Background Following a vegetarian diet has become increasingly popular and some evidence suggests that being vegetarian may be associated with a lower risk of cancer overall. However, for specific cancer sites, the evidence is limited. Our aim was to assess the associations of vegetarian and non-vegetarian diets with risks of all cancer, colorectal cancer, postmenopausal breast cancer, and prostate cancer and to explore the role of potential mediators between these associations. Methods We conducted a prospective analysis of 472,377 UK Biobank participants who were free from cancer at recruitment. Participants were categorised into regular meat-eaters (n = 247,571), low meat-eaters (n = 205,385), fish-eaters (n = 10,696), and vegetarians (n = 8685) based on dietary questions completed at recruitment. Multivariable-adjusted Cox regressions were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for all cancer incidence and separate cancer sites across diet groups. Results After an average follow-up of 11.4 years, 54,961 incident cancers were identified, including 5882 colorectal, 7537 postmenopausal breast, and 9501 prostate cancers. Compared with regular meat-eaters, being a low meat-eater, fish-eater, or vegetarian were all associated with a lower risk of all cancer (HR: 0.98, 95% CI: 0.96–1.00; 0.90, 0.84–0.96; 0.86, 0.80–0.93, respectively). Being a low meat-eater was associated with a lower risk of colorectal cancer in comparison to regular meat-eaters (0.91, 0.86–0.96); however, there was heterogeneity in this association by sex (p = 0.007), with an inverse association across diet groups in men, but not in women. Vegetarian postmenopausal women had a lower risk of breast cancer (0.82, 0.68–0.99), which was attenuated and non-significant after adjusting for body mass index (BMI; 0.87, 0.72–1.05); in mediation analyses, BMI was found to possibly mediate the observed association. In men, being a fish-eater or a vegetarian was associated with a lower risk of prostate cancer (0.80, 0.65–0.99 and 0.69, 0.54–0.89, respectively). Conclusion The lower risk of colorectal cancer in low meat-eaters is consistent with previous evidence suggesting an adverse impact of meat intake. The lower risk of postmenopausal breast cancer in vegetarian women may be explained by their lower BMI. It is not clear whether the other differences observed for all cancers and for prostate cancer reflect any causal relationships or are due to other factors such as residual confounding or differences in cancer detection.

Background & aims: Circulating insulin-like growth factor-I (IGF-I) is associated with the risk of several cancers. Dietary protein intake, particularly dairy protein, may increase circulating IGF-I; however, associations with different protein sources, other macronutrients, and fibre are inconclusive. Aim: To investigate the associations between intake of protein, macronutrients and their sources, fibre, and alcohol with serum IGF-I concentrations. Methods: A total of 11,815 participants from UK Biobank who completed !4 24-h dietary assessments and had serum IGF-I concentrations measured at baseline were included. Multivariable linear regression was used to assess the crossesectional associations of macronutrient and fibre intake with circulating IGF-I concentrations. Results: Circulating IGF-I concentrations were positively associated with intake of total protein (per 2.5% higher energy intake: 0.56 nmol/L (95% confidence interval: 0.47, 0.66)), milk protein: 1.20 nmol/L (0.90, 1.51), and yogurt protein: 1.33 nmol/L (0.79, 1.86), but not with cheese protein: À0.07 nmol/L (À0.40, 0.25). IGF-I concentrations were also positively associated with intake of fibre (per 5 g/day higher intake: 0.46 nmol/L (0.35, 0.57)) and starch from wholegrains (Q5 vs. Q1: 1.08 nmol/L (0.77, 1.39)), and inversely associated with alcohol consumption (>40 g/day vs < 1 g/day: À1.36 nmol/L (À1.00, À1.71)). Conclusions: These results show differing associations with IGF-I concentrations depending on the source of dairy protein, with positive associations with milk and yogurt protein but no association with cheese protein. The positive association of fibre and starch from wholegrains with IGF-I warrants further investigation.

Complementary and alternative medicine (CAM) use is common among individuals with cancer, but many choose not to discuss CAM with healthcare providers (HCPs). Moreover, there is variability in the provision of evidence-informed decision making about CAM use. A clinical practice guideline was developed to standardize how oncology HCPs address CAM use as well as to inform how individuals with cancer can be supported in making evidence-informed decisions about CAM. An integrative review of the literature, from inception to December 31st, 2018, was conducted in MEDLINE, EMBASE, PsychINFO, CINAHL, and AMED databases. Eligible articles included oncology HCPs’ practice related to discussing, assessing, documenting, providing decision support, or offering information about CAM. Two authors independently searched the literature and selected articles were summarised. Recommendations for clinical practice were formulated from the appraised evidence and clinical experiences of the research team. An expert panel reviewed the guideline for usability and appropriateness and recommendations were finalised. The majority of the 30 studies eligible for inclusion were either observational or qualitative, with only three being reviews and three being experimental. From the literature, seven practice recommendations were formulated for oncology HCPs regarding how to address CAM use by individuals with cancer, including communicating, assessing, educating, decision-coaching, documenting, active monitoring, and adverse event reporting. It is imperative for safe and comprehensive care that oncology HCPs address CAM use as part of standard practice. This clinical practice guideline offers directions on how to support evidence-informed decision making about CAM among individuals with cancer.

Objective: Macronutrients may relate differently with serum lipids depending on their source, and understanding this relationship is important for cardiovascular disease prevention. We aimed to investigate the associations between macronutrients and macronutrients from different sources with serum lipids in UK Biobank. Approach and Results: Serum lipids were obtained from serum collected at baseline in 24 639 participants with diet assessed using ≥2 twenty-four–hour dietary assessments completed at baseline and during follow-up. Multivariable linear regressions were conducted to calculate geometric mean concentrations of serum lipids by quintiles of macronutrients. We modeled the association between isoenergetic substitution of 5% energy intake from saturated fatty acids (SFA) with other macronutrients and serum lipids. Free sugar intake was positively associated with triglycerides (0.15 mmol/L geometric mean difference between highest and lowest quintile of intake [95% CI, 0.12–0.17 mmol/L]), whereas nonfree sugar intake was inversely associated with triglycerides (−0.08 [−0.10 to −0.05]). SFA intake was positively associated with LDL-C (low-density lipoprotein cholesterol; 0.17 [0.13–0.20]), omega-3 fatty acid intake was inversely associated with triglycerides (−0.15 [−0.17 to −0.12]). Modeled substitution of SFA with polyunsaturated fatty acids was associated with lower total cholesterol, LDL-C, and triglycerides. Conclusions: The relationship between carbohydrates and triglycerides may depend on their quality, and reducing free sugar intake may be important in cardiovascular disease prevention. Consistent with previous studies, SFA intake is associated with LDL-C and substitution of SFA intake with polyunsaturated fatty acids intake may be associated with a more favorable serum lipid profile.

Background Recent studies have reported that the associations between dietary carbohydrates and cardiovascular disease (CVD) may depend on the quality, rather than the quantity, of carbohydrates consumed. This study aimed to assess the associations between types and sources of dietary carbohydrates and CVD incidence. A secondary aim was to examine the associations of carbohydrate intakes with triglycerides within lipoprotein subclasses. Methods A total of 110,497 UK Biobank participants with ≥ two (maximum five) 24-h dietary assessments who were free from CVD and diabetes at baseline were included. Multivariable-adjusted Cox regressions were used to estimate risks of incident total CVD (4188 cases), ischaemic heart disease (IHD; 3138) and stroke (1124) by carbohydrate intakes over a median follow-up time of 9.4 years, and the effect of modelled dietary substitutions. The associations of carbohydrate intakes with plasma triglycerides within lipoprotein subclasses as measured by nuclear magnetic resonance (NMR) spectroscopy were examined in 26,095 participants with baseline NMR spectroscopy measurements. Results Total carbohydrate intake was not associated with CVD outcomes. Free sugar intake was positively associated with total CVD (HR; 95% CI per 5% of energy, 1.07;1.03–1.10), IHD (1.06;1.02–1.10), and stroke (1.10;1.04–1.17). Fibre intake was inversely associated with total CVD (HR; 95% CI per 5 g/d, 0.96;0.93–0.99). Modelled isoenergetic substitution of 5% of energy from refined grain starch with wholegrain starch was inversely associated with total CVD (0.94;0.91–0.98) and IHD (0.94;0.90–0.98), and substitution of free sugars with non-free sugars was inversely associated with total CVD (0.95;0.92–0.98) and stroke (0.91;0.86–0.97). Free sugar intake was positively associated with triglycerides within all lipoproteins. Conclusions Higher free sugar intake was associated with higher CVD incidence and higher triglyceride concentrations within all lipoproteins. Higher fibre intake and replacement of refined grain starch and free sugars with wholegrain starch and non-free sugars, respectively, may be protective for incident CVD.