Genetic risk of depression is different in subgroups of dietary ratio of tryptophan to large neutral amino acids.

Manipulation of intake of serotonin precursor tryptophan has been exploited to rapidly induce and alleviate depression symptoms. While studies show that this latter effect is dependent on genetic vulnerability to depression, the effect of habitual tryptophan intake in the context of predisposing genetic factors has not been explored. Our aim was to investigate the effect of habitual tryptophan intake on mood symptoms and to determine the effect of risk variants on depression in those with high and low tryptophan intake in the whole genome and specifically in serotonin and kynurenine pathways. 63,277 individuals in the UK Biobank with data on depressive symptoms and tryptophan intake were included. We compared two subpopulations defined by their habitual diet of a low versus a high ratio of tryptophan to other large amino acids (TLR). A modest protective effect of high dietary TLR against depression was found. NPBWR1 among serotonin genes and POLI in kynurenine pathway genes were significantly associated with depression in the low but not in the high TLR group. Pathway-level analyses identified significant associations for both serotonin and kynurenine pathways only in the low TLR group. In addition, significant association was found in the low TLR group between depressive symptoms and biological process related to adult neurogenesis. Our findings demonstrate a markedly distinct genetic risk profile for depression in groups with low and high dietary TLR, with association with serotonin and kynurenine pathway variants only in case of habitual food intake leading to low TLR. Our results confirm the relevance of the serotonin hypothesis in understanding the neurobiological background of depression and highlight the importance of understanding its differential role in the context of environmental variables such as complexity of diet in influencing mental health, pointing towards emerging possibilities of personalised prevention and intervention in mood disorders in those who are genetically vulnerable.

Measurement of Muscle Mass and Sarcopenia Using Anthropometry, Bioelectrical Impedance, and Computed Tomography in Surgical Patients with Colorectal Malignancy: Comparison of Agreement Between Methods.

Background: Low skeletal muscle index (SMI) and sarcopenia adversely affect clinical outcomes in oncology patients. Study aims were to assess the agreement of bioelectrical impedance analysis (BIA), mid-arm muscle circumference (MAMC), and computed tomography (CT) at the third lumbar vertebra (L3), for the measurement of muscle mass and identification of sarcopenia, in patients with colorectal cancer (CRC).Method: A comparison study of low SMI and sarcopenia determined by BIA and MAMC, compared to CT. Sensitivity, specificity and area under the curve (AUC) were calculated.Results: CT scans were obtained for 100 participants. Low SMI was identified in 29%, 57%, and 20% of participants using CT at L3, BIA, and MAMC, respectively. For low muscle mass BIA showed 60% of participants were correctly classified (AUC 0.619, sensitivity 80%, specificity 52%, kappa 0.241, P = 0.009) and for MAMC, 73% of participants were correctly classified (AUC 0.625, sensitivity 38%, specificity 88%, kappa 0.286, P = 0.005). There were 14%, 31%, and 10% of participants identified as having sarcopenia from CT, BIA, and MAMC, respectively.Conclusions: Both BIA and MAMC show a poor level of agreement for measuring muscle mass compared to CT scans using L3 in patients with CRC.

Dietary interventions for adult cancer survivors.

BACKGROUND: International dietary recommendations include guidance on healthy eating and weight management for people who have survived cancer; however dietary interventions are not provided routinely for people living beyond cancer. OBJECTIVES: To assess the effects of dietary interventions for adult cancer survivors on morbidity and mortality, changes in dietary behaviour, body composition, health-related quality of life, and clinical measurements. SEARCH METHODS: We ran searches on 18 September 2019 and searched the Cochrane Central Register of Controlled trials (CENTRAL), in the Cochrane Library; MEDLINE via Ovid; Embase via Ovid; the Allied and Complementary Medicine Database (AMED); the Cumulative Index to Nursing and Allied Health Literature (CINAHL); and the Database of Abstracts of Reviews of Effects (DARE). We searched other resources including reference lists of retrieved articles, other reviews on the topic, the International Trials Registry for ongoing trials, metaRegister, Physicians Data Query, and appropriate websites for ongoing trials. We searched conference abstracts and WorldCat for dissertations. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that recruited people following a cancer diagnosis. The intervention was any dietary advice provided by any method including group sessions, telephone instruction, written materials, or a web-based approach. We included comparisons that could be usual care or written information, and outcomes measured included overall survival, morbidities, secondary malignancies, dietary changes, anthropometry, quality of life (QoL), and biochemistry. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. Two people independently assessed titles and full-text articles, extracted data, and assessed risk of bias. For analysis, we used a random-effects statistical model for all meta-analyses, and the GRADE approach to rate the certainty of evidence, considering limitations, indirectness, inconsistencies, imprecision, and bias. MAIN RESULTS: We included 25 RCTs involving 7259 participants including 977 (13.5%) men and 6282 (86.5%) women. Mean age reported ranged from 52.6 to 71 years, and range of age of included participants was 23 to 85 years. The trials reported 27 comparisons and included participants who had survived breast cancer (17 trials), colorectal cancer (2 trials), gynaecological cancer (1 trial), and cancer at mixed sites (5 trials). For overall survival, dietary intervention and control groups showed little or no difference in risk of mortality (hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.77 to 1.23; 1 study; 3107 participants; low-certainty evidence). For secondary malignancies, dietary interventions versus control trials reported little or no difference (risk ratio (RR) 0.99, 95% CI 0.84 to 1.15; 1 study; 3107 participants; low-certainty evidence). Co-morbidities were not measured in any included trials. Subsequent outcomes reported after 12 months found that dietary interventions versus control probably make little or no difference in energy intake at 12 months (mean difference (MD) -59.13 kcal, 95% CI -159.05 to 37.79; 5 studies; 3283 participants; moderate-certainty evidence). Dietary interventions versus control probably led to slight increases in fruit and vegetable servings (MD 0.41 servings, 95% CI 0.10 to 0.71; 5 studies; 834 participants; moderate-certainty evidence); mixed results for fibre intake overall (MD 5.12 g, 95% CI 0.66 to 10.9; 2 studies; 3127 participants; very low-certainty evidence); and likely improvement in Diet Quality Index (MD 3.46, 95% CI 1.54 to 5.38; 747 participants; moderate-certainty evidence). For anthropometry, dietary intervention versus control probably led to a slightly decreased body mass index (BMI) (MD -0.79 kg/m², 95% CI -1.50 to -0.07; 4 studies; 777 participants; moderate-certainty evidence). Dietary interventions versus control probably had little or no effect on waist-to-hip ratio (MD -0.01, 95% CI -0.04 to 0.02; 2 studies; 106 participants; low-certainty evidence). For QoL, there were mixed results; several different quality assessment tools were used and evidence was of low to very low-certainty. No adverse events were reported in any of the included studies. AUTHORS' CONCLUSIONS: Evidence demonstrated little effects of dietary interventions on overall mortality and secondary cancers. For comorbidities, no evidence was identified. For nutritional outcomes, there was probably little or no effect on energy intake, although probably a slight increase in fruit and vegetable intake and Diet Quality Index. Results were mixed for fibre. For anthropometry, there was probably a slight decrease in body mass index (BMI) but probably little or no effect on waist-to-hip ratio. For QoL, results were highly varied. Additional high-quality research is needed to examine the effects of dietary interventions for different cancer sites, and to evaluate important outcomes including comorbidities and body composition. Evidence on new technologies used to deliver dietary interventions was limited.

Needs-based quality of life in adults dependent on home parenteral nutrition.

BACKGROUND & AIMS: Home parenteral nutrition (HPN) provides life sustaining treatment for people with chronic intestinal failure. Individuals may require HPN for months or years and are dependent on regular intravenous infusions, usually 12-14 h overnight between 1 and 7 days each week. This regime can have adverse impact on the life of people dependent on the treatment. The aim of this study was to establish mean values for the Parenteral Nutrition Impact Questionnaire (PNIQ) and to determine the effect of disease, frequency of infusions per week and patient characteristics on quality of life of patients fed HPN. METHOD: The PNIQ was distributed to patients across nine UK HPN clinics. Data were analysed using linear regression, with PNIQ score as the dependent variable and potential confounders as independent variables. Unadjusted and adjusted models are presented. Higher PNIQ scores reflect poorer quality of life. RESULTS: Completed questionnaires were received from 466 people dependent on HPN. Mean PNIQ score was 11.04 (SD 5.79). A higher PNIQ score (effect size 0.52, CI 0.184 to 0.853) was recorded in those dependent on a higher frequency of HPN infusions per week. Respondents with cancer had a similar mean PNIQ score to those with inflammatory bowel disease (mean 10.82, SD 6.00 versus 11.04, SD 5.91). Those with surgical complications reported a poorer QoL (effect size 3.03, CI 0.642 to 5.418) and those with severe gastro-intestinal dysmotility reported a better QoL (effect size -3.03, CI -5.593 to -0.468), compared to other disease states. CONCLUSIONS: This large cohort study of quality of life in chronic intestinal failure demonstrates that HPN impacts individuals differently depending on their underlying disease. Furthermore, since the number of HPN infusions required per week is inversely related to an individual's needs-based quality of life, therapies that reduce PN burden should lead to an improvement in QoL.