Chocolate Consumption and Risk of Atrial Fibrillation (from the Physicians' Health Study)

Dietary interventions in the management of atrial fibrillation

Atrial fibrillation (AF) represents the most common cardiac arrhythmia with significant morbidity and mortality implications. It is a common cause of hospital admissions, significantly impacts quality of life, increases morbidity and decreases life expectancy. Despite advancements in treatment options, prevalence of AF remains exceptionally high. AF is a challenging disease to manage, not just clinically but also financially. Evidence suggests lifestyle modification, including dietary changes, plays a significant role in the treatment of AF. This review aims to analyze the existing literature on the effects of dietary modifications on the incidence, progression, and outcomes of atrial fibrillation. It examines various dietary components, including alcohol, caffeine, omega-3 polyunsaturated fatty acids and minerals, and their impact on AF incidence, progression, and outcomes. The evidence surrounding the effects of dietary patterns, such as the Mediterranean and low carbohydrate diets, on AF is also evaluated. Overall, this review underscores the importance of dietary interventions as part of a comprehensive approach to AF management and highlights the need for further research in this emerging field.

Association of chocolate consumption with neurological and cardiovascular outcomes in atrial fibrillation: data from two Swiss atrial fibrillation cohort studies (Swiss-AF and BEAT-AF)

AIM

To assess the associations of chocolate consumption with neurocognitive function, brain lesions on magnetic resonance imaging (MRI), and cardiovascular outcome in patients with atrial fibrillation (AF).

METHODS

We analysed data from patients of two prospective multicentre Swiss atrial fibrillation cohort studies (Swiss-AF) and (BEAT-AF). Assessments of MRI findings and neurocognitive function were performed only in the Swiss-AF population (in 1727 of 2415 patients [71.5%] with a complete data set), as patients enrolled in BEAT-AF were not systematically evaluated for these outcomes. Otherwise, the two cohorts had an equivalent set of clinical assessments. Clinical outcome analysis was performed in 3931 patients of both cohorts. Chocolate consumption was assessed by questionnaire. Patients were categorised as no/low chocolate consumption (No/Low-Ch) ≤1 servings/week, moderate chocolate consumption (Mod-Ch) >1-6 servings/week, and high chocolate consumption (High-Ch) >6 servings/week, respectively. Brain lesions were evaluated by MRI. Assessment of cognitive function was performed by neurocognitive functional testing and included global cognition measurement with a cognitive construct score. Cerebral MRI and cognition were evaluated at baseline. Cross-sectional associations between chocolate consumption and MRI findings were analysed by multivariate logistic regression models and associations with neurocognitive function by multivariate linear regression models. Clinical outcome events during follow-up were recorded and assessed by a clinical event committee. The associations between chocolate consumption and clinical outcomes were evaluated by Cox regression models. The median follow-up time was 6 years.

RESULTS

Chocolate consumption was not associated with prevalence or volume of vascular brain lesions on MRI, nor major adverse cardiac events (ischaemic stroke, myocardial infarction, cardiovascular death). However, No/Low-Ch was independently associated with a lower cognitive construct score compared to Mod-Ch (No/Low-Ch vs. Mod-Ch: coeff. -0.05, 95% CI -0.10-0), whereas other neurocognitive function tests were not independently associated with chocolate consumption categories. In addition, there was a higher risk of heart failure hospitalisation (No/Low-Ch vs. Mod-Ch: HR 1.24, 95% CI 1.01-1.52) and of all-cause mortality (No/Low-Ch vs. Mod-Ch: HR 1.29, 95% CI 1.06-1.58) in No/Low-Ch compared to Mod-Ch. No significant associations with the evaluated outcomes were observed when High-Ch was compared to Mod-Ch.

CONCLUSION

While chocolate consumption was not associated with MRI findings and major adverse cardiac events in an atrial fibrillation population, No/Low-Ch was associated with a lower cognitive construct score, higher risk of heart failure hospitalisation and increased all-cause mortality compared to Mod-Ch.

CLINICALTRIALS

gov Identifier: NCT02105844.

Relationship between chocolate consumption and overall and cause-specific mortality, systematic review and updated meta-analysis

Chocolate is a rich dietary source of various bioactive flavonoid compounds. Despite being one of the most popular foods worldwide, the association between chocolate consumption and long-term mortality remains unclear. The objective of this study is to determine the associations between chocolate consumption and long-term overall and cause-specific mortality, to evaluate dose-response and potential mediators, and to conduct an updated meta-analysis based on prospective cohort studies. We performed a prospective analysis in the Alpha-Tocopherol, Beta-Carotene cancer prevention (ATBC) Study with a total of 27,111 men who were recruited between 1985 and 1988 and followed through 2015. Exposure data of daily chocolate consumption was obtained from validated baseline food frequency questionnaire. Hazard ratios (HRs) and 30-year absolute risk differences (ARDs) including 95% confidence intervals (CI) for overall and cause-specific mortality were estimated using multivariable-adjusted Cox proportional hazards regression models. An updated meta-analysis of cohort studies was also conducted. During 482,807 person-years of follow-up, a total of 22,064 men died. The multivariable analyses showed a statistically significant inverse association between chocolate consumption and risk of overall mortality, with HRs of 0.91, 0.89, 0.89, and 0.88 for the increasing categories 2-5 as compared with those in the lowest category (Ptrend < 0.0001, and P for nonlinearity < 0.0001). We observed significantly lower mortality from cardiovascular disease (CVD), heart disease and cancer, representing 13%, 16% and 12% risk reductions for the highest compared to lowest chocolate category, respectively (all Ptrend ≤ 0.002; all P for nonlinearity < 0.0001). The inverse associations of chocolate consumption with risk of overall, CVD and heart disease mortality were generally consistent across cohort subgroups (e.g., body mass index and serum cholesterol). Mediation analysis showed that 4.3% of the inverse association of chocolate and overall mortality was mediated through reducing blood pressure. Within the updated meta-analysis of cohort studies (21 risk estimates, 908,390 participants and 65,407 events), greater consumption of chocolate (per 5 g/day) was associated with a lower risk of CVD incidence and mortality (pooled relative risk = 0.98, P value < 0.001; P for nonlinearity < 0.001). The predefined subgroup analyses generally revealed consistent inverse chocolate-CVD risk associations. In this prospective study, calorie-balanced greater consumption of chocolate was inversely associated with lower overall, CVD, heart disease and cancer mortality. The systematic review and meta-analysis provide support for the inverse chocolate-CVD association. Our findings may provide evidence to partially allay concerns regarding adverse health outcomes from low-to-moderate chocolate consumption.

Mediterranean Diet: A Tool to Break the Relationship of Atrial Fibrillation with the Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease

Atrial fibrillation (AF) is the most common supraventricular arrhythmia associated with increased cardiovascular and non-cardiovascular morbidity and mortality. As multiple factors may predispose the onset of AF, the prevention of the occurrence, recurrence and complications of this arrhythmia is still challenging. In particular, a high prevalence of cardio-metabolic comorbidities such as the metabolic syndrome (MetS) and in its hepatic manifestation, the non-alcoholic fatty liver disease (NAFLD), have been described in the AF population. A common pathogenetic mechanism linking AF, MetS and NAFLD is represented by oxidative stress. For this reason, in the past decades, numerous studies have investigated the effect of different foods/nutrients with antioxidant properties for the prevention of, and their therapeutic role is still unclear. In this narrative comprehensive review, we will summarize current evidence on (1) the association between AF, MetS and NAFLD (2) the antioxidant role of Mediterranean Diet and its components for the prevention of AF and (3) the effects of Mediterranean Diet on MetS components and NAFLD.

Social Risk Factors and Atrial Fibrillation

Modifiable risk factor management is becoming one of the 3 treatment pillars in atrial fibrillation management along with anticoagulation as well as conventional rate and rhythm control strategies. Preventive therapies, such as reducing blood pressure and treating obstructive sleep apnea, are paramount in the strategy of preventing atrial fibrillation. Identification of new modifiable risk factors and triggers also could help in the global strategy to reduce atrial fibrillation. This article covers alcohol intake, tobacco smoking, caffeine, chocolate, cannabis use, and air pollution as social risk factors related to lifestyle habits that potentially could contribute to atrial fibrillation development.

Chocolate, "Food of the Gods": History, Science, and Human Health

Chocolate is well known for its fine flavor, and its history began in ancient times, when the Maya considered chocolate (a cocoa drink prepared with hot water) the "Food of the Gods". The food industry produces many different types of chocolate: in recent years, dark chocolate, in particular, has gained great popularity. Interest in chocolate has grown, owing to its physiological and potential health effects, such as regulation of blood pressure, insulin levels, vascular functions, oxidation processes, prebiotic effects, glucose homeostasis, and lipid metabolism. However, further translational and epidemiologic studies are needed to confirm available results and to evaluate other possible effects related to the consumption of cocoa and chocolate, verifying in humans the effects hitherto demonstrated only in vitro, and suggesting how best to consume (in terms of dose, mode, and time) chocolate in the daily diet.

Cardioprotective Mechanisms of Cocoa

Cardiovascular diseases are the main cause of deaths in highly developed countries. Dietetic interventions that involve recommendations for consumption of products with a confirmed health-improving action are an important aspect of prevention of cardiovascular diseases. Cocoa is an alimentary product with significant cardioprotective potential due to its high content of bioactive compounds. The aim of the present study was to review the most recent literature concerning the effectiveness and mechanisms of action of compounds contained in cocoa with regard to selected cardiovascular risk factors and cardiometabolic markers. Study results indicate that cocoa consumption, especially in the form of dark chocolate with high flavonoid content, may be a good strategy to diminish cardiovascular risk due to its beneficial effect on platelet aggregation, decreasing blood pressure, diminishing dyslipidemia, and decreasing blood plasma glucose concentration. Many studies have shown that cocoa-derived flavonoids have antioxidant and anti-inflammatory activity and also play a significant role in preventing insulin resistance. However, in order to completely confirm the potential cardiovascular benefits, it is necessary to conduct larger and longer studies, also with regard to potential dangers associated with long-term consumption of large amounts of flavonoids and determination of a safe and effective dose. Key teaching points Cocoa consumption may be a good strategy in diminishing cardiovascular risk. Beneficial effects on platelet aggregation, blood pressure, dyslipidemia, glycemia, as well as antioxidant and anti-inflammatory activity are observed. There is a need to conduct larger and longer studies to determine a safe and effective dose of cocoa flavonoids.

Food-Related Atrial Fibrillation? The Potential Role of Biogenic Amines in “Nutri-Arrhythmias” Genesis

Atrial fibrillation (AF) is the most common type of arrhythmia: a disorganized electrical atrial activity leading to irregular ventricular beats. Its most common risk factors include high blood pressure, congenital and valvular heart diseases, aging, heart failure and coronary heart diseases. Other risk factors include excessive alcohol intake, tobacco smoking, diabetes mellitus and thyrotoxicosis. However, many cases are not associated with any of these risk factors: probably, in these patients, immunological, functional and even dietary mechanisms may be responsible to induce cardiac arrhythmias. Several studies have focused on immunological and neurohumoral mechanisms; however, little information is available about the potential relationship between dietary patterns and atrial fibrillation episodes. This case report describes a potential correlation between biogenic amines in ingested food and recurrent atrial fibrillation onset in a 61-years old man in absence of a remarkable clinical history and of the most common risk factors. The nutritional team instituted a food protocol: a low calories diet and eliminating biogenic amines-rich foods. During the follow-up (16 months), there was a noticeable weight loss and no arrhythmic episodes happened again. This clinical case provides evidence for a possible new relationship between some kinds of food and heart conduction (defining the very novel field of arrhythmogenic foods and of “nutri-arrhythmias”), recognizing biogenic amines-rich foods abuse as the potential trigger and substrate for atrial fibrillation. Therefore, we suggested that clinical history in patients with new onset AF should also include questions concerning the ingestion of histamine-rich foodstuffs (or other amines-rich food) and alcohol consumption: their effects may result to be synergistic in the alteration of cardiac rhythm and may explain the recurrence of an unexplained atrial fibrillation.

Effect of Dietary Factors on Cardiac Rhythm

The interaction between arrhythmias and certain lifestyle factors such as obesity and alcohol consumption is well-established. There is significant public and professional interest in the role of various diets, vitamins, and minerals in cardiovascular health. However, many widely held beliefs are not supported by the literature. There is limited evidence for routine magnesium and omega-3 poly-unsaturated fatty acids supplementation, while coffee, tea, nuts, antioxidant vitamins, and even chocolate may have some antiarrhythmic properties. Saturated fat, added salt, and excessive energy drink consumption appear to be harmful for patients with rhythm disorders. However most recommendations are based on observation studies, and this remains a fertile area for further research.

Chocolate consumption and risk of atrial fibrillation: Two cohort studies and a meta-analysis

BACKGROUND

Chocolate consumption has been inconsistently associated with risk of atrial fibrillation (AF). We investigated the association between chocolate consumption and risk of AF in Swedish adults from two cohort studies and conducted a meta-analysis to summarize available evidence from cohort studies on this topic.

METHODS

Our study population comprised 40,009 men from the Cohort of Swedish Men and 32,486 women from the Swedish Mammography Cohort. Incident AF cases were ascertained through linkage with the Swedish National Patient Register. Published cohort studies of chocolate consumption in relation to risk of AF were identified by a PubMed search through September 14, 2017.

RESULTS

During a mean follow-up of 14.6 years, AF was diagnosed in 9978 Swedish men and women. Compared with non-consumers, the multivariable hazard ratio of AF for those in the highest category of chocolate consumption (≥3-4 servings/week) was 0.96 (95% CI 0.88-1.04). In a random-effects meta-analysis of 5 cohort studies, including 180,454 participants and 16,356 AF cases, the hazard ratios of AF were 0.97 (95% CI 0.94-1.01) per 2 servings/week increase in chocolate consumption and 0.96 (95% CI 0.90-1.03) for the highest versus lowest category of chocolate consumption.

CONCLUSION

Available data provide no evidence of an association of chocolate consumption with risk of AF.

Chocolate intake and risk of clinically apparent atrial fibrillation: the Danish Diet, Cancer, and Health Study

OBJECTIVE

To evaluate the association between chocolate intake and incident clinically apparent atrial fibrillation or flutter (AF).

METHODS

The Danish Diet, Cancer, and Health Study is a large population-based prospective cohort study. The present study is based on 55 502 participants (26 400 men and 29 102 women) aged 50-64 years who had provided information on chocolate intake at baseline. Incident cases of AF were ascertained by linkage with nationwide registries.

RESULTS

During a median of 13.5 years there were 3346 cases of AF. Compared with chocolate intake less than once per month, the rate of AF was lower for people consuming 1-3 servings/month (hazard ratio (HR) 0.90, 95% confidence interval (CI) 0.82 to 0.98), 1 serving/week (HR 0.83, 95% CI 0.74 to 0.92), 2-6 servings/week (HR 0.80, 95% CI 0.71 to 0.91) and ≥1 servings/day (HR 0.84, 95% CI 0.65 to 1.09; p-linear trend <0.0001), with similar results for men and women.

CONCLUSIONS

Accumulating evidence indicates that moderate chocolate intake may be inversely associated with AF risk, although residual confounding cannot be ruled out.

Measuring the effects of CVD interventions and studies across socioeconomic groups: A brief review

There is a known socioeconomic skew in prevalence and outcomes of cardiovascular disease (CVD). To document the proportion of clinical trials and observational studies related to CVD recently published in peer-reviewed journals that report the socio-economic distributional differences in their outcomes. We undertook a review of peer-reviewed clinical trials and observational studies relating to CVD published between 01/06/2015-31/12/2015 in PubMed; and identified the proportion that included measures of socioeconomic status and the proportion that stratified results by, or controlled for, socioeconomic status when reporting outcomes. 414 peer reviewed publications reporting the outcomes of clinical trials or observational studies that related to CVD were identified. 32 of these reported on the socioeconomic status of participants. Of these, 20 stratified the results by socioeconomic status or adjusted the results for socioeconomic status. 18 studies measured education attainment, 5 measured income, 1 measured rurality and 1 measured occupation. Of the 414 articles reporting the outcomes of clinical trials or observational studies related to cardiovascular disease in 2015, the effectiveness of the intervention, or the differences in outcomes, between socioeconomic groups was assessed in 5% of studies. This lack of consideration of the effectiveness of trial outcomes or the differences in outcomes across socioeconomic groups impairs the ability of readers, healthcare professionals and policy makers to assess the impact of new treatments or interventions in closing the inequality gap associated with CVD.