Tea-and-Aging Study Everyone Shared Barely Looked at Oolong
A 2025 tea-and-aging review found tea may guard against several diseases of age, and a ScienceDaily write-up sent it around again this June. Almost all of it rests on green tea, and the authors say plainly that oolong is little studied.
A review of tea and healthy aging that circulated widely this month rests almost entirely on green tea, and its authors state plainly that oolong's effects are little studied by comparison.
The paper, by Mingchuan Yang, Li Zhou, and colleagues at the Tea Research Institute of the Chinese Academy of Agricultural Sciences, appeared in the journal Beverage Plant Research. It gathered the evidence linking tea drinking to lower rates of heart disease, diabetes, some cancers, cognitive decline, and age-related muscle loss. Read the sourcing under those associations and one leaf accounts for most of it: the effects of different tea types have been compared in animal studies, but, the authors write, "the results of these studies have not provided sufficient evidence, nor are there enough human data to assess whether Oolong tea, white tea, dark tea, or yellow tea is more or less effective than green tea in providing health benefits to tea consumers."
The distinction matters for what follows. Oolong is not green tea: it is partly oxidized, from perhaps 8% to 80% depending on the maker, and often roasted over charcoal after that. Oxidation and roast change the chemistry the health studies measure, the catechins and their oxidation products, in ways no one has yet mapped against green tea in a careful trial. On the evidence the review gathers, oolong has simply not been tested the way green tea has.
The review adds one caution that needs no trial to trust. Sweetened ready-to-drink teas, the authors write, carry "sugar, artificial sweeteners, or refined starch, as well as flavoring agents and preservatives" that "may cause health concerns in reducing or overshadowing the beneficial health effects of tea." A bottled oolong falls outside the kind of tea these associations were measured on.
None of this settles whether to drink oolong. What the review shows is narrower than the headlines: when a study says tea guards against the diseases of age, it is, for now, mostly saying green tea. The seventh steep has yet to be measured on its own.
Sources: ScienceDaily, "Tea can improve your health and longevity, but the way you drink it matters" (June 9, 2026); Yang, M. et al., "Beneficial health effects and possible health concerns of tea consumption: a review," Beverage Plant Research, doi:10.48130/bpr-0025-0036.