Extra virgin olive oil high in polyphenols improves antioxidant status in adults: a double-blind, randomized, controlled, cross-over study (OLIVAUS).

PURPOSE: Olive oil polyphenols have been associated with cardiovascular health benefits. This study examined the antioxidant and anti-inflammatory effect of extra-virgin high polyphenol olive oil (HPOO) vs. low polyphenol olive oil (LPOO) in healthy Australian adults. METHODS: In a double-blind cross-over trial, 50 participants (aged 38.5 ± 13.9 years, 66% females) were randomized to consume 60 mL/day of HPOO (320 mg/kg polyphenols) or LPOO (86 mg/kg polyphenols) for three weeks. Following a 2-week wash-out period, participants crossed-over to the alternate treatment. Plasma oxidized low-density lipoprotein (ox-LDL), total antioxidant capacity (TAC), high-sensitivity C-reactive protein (hs-CRP) and anthropometrics were measured at baseline and follow-up. RESULTS: Fourty-three participants completed the study. Although there were no significant differences between treatments in the total sample, plasma ox-LDL decreased by 6.5 mU/mL (95%CI - 12.4 to - 0.5) and TAC increased by 0.03 mM (95% CI 0.006-0.05) only in the HPOO arm. Stratified analyses were also performed by cardiovascular disease risk status defined by abdominal obesity (WC > 94 cm in males, > 80 cm in females) or inflammation (hs-CRP > 1 mg/L). In the subgroup with abdominal obesity, ox-LDL decreased by 13.5 mU/mL (95% CI - 23.5 to - 3.6) and TAC increased by 0.04 mM (95% CI 0.006-0.07) only after HPOO consumption. In the subgroup with inflammation, hs-CRP decreased by 1.9 mg/L (95% CI - 3.7 to -0.1) only in the HPOO arm. CONCLUSIONS: Although there were no significant differences between treatments, the changes observed after HPOO consumption demonstrate the antioxidant and anti-inflammatory effect of this oil, which is more pronounced in adults with high cardiometabolic risk (Clinical Trial Registration: ACTRN12618000706279).

Dietary Interventions with or without Omega-3 Supplementation for the Management of Rheumatoid Arthritis: A Systematic Review.

Rheumatoid Arthritis (RA) is a chronic autoimmune condition characterized by symptoms of inflammation and pain in the joints. RA is estimated to have a worldwide prevalence of 0.5-1%, with a predominance in females. Diet may play an important role in the symptoms of RA; however, little is known about the effects of various diets. The aim of this systematic review is to explore the effect of dietary interventions, with or without omega-3 supplementation for the management of RA. The electronic databases MEDLINE, EMBASE, CINAHL, and the Cochrane Library were systematically searched for clinical trials investigating dietary interventions, with or without omega-3 supplementation to retrieve papers from inception to April 2021. Randomized and non-randomized controlled trials of dietary interventions in adults with RA were eligible for inclusion. Twenty studies with a total of 1063 participants were included. The most frequently reported outcomes were pain, duration of morning stiffness, joint tenderness, grip strength and inflammatory markers. Dietary interventions with an anti-inflammatory basis may be an effective way for adults with RA seeking complementary treatments, potentially leading to improvements in certain parameters. However, there is a need for longer duration studies that are well-designed and sufficiently powered to investigate the influence of diet on RA.

The Effect of High Polyphenol Extra Virgin Olive Oil on Blood Pressure and Arterial Stiffness in Healthy Australian Adults: A Randomized, Controlled, Cross-Over Study.

Extra virgin olive oil (EVOO) is suggested to be cardioprotective, partly due to its high phenolic content. We investigated the effect of extra virgin high polyphenol olive oil (HPOO) versus low polyphenol olive oil (LPOO) on blood pressure (BP) and arterial stiffness in healthy Australian adults. In a double-blind, randomized, controlled cross-over trial, 50 participants (age 38.5 ± 13.9 years, 66% female) were randomized to consume 60 mL/day of either HPOO (360 mg/kg polyphenols) or LPOO (86 mg/kg polyphenols) for three weeks. Following a two-week washout period, participants crossed over to consume the alternate oil. Anthropometric data, peripheral BP, central BP and arterial stiffness were measured at baseline and follow up. No significant differences were observed in the changes from baseline to follow up between the two treatments. However, a significant decrease in peripheral and central systolic BP (SBP) by 2.5 mmHg (95% CI: -4.7 to -0.3) and 2.7 mmHg (95% CI: -4.7 to -0.6), respectively, was observed after HPOO consumption. Neither olive oil changed diastolic BP (DBP) or measures of arterial stiffness. The reductions in SBP after HPOO consumption provide evidence for a potentially widely accessible dietary intervention to prevent cardiovascular disease in a multiethnic population. Longer intervention studies and/or higher doses of EVOO polyphenols are warranted to elucidate the potential effect on DBP and arterial stiffness.

Effect of Dietary and Supplemental Lycopene on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis.

Cardiovascular disease (CVD) is the leading cause of death globally and the presence of ≥1 cardiovascular risk factors elevates total risk. Lycopene, a carotenoid with high antioxidant capacity, may be protective. The aim of this systematic review and meta-analyses is to determine the efficacy of consuming dietary and/or supplemental lycopene on cardiovascular risk factors. Using the PRISMA guidelines, 4 databases were systematically searched from inception: Medline, Cinahl, Proquest, and Scopus. Intervention trials assessing dietary or supplemental lycopene on CVD outcomes were included. The Cochrane Risk-of-Bias tool was used to assess the quality of the included papers. Pooled analysis was conducted using outcomes with available data. Forty-three studies were included. Lycopene interventions were highly variable (supplement with or without food, based as tomato juice/paste/raw product, or combined with olive oil), the dose ranged from 1.44 to 75 mg lycopene/d and was not reported in 11 of 43 included studies. Studies reported conflicting findings for the effect of lycopene on cardiovascular risk factors, This was supported by meta-analyses where there were no significant differences between lycopene intervention and control groups for blood pressure and lipids (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides). This was observed for overall groups and in subgroup analyses for individuals with elevated risk factor concentrations at baseline. Lycopene interventions for cardiovascular risk factors were highly variable across studies in both the dosage provided and the mode of delivery (supplement or food based). As such, there are conflicting findings regarding the efficacy of lycopene to improve cardiovascular risk factors. This systematic review was registered with PROSPERO as CRD42018112174.

Practical Dietary Recommendations for the Prevention and Management of Nonalcoholic Fatty Liver Disease in Adults.

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. In the absence of effective pharmacotherapies, clinical guidelines focus primarily on weight loss to treat this condition. Established consensus, evidence-based, and clinical dietary recommendations for NAFLD are currently lacking. The aim of this paper is to provide evidence-based practical dietary recommendations for the prevention and management of NAFLD in adults. A literature review focusing on established principles for the development of clinical practice recommendations was employed using the following criteria: based on substantial evidence, ensures risk minimization, is flexible for an individual patient approach, and is open to further modification as evidence emerges. The Practice-based Evidence in Nutrition classification system was used to grade these principles. Five key dietary recommendations were developed: 1) follow traditional dietary patterns, such as the Mediterranean diet; 2) limit excess fructose consumption and avoid processed foods and beverages with added fructose; 3) PUFAs, especially long-chain omega-3 rich foods and MUFAs, should replace SFAs in the diet; 4) replace processed food, fast food, commercial bakery goods, and sweets with unprocessed foods high in fiber, including whole grains, vegetables, fruits, legumes, nuts, and seeds; and 5) avoid excess alcohol consumption. Improving diet quality may reduce the incidence and progression of NAFLD and associated risk factors. Many of the benefits are likely to result from the collective effect of dietary patterns. High-quality research-in particular, randomized clinical trials assessing dietary interventions that focus on liver-specific endpoints-are needed as a priority.