Green Tea vs. Oolong Tea: Is One Actually Better for You? Here’s What the Research Says

Green tea gets a lot of attention for its antioxidants. Oolong, meanwhile, often sits somewhere between green and black tea; less talked about, but surprisingly interesting when you look at the research.(I know, “research” doesn't sound like the most exciting tea-time conversation)

So, is one actually healthier than the other?

The short answer is: there's no clear winner.

Both green tea and oolong contain polyphenols, including catechins such as EGCG, and researchers have studied their potential effects on everything from blood pressure and cholesterol to metabolism and cardiovascular health.

But the science is more nuanced than the usual “this tea is good for you” headlines suggest. Some studies find small benefits, while others show limited or inconsistent effects. And importantly, many studies look at associations rather than proving that drinking tea directly causes a health outcome.

So rather than asking “Which tea is healthier?”, it may be more useful to ask:

What does the research actually tell us about each tea and what can you realistically expect from drinking it?

Let's look at what the studies have found.

Green Tea: What Research Has Found

• Blood pressure: A meta-analysis of 13 randomized controlled trials found that green tea catechins were associated with an average reduction of 2.08 mmHg in systolic blood pressure and 1.71 mmHg in diastolic blood pressure compared with control. The effect appeared greater in people with systolic BP ≥130 mmHg [5].
• Cholesterol: Studies suggest that green tea catechins may contribute to modest reductions in total and LDL ("bad") cholesterol , although results vary between studies [5][6].
• Cardiovascular health: In a large Japanese cohort study, drinking 2 cups of green tea per day was associated with a 22–33% lower risk of cardiovascular-disease-related mortality . As this was an observational study, the findings show an association rather than proving that green tea itself caused the difference [7].
• Metabolic markers: A 2022 systematic review of 55 randomized controlled trials found modest changes in blood pressure, blood lipids, and markers such as fasting blood sugar and HbA1c [7][8]. The clinical significance of these changes is still an area of research.

Oolong Tea: What Research Has Found

• Energy expenditure: In a controlled crossover study, men drinking oolong tea brewed from 15 g of leaf/day showed higher 24-hour energy expenditure and fat oxidation compared with water. Researchers suggested that both caffeine and oolong-specific polyphenols may have contributed to the effect [9][10].
• Weight management: A 2009 study in the  Chinese Journal of Integrative Medicine  followed 102 overweight or obese participants who consumed 8 g of oolong tea daily for 6 weeks. It found that 70% of the participants classified as severely obese lost more than 1 kg over that period, with 22% losing more than 3 kg [10]. However, this was a relatively small and short-term study, so the results should not be interpreted as evidence that oolong tea causes weight loss.
• Cardiovascular markers: In patients with coronary artery disease, oolong tea intake was associated with changes in plasma adiponectin and LDL particle size [11]. These are potential cardiovascular markers, but the findings do not establish that oolong tea improves cardiovascular health.
• Bone health: An observational study of postmenopausal women in southern China found that women drinking 1–5 cups of oolong tea per day had higher bone mineral density than non-tea-drinkers [13]. Because this was an observational study, other lifestyle factors may also have contributed to the difference.

Is Oolong Tea Healthier Than Green Tea?

There isn't a definitive answer.

The two teas have simply been studied for different health outcomes.

Green tea has more research around blood pressure and cholesterol, while oolong has more research around energy expenditure and metabolic markers [5][7][9][11].

The effects reported in these studies are generally modest, not dramatic.

So, Which Tea Should You Drink?

The simplest answer: choose the one you'll actually enjoy drinking regularly.

If you love fresh, vegetal flavors, green tea may be your go-to.

If you prefer floral, creamy, fruity, or roasted flavors, oolong gives you more variety.

And if you love exploring different flavors, oolong's ability to change across multiple infusions makes it especially fun to brew.

Brewing Green Tea vs. Oolong Tea

Green tea: Use cooler water, around 70–80°C, and steep for 1–3 minutes. This helps reduce bitterness from over-extraction.

Oolong tea: Use hotter water, around 85–100°C, depending on the oxidation level. Many oolongs can also be re-steeped 3 or more times, with new flavors appearing in each infusion.

Stay for a Little While

Life moves quickly. We don’t always get to choose the pace.

But we can choose the little moments we make for ourselves.

At Tea Studio Lu, we want tea to be one of those moments: a familiar presence through busy days, quiet mornings, new adventures, and everything in between.

Thoughtfully selected Taiwanese teas, brought to Switzerland with the hope that every cup gives you a reason to pause, breathe, and keep going.

Whatever kind of day you’re having, we’re here for it. 🍵

FAQ

Does oolong tea have more caffeine than green tea?

Usually, yes. Oolong typically contains 30–75 mg per 240ml cup, compared with 20–45 mg for green tea. However, steeping time, water temperature, and the amount of tea used can have a bigger effect than tea type alone [1][2][4].

Is oolong tea healthier than green tea?

There is no single answer. Both contain beneficial polyphenols. Green tea has stronger research support for blood pressure and cholesterol, while oolong has research around energy expenditure and metabolic markers [5][7][9][11].

Can oolong or green tea help with weight loss?

Both have shown modest effects in clinical studies. One oolong study found around 1 kg of weight loss over 6 weeks, while green tea studies have found small reductions in weight and waist circumference. Neither replaces diet and exercise for weight management [9][13].

Which has a milder taste, oolong or green tea?

Green tea is generally milder and more vegetal. Oolong can range from light and floral to bold and roasted, depending on the style.

Sources

1. The Republic of Tea, Tea and Caffeine — https://www.republicoftea.com/blogs/tea-library/tea-and-caffeine
2. Caffeine Informer, Caffeine in Tea (Oolong) — https://www.caffeineinformer.com/caffeine-content/oolong-tea
3. Art of Tea, Does Oolong Tea Have Caffeine? How Much + How to Control — https://www.artoftea.com/blogs/tea-profiles/does-oolong-tea-have-caffeine
4. Determination of L-Theanine and Caffeine Contents in Tea Infusions with Different Fermentation Degrees and Brewing Conditions, PMC — https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12248710/
5. Khalesi S, et al. Green tea catechins and blood pressure: a systematic review and meta-analysis of randomised controlled trials, PubMed — https://pubmed.ncbi.nlm.nih.gov/24861099/
6. Green tea catechins decrease total and low-density lipoprotein cholesterol: a systematic review and meta-analysis, PubMed — https://pubmed.ncbi.nlm.nih.gov/22027055/
7. The effects of green tea supplementation on cardiovascular risk factors: A systematic review and meta-analysis, PMC — https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9871939/
8. Frontiers in Nutrition, The effects of green tea supplementation on cardiovascular risk factors — https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.1084455/full
9. Rumpler W, et al. Oolong Tea Increases Metabolic Rate and Fat Oxidation in Men, The Journal of Nutrition — https://jn.nutrition.org/article/S0022-3166(22)14493-7/fulltext
10. Beneficial effects of oolong tea consumption on diet-induced overweight and obese subjects, Chinese Journal of Integrative Medicine — https://link.springer.com/article/10.1007/s11655-009-0034-8
11. Oolong tea increases plasma adiponectin levels and low-density lipoprotein particle size in patients with coronary artery disease, ScienceDirect — https://www.sciencedirect.com/science/article/abs/pii/S016882270400021X
12. Multifunctional health-promoting effects of oolong tea and its products, ScienceDirect — https://www.sciencedirect.com/science/article/pii/S2213453021001373
13. A comprehensive overview on the effects of green tea on anthropometric measures, blood pressure, glycemic and lipidemic status: An umbrella review and meta meta-analysis study, Nutrition, Metabolism and Cardiovascular Diseases — https://www.nmcd-journal.com/article/S0939-4753(22)00247-2/abstract