Previous studies have proved that tea intake is advantageous to human health, and the beneficial impacts include mood improvement and cardiovascular disease prevention. Outcomes of a longitudinal study directed by Asst Prof Feng which was published in 2017 even revealed that daily consumption of tea can lessen the risk of cognitive decline in aged people by 50 per cent.
In trail of this discovery, Asst Prof Feng and his team continued to examine the explicit effect of tea on brain networks.
The research team enrolled 36 adults aged 60 and above, and compiled data about their health, lifestyle, and psychological well-being. The aged participants also had to go through neuropsychological tests and magnetic resonance imaging (MRI). The study was conducted from 2015 to 2018.
After assessing the participants’ cognitive performance and imaging results, the research team discovered that people who consumed either green tea, oolong tea, or black tea at least four times a week for about 25 years had brain regions that were interconnected in a more productive way.
“Take the analogy of road traffic as an example, consider brain regions as destinations, while the connections between brain regions are roads. When a road system is better organised, the movement of vehicles and passengers is more efficient and uses less resources. Similarly, when the connections between brain regions are more structured, information processing can be performed more efficiently,” explained Asst Prof Feng.
He added, “We have shown in our previous studies that tea drinkers had better cognitive function as compared to non-tea drinkers. Our current results relating to brain network indirectly support our previous findings by showing that the positive effects of regular tea drinking are the result of improved brain organisation brought about by preventing disruption to interregional connections.”
A research published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC) says that drinking tea at least three times a week is connected with a longer and healthier life.
“Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death,” said first author Dr Xinyan Wang, Chinese Academy of Medical Sciences, Beijing, China.
“The favourable health effects are the most robust for green tea and for long-term habitual tea drinkers.”
The examination included 100,902 participants of the China-PAR project2 with no record of heart attack, stroke, or cancer. Participants were categorized into two groups: habitual tea drinkers (three or more times a week) and never or non-habitual tea drinkers (less than three times a week) and followed-up for a median of 7.3 years.
Habitual tea consumption was linked with more healthy years of life and longer life expectancy.
The probable impact of changes in tea drinking behaviour were examined in a subset of 14,081 participants with inspections at two time points. The average interval between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years.
Regular tea drinkers who retained their habit in both surveys had a 39% lower danger of heart disease and stroke, 56% lower danger of fatal heart disease and stroke, and 29% lessened danger of all-cause death compared to consistent never or non-habitual tea drinkers.
Senior author Dr. Dongfeng Gu, Chinese Academy of Medical Sciences, disclosed : “The protective effects of tea were most pronounced among the consistent habitual tea drinking group. Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect.”
In a subanalysis by variety of tea, drinking green tea was associated with about 25% lower dangers for heart disease and stroke, fatal heart disease and stroke, and all-cause death. But, no substantial links were detected for black tea.
Dr. Gu reported that an appreciation for green tea is outstanding to East Asia. “In our study population, 49% of habitual tea drinkers consumed green tea most frequently, while only 8% preferred black tea. The small proportion of habitual black tea drinkers might make it more difficult to observe robust associations, but our findings hint at a differential effect between tea types.”
Two conditions may be at stage. First, green tea is an abundant source of polyphenols which defend against cardiovascular disease and its risk factors including high blood pressure and dyslipidaemia.
Black tea is completely fermented and during this procedure polyphenols are oxidised into pigments and may lose their antioxidant effects. Additionally, black tea is mostly served with milk, which prior study has revealed may neutralize the favourable health effects of tea on vascular function.
Gender-specific evaluation revealed that the protective impacts of habitual tea consumption were affirmed and concentrated across different outcomes for men, but only modest for women.
Dr. Wang said: “One reason might be that 48% of men were habitual tea consumers compared to just 20% of women. Secondly, women had much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men.”
She added: “The China-PAR project is ongoing, and with more person-years of follow-up among women the associations may become more pronounced.”
The researchers surmised that randomised assessments are guaranteed to substantiate the outcomes and give proof for dietary tactic and lifestyle suggestions.