Medical Bulletin 24/ April/ 2024

In a cross-sectional study published in the Journal of the Academy of Nutrition and Dietetics, researchers from Mexico investigated the potential association between avocado consumption and diabetes in Mexican adults.

Avocados, rich in nutrients and increasingly popular, have been associated with metabolic health benefits. Understanding how individual foods like avocados impact diabetes risk is essential, especially considering the influence of biological sex on diabetes pathogenesis. The study examined the link between avocado consumption and diabetes risk in both males and females, recognising the global rise in diabetes rates and the potential of dietary modifications to mitigate risk.

The study analysed data from 25,640 participants aged ≥20 years, with approximately 59% female. Most participants were overweight or obese, with over 60% having abdominal obesity. Diabetes was defined as glycated haemoglobin (HbA1c) ≥ 6.5% or fasting plasma glucose (FPG) ≥ 126 mg/dL. Various covariates, including body mass index (BMI), abdominal obesity, physical activity, healthy eating index score, energy intake, smoking, alcohol consumption, hypertension, and acute myocardial infarction, were considered in the analysis. Additionally, a subset of participants underwent a sensitivity analysis using laboratory data.

The results showed that of the participants from the three surveys, about 45% were avocado consumers, with an average daily consumption of 34.7 grams for men and 29.8 grams for women. Avocado consumption was found to be associated with lower odds of diabetes among women but not among men.

These findings highlight the potential protective role of avocado consumption against diabetes. Furthermore, researchers also found that compared to those who did not consume avocados, avocado-consuming women showed a lower risk of diabetes, while no significant association was observed among men.

Reference: Association between avocado consumption and diabetes in Mexican adults: Results from the 2012, 2016, and 2018 Mexican National Health and Nutrition Surveys. Cheng, F. W. et al., Journal of the Academy of Nutrition and Dietetics (2024), DOI: 10.1016/j.jand.2024.04.012, https://www.sciencedirect.com/science/article/pii/S2212267224001928

According to a study published in Circulation Arrhythmia and Electrophysiology, atrial fibrillation, a common type of arrhythmia that is on the rise in people under the age of 65, is more dangerous in this increasingly younger population than previously thought.

Atrial fibrillation disrupts the heart's rhythm, leading to irregular and often faster heartbeats. This can cause blood to pool in the heart's chambers, increasing the risk of blood clots and stroke. It can also weaken the heart muscle over time, leading to heart failure and other cardiovascular complications.

In the study, researchers analysed electronic health records of 67,221 patients from UPMC Heart and Vascular Institute seeking care for atrial fibrillation from 2010 through 2019 and found that more than a quarter of them (17,335) were under the age of 65.

The team also found that over the course of a decade, survival rates for those with the arrhythmia were 1.3 to 1.5 times worse for men with atrial fibrillation, and 1.82 to 3.16 times worse for women, compared to similarly aged patients who did not have atrial fibrillation The patients studied also had high rates of cardiovascular disease risk factors, including smoking, obesity, hypertension and sleep apnea, which contribute to damaging structural and electrical changes in the heart over time.

“Common knowledge among cardiologists is that, in people under 65, Afib is extremely uncommon and not detrimental. But there hasn’t been any data to back that up,” said lead author Dr. Aditya Bhonsale, M.D., M.H.S, a UPMC cardiac electrophysiologist in HVI’s Division of Cardiology.

The findings suggested that patients with atrial fibrillation aged <65 years have significant comorbidity burden and considerable long-term mortality. They are also at a significantly increased risk of hospitalization for heart failure, stroke, and myocardial infarction.

Reference: Aditya Bhonsale, et al; Mortality, Hospitalization, and Cardiac Interventions in Patients With Atrial Fibrillation Aged <65 Years; Circulation Arrhythmia and Electrophysiology; https://doi.org/10.1161/CIRCEP.123.012143

A recent study published in Scientific Reports explored the potential acute impacts of roasted green tea and green tea consumption on mental task performance compared to plain water.

Green tea, in particular, is consumed worldwide as a healthy drink because of its characteristic inhibition of cholesterol absorption by the body through tea catechins, as well as its antioxidant and antibacterial effects. Previous research has highlighted the cognitive benefits of green tea consumption, though the research has often focused on long-term effects, individual compounds in isolation, or high consumption.

The study involved 20 healthy adult men aged around 23. They underwent a mental arithmetic task six times over two sessions in one day. In the first session, they drank hot water before three tasks and then had a rest, repeating four times. In the second session, they consumed either green tea or roasted green tea before the remaining tasks and another rest, also four times. This process was repeated a month later, with participants trying both teas. Researchers assessed 11 physiological responses and gathered self-evaluations on fatigue, stress, mental workload, and workflow to gauge the effects of hot water and different teas on mental performance.

The results revealed that compared to drinking hot water, tea consumption during tasks resulted in significantly lower tissue blood volume (TBV), tissue blood flow (TBF), and near-infrared spectroscopy responses (NIRS) in participants. Aromatic compounds present in green tea, known to have relaxation effects, appeared to play a significant role in these positive outcomes.

The findings suggested that drinking green tea or roasted green tea may help moderate the participants’ physiological stress responses. Through examining the multiple indicators, aromatic stimulation from tea drinks suggested the potential to exert positive physiological and subjective effects in a short duration and in small quantities, similar to amounts consumed daily.

“The study highlights the role of aromatic stimulation from tea, particularly compounds like pyrazines in roasted green tea, in influencing mood, relaxation, and alertness by directly affecting brain activity. Additionally, tea consumption induces peripheral vasoconstriction, potentially contributing to feelings of refreshment and increased alertness,” said Alyssa Simpson, registered dietitian and medical nutrition advisor.

Reference: Kurosaka, C., Tagata, C., Nakagawa, S. et al. Effects of green tea and roasted green tea on human responses. Sci Rep 14, 8588 (2024). https://doi.org/10.1038/s41598-024-59383-y