consumption among breast cancer survivors was associated with higher breast cancer-specific mortality and death from all causes.

Diet and Prognosis in Women with Breast Cancer

Women who have obesity or who have metabolic abnormalities, including diabetes, prediabetes, or hyperglycemia/insulinemia, have poorer survival compared with other women with breast cancer. Data are lacking on specific lifestyle modifications to prevent or treat these conditions to improve women's chances of survival from breast cancer. The Nurses' Health Study cohorts provide new evidence that diets with the potential to elevate circulating insulin or glucose are associated with breast cancer prognosis. The researchers found statistically significant evidence that women in the highest quintile of glycemic load had a 31% higher risk of breast cancer-specific mortality and a 26% higher risk of all-cause mortality. While a randomized controlled clinical trial testing if a reduced glycemic load diet reduces recurrence or death would be optimal, evidence from this observational study suggests that diet matters in survival from breast cancer. The dietary guidelines provided by the World Cancer Research Fund/American Institute for Cancer Research, the American Cancer Society, and the American Society for Clinical Oncology, which collectively emphasize increased intake of vegetables, fruits, whole grains, and legumes, and reduced intake of sugar, calorie-dense foods, and sugary drinks, are reasonable for most breast cancer survivors to follow for optimal health.See related article by Farvid et al., p. 335.