Tea plus exercise may reduce the risk for death

Key takeaways:

• Tea consumption reduced the risk for mortality in those who were physically active vs. inactive.
• Tea intake only reduced the risk for cancer-related mortality in those who were physically active and not by itself.

Combining high consumption of tea with physical activity could substantially decrease the risk for death, results from a cohort analysis suggested.

Both tea and physical activity have been independently associated with a lower risk for mortality and several other health outcomes in prior studies.

However, there is a lack of research on whether the consumption of tea combined with physical activity could further lower the risk for all-cause or cancer-specific mortality, Yiqun Hu, from the Third Xiangya Hospital of Central South University in China, and colleagues explained in Scientific Reports.

“It is also unclear whether [physical activity] influences the effect of tea drinking on mortality reduction,” they added.

The researchers assessed National Health and Nutrition Examination Survey data from 2009 to 2018 on 49,693 participants aged 20 to 80 years. The final analysis included 21,350 individuals.

At an average follow-up of 74.9 months, 1,575 deaths occurred in the study sample.

Both tea consumption (HR = 0.98; 95% CI, 0.966-0.994) and physical activity (HR = 0.595; 95% CI, 0.535-0.661) independently reduced the risk for mortality.

Tea consumption further reduced the risk for all-cause mortality in the physically active group (HR = 0.969; 95% CI, 0.947-0.993) but not in the physically inactive group.

Risk reductions in the physically active group varied depending on the levels of tea consumption and exercise. In adults with the highest level of physical activity, HRs for mortality were 0.43, 0.45 and 0.48 among those with high, low and no tea consumption, respectively.

Hu and colleagues noted that tea intake alone did not significantly reduce the risk for cancer-specific mortality. Instead, only tea consumption in the physically active group reduced the risk (HR = 0.64; 95% CI, 0.421-0.973).

When the researchers analyzed specific populations, they found that tea consumption in the physically active group particularly reduced the risk for all-cause mortality among:

• adults aged 60 years and older (HR = 0.947; 95% CI, 0.916-0.98);
• men (HR = 0.966; 95% CI, 0.938-0.995);
• non-Hispanic white adults (HR = 0.966; 95% CI, 0.939-0.994); and
• adults of other diverse populations (HR = 0.814; 95% CI, 0.686-0.967).

Meanwhile, tea consumption reduced only the risk for all-cause death in the inactive group among those with hypertension (HR = 0.975; 95% CI, 0.952-0.999).

Notably, tea consumption increased the risk for all-cause mortality among those aged 20 to 40 years regardless of whether they were physically active (HR = 1.048; 95% CI, 1.009-1.088) or inactive (HR = 1.091; 95% CI, 1.032-1.153).

Hu and colleagues pointed out that a larger number of participants aged 20 to 40 years were excluded from the final analysis vs. those aged 40 to 60 years or older, which “could introduce bias in age-stratified analyses.”

“[T]hus, age-related results should be approached with caution,” they noted.

The researchers highlighted some possible mechanisms behind the health benefits of tea.

They explained that green tea has antioxidant activity that can fight oxidative stress, “which may reduce the possible negative effects of exercise to a certain extent, so as to further improve health.”