Dietary sugar restriction reduces hepatic de novo lipogenesis in adolescent boys with fatty liver disease.

BACKGROUNDHepatic de novo lipogenesis (DNL) is elevated in nonalcoholic fatty liver disease (NAFLD). Improvements in hepatic fat by dietary sugar reduction may be mediated by reduced DNL, but data are limited, especially in children. We examined the effects of 8 weeks of dietary sugar restriction on hepatic DNL in adolescents with NAFLD and correlations between DNL and other metabolic outcomes.METHODSAdolescent boys with NAFLD (n = 29) participated in an 8-week, randomized controlled trial comparing a diet low in free sugars versus their usual diet. Hepatic DNL was measured as percentage contribution to plasma triglyceride palmitate using a 7-day metabolic labeling protocol with heavy water. Hepatic fat was measured by magnetic resonance imaging-proton density fat fraction.RESULTSHepatic DNL was significantly decreased in the treatment group (from 34.6% to 24.1%) versus the control group (33.9% to 34.6%) (adjusted week 8 mean difference: -10.6% [95% CI: -19.1%, -2.0%]), which was paralleled by greater decreases in hepatic fat (25.5% to 17.9% vs. 19.5% to 18.8%) and fasting insulin (44.3 to 34.7 vs. 35.5 to 37.0 µIU/mL). Percentage change in DNL during the intervention correlated significantly with changes in free-sugar intake (r = 0.48, P = 0.011), insulin (r = 0.40, P = 0.047), and alanine aminotransferase (ALT) (r = 0.39, P = 0.049), but not hepatic fat (r = 0.13, P = 0.532).CONCLUSIONOur results suggest that dietary sugar restriction reduces hepatic DNL and fasting insulin, in addition to reductions in hepatic fat and ALT, among adolescents with NAFLD. These results are consistent with the hypothesis that hepatic DNL is a critical metabolic abnormality linking dietary sugar and NAFLD.TRIAL REGISTRYClinicalTrials.gov NCT02513121.FUNDINGThe Nutrition Science Initiative (made possible by gifts from the Laura and John Arnold Foundation, Ambrose Monell Foundation, and individual donors), the UCSD Altman Clinical and Translational Research Institute, the NIH, Children's Healthcare of Atlanta and Emory University's Children's Clinical and Translational Discovery Core, Children's Healthcare of Atlanta and Emory University Pediatric Biostatistical Core, the Georgia Clinical and Translational Science Alliance, and the NIH National Institute of Diabetes, Digestive, and Kidney Disease.

Adoption of a plant-based diet by patients with recurrent prostate cancer.

The Western diet has been associated with prostate cancer incidence as well as risk of disease progression after treatment. Conversely, plant-based diets have been associated with decreased risks. A pilot clinical trial of a 6-month dietary change and stress reduction intervention for asymptomatic, hormonally untreated patients experiencing a consistently rising PSA level, the first sign of recurrence of prostate cancer after surgery or radiation therapy, was conducted to investigate the level of intake of plant-based foods and the relationship between intake and the change in the rate of PSA rise. A pre-post design was employed in which each patient served as his own control. In this multifaceted intervention, patients and their spouses were encouraged to adopt and maintain a plant-based diet. The prestudy rate of PSA rise (from the time of posttreatment recurrence to the start of the study) was ascertained by review of patients' medical records. Dietary assessments were performed and prostate-specific antigen (PSA) levels ascertained at baseline, prior to the start of intervention, and at 3 and 6 months. Changes in numbers of servings of plant-based food groups were calculated and compared with rates of PSA rise over the corresponding time intervals. Median intake of whole grains increased from 1.7 servings/d at baseline to 6.9 and 5.0 servings/d at 3 and 6 months, respectively. Median intake of vegetables increased from 2.8 servings/d at baseline to 5.0 and 4.8 servings/d at 3 and 6 months, respectively. The rate of PSA rise decreased when comparing the prestudy period (0.059) to the period from 0 to 3 months (-0.002, P < .01) and increased slightly, though not significantly, when comparing the period from 0 to 3 months to the period from 3 to 6 months (0.029, P = .4316). These results provide preliminary evidence that adoption of a plant-based diet is possible to achieve as well as to maintain for several months in patients with recurrent prostate cancer. Changes in the rate of rise in PSA, an indicator of disease progression, were in the opposite direction as changes in the intake of plant-based food groups, raising the provocative possibility that PSA may have inversely tracked intake of these foods and suggesting that adoption of a plant-based diet may have therapeutic potential in the management of this condition.