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Total and Subtypes of Dietary Fat Intake and Its Association with Components of the Metabolic Syndrome in a Mediterranean Population at High Cardiovascular Risk.
Julibert, A, Bibiloni, MDM, Bouzas, C, Martínez-González, MÁ, Salas-Salvadó, J, Corella, D, Zomeño, MD, Romaguera, D, Vioque, J, Alonso-Gómez, ÁM, et al
Nutrients. 2019;11(7)
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Obesity, Metabolic Syndrome (MetS) and Cardiovascular Disease (CVD) are becoming a global epidemic and the role of dietary fats is still unclear. The PREDIMED trial is a large study of 6560 Mediterranean men and women, aged 55–75 years old, with overweight/obesity and MetS in which they have tracked all types of dietary fat consumed over a 6-year period to assess the risk factors for CVD. Quality of fat is thought to play an important role in MetS. This study used food questionnaires to measure intake of the following fats: total fat, monounsaturated fatty acids: MUFA, polyunsaturated fatty acids: PUFA, saturated fatty acids: SFA, trans-fatty acids: trans-FA, linoleic acid, a-linolenic acid, and w-3 FA). They were able to divide the participants into groups ranging from highest to lowest fat intake and assess the types of foods and fats being consumed. They found that the group with the highest fat intakes ate less carbohydrates, protein and fibre and had a higher risk of hyperglycaemia (high blood glucose levels). The total fats consumed in this group also included high levels of harmful trans-fatty acids so the researchers concluded that the risk is influenced by the combination of nutrients of the food consumed. They also found that participants who consumed high levels of linoleic acid had significantly higher healthy HDL cholesterol levels and those who consumed high levels of saturated fatty acids and omega 3 had significantly less risk of high triglycerides (another cholesterol marker). Overall they recommend further studies into types of dietary fat to help reduce MetS in the population.
Abstract
Background: The effect of dietary fat intake on the metabolic syndrome (MetS) and in turn on cardiovascular disease (CVD) remains unclear in individuals at high CVD risk. Objective: To assess the association between fat intake and MetS components in an adult Mediterranean population at high CVD risk. Design: Baseline assessment of nutritional adequacy in participants (n = 6560, men and women, 55-75 years old, with overweight/obesity and MetS) in the PREvención con DIeta MEDiterránea (PREDIMED)-Plus randomized trial. Methods: Assessment of fat intake (total fat, monounsatured fatty acids: MUFA, polyunsaturated fatty acids: PUFA, saturated fatty acids: SFA, trans-fatty acids: trans-FA, linoleic acid, α-linolenic acid, and ω-3 FA) using a validated food frequency questionnaire, and diet quality using 17-item Mediterranean dietary questionnaire and fat quality index (FQI). Results: Participants in the highest quintile of total dietary fat intake showed lower intake of energy, carbohydrates, protein and fiber, but higher intake of PUFA, MUFA, SFA, TFA, LA, ALA and ω-3 FA. Differences in MetS components were found according to fat intake. Odds (5th vs. 1st quintile): hyperglycemia: 1.3-1.6 times higher for total fat, MUFA, SFA and ω-3 FA intake; low high-density lipoprotein cholesterol (HDL-c): 1.2 higher for LA; hypertriglyceridemia: 0.7 lower for SFA and ω-3 FA intake. Conclusions: Dietary fats played different role on MetS components of high CVD risk patients. Dietary fat intake was associated with higher risk of hyperglycemia.
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Effect of Fish Oil Supplementation on Hepatic and Visceral Fat in Overweight Men: A Randomized Controlled Trial.
Parker, HM, Cohn, JS, O'Connor, HT, Garg, ML, Caterson, ID, George, J, Johnson, NA
Nutrients. 2019;11(2)
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Being overweight increases the risk of the development of metabolic conditions such as non-alcoholic fatty liver disease (NAFLD). Omega-3 polyunsaturated fatty acid (PUFA) supplementation is recommended for prevention of chronic disease, and is thought to reduce liver fat, but there have been few randomised controlled trials that accurately measure liver fat. The aim of this double-blind randomised controlled trial was to assess the effect of 12 weeks of supplementation with omega-3 PUFA from fish oil on liver fat, liver tests, and body composition. Fifty healthy overweight men were given either fish oil (1,728 mg marine triglycerides, of which 588 mg EPA and 412 mg DHA, combined with 200 mg antioxidant, coenzyme Q10) or placebo (capsules containing 2g olive oil) daily for 12 weeks. Participants were assessed at the beginning of the study, and following 6 and 12 weeks of supplementation. At the start of the study, 16 (32%) participants met the criteria for NAFLD (>5.5% liver fat). There were no significant changes in liver fat, liver function or body composition in either of the groups over 12 weeks. When the researchers looked at the results for those participants with NAFLD at the start of the study, there were no significant changes here either. The authors concluded that omega-3 PUFA did not appear to be an effective agent for reducing liver fat in overweight men. The factors determining the health benefits of omega-3 PUFA supplementation on an individual level need to be clarified.
Abstract
Being overweight increases the risk of the development of metabolic conditions such as non-alcoholic fatty liver disease (NAFLD), which is itself an independent predictor of cardiovascular disease. Omega-3 polyunsaturated fatty acid (PUFA) supplementation is recommended for prevention of chronic disease, and is thought to reduce raised liver fat, yet there have been few randomized controlled trials with accurate measurement of liver fat. We assessed the effect of 12 weeks of supplementation with omega-3 PUFA from fish oil versus placebo on quantified liver fat, liver tests, and body composition including visceral adipose tissue (VAT) in a double-blind randomized controlled trial. Fifty apparently healthy overweight men (BMI 25.0⁻29.9 kg/m²; waist > 94 cm) were randomly allocated to consume fish oil (total daily dose: 1728 mg marine triglycerides, of which 588 mg EPA and 412 mg DHA, combined with 200 mg antioxidant, coenzyme Q10) or placebo (olive oil capsules) daily for 12 weeks. Liver fat was assessed using proton magnetic resonance spectroscopy. All outcomes were assessed at baseline and following 6 and 12 weeks of supplementation. Baseline liver fat was 4.6 ± 0.5% (range: 0.6 to 18.2%); 16 (32%) participants met the criteria for NAFLD (>5.5% liver fat). Repeated measures ANOVA revealed no significant time or group × time effect for fish oil versus placebo for liver fat, liver enzymes, anthropometry, or body composition including VAT (p > 0.05 for all), with similar finding for sub-analysis of participants with NAFLD. Omega-3 PUFA did not appear to be an effective agent for reducing liver fat in overweight men. The factors determining the health benefits of omega-3 PUFA supplementation on an individual level need to be clarified.
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Impact of Consuming Extra-Virgin Olive Oil or Nuts within a Mediterranean Diet on DNA Methylation in Peripheral White Blood Cells within the PREDIMED-Navarra Randomized Controlled Trial: A Role for Dietary Lipids.
Arpón, A, Milagro, FI, Razquin, C, Corella, D, Estruch, R, Fitó, M, Marti, A, Martínez-González, MA, Ros, E, Salas-Salvadó, J, et al
Nutrients. 2017;10(1)
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Our genes are not fixed. They interact constantly with the environment through dietary and lifestyle factors, which affect whether genes are expressed or not. This is often referred to as epigenetic modulation. DNA methylation is an epigenetic mechanism that adds a methyl group to DNA, thereby modifying the function of the genes and affecting gene expression. Epigenetic alterations have been associated with conditions, such as obesity, type 2 diabetes, cardiovascular disease and immunological conditions. It is suggested that epigenetic marks are reversible and can be modulated by nutrient status and certain dietary components. The aim of the current study was to explore methylation changes in genes of peripheral white blood cells in a subset of participants from the PREDIMED-Navarra randomised controlled trial. 36 participants were allocated to three groups, all consuming a Mediterranean diet. In the first group, the diet was supplemented with extra virgin olive oil (EVOO), in the second group, with mixed nuts, and the third group, which served as the control group, were advised to consume a low-fat diet. Changes in DNA methylation were analysed from blood samples at baseline and at five-year follow-up. The authors observed methylation changes in several genes, related to metabolism, glucose and energy regulation, diabetes and inflammation, after the consumption of EVOO and nuts. They concluded that the beneficial effects of Mediterranean diets that include EVOO and nuts, may, at least in part, be mediated via epigenetic mechanisms. As these foods are high in monounsaturated and polyunsaturated fats, the quality of fat may be playing an important role in this mediation.
Abstract
DNA methylation could be reversible and mouldable by environmental factors, such as dietary exposures. The objective was to analyse whether an intervention with two Mediterranean diets, one rich in extra-virgin olive oil (MedDiet + EVOO) and the other one in nuts (MedDiet + nuts), was influencing the methylation status of peripheral white blood cells (PWBCs) genes. A subset of 36 representative individuals were selected within the PREvención con DIeta MEDiterránea (PREDIMED-Navarra) trial, with three intervention groups in high cardiovascular risk volunteers: MedDiet + EVOO, MedDiet + nuts, and a low-fat control group. Methylation was assessed at baseline and at five-year follow-up. Ingenuity pathway analysis showed routes with differentially methylated CpG sites (CpGs) related to intermediate metabolism, diabetes, inflammation, and signal transduction. Two CpGs were specifically selected: cg01081346-CPT1B/CHKB-CPT1B and cg17071192-GNAS/GNASAS, being associated with intermediate metabolism. Furthermore, cg01081346 was associated with PUFAs intake, showing a role for specific fatty acids on epigenetic modulation. Specific components of MedDiet, particularly nuts and EVOO, were able to induce methylation changes in several PWBCs genes. These changes may have potential benefits in health; especially those changes in genes related to intermediate metabolism, diabetes, inflammation and signal transduction, which may contribute to explain the role of MedDiet and fat quality on health outcomes.
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Dietary inflammatory index and risk of pancreatic cancer in an Italian case-control study.
Shivappa, N, Bosetti, C, Zucchetto, A, Serraino, D, La Vecchia, C, Hébert, JR
The British journal of nutrition. 2015;113(2):292-8
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Pancreatic cancer has the highest mortality rate amongst gastro-intestinal cancers and evidence suggests that diet plays a pivotal role in the aetiology of the disease. Chronic inflammation is often present with cancers however it is not known if inflammation has a causal role or is simply part of the body’s natural response mechanism. This 2015 case control study evaluated food frequency questionnaire (FFQ) data from 326 incident cases and 652 controls and indexed foods based on their inflammatory status using a global database derived from previous studies: the dietary inflammatory index (DII). The DII ranks foods against forty-five nutrient parameters to generate an overall score. The higher DII scores reflect a greater pro-inflammatory potential of the diet. Food parameters measured included: carbohydrate; protein; fat; alcohol; fibre; cholesterol; SFA; MUFA; PUFA; n -3; n -6; niacin; thiamin; riboflavin; vitamin B6; Fe; Zn; vitamin A; vitamin C; vitamin D; vitamin E; folic acid; β-carotene; anthocyanidins; flavan-3-ol; flavonol; flavonones; flavones; isoflavones; caffeine and tea. The DII is designed to consider all pro-inflammatory foods (such as red meat) and all anti-inflammatory foods (such as fruits and vegetables) to represent the potential inflammatory effect of diet as a whole. After adjustments for sex, age and other lifestyle factors the results showed that subjects with higher DII scores (i.e. representing a more pro-inflammatory diet) had a higher risk of developing pancreatic cancer.
Abstract
Previous studies have shown that various dietary components may be implicated in the aetiology of pancreatic cancer. However, the possible relationship between diet-related inflammation and the risk of pancreatic cancer has not yet been investigated. We examined the ability of a newly developed literature-derived dietary inflammatory index (DII) to predict the risk of pancreatic cancer in a case-control study conducted in Italy between 1991 and 2008. This included 326 incident cases and 652 controls admitted to the major teaching and general hospitals for non-neoplastic diseases, frequency-matched to cases by study centre, sex and age. The DII was computed based on dietary intake assessed using a validated and reproducible seventy-eight-item FFQ. Logistic regression models were used to estimate multivariable OR adjusted for age, sex, study centre, education, BMI, smoking status, alcohol drinking and history of diabetes. Energy adjustment was performed using the residual method. Subjects with higher DII scores (i.e., representing a more pro-inflammatory diet) had a higher risk of pancreatic cancer, with the DII being used as both a continuous variable (ORcontinuous 1.24, 95% CI 1.11, 1.38) and a categorical variable (i.e., compared with the subjects in the lowest quintile of the DII, those in the second, third, fourth and fifth quintiles had, respectively, OR(quintile2 v. 1) 1.70, 95% CI 1.02, 2.80; OR(quintile3 v. 1) 1.91, 95% CI 1.16, 3.16; OR(quintile4 v. 1) 1.98, 95% CI 1.20, 3.27; OR(quintile5 v. 1) 2.48, 95% CI 1.50, 4.10; P trend= 0.0015). These data suggest that a pro-inflammatory diet increases the risk of pancreatic cancer.
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Long-chain n-3 PUFAs reduce adipose tissue and systemic inflammation in severely obese nondiabetic patients: a randomized controlled trial.
Itariu, BK, Zeyda, M, Hochbrugger, EE, Neuhofer, A, Prager, G, Schindler, K, Bohdjalian, A, Mascher, D, Vangala, S, Schranz, M, et al
The American journal of clinical nutrition. 2012;96(5):1137-49
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Adipose tissue inflammation is the basis of obesity-related systemic inflammation, which predisposes patients to the development of metabolic and cardiovascular disease. Previous studies show that long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) reduce cardiovascular events and exert anti-inflammatory effects but their effects on human adipose tissue inflammation have so far been unknown. This randomized open-label controlled clinical trial evaluated the effect of an 8-week treatment with n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on adipose tissue and systemic inflammation and on metabolic control. Fifty-five severely obese non-diabetic patients, scheduled for bariatric surgery, were allocated to receive either n-3 PUFAs (n=27) or an equivalent amount of butterfat as control (n=28). Systemic inflammatory markers and metabolic variables were measured at baseline and at the end of the intervention before the participants underwent bariatric surgery. Adipose tissue samples were collected during surgery for the assessment of inflammatory gene expression and lipid mediator production. Treatment with n-3 PUFAs for 8 weeks favourably affected adipose tissue and systemic inflammation. In adipose tissue, the expression of most inflammatory genes was reduced and the concentrations of lipid mediators, responsible for the resolution of inflammation (resolving lipid mediators), were increased. Systemically, the results showed a shift to a more anti-inflammatory plasma fatty acid profile and a decrease in circulating triglyceride levels. The authors concluded that the observed beneficial effects of n-3 PUFAs may be useful in the long-term treatment of obesity.
Abstract
BACKGROUND Chronic adipose tissue inflammation is a hallmark of obesity, triggering the development of associated pathologies, particularly type 2 diabetes. Long-chain n-3 PUFAs reduce cardiovascular events and exert well-established antiinflammatory effects, but their effects on human adipose tissue inflammation are unknown. OBJECTIVE We investigated whether n-3 PUFAs reduce adipose tissue inflammation in severely obese nondiabetic patients. DESIGN We treated 55 severely obese nondiabetic patients, scheduled to undergo elective bariatric surgery, with 3.36 g long-chain n-3 PUFAs/d (EPA, DHA) or an equivalent amount of butterfat as control, for 8 wk, in a randomized open-label controlled clinical trial. The primary efficacy measure was inflammatory gene expression in visceral and subcutaneous adipose tissue samples (subcutaneous adipose tissue and visceral adipose tissue), collected during surgery after the intervention. Secondary efficacy variables were adipose tissue production of antiinflammatory n-3 PUFA-derived eicosanoids, plasma concentrations of inflammatory markers, metabolic control, and the effect of the Pro12Ala PPARG polymorphism on the treatment response. RESULTS Treatment with n-3 PUFAs, which was well tolerated, decreased the gene expression of most analyzed inflammatory genes in subcutaneous adipose tissue (P < 0.05) and increased production of antiinflammatory eicosanoids in visceral adipose tissue and subcutaneous adipose tissue (P < 0.05). In comparison with control subjects who received butterfat, circulating interleukin-6 and triglyceride concentrations decreased significantly in the n-3 PUFA group (P = 0.04 and P = 0.03, respectively). The Pro12Ala polymorphism affected the serum cholesterol response to n-3 PUFA treatment. CONCLUSIONS Treatment with long-chain n-3 PUFAs favorably modulated adipose tissue and systemic inflammation in severely obese nondiabetic patients and improved lipid metabolism. These effects may be beneficial in the long-term treatment of obesity. This trial was registered at clinicaltrials.gov as NCT00760760.
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Fish consumption and markers of colorectal cancer risk: a multicenter randomized controlled trial.
Pot, GK, Majsak-Newman, G, Geelen, A, Harvey, LJ, Nagengast, FM, Witteman, BJ, van de Meeberg, PC, Timmer, R, Tan, A, Wahab, PJ, et al
The American journal of clinical nutrition. 2009;90(2):354-61
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Colorectal cancer (CC) risk is strongly related to dietary habits, with 65–75% of the incidence of CC attributed to dietary factors. This RCT studied the effects of fish consumption on markers of CC risk. 242 patients, either at high risk of developing CC or with a healthy bowel, were randomly assigned to 3 groups - 2 portions of oily fish per week, 2 portions of lean fish per week, or a control group who received dietary advice only for 6 months. 216 patients completed the trail. No statistically significant effect on CC risk markers was found between the fish groups and controls at 6 months. These results did not support the hypothesis that additional fish consumption over a 6-month period changes the number of colonic precancerous cells. The authors call for further studies to include non-fish eaters to further test their hypothesis.
Abstract
BACKGROUND Diet is a major factor in the etiology of colorectal cancer, with high fish consumption possibly decreasing colorectal cancer risk, as was shown in several observational studies. To date, no intervention trials have examined the possible beneficial effects of fish intake on colorectal cancer risk. OBJECTIVE The objective was to investigate the effects of a 6-mo intervention with oil-rich or lean fish on apoptosis and mitosis within the colonic crypt. DESIGN In a multicenter, randomized, controlled intervention trial, patients with colorectal polyps, inactive ulcerative colitis, or no macroscopic signs of disease were recruited (n = 242) and randomly allocated to receive dietary advice plus either 300 g oil-rich fish (salmon) per week (n = 82), 300 g lean fish (cod) per week (n = 78), or only dietary advice (DA) (n = 82). Apoptosis and mitosis were measured in colonic biopsy samples collected before and after intervention (n = 213). RESULTS The total number of apoptotic cells per crypt did not increase in the salmon or cod group: -0.10 (95% CI: -0.36, 0.16) and -0.06 (95% CI: -0.32, 0.20), respectively, compared with the DA group. The total number of mitotic cells per crypt decreased nonsignificantly in the salmon group (-0.87; 95% CI: -2.41, 0.68) and in the cod group (-1.04; 95% CI: -2.62, 0.53) compared with the DA group. Furthermore, the distribution of mitosis within the crypt did not significantly change in either group. CONCLUSION An increase in the consumption of either oil-rich or lean fish to 2 portions weekly over 6 mo does not markedly change apoptotic and mitotic rates in the colonic mucosa. This trial was registered at www.clinicaltrials.gov as NCT00145015.
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Separation of cinchona alkaloids, opium alkaloids, heroin, and related narcotics by dynamic-coating high-speed liquid chromaotgraphy.
Wu, CY, Siggia, S, Robinson, T, Waskiewicz, RD
Analytica chimica acta. 1973;63(2):393-402
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It has already been shown that replacing saturated fatty acids (SFA) with omega 6 (n-6) linoleic acid (LA) can reduce low density lipoproteins (LDL) which is hypothesised to reduce the risk of cardiovascular disease. However, this study looked at the prevention of secondary heart disease and mortality in recovered data from a single-blinded, parallel group, randomised controlled trial carried out between 1966-1973 which replaced dietary SFAs with n-6 polyunsaturated fatty acids (PUFAs) derived from safflower oil. This study also used this recovered data to update their meta-analysis published in 2010. The study was of 458 men who had suffered a recent coronary event and measured mortality over the 7 year period. Results showed a significant reduction in total cholesterol in the intervention group, however, it showed an increase in mortality. The study concluded that the mechanism of cardiovascular disease is independent of cholesterol levels which contradicts traditional understanding and worldwide dietary advice. The updated meta-analysis showed no benefit in replacing SFAs for n-6 or PUFAs for cardiovascular health.