The association between postdiagnosis dietary supplement use and total mortality differs by diet quality among older female cancer survivors

Association between fish oil and glucosamine use and mortality in patients diagnosed with cancer: the role of the Life Essential 8 score and cancer prognosis

BACKGROUND

The effect of supplements on mortality risk in patients with cancer remains uncertain and has scarcely been investigated in subgroups of patients with varying characteristics. This study aimed to investigate the association between two popular supplements, fish oil and glucosamine, and mortality risk in a large population-based cohort and determine whether cardiovascular health and clinical prognosis influence these associations.

METHODS

This prospective cohort study analyzed the data of UK Biobank participants who were diagnosed with cancer. The associations of fish oil and glucosamine consumption with mortality were analyzed using Cox proportional hazards models. Subgroup analyses were performed to assess the effects of Life Essential 8 [LE8] scores (a measure of cardiovascular health) and cancer prognosis (grouped according to the survival rates of specific cancer types) on the associations between supplement use and mortality.

RESULTS

This analysis included 14,920 participants (mean age = 59.9 years; 60.2% female). One third (34.1%) of the participants reported using fish oil, and one fifth (20.5%) reported using glucosamine. Over a median follow-up of 12.0 years, 2,708 all-cause deaths were registered. The use of fish oil was associated with reduced risks of all-cause mortality (adjusted hazard ratio [aHR] = 0.89, 95% Confidence Interval [CI] = 0.81-0.97) and cancer mortality (aHR = 0.89, 95% CI = 0.81-0.98). Similarly, glucosamine use was associated with reduced risks of all-cause mortality (aHR = 0.83, 95% CI = 0.74-0.92) and cancer mortality (aHR = 0.83, 95% CI = 0.74-0.93) in the fully adjusted model. Subgroup analyses revealed that the protective effects of fish oil and glucosamine against mortality risk were only observed in patients with LE8 scores lower than the mean score or a poor cancer prognosis. Additionally, the association between glucosamine use and a reduced risk of CVD-related mortality was only observed in patients with lower LE8 scores.

CONCLUSIONS

This large cohort study identified the potential differential impact of LE8 scores and cancer prognosis on the associations of fish oil and glucosamine supplementation with survival in patients with cancer. This suggests the importance of considering these factors in future research on supplements and in the provision of personalized integrative cancer care.

Post-diagnosis dietary factors, supplement use and colorectal cancer prognosis: A Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

The role of diet in colorectal cancer prognosis is not well understood and specific lifestyle recommendations are lacking. We searched for randomised controlled trials (RCTs) and longitudinal observational studies on post-diagnosis dietary factors, supplement use and colorectal cancer survival outcomes in PubMed and Embase from inception until 28th February 2022. Random-effects dose-response meta-analyses were conducted when at least three studies had sufficient information. The evidence was interpreted and graded by the CUP Global independent Expert Committee on Cancer Survivorship and Expert Panel. Five RCTs and 35 observational studies were included (30,242 cases, over 8700 all-cause and 2100 colorectal cancer deaths, 3700 progression, recurrence, or disease-free events). Meta-analyses, including 3-10 observational studies each, were conducted for: whole grains, nuts/peanuts, red and processed meat, dairy products, sugary drinks, artificially sweetened beverages, coffee, alcohol, dietary glycaemic load/index, insulin load/index, marine omega-3 polyunsaturated fatty acids, supplemental calcium, circulating 25-hydroxyvitamin D (25[OH]D) and all-cause mortality; for alcohol, supplemental calcium, circulating 25(OH)D and colorectal cancer-specific mortality; and for circulating 25(OH)D and recurrence/disease-free survival. The overall evidence was graded as 'limited'. The inverse associations between healthy dietary and/or lifestyle patterns (including diets that comprised plant-based foods), whole grains, total, caffeinated, or decaffeinated coffee and all-cause mortality and the positive associations between unhealthy dietary patterns, sugary drinks and all-cause mortality provided 'limited-suggestive' evidence. All other exposure-outcome associations provided 'limited-no conclusion' evidence. Additional, well-conducted cohort studies and carefully designed RCTs are needed to develop specific lifestyle recommendations for colorectal cancer survivors.

Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts

Importance

One in 3 US adults uses multivitamins (MV), with a primary motivation being disease prevention. In 2022, the US Preventive Services Task Force reviewed data on MV supplementation and mortality from randomized clinical trials and found insufficient evidence for determining benefits or harms owing, in part, to limited follow-up time and external validity.

Objective

To estimate the association of MV use with mortality risk, accounting for confounding by healthy lifestyle and reverse causation whereby individuals in poor health initiate MV use.

Design, Setting, and Participants

This cohort study used data from 3 prospective cohort studies in the US, each with baseline MV use (assessed from 1993 to 2001), and follow-up MV use (assessed from 1998 to 2004), extended duration of follow-up up to 27 years, and extensive characterization of potential confounders. Participants were adults, without a history of cancer or other chronic diseases, who participated in National Institutes of Health-AARP Diet and Health Study (327 732 participants); Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (42 732 participants); or Agricultural Health Study (19 660 participants). Data were analyzed from June 2022 to April 2024.

Exposure

Self-reported MV use.

Main Outcomes and Measures

The main outcome was mortality. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% CIs.

Results

Among 390 124 participants (median [IQR] age, 61.5 [56.7-66.0] years; 216 202 [55.4%] male), 164 762 deaths occurred during follow-up; 159 692 participants (40.9%) were never smokers, and 157 319 participants (40.3%) were college educated. Among daily MV users, 49.3% and 42.0% were female and college educated, compared with 39.3% and 37.9% among nonusers, respectively. In contrast, 11.0% of daily users, compared with 13.0% of nonusers, were current smokers. MV use was not associated with lower all-cause mortality risk in the first (multivariable-adjusted HR, 1.04; 95% CI, 1.02-1.07) or second (multivariable-adjusted HR, 1.04; 95% CI, 0.99-1.08) halves of follow-up. HRs were similar for major causes of death and time-varying analyses.

Conclusions and Relevance

In this cohort study of US adults, MV use was not associated with a mortality benefit. Still, many US adults report using MV to maintain or improve health.

Multivitamin use and all-cause and cause-specific mortality in cancer survivors

BACKGROUND

Despite no sufficient evidence on benefits and harms of multivitamin use, cancer survivors use multivitamins as a self-care strategy to improve or maintain health. We examined if multivitamin use was associated with mortality in cancer survivors.

METHODS

15,936 male and 7026 female cancer survivors in the NIH-AARP Diet and Health Study were included in the analysis. Types and frequency of multivitamin use at on average 4.6 years after cancer diagnosis were assessed. Multivariable-adjusted relative risks (RR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression models.

RESULTS

Multivitamin use was not associated with lower all-cause mortality risk in all female (RR = 0.94, 95% CI:0.87-1.01 daily vs. no use) or male cancer survivors (RR = 0.96, 95% CI:0.91-1.00); however, a modest inverse association for CVD mortality was observed in female survivors of reproductive cancers (RR = 0.75, 95% CI:0.61-0.92) and male survivors of non-reproductive cancers (RR = 0.81, 95% CI:0.70-0.94). Multivitamin use was also associated with a lower risk of cancer-specific mortality in survivors of skin (RR = 0.65, 95% CI:0.48-0.88) and breast (RR = 0.79, 95% CI:0.65-0.95) cancer.

DISCUSSION

Multivitamin use may provide a modest survival benefit to some cancer survivors. Cancer care providers should talk with cancer survivors about potential benefits and harms of multivitamin use.

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.

The Self-Administered Use of Complementary and Alternative Medicine (CAM) Supplements and Antioxidants in Cancer Therapy and the Critical Role of Nrf-2-A Systematic Review

Complementary and alternative medicine (CAM) supplements are widely used by cancer patients. Dietary supplements, vitamins and minerals, herbal remedies, and antioxidants are especially popular. In a systematic literature review, 37 studies, each including more than 1000 participants, on CAM, dietary supplement, and vitamin use among cancer patients were identified. Accordingly, cancer patients use antioxidants such as vitamin C (from 2.6% (United Kingdom) to 41.6% (United States)) and vitamin E (from 2.9% (China) to 48% (United States)). Dietary supplements and vitamins are taken for different reasons, but often during conventional cancer treatment involving chemotherapy or radiotherapy and in a self-decided manner without seeking medical advice from healthcare professionals. Drug-drug interactions with dietary supplements or vitamins involving multiple signaling pathways are well described. Since most of the anticancer drugs generate reactive oxygen species (ROS), an adaptive stress response of healthy and malignant cells, mainly driven by the Nrf-2-Keap I network, can be observed. On the one hand, healthy cells should be protected from ROS-overproducing chemotherapy and radiotherapy; on the other hand, ROS production in cancer cells is a "desirable side effect" during anticancer drug treatment. We here describe the paradoxical use of antioxidants and supplements during cancer therapy, possible interactions with anticancer drugs, and the involvement of the Nrf-2 transcription factor.

Post-Diagnosis Vitamin D Supplement Use and Survival among Cancer Patients: A Meta-Analysis

Vitamin D administered pre-diagnostically has been shown to reduce mortality. Emerging evidence suggests a role of post-diagnosis vitamin D supplement intake for survival among cancer patients. Thus, we conducted a meta-analysis to evaluate the relationship. PubMed and Embase were searched for relevant observational cohort studies and randomized trials published through April 2022. Summary relative risk (SRR) and 95% confidence interval (CI) were estimated using the DerSimonian–Laird random-effects model. The SRR for post-diagnosis vitamin D supplement use vs. non-use, pooling cohort studies and randomized trials, was 0.87 (95% CI, 0.78–0.98; p = 0.02; I² = 0%) for overall survival, 0.81 (95% CI, 0.62–1.06; p = 0.12; I² = 51%) for progression-free survival, 0.86 (95% CI, 0.72–1.03; p = 0.10; I² = 0%) for cancer-specific survival, and 0.86 (95% CI, 0.64–1.14; p = 0.29; I² = 0%) for relapse. Albeit not significantly heterogeneous by variables tested, a significant inverse association was limited to cohort studies and supplement use during cancer treatment for overall survival, and to studies with ≤3 years of follow-up for progression-free survival. Post-diagnosis vitamin D supplement use was associated with improved overall survival, but not progression-free or cancer-specific survival or relapse. Our findings require confirmation, as randomized trial evidence was insufficient to establish cause-and-effect relationships.

Multivitamins in the prevention of cancer and cardiovascular disease: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial

BACKGROUND

Although older adults commonly take multivitamin-multimineral (MVM) supplements to promote health, evidence on the use of daily MVMs on invasive cancer is limited.

OBJECTIVES

The study objective was to determine if a daily MVM decreases total invasive cancer among older adults.

METHODS

We performed a randomized, double-blind, placebo-controlled, 2-by-2 factorial trial of a daily MVM and cocoa extract for prevention of cancer and cardiovascular disease (CVD) among 21,442 US adults (12,666 women aged ≥65 y and 8776 men aged ≥60 y) free of major CVD and recently diagnosed cancer. The intervention phase was from June 2015 through December 2020. This article reports on the MVM intervention. Participants were randomly assigned to daily MVM or placebo. The primary outcome was total invasive cancer, excluding nonmelanoma skin cancer. Secondary outcomes included major site-specific cancers, total CVD, all-cause mortality, and total cancer risk among those with a baseline history of cancer.

RESULTS

During a median follow-up of 3.6 y, invasive cancer occurred in 518 participants in the MVM group and 535 participants in the placebo group (HR: 0.97; 95% CI: 0.86, 1.09; P = 0.57). We observed no significant effect of a daily MVM on breast cancer (HR: 1.06; 95% CI: 0.79, 1.42) or colorectal cancer (HR: 1.30; 95% CI: 0.80, 2.12). We observed a protective effect of a daily MVM on lung cancer (HR: 0.62; 95% CI: 0.42, 0.92). The composite CVD outcome occurred in 429 participants in the MVM group and 437 participants in the placebo group (HR: 0.98; 95% CI: 0.86, 1.12). MVM use did not significantly affect all-cause mortality (HR: 0.93; 95% CI: 0.81, 1.08). There were no safety concerns.

CONCLUSIONS

A daily MVM supplement, compared with placebo, did not significantly reduce the incidence of total cancer among older men and women. Future studies are needed to determine the effects of MVMs on other aging-related outcomes among older adults. This trial is registered at www.clinicaltrials.gov as NCT02422745.

Patient Perspectives on the Development of a Novel Mobile Health (mHealth) Application for Dietary Supplement Tracking and Reconciliation – A Qualitative Focus Group Study

Background: More than 170 million adults use dietary supplements (DS) in the United States, which can have both benefit and harm to patient health. DS use is often poorly documented in the medical record and can pose health risks if not properly communicated with providers. Reasons for poor DS documentation include low disclosure rates, time constraints of clinical encounters, and providers’ failure to inquire about DS use. This study was conducted to assess patients’ views on the facilitators and barriers to using a mobile health (mHealth) application (app) to collect and share DS information with their healthcare providers. Methods: Utilizing a theory-based conceptual model, we conducted seven patient focus groups (FGs) to assess opinions on DS safety, provider communication, comfort with technology use, and our proposed mHealth app. Participants were recruited from the general public and through patient advisory groups. Patient views will inform the creation of an mHealth app to improve DS patient-provider communication and tracking and reconciliation in the electronic medical record (EMR). Results: Overall, participants believe their DS information is inaccurately represented in the EMR leading to safety concerns and negatively impacting overall quality-of-care. Participants desired an app designed with: 1) Health Insurance Portability and Accountability Act (HIPAA)-compliance; 2) ease of use for a variety of technical efficacy levels; 3) access to reliable DS information, including a DS-drug interaction checker; 4) integration with the EMR. Conclusion: An app to simplify and improve DS entry and reconciliation was of interest to patients, as long as it maintained health autonomy and privacy and possessed key valuable features.

Cost-Effectiveness of Nutrient Supplementation in Cancer Survivors

Cancer patients are at risk for malnutrition; the aim of this study was to provide a cost-effectiveness analysis of dietary supplementation in cancer survivors. We estimated prevalence of supplementation, hospitalization rates, quality of life (QOL), cost of care and mortality among cancer survivors. We built a decision analytic model to simulate life-long costs of health care and supplementation and QOL among cancer survivors with and without supplementation. Cost of supplements was derived from national pharmacy databases including single- and multivitamin formularies. One-way and probabilistic sensitivity analysis were performed to evaluate the robustness of the incremental cost-effectiveness ratio (ICER) to changes in supplementation costs and duration. The study cohort represented the national cancer survivor population (average age 61 years, 85% white, 52% male, and 94% insured). Hospitalization rates for supplement users and non-users were 12% and 21%, respectively. The cost of hospitalization was $4030. Supplementation was associated with an additional 0.48 QALYs (10.26 vs. 9.78) at the incremental cost of $2094 ($236,933 vs. $234,839) over the remaining lifetime of survivors (on average 13 years). Adequate nutrition provides a cost-effective strategy to achieving potentially optimum health. Further studies are needed to determine the effects of specific nutrient doses and supplementation on long-term outcomes per cancer type.

Post-Diagnosis use of Antioxidant Vitamin Supplements and Breast Cancer Prognosis: A Systematic Review and Meta-Analysis

Antioxidant vitamin supplements (AVSs) are widely used among breast cancer survivors. Whether post-diagnosis use of AVSs would impair cancer survival is unclear. To assess the association between breast cancer survival and post-diagnosis AVSs use. We performed a literature search using PubMed, Cochrane Library, and Embase from their inception to October 1, 2020. Studies that investigated the association between breast cancer survival and post-diagnosis AVS use included. The AVSs included 1 or more of the following: vitamin A, C, or E. The meta-analysis included 8 studies with 17,062 patients. There was no significant difference between AVS use or not after diagnosis (HR 0.92, 95% CI 0•82-1•03) or during chemotherapy (HR 1.15, 95% CI 0.78-1.68) in overall survival (OS). Whenever during chemotherapy or after diagnosis, AVS users had a worse prognosis in the later studies. There was no significant inverse association between post-diagnosis vitamin A or E supplements use and OS. Vitamin C intake after breast cancer diagnosis was significantly associated with better OS (HR 0.84, 95% CI 0.76-0.93). Our findings suggest that post-diagnosis AVSs use would not worsen breast cancer survival, while vitamin C use after diagnosis might benefit OS. The discrepancy of survivals associated with post-diagnosis AVS use between earlier and later studies may cast doubt on the recommendation on guidelines. RCTs with large sample sizes are needed.

Convalescent Hospital Use among Young and Older Female Cancer Survivors

This study analyzed national health data to assess convalescent hospital use among female cancer survivors according to age group. This retrospective study collected data from women recovering from breast, colon, and stomach cancer, based on health insurance claim data over 5 years (2013-2017), from the Korea Health Insurance Review and Assessment Service (KHIRA). Interestingly, the number of young and older women who were treated in convalescent hospitals increased every year. In addition, total medical expenses increased in both groups. The annual rate of convalescent hospitalization was higher in older women (8.29~16.39%) than in younger women (4.01~7.46%). The total yearly medical expenses of cancer survivors in convalescent hospitals increased in both age groups and all cancer types, and the range of increase rate was from 7.7% in young breast cancer survivors to 32.2% in young colon cancer survivors. Visit days and days of medication increased noticeably in young colon cancer survivors. Taken together, these data have confirmed the importance of developing standard guidelines for inpatient management in convalescent hospitals and the health management of women cancer survivors by cancer type. This includes establishing a health management system and medical policies.

Total, Dietary, and Supplemental Magnesium Intakes and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

A meta-analysis of prospective studies was conducted to examine the association of total, supplemental, and dietary magnesium intakes with risk of all-cause, cancer, and cardiovascular disease (CVD) mortality and identify the dose-response relations involved in these association. We performed a systematic search of PubMed, Scopus, Google Scholar, and ISI Web of Knowledge up to April 2020. Prospective cohort studies that reported risk estimates for the association between total, supplemental, and dietary magnesium intakes and risk of mortality were included. Random effects models were used. Nineteen publication with a total of 1,168,756 participants were included in the current meta-analysis. In total, 52,378 deaths from all causes, 23,478 from CVD, and 11,408 from cancer were identified during the follow-up period of 3.5 to 32 years. Dietary magnesium intake was associated with a lower risk of all-cause [pooled effect size (ES): 0.87; 95% CI: 0.79, 0.97; P = 0.009; I2 = 70.7%; P < 0.001] and cancer mortality (pooled ES: 0.80; 95% CI: 0.67, 0.97; P = 0.023; I2 = 55.7%; P = 0.027), but not with CVD mortality (pooled ES: 0.93; 95% CI: 0.82, 1.07; P = 0.313; I2 = 72.3%; P < 0.001). For supplemental and total magnesium intakes, we did not find any significant associations with risks of all-cause, CVD, and cancer mortality. However, linear dose-response meta-analysis indicated that each additional intake of 100 mg/d of dietary magnesium was associated with a 6% and 5% reduced risk of all-cause and cancer mortality, respectively. In conclusion, higher intake of dietary magnesium was associated with a reduced risk of all-cause and cancer mortality, but not CVD mortality. Supplemental and total magnesium intakes were not associated with the risk of all-cause, CVD, and cancer mortality. These findings indicate that consumption of magnesium from dietary sources may be beneficial in reducing all-cause and cancer mortality and thus have practical importance for public health.

The effect of vitamin D supplementation on survival in patients with colorectal cancer: systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Low circulating vitamin D levels are associated with poor colorectal cancer (CRC) survival. We assess whether vitamin D supplementation improves CRC survival outcomes.

METHODS

PubMed and Web of Science were searched. Randomised controlled trial (RCTs) of vitamin D supplementation reporting CRC mortality were included. RCTs with high risk of bias were excluded from analysis. Random-effects meta-analysis models calculated estimates of survival benefit with supplementation. The review is registered on PROSPERO, registration number: CRD42020173397.

RESULTS

Seven RCTs (n = 957 CRC cases) were identified: three trials included patients with CRC at outset, and four population trials reported survival in incident cases. Two RCTs were excluded from meta-analysis (high risk of bias; no hazard ratio (HR)). While trials varied in inclusion criteria, intervention dose and outcomes, meta-analysis found a 30% reduction in adverse CRC outcomes with supplementation (n = 815, HR = 0.70; 95% confidence interval (CI): 0.48-0.93). A beneficial effect was seen in trials of CRC patients (progression-free survival, HR = 0.65; 95% CI: 0.36-0.94), with suggestive effect in incident CRC cases from population trials (CRC-specific survival, HR = 0.76; 95% CI: 0.39-1.13). No heterogeneity or publication bias was noted.

CONCLUSIONS

Meta-analysis demonstrates a clinically meaningful benefit of vitamin D supplementation on CRC survival outcomes. Further well-designed, adequately powered RCTs are needed to fully evaluate benefit of supplementation in augmenting 'real-life' follow-up and adjuvant chemotherapy regimens, as well as determining optimal dosing.

Evaluation of How Integrative Oncology Services Are Valued between Hematology/Oncology Patients and Hematologists/Oncologists at a Tertiary Care Center

Evidence regarding opinions on integrative modalities by patients and physicians is lacking. Methods. A survey study was conducted assessing how integrative modalities were valued among hematology/oncology patients and hematologists and oncologists at a major tertiary medical center. Results. 1008 patients and 55 physicians were surveyed. With the exception of support groups, patients valued nutrition services, exercise therapy, spiritual/religious counseling, supplement/herbal advice, support groups, music therapy, and other complimentary medicine services significantly more than physicians (P ≤ 0.05). Conclusion. With the exception of support groups, patients value integrative modalities more than physicians. Perhaps with increasing education, awareness, and acceptance by providers and traditional institutions, integrative modalities could be equally valued between patients and providers. It is possible that increased availability and utilization of integrative oncology modalities at tertiary hospital sites could improve patient satisfaction, quality of life, and other clinical endpoints.

Dietary Supplements Commonly Used by Cancer Survivors: Are There Any Benefits?

Following a cancer diagnosis, dietary supplements are reportedly used by 20%-80% of individuals. Supplements are most commonly used by breast cancer survivors, followed by patients with prostate, colorectal, and lung cancers, which is not surprising since these are the most common types of cancer diagnosed in adults. Reasons cited for such use include improving quality of life, reducing symptoms related to treatment and/or the disease process, and recommendation from medical practitioners; family and friends may also be an influence. However, controversy surrounds the use of dietary supplements, particularly during treatment-specifically, whether supplements affect treatment efficacy is unknown. This article discusses the evidence related to common dietary supplements used to prevent cancer or a recurrence.

Dietary supplement use among cancer survivors of the NutriNet-Santé cohort study

Dietary supplements (DS) may influence cancer prognosis. Their use in cancer patients has been described in the United States, but data are largely lacking in Europe and notably in France. The present study's objectives were (1) to assess DS use and its sociodemographic, lifestyle, and dietary correlates in a large sample of French cancer survivors; (2) to evaluate the involvement of physicians in such DS use; and (3) to assess the extent of potentially harmful practices. Data were collected by self-administered web-based questionnaires among participants of the NutriNet-Santé cohort. Data on DS use was available for 1081 cancer survivors. DS users were compared to non-users with unconditional logistic regressions. DS use was reported by 62% of women and 29% of men. Vitamins D, B6, C and Mg were the most frequently consumed nutrients. 14% of cancer survivors initiated DS use after diagnosis. For 35% of the DS consumed, subjects did not inform their attending physician. DS use was associated with a healthier lifestyle (normal weight, never smoking and better diet) and substantially contributed to nutrient intake. 18% of DS users had potentially harmful DS use practices, such as the simultaneous use of vitamin E and anticoagulant/antiplatelet agents, the use of β-carotene and smoking or the use of phyto-oestrogens in hormone-dependent cancer patients. The present study suggests that DS use is widespread among cancer survivors, a large amount of that use is performed without any medical supervision and a substantial proportion of that use involves potentially harmful practices. Physicians should be encouraged to more routinely discuss DS use with their cancer patients.

High plasma folate is negatively associated with leukocyte telomere length in Framingham Offspring cohort

PURPOSE

Shortening of telomeres, the protective structures at the ends of eukaryotic chromosomes, is associated with age-related pathologies. Telomere length is influenced by DNA integrity and DNA and histone methylation. Folate plays a role in providing precursors for nucleotides and methyl groups for methylation reactions and has the potential to influence telomere length.

METHOD

We determined the association between leukocyte telomere length and long-term plasma folate status (mean of 4 years) in Framingham Offspring Study (n = 1,044, females = 52.1 %, mean age 59 years) using data from samples collected before and after folic acid fortification. Leukocyte telomere length was determined by Southern analysis and fasting plasma folate concentration using microbiological assay.

RESULTS

There was no significant positive association between long-term plasma folate and leukocyte telomere length among the Framingham Offspring Study participants perhaps due to their adequate folate status. While the leukocyte telomere length in the second quintile of plasma folate was longer than that in the first quintile, the difference was not statistically significant. The leukocyte telomere length of the individuals in the fifth quintile of plasma folate was shorter than that of those in the second quintile by 180 bp (P < 0.01). There was a linear decrease in leukocyte telomere length with higher plasma folate concentrations in the upper four quintiles of plasma folate (P for trend = 0.001). Multivitamin use was associated with shorter telomeres in this cohort (P = 0.015).

CONCLUSIONS

High plasma folate status possibly resulting from high folic acid intake may interfere with the role of folate in maintaining telomere integrity.