L-arginine supplementation to mitigate cardiovascular effects of walking outside in the context of traffic-related air pollution in participants with elevated blood pressure: A randomized, double-blind, placebo-controlled trial

Dietary supplementations to mitigate the cardiopulmonary effects of air pollution toxicity: A systematic review of clinical trials

BACKGROUND

There is a consistent association between exposure to air pollution and elevated rates of cardiopulmonary illnesses. As public health activities emphasize the paramount need to reduce exposure, it is crucial to examine strategies like the antioxidant diet that could potentially protect individuals who are unavoidably exposed.

METHODS

A systematic search was performed in PubMed/Medline, EMBASE, CENTRAL, and ClinicalTrials.gov up to March 31, 2023, for clinical trials assessing dietary supplements against cardiovascular (blood pressure, heart rate, heart rate variability, brachial artery diameter, flow-mediated dilation, and lipid profile) or pulmonary outcomes (pulmonary function and airway inflammation) attributed to air pollution exposure.

RESULTS

After reviewing 4681 records, 18 studies were included. There were contradictory findings on the effects of fish oil and olive oil supplementations on cardiovascular outcomes. Although with limited evidence, fish oil offered protection against pulmonary dysfunction induced by pollutants. Most studies on vitamin C did not find protective cardiovascular effects; however, the combination of vitamin C and E offered protective effects against pulmonary dysfunction but showed conflicting results for cardiovascular outcomes. Other supplements like sulforaphane, L-arginine, n-acetylcysteine, and B vitamins showed potential beneficial effects but need further research due to the limited number of existing trials.

CONCLUSIONS

Although more research is needed to determine the efficacy and optimal dose of anti-inflammatory and antioxidant dietary supplements against air pollution toxicity, this low-cost preventative strategy has the potential to offer protection against outcomes of air pollution exposure.

A review of air pollution as a driver of cardiovascular disease risk across the diabetes spectrum

The prevalence of diabetes is estimated to reach almost 630 million cases worldwide by the year 2045; of current and projected cases, over 90% are type 2 diabetes. Air pollution exposure has been implicated in the onset and progression of diabetes. Increased exposure to fine particulate matter air pollution (PM2.5) is associated with increases in blood glucose and glycated hemoglobin (HbA1c) across the glycemic spectrum, including normoglycemia, prediabetes, and all forms of diabetes. Air pollution exposure is a driver of cardiovascular disease onset and exacerbation and can increase cardiovascular risk among those with diabetes. In this review, we summarize the literature describing the relationships between air pollution exposure, diabetes and cardiovascular disease, highlighting how airborne pollutants can disrupt glucose homeostasis. We discuss how air pollution and diabetes, via shared mechanisms leading to endothelial dysfunction, drive increased cardiovascular disease risk. We identify portable air cleaners as potentially useful tools to prevent adverse cardiovascular outcomes due to air pollution exposure across the diabetes spectrum, while emphasizing the need for further study in this particular population. Given the enormity of the health and financial impacts of air pollution exposure on patients with diabetes, a greater understanding of the interventions to reduce cardiovascular risk in this population is needed.

Short-term effects of ambient gaseous air pollution on blood platelet mitochondrial DNA methylation and myocardial ischemia

BACKGROUND

The potential effects of short-term exposure to major ambient gaseous pollutants (ozone: O3, carbon monoxide: CO, and sulfur dioxide: SO2) on platelet mitochondrial DNA (mtDNA) methylation have been uncertain and no studies have examined whether platelet mtDNA methylation levels could modify the associations between ambient gaseous pollutants and the risks of ST-segment depression (STDE) and T-wave inversion events (TIE), two indicators of myocardial ischemia.

METHODS

This study used data from a randomized, double-blind, placebo-controlled intervention study with a standardized 24-hour exposure protocol among 110 participants in Beijing. Absolute changes in platelet mtDNA methylation (ACmtDNAm) levels were determined by two repeated measurements on platelet mtDNA methylation levels in blood samples collected before and after the 24-hour exposure period. A multivariable linear regression model and a generalized linear model with a Poisson link function were used to investigate the associations of ambient gaseous pollutants with platelet mtDNA methylation levels, STDE, and TIE, respectively.

RESULTS

Short-term O3 exposure was significantly associated with decreased ACmtDNAm at ATP6_P1 but increased ACmtDNAm at mt12sRNA, MT-COX1, and MT-COX1_P2; short-term CO and SO2 exposures were significantly associated with decreased ACmtDNAm at D-loop, MT-COX3- and ATP-related genes. Moreover, short-term O3 exposure was significantly associated with increased risks of STDE and TIE, and ACmtDNAm at MT-COX1 and MT-COX1_P2 modified the association between short-term O3 exposure and STDE events. L-Arg supplementation attenuated the effects of ambient gaseous pollutants, particularly O3, on ACmtDNAm and STDE.

CONCLUSIONS

Platelet mtDNA methylation levels are promising biomarkers of short-term exposure to ambient gaseous air pollution, and are likely implicated in the mechanism behind the association of ambient O3 pollution with adverse cardiovascular effects. L-Arg supplementation showed the potential to mitigate the adverse effects of ambient O3 pollution.

Adherence to the Mediterranean Diet Association with Serum Levels of Nitric Oxide, Prostacyclin, and Thromboxane B2 among Prinzmetal Angina Patients and Healthy Persons

This study aimed to assess the association between adherence to the Mediterranean diet with serum Nitric oxide, Prostacyclin, and Thromboxane B₂ among Prinzmetal angina patients and healthy persons. This case-control study was conducted among 100 Prinzmetal angina patients and 100 healthy persons referred to the Ardabil Imam Khomeini hospital between 2021 and 2022. Blood samples were obtained from all study participants for measurement of serum Nitric oxide, Prostacyclin, and Thromboxane B₂. To calculate adherence to the Mediterranean diet, the ten-item screener was used. The serum Nitric oxide in patients who adhered more to the Mediterranean diet was higher than patients with less adherence (coeff. = 0.41 p = 0.04). The serum Prostacyclin level in patients with greater adherence to the Mediterranean diet was 0.34 units higher than patients with less adherence (coeff. = 0.34 p = 0.02). The level of serum Thromboxane B₂ had a negative association with adherence to the Mediterranean diet (coeff. = -0.48 p = 0.04). The amount of consumption of olive oil, fruits, vegetables, and legumes in healthy people was more than Prinzmetal angina patients. In Prinzmetal angina patients, more adherence to the Mediterranean diet can decrease the serum Thromboxane B₂ and increase the serum Nitric oxide and Prostacyclin.

The protective effects of taurine and fish oil supplementation on PM2.5-induced heart dysfunction among aged mice: A random double-blind study

As it is nearly impossible to reduce PM2.5 concentrations in most cities to safe limits in a short period of time, dietary supplementation presents a promising approach for mitigating the adverse effects of PM2.5 exposure. A cross-sectional study showed that the elderly population of Linfen (PM2.5: 102 μg/m3) exhibited significantly lower serum taurine levels, as well as higher oxidative stress levels and cardiovascular health risks, than the corresponding population in Guangzhou (PM2.5: 39 μg/m3). We conducted a random double-blind study on aged mice that employed a "real-world" PM2.5 exposure system to simulate the conditions of Linfen with the aim of investigating the protective effects of taurine and fish oil supplementation on PM2.5-induced heart dysfunction. When compared with the placebo group, supplementation with taurine and fish oil not only maintained normal taurine levels, but also suppressed oxidative stress and inflammation in aged mice subjected to high concentrations of PM2.5. Variations in heart rate, contractile function, cardiac oxidative stress, inflammation and fibrosis among different groups of aged mice were used to clarify the beneficial effects of taurine and fish oil supplementation. Our results not only revealed the protective effects of taurine and fish oil supplementation on heart dysfunction induced by PM2.5 exposure from the aged mice experiments and also provided new means for the elderly to resist PM2.5 pollution at the individual level.

Overview of particulate air pollution and human health in China: Evidence, challenges, and opportunities

Ambient particulate matter (PM) pollution in China continues to be a major public health challenge. With the release of the new WHO air quality guidelines in 2021, there is an urgent need for China to contemplate a revision of air quality standards (AQS). In the recent decade, there has been an increase in epidemiological studies on PM in China. A comprehensive evaluation of such epidemiological evidence among the Chinese population is central for revision of the AQS in China and in other developing countries with similar air pollution problems. We thus conducted a systematic review on the epidemiological literature of PM published in the recent decade. In summary, we identified the following: (1) short-term and long-term PM exposure increase mortality and morbidity risk without a discernible threshold, suggesting the necessity for continuous improvement in air quality; (2) the magnitude of long-term associations with mortality observed in China are comparable with those in developed countries, whereas the magnitude of short-term associations are appreciably smaller; (3) governmental clean air policies and personalized mitigation measures are potentially effective in protecting public and individual health, but need to be validated using mortality or morbidity outcomes; (4) particles of smaller size range and those originating from fossil fuel combustion appear to show larger relative health risks; and (5) molecular epidemiological studies provide evidence for the biological plausibility and mechanisms underlying the hazardous effects of PM. This updated review may serve as an epidemiological basis for China’s AQS revision and proposes several perspectives in designing future health studies.

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Acute effects of PM are smaller in China compared with developed countries

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Health effects caused by PM depend on particle composition, source, and size

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There are no thresholds for the health effects of PM

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Mechanistic studies support the biological plausibility of PM’s health effects

L-lysine: its antagonism with L-arginine in controlling viral infection. Narrative Literature Review

Knowledge about viral characteristics, mechanisms of entry into the host cell and multiplication/dissemination can help in the control and treatment of viral pathologies. Several nutritional factors linked to the host may favor viral multiplication and their control, may lead to new prophylactic alternatives and/or antiviral therapies. The objective of this review is to discuss the relationship between the amino acid L-lysine and the control of viral infections, aiming at a possible therapeutic property. This research used databases such as PubMed, Web of Science, Scielo, Medline and Google Scholar, as well as searching for references cited by journals. The time frame covered the period between 1964 and January 2022. The observed studies have shown that the usual antiviral therapies are not able to interfere with the viruses in their latent state, however, they can interfere with the adhesion and fusion of viral particles or the production of proteins, which play an important role in viral epidemiology and control, particularly in the initial moment and in the reactivation. Lysine is an amino acid that can interfere mainly in the formation of capsid proteins and DNA by a competitive antagonism with amino acid arginine, which is an essential amino acid for some viruses and also by promoting the increase of arginase, increasing the catabolism of arginine. Although there is evidence of the importance of L-lysine in viral control, more studies are needed, with a view to new antiviral therapies.