Blood Pressure: The Best Morning Drinks

A glass of water, a cup of coffee, perhaps a tea – the first drinks of the day are pure routine for most people. Some of them noticeably affect blood pressure – and not always in the way you'd expect.

Why morning blood pressure is worth a closer look

Blood pressure naturally rises and falls throughout the day. In the first hours after waking, it goes up in most people – that's completely normal, the body is simply switching from rest mode to wake mode. And that's exactly when we drink our first beverages of the day. No wonder, then, that water, beetroot juice, hibiscus tea, green tea and coffee have all been studied for their effect on blood pressure.

A quick note on the numbers: blood pressure is given as two figures – the upper (systolic) and lower (diastolic) reading, measured in mmHg. When we mention "−4 mmHg" below, it means the reading was, on average, 4 points lower than without that drink.

Water: the underrated drink with a surprise effect

Water is generally considered the most neutral of all beverages – yet the opposite is closer to the truth. When we drink water, the body briefly reacts with a kind of small alarm reflex: the nervous system becomes more active for a few minutes, and the upper blood pressure reading rises slightly instead of dropping. In young, healthy people this is barely noticeable. In older adults, one study measured a rise of around 11 mmHg roughly half an hour after drinking a large glass of water (480 ml). Another study found the same short-term effect in people with and without high blood pressure.

This doesn't mean drinking water in the morning is a problem – getting enough fluids after the night is sensible either way. It just shows that "lowering blood pressure" and "having a mildly stimulating effect" are two different things when it comes to water. The effect is reliable enough that researchers even put it to deliberate use, for example with people who have circulation problems.

Beetroot juice: the morning nitrate effect

Beetroot juice is naturally rich in nitrate, a plant compound the body converts into a substance that relaxes and widens blood vessels. In a combined analysis of several studies with 254 participants in total, the upper blood pressure reading dropped by an average of 4.4 mmHg after beetroot juice or nitrate intake – the lower reading barely changed. A further review in people with diagnosed high blood pressure found a similar result. The individual studies do vary quite a bit in length and the people involved, so these numbers are best read as a trend rather than a fixed figure.

A word of caution: people prone to kidney stones should go easy on larger amounts of beetroot juice, since it's high in oxalic acid. Anyone already taking blood-vessel-widening medication should check with their doctor before drinking larger amounts, as the effects can add up.

Hibiscus tea: the strongest effect among the drinks

Hibiscus tea (sometimes called "sour tea") has the clearest evidence behind it so far. In one study of 65 people with mildly elevated blood pressure, the upper reading dropped by an average of 7.2 mmHg after six weeks of drinking three cups of hibiscus tea a day – compared with just 1.3 mmHg in the group that got a plain comparison drink. A larger review with over 1,200 participants confirmed this blood-pressure-lowering effect. The red plant pigments in hibiscus (anthocyanins) are thought to be behind it, believed to help relax blood vessels. Worth knowing: most studies used a clearly measured, pure hibiscus infusion (around 10 g of dried calyces a day) over several weeks. Store-bought blends, for example with rosehip or other fruits, usually contain less hibiscus per cup – so the effect measured in these studies doesn't automatically carry over to every tea blend.

Hibiscus tea shouldn't be casually combined with blood-pressure-lowering medication, since blood pressure can then drop too far; interactions with certain diuretics and diabetes medication are also possible. Regular use isn't recommended during pregnancy or breastfeeding, as there isn't enough data on this.

If you'd rather enjoy hibiscus in a milder, fruitier form, it's often found blended with other fruits – rosehip, for instance, adds a natural, fruity depth to the infusion.

Green tea: a small effect, and mixed opinions

For green tea, the picture is less clear. A combined analysis of several studies found a slight drop of around 2 mmHg in both the upper and lower readings – most noticeable in people who already had a somewhat elevated starting value. A more recent study focused specifically on overweight individuals, however, found no measurable effect on blood pressure at all, even though waist size and blood fats improved slightly. Why the results differ so much isn't fully clear yet – dosage and the group of people studied likely play a role. Green tea also contains caffeine, worth bearing in mind if you're sensitive to it.

Coffee: a short-term outlier that settles down long term

Coffee tells two very different stories. In the short term – in the first one to three hours after drinking it – blood pressure rises noticeably, especially in people who don't drink coffee often. At a caffeine amount roughly equal to two to three cups of coffee, one study in people with high blood pressure measured a rise of around 8 mmHg in the upper reading and nearly 6 mmHg in the lower one. In people who drink coffee every day, this short-term spike is much smaller in several studies, or doesn't happen at all – the body seems to get used to it. Looking at the bigger picture, large long-term studies on moderate, regular coffee drinking (around one to three cups a day) mostly show no increased risk of developing high blood pressure – some even point to a slightly lower risk.

People with heart rhythm issues, pregnant women, and those who are especially sensitive to caffeine are best off discussing their coffee habits individually with a healthcare professional.

At a glance: five morning drinks and their effect on blood pressure

Beverage	What's behind it	What studies have observed	Magnitude
Water (one large glass)	A brief nudge to the nervous system	Short-term rise in the upper reading	e.g. around +11 mmHg in older adults
Beetroot juice	Natural nitrate	Drop in the upper reading	around −4.4 mmHg
Hibiscus tea	Red plant pigments	Drop in both the upper and lower reading	around −4 to −7 mmHg
Green tea	Plant compounds (catechins)	Inconsistent: mild drop or no effect	around −2 mmHg or no effect
Coffee	Caffeine	Short-term rise, smaller in habitual drinkers	around +3 to +8 mmHg (short term)

A quick word of context: all the figures above come from scientific studies with specific groups of people. They're interesting observations, but no substitute for medical advice – especially if you've already been diagnosed with high blood pressure or take medication for it. All the studies were also done with adults, so the results can't simply be applied to children.

Conclusion

Five drinks, five very different stories: beetroot juice and hibiscus tea repeatedly lower the upper blood pressure reading in studies, green tea only sometimes, and the seemingly most neutral drink of all – water – actually causes a slight short-term rise. Coffee, meanwhile, shows a wide gap between its short-term and long-term effects. How all this plays out in everyday life, beyond controlled study conditions, isn't fully settled yet. Either way, it's a good reason to look at your own morning routine with a little more curiosity and a little less blanket assumption.

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This article is intended for general information about nutrition-related topics and does not replace medical advice, diagnosis, or treatment. If you have health concerns, please consult a doctor or pharmacist.

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