Hibiscus or coffee before three hours of sitting: lower blood pressure with hibiscus in a small trial

Two drinks compared in the same participants

Participants completed two sessions of three hours of uninterrupted sitting after drinking either hibiscus tea or coffee. The crossover design allows the two conditions to be compared in the same people, limiting the influence of individual differences.

The average age was 24.9 years. Half the participants were women, and 54.2% had overweight or obesity. Nevertheless, the abstract describes this population as healthy. The researchers measured blood pressure and several indices of heart rate variability.

A difference in blood pressure, not a demonstrated reduction compared with no drink

After adjustment for baseline values, systolic pressure was 4.2 mmHg lower, diastolic pressure 3.3 mmHg lower, and mean arterial pressure 3.6 mmHg lower in the hibiscus condition than in the coffee condition. These differences were statistically significant.

These are differences between two drinks, not necessarily reductions from baseline. The abstract does not report a water or no-drink condition. It therefore cannot establish whether the difference stems from an effect of hibiscus, coffee, or both.

One heart rate variability index, log-transformed high-frequency power, was also higher with hibiscus. The other indices did not differ significantly. This isolated finding is not enough to conclude that cardiovascular function improved overall.

What this trial does not support recommending

The study examines an immediate response in a small group of young adults. It measures neither the development of cardiovascular disease nor the effect of regular consumption. Nor can its findings be extrapolated to people with hypertension or older adults.

The analyses by sex and body mass index remain exploratory: no formal interaction test was performed. Finally, the supplied abstract specifies neither how the drinks were prepared nor their quantities. It does not provide enough information to suggest a recipe or a reproducible protocol.

What we can take away

Here, hibiscus shows a more favorable blood pressure profile than coffee during three hours of sitting. This is a limited experimental signal, not proof that a drink offsets a prolonged period of sedentary behavior.