Drinking Roselle Tea Lowered Blood Pressure

Roselle — กระเจี๊ยบแดง (kra-jiap-daeng) — Hibiscus sabdariffa.

Roselle — gra-jiap-daeng — the tart red calyx that gives Thai hibiscus tea its ruby color, plus how to use it and what one trial tested. The edible parts are the red calyces and the sour young leaves. In one controlled trial, adults with high blood pressure drank roselle tea to study its effects. Roselle nutrition includes calcium, the mineral bones and teeth are built from, plus iron, which sits at the center of hemoglobin, the protein that ferries oxygen through your red blood cells. In tom yam pla, fish simmers in a hot, sour broth where fresh roselle leaves do the souring in place of lime, and the finished soup is served with jasmine rice. For a sparkling roselle drink, boil dried calyces with sugar into a deep-red syrup, then cut it with cold soda water and pour it over ice. Pick the red calyces about ten days after the flower drops, while they're still fleshy and tender. To get more of that iron, pair it with a squeeze of lime or another vitamin-C food, which helps the body absorb it. For a new Thai plant every day, follow Longevity Biome.

Tom Yam Pla Bai Kra Jiap Daeng — ต้มยำปลาใบกระเจี๊ยบแดง (tom-yam-pla-bai-kra-jiap-daeng)
Nam Kra Jiap Sa — น้ำกระเจี๊ยบซ่า (nam-kra-jiap-sa)

Food and nutrients

Rich in: calcium, iron

Research context

Roselle tea lowered systolic blood-pressure readings in a trial — Journal of Nutrition, 2010

Sources

Source: McKay DL et al. (2010). Hibiscus sabdariffa tea lowers BP in pre/mildly hypertensive adults. J Nutr 140(2):298-303. DOI:10.3945/jn.109.115097 (PMID 20018807)

Narration transcript

Opening

That ruby-red Thai roselle tea gets its color from something most people never see: the calyx, the tart, fleshy cup left behind on the stem after the flower's petals fall. Roselle — กระเจี๊ยบแดง, kra-jiap-daeng. You steep those red calyces for tea and drinks, and cook the sour young leaves as a vegetable too.

ต้มยำปลาใบกระเจี๊ยบแดง

In tom yum pla bai krachiap daeng, a hot-and-sour fish soup, the fish simmers in a broth where roselle leaves do the souring in place of lime; the finished soup is served with jasmine rice.

น้ำกระเจี๊ยบซ่า

The sparkling version — nam krachiap sa, nam-kra-jiap-sa — starts with dried calyces boiled down with sugar into a deep-red syrup, then cut with cold soda water and poured over ice.

Nutrition summary

Steeped or cooked, roselle calyces bring useful calcium, vitamin C, and magnesium, with some iron too.

Calcium

Calcium is needed to maintain normal bones and teeth, supports normal muscle and nerve function, and contributes to normal blood clotting.

Iron

Iron is part of hemoglobin, the protein that carries oxygen in your blood, and it supports normal energy metabolism.

Closing

Harvest the calyces about ten days after the petals drop, while they're still plump and tender, because they turn woody if you leave them longer. To get more from the iron in the leaves, eat them with a squeeze of lime or another vitamin-C food, which helps your body take that iron up. Follow Longevity Biome, and LIKE this video for regular updates.

Related playlists