Cardiovascular Disease and the Mediterranean Diet: Insights into Sex-Specific Responses.

Cardiovascular disease (CVD) is a leading cause of mortality and disease burden in women globally. A healthy diet is important for the prevention of CVD. Research has consistently favoured the Mediterranean diet as a cardio-protective diet. Several studies have evaluated associations between the Mediterranean diet and cardiovascular outcomes, including traditional risk factors like hypertension, type 2 diabetes mellitus, and obesity. In addition, consistent evidence suggests that the components of the Mediterranean diet have a synergistic effect on cardiovascular risk due to its anti-inflammatory profile and microbiome effects. While the benefits of the Mediterranean diet are well-established, health advice and dietary guidelines have been built on largely male-dominant studies. Few studies have investigated the beneficial associations of the Mediterranean diet in sex-specific populations, including those with non-traditional risk factors that are specific to women, for instance polycystic ovarian syndrome and high-risk pregnancies, or more prevalent in women, such as chronic inflammatory diseases. Therefore, this review aims to provide a comprehensive overview of the current evidence regarding the Mediterranean diet in women in relation to cardiovascular health outcomes.

Ultra-processed foods and incident cardiovascular disease and hypertension in middle-aged women.

PURPOSE: Ultra-processed food (UPF) intake has increased in recent decades, yet limited knowledge of long-term effects on cardiovascular health persists and sex-specific data is scant. We determined the association of UPF intake with incident cardiovascular disease (CVD) and/or hypertension in a population-based cohort of women. METHODS: In the Australian Longitudinal Study on Women's Health, women aged 50-55 years were prospectively followed (2001-2016). UPFs were identified using NOVA classification and contribution of these foods to total dietary intake by weight was estimated. Primary endpoint was incident CVD (self-reported heart disease/stroke). Secondary endpoints were self-reported hypertension, all-cause mortality, type 2 diabetes mellitus, and/or obesity. Logistic regression models assessed associations between UPF intake and incident CVD, adjusting for socio-demographic, medical comorbidities, and dietary variables. RESULTS: We included 10,006 women (mean age 52.5 ± 1.5; mean UPF intake 26.6 ± 10.2% of total dietary intake), with 1038 (10.8%) incident CVD, 471 (4.7%) deaths, and 4204 (43.8%) hypertension cases over 15 years of follow-up. In multivariable-adjusted models, the highest [mean 42.0% total dietary intake] versus the lowest [mean 14.2% total dietary intake] quintile of UPF intake was associated with higher incident hypertension [odds ratio (OR) 1.39, 95% confidence interval (CI) 1.10-1.74; p = 0.005] with a linear trend (ptrend = 0.02), but not incident CVD [OR 1.22, 95% CI 0.92-1.61; p = 0.16] or all-cause mortality (OR 0.80, 95% CI 0.54-1.20; p = 0.28). Similar results were found after multiple imputations for missing values. CONCLUSION: In women, higher UPF intake was associated with increased hypertension, but not incident CVD. These findings may support minimising UPFs within a healthy diet for women.

Primary prevention of cardiovascular disease in women with a Mediterranean diet: systematic review and meta-analysis.

BACKGROUND: Dietary modification is a cornerstone of cardiovascular disease (CVD) prevention. A Mediterranean diet has been associated with a lower risk of CVD but no systematic reviews have evaluated this relationship specifically in women. OBJECTIVE: To determine the association between higher versus lower adherence to a Mediterranean diet and incident CVD and total mortality in women. METHODS: A systematic search of Medline, Embase, CINAHL, Scopus, and Web of Science (2003-21) was performed. Randomised controlled trials and prospective cohort studies with participants without previous CVD were included. Studies were eligible if they reported a Mediterranean diet score and comprised either all female participants or stratified outcomes by sex. The primary outcome was CVD and/or total mortality. A random effects meta-analysis was conducted to calculate pooled hazard ratios (HRs) and confidence intervals (CIs). RESULTS: Sixteen prospective cohort studies were included in the meta-analysis (n=7 22 495 female participants). In women, higher adherence to a Mediterranean diet was associated with a lower CVD incidence (HR 0.76, 95% CI 0.72 to 0.81; I2=39%, p test for heterogeneity=0.07), total mortality (HR 0.77, 95% CI 0.74 to 0.80; I2=21%, p test for heterogeneity=0.28), and coronary heart disease (HR 0.75, 95% CI 0.65 to 0.87; I2=21%, p test for heterogeneity=0.28). Stroke incidence was lower in women with higher Mediterranean diet adherence (HR 0.87, 95% CI 0.76 to 1.01; I2=0%, p test for heterogeneity=0.89), but this result was not statistically significant. CONCLUSION: This study supports a beneficial effect of the Mediterranean diet on primary prevention of CVD and death in women, and is an important step in enabling sex specific guidelines.

Effects of air pollution on human health - Mechanistic evidence suggested by in vitro and in vivo modelling.

Airborne particulate matter (PM) comprises both solid and liquid particles, including carbon, sulphates, nitrate, and toxic heavy metals, which can induce oxidative stress and inflammation after inhalation. These changes occur both in the lung and systemically, due to the ability of the small-sized PM (i.e. diameters ≤2.5 µm, PM2.5) to enter and circulate in the bloodstream. As such, in 2016, airborne PM caused ∼4.2 million premature deaths worldwide. Acute exposure to high levels of airborne PM (eg. during wildfires) can exacerbate pre-existing illnesses leading to hospitalisation, such as in those with asthma and coronary heart disease. Prolonged exposure to PM can increase the risk of non-communicable chronic diseases affecting the brain, lung, heart, liver, and kidney, although the latter is less well studied. Given the breadth of potential disease, it is critical to understand the mechanisms underlying airborne PM exposure-induced disorders. Establishing aetiology in humans is difficult, therefore, in-vitro and in-vivo studies can provide mechanistic insights. We describe acute health effects (e.g. exacerbations of asthma) and long term health effects such as the induction of chronic inflammatory lung disease, and effects outside the lung (e.g. liver and renal change). We will focus on oxidative stress and inflammation as this is the common mechanism of PM-induced disease, which may be used to develop effective treatments to mitigate the adverse health effect of PM exposure.

Particulate Matter, an Intrauterine Toxin Affecting Foetal Development and Beyond.

Air pollution is the 9th cause of the overall disease burden globally. The solid component in the polluted air, particulate matters (PMs) with a diameter of 2.5 µm or smaller (PM2.5) possess a significant health risk to several organ systems. PM2.5 has also been shown to cross the blood-placental barrier and circulate in foetal blood. Therefore, it is considered an intrauterine environmental toxin. Exposure to PM2.5 during the perinatal period, when the foetus is particularly susceptible to developmental defects, has been shown to reduce birth weight and cause preterm birth, with an increase in adult disease susceptibility in the offspring. However, few studies have thoroughly studied the health outcome of foetuses due to intrauterine exposure and the underlying mechanisms. This perspective summarises currently available evidence, which suggests that intrauterine exposure to PM2.5 promotes oxidative stress and inflammation in a similar manner as occurs in response to direct PM exposure. Oxidative stress and inflammation are likely to be the common mechanisms underlying the dysfunction of multiple systems, offering potential targets for preventative strategies in pregnant mothers for an optimal foetal outcome.