Dietary energy restriction reduces high-fat diet-enhanced metastasis of Lewis lung carcinoma in mice.
Oncotarget. 2016 Oct 4 ;7(40):65669-65675. PMID: 27582541
Sneha Sundaram, Lin Yan
The objective of this study was to determine whether a reduction in energy intake ameliorated the high-fat diet-enhanced spontaneous metastasis of Lewis lung carcinoma in mice. Male C57BL/6 mice were fed the AIN93G diet, a high-fat diet or a high-fat diet with a 5% restriction of the intake. Energy restriction reduced body adiposity and body weight, but maintained growth similar to mice fed the AIN93G diet. The high-fat diet significantly increased the number and size (cross-sectional area and volume) of metastases formed in lungs. Restricted feeding reduced the number of metastases by 23%, metastatic cross-sectional area by 32% and volume by 45% compared to the high-fat diet. The high-fat diet elevated plasma concentrations of proinflammatory cytokines (monocyte chemotactic protein-1, plasminogen activator inhibitor-1, leptin), angiogenic factors (vascular endothelial growth factor, tissue inhibitor of metalloproteinase-1) and insulin. Restricted feeding significantly reduced the high-fat diet-induced elevations in plasma concentrations of proinflammatory cytokines, angiogenic factors and insulin. These results demonstrated that a reduction in diet intake by 5% reduced high-fat diet-enhanced metastasis, which may be associated with the mitigation of adiposity and down-regulation of cancer-promoting proinflammatory cytokines and angiogenic factors.
Article Published Date : Oct 03, 2016
Effect of diet and exercise intervention on the growth of prostate epithelial cells.
1: Prostate Cancer Prostatic Dis. 2008;11(4):362-6. Epub 2008 Feb 19. PMID: 18283296
R J Barnard, N Kobayashi, W J Aronson
Epidemiological studies suggest a positive association between nutrient intake, hyperinsulinemia and risk of Benign prostatic hyperplasis (BPH). This study tests the hypothesis that a low-fat, high-fiber diet and daily exercise would lower serum insulin and reduce the growth of serum-stimulated primary prostate epithelial cells in culture. Serum samples were obtained from eight overweight men before and after the Pritikin residential, 2-week diet and exercise intervention and from seven men who were long-term followers of the low-fat, high-fiber diet and regular exercise lifestyle. The serum was used to stimulate primary prostate epithelial cells in culture. Growth was measured after 48 and 96 h and apoptosis after 96 h. At 48 h there was no significant difference in growth within the Pre, 2-week or Long-Term groups. At 96 h growth was significantly reduced in the 2-week (13%) and in the Long-Term (14%) groups compared to the Pre data. At 96 h, apoptosis was not significantly different among the three groups. Fasting insulin was reduced by 30% in the 2-week group and by 52% in the Long-Term group compared to the Pre data. Testosterone was unchanged in the 2-week group. The results of this study indicate that a low-fat, high-fiber diet and daily exercise lowers insulin and reduces growth of prostate primary epithelial cells and suggests that lifestyle may be an important factor in the development or progression of BPH. Future prospective trials should address the effects of this lifestyle modification on BPH symptomatology and progression.
Article Published Date : Jan 01, 2008
Dietary fat and meat intake and idiopathic pulmonary fibrosis: a case-control study in Japan.
Int J Tuberc Lung Dis. 2006 Mar;10(3):333-9. PMID: 16562716
Y Miyake, S Sasaki, T Yokoyama, K Chida, A Azuma, T Suda, S Kudoh, N Sakamoto, K Okamoto, G Kobashi, M Washio, Y Inaba, H Tanaka,
SETTING: There is sparse epidemiologic information regarding the role of dietary factors in the development of idiopathic pulmonary fibrosis (IPF). OBJECTIVE: To examine the relationship between specific types of fatty acids and selected foods high in fat and IPF in Japan. DESIGN: Included were 104 cases aged>or = 40 years who had been diagnosed in the last 2 years in accordance with the most recent criteria. Controls aged>or = 40 years consisted of 56 hospitalised patients diagnosed as having acute bacterial pneumonia and four out-patients with common cold. RESULTS: Intake of saturated fatty acids, mono-unsaturated fatty acids, n-6 polyunsaturated fatty acids and meat was independently associated with an increased risk of IPF. Specifically, the multivariate OR for comparison of the highest with the lowest quartile of intake of saturated fatty acids was 6.26 (95%CI 1.79-24.96, P for trend = 0.01) and for meat it was 7.19 (95%CI 2.15-27.07, P for trend = 0.02). Intake of cholesterol, n-3 polyunsaturated fatty acids, fish, eggs and dairy products was not related to the risk. CONCLUSION: These findings suggest that consumption of saturated fatty acids and meat may increase the risk of IPF.
Article Published Date : Mar 01, 2006
A low-fat diet and/or strenuous exercise alters the IGF axis in vivo and reduces prostate tumor cell growth in vitro.
Prostate. 2003 Aug 1;56(3):201-6. PMID: 12772189
R James Barnard, Tung H Ngo, Pak-Shan Leung, William J Aronson, Lawrence A Golding
BACKGROUND: Prostate cancer is the most common solid-tumor cancer in US males but is rare in Asian males. When Asian men adopt the US lifestyle, clinical prostate cancer increases greatly. Epidemiological data from men in the US indicate that regular activity may reduce the risk for prostate cancer. METHODS: Serum was obtained from three groups of similar-aged men, Control, Diet and Exercise, and Exercise alone were used to stimulate LNCaP cells in culture. Growth and apoptosis of tumor cells were measured. Serum samples were also used to measure insulin, IGF-1, IGFBP-1. RESULTS: The Diet and Exercise and the Exercise alone groups had lower serum insulin and IGF-1 but higher IGFBP-1 compared to Controls. LNCaP cell growth was reduced in both groups compared to Control and there was a major increase in apoptosis of tumor cells. CONCLUSIONS: A low-fat diet and/or intensive exercise results in change in serum hormones and growth factors in vivo that can reduce growth and induce apoptosis of LNCaP prostate tumor cells in vitro. Copyright 2003 Wiley-Liss, Inc.
Article Published Date : Aug 01, 2003
Effects of a very low fat, high fiber diet on serum hormones and menstrual function. Implications for breast cancer prevention.
Cancer. 1995 Dec 15;76(12):2491-6. PMID: 8625075
D Bagga, J M Ashley, S P Geffrey, H J Wang, R J Barnard, S Korenman, D Heber
BACKGROUND. Low fat, high fiber dietary interventions that decrease blood estrogen levels may reduce breast cancer risk. Asian women consuming their traditional low fat, high fiber diets have lower blood estrogen levels before and after menopause and lower rates of breast cancer compared with Western women. The current controlled feeding study of premenopausal women was designed to determine the effects of a very low fat (10% of calories) and high fiber (35-45 g/day) diet on blood estrogen levels and menstrual function. METHOD. Twelve healthy premenopausal women with regular ovulatory cycles were followed for 3 months. Subjects consumed a diet providing 30% of their energy from fat and 15-25 g of dietary fiber per day for 1 month, and they consumed a very low fat, high fiber and libitum diet providing 10% of their energy from fat and 25-35 g of dietary fiber per day for 2 months. RESULTS. At the end of the second month of the very low fat, high fiber diet, there was a significant reduction in serum estrone and estradiol levels during the early follicular and late luteal phases. There were no significant changes observed in serum estrone sulfate, sex hormone binding globulin, or progesterone. Despite a significant decrease in serum estradiol and estrone levels after 2 months of a very low fat, high fiber diet, there was no interference with ovulation or the magnitude of the mid-cycle leuteinizing hormone surge. Small changes in menstrual cycle length of up to 3 days were not ruled out due to the small sample size of the study. CONCLUSIONS. A very low fat, high fiber diet in healthy premenopausal women can reduce estradiol and estrone levels without affecting ovulation, thereby providing a rationale for the prevention of breast cancer through a very low fat, high fiber diet.
Article Published Date : Dec 15, 1995
Effect of a low-fat diet on the incidence of actinic keratosis.
N Engl J Med. 1994 May 5;330(18):1272-5. PMID: 8145782
H S Black, J A Herd, L H Goldberg, J E Wolf, J I Thornby, T Rosen, S Bruce, J A Tschen, J P Foreyt, L W Scott
BACKGROUND. Actinic keratoses are premalignant lesions and are a sensitive and important manifestation of sun-induced skin damage. Studies in animals have shown that dietary fat influences the incidence of sun-induced skin cancer, but the effect of diet on the incidence of actinic keratosis in humans is not known. METHODS. We randomly assigned 76 patients with nonmelanoma skin cancer either to continue their usual diet (control group) or to eat a diet with 20 percent of total caloric intake as fat (dietary-intervention group). For 24 months, the patients were examined for the presence of new actinic keratoses by physicians unaware of their assigned diets. RESULTS. At base line, the mean (+/- SD) percentage of caloric intake as fat was 40 +/- 4 percent in the control group and 39 +/- 3 percent in the dietary-intervention group. After 4 months of dietary therapy the percentage of calories as fat had decreased to 21 percent in the dietary-intervention group, and it remained below this level throughout the 24-month study period. The percentage of calories as fat in the control group did not fall below 36 percent at any time. The cumulative number of new actinic keratoses per patient from months 4 through 24 was 10 +/- 13 in the control group and 3 +/- 7 in the dietary-intervention group (P = 0.001). CONCLUSIONS. In patients with a history of nonmelanoma skin cancer, a low-fat diet reduces the incidence of actinic keratosis.
Article Published Date : May 05, 1994
Resting metabolic rate of obese patients under very low calorie ketogenic diet.
Nutr Metab (Lond). 2018;15:18
Authors: Gomez-Arbelaez D, Crujeiras AB, Castro AI, Martinez-Olmos MA, Canton A, Ordoñez-Mayan L, Sajoux I, Galban C, Bellido D, Casanueva FF
Background: The resting metabolic rate (RMR) decrease, observed after an obesity reduction therapy is a determinant of a short-time weight regain. Thus, the objective of this study was to evaluate changes in RMR, and the associated hormonal alterations in obese patients with a very low-calorie ketogenic (VLCK)-diet induced severe body weight (BW) loss.
Method: From 20 obese patients who lost 20.2 kg of BW after a 4-months VLCK-diet, blood samples and body composition analysis, determined by DXA and MF-Bioimpedance, and RMR by indirect calorimetry, were obtained on four subsequent visits: visit C-1, basal, initial fat mass (FM) and free fat mass (FFM); visit C-2, - 7.2 kg in FM, - 4.3 kg in FFM, maximal ketosis; visit C-3, - 14.4 kg FM, - 4.5 kg FFM, low ketosis; visit C-4, - 16.5 kg FM, - 3.8 kg FFM, no ketosis. Each subject acted as his own control.
Results: Despite the large BW reduction, measured RMR varied from basal visit C-1 to visit C-2, - 1.0%; visit C-3, - 2.4% and visit C-4, - 8.0%, without statistical significance. No metabolic adaptation was observed. The absent reduction in RMR was not due to increased sympathetic tone, as thyroid hormones, catecholamines, and leptin were reduced at any visit from baseline. Under regression analysis FFM, adjusted by levels of ketonic bodies, was the only predictor of the RMR changes (R2 = 0.36; p < 0.001).
Conclusion: The rapid and sustained weight and FM loss induced by VLCK-diet in obese subjects did not induce the expected reduction in RMR, probably due to the preservation of lean mass.
Trial registration: This is a follow up study on a published clinical trial.
PMID: 29467800 [PubMed]
Effect of tempol on peripheral neuropathy in diet-induced obese and high-fat fed/low-dose streptozotocin-treated C57Bl6/J mice.
Free Radic Res. 2017 Apr;51(4):360-367
Authors: Obrosov A, Shevalye H, Coppey LJ, Yorek MA
In this study, we sought to determine the efficacy of tempol on multiple neuropathic endpoints in a diet-induced obese mouse, a model of pre-diabetes, and a high-fat fed low-dose streptozotocin treated mouse, a model of type 2 diabetes. Tempol (4-hydroxy-2,2,6,6-tetramethylpiperdine -1-oxyl) is a low molecular weight, water soluble, membrane permeable, and metal-independent superoxide dismutase mimetic that has been widely used in cellular studies for the removal of intracellular and extracellular superoxide. This in vivo study was designed to be an early intervention. Fourteen weeks post-high-fat diet (6 weeks post-hyperglycemia) control, obese, and diabetic mice were divided into no treatment and treatment groups. The treated mice received tempol by gavage (150 mg/kg in water), while the untreated mice received vehicle. The diet-induced obese and the diabetic mice were maintained on the high-fat diet for the duration of the study, while the control group was maintained on the standard diet. Obesity and diabetes caused slowing of motor and sensory nerve conduction, reduction in intraepidermal nerve fiber density, thermal hypoalgesia, and mechanical allodynia. Treatment with tempol partially or completely protected obese and diabetic mice from these deficits. These studies suggest that tempol or other effective scavengers of reactive oxygen species may be a viable option for treating neural complications associated with obesity or type 2 diabetes.
PMID: 28376643 [PubMed - indexed for MEDLINE]
An informative approach on differential abundance analysis for time-course metagenomic sequencing data.
Bioinformatics. 2017 May 01;33(9):1286-1292
Authors: Luo D, Ziebell S, An L
Motivation: The advent of high-throughput next generation sequencing technology has greatly promoted the field of metagenomics where previously unattainable information about microbial communities can be discovered. Detecting differentially abundant features (e.g. species or genes) plays a critical role in revealing the contributors (i.e. pathogens) to the biological or medical status of microbial samples. However, currently available statistical methods lack power in detecting differentially abundant features contrasting different biological or medical conditions, in particular, for time series metagenomic sequencing data. We have proposed a novel procedure, metaDprof, which is built upon a spline-based method assuming heterogeneous error, to meet the challenges of detecting differentially abundant features from metagenomic samples by comparing different biological/medical conditions across time. It contains two stages: (i) global detection on features and (ii) time interval detection for significant features. The detection procedures in both stages are based on sound statistical support.
Results: Compared with existing methods the new method metaDprof shows the best performance in comprehensive simulation studies. Not only can it accurately detect features relating to the biological condition or disease status of samples but it also can accurately detect the starting and ending time points when the differences arise. The proposed method is also applied to a real metagenomic dataset and the results provide an interesting angle to understand the relationship between the microbiota in mouse gut and diet type.
Availability and Implementation: R code and an example dataset are available at https://cals.arizona.edu/∼anling/sbg/software.htm.
Supplementary information: Supplementary data are available at Bioinformatics online.
PMID: 28057680 [PubMed - indexed for MEDLINE]