New Study Finds Yerba Mate Drinkers Have Significantly Stronger Bones After Menopause — With Three Times Lower Osteoporosis Rates

After menopause, the human skeleton enters a period of accelerated decline. Estrogen, which for decades acted as a brake on the cells that break down bone, drops sharply — and within the first five to seven years after menopause, women can lose up to 20% of their bone density. The consequences are not abstract: osteoporosis affects an estimated 200 million women worldwide and causes more than 8.9 million fractures every year, with hip fractures alone carrying a first-year mortality rate of 20-24% in elderly patients. [2]

Against this backdrop, a research team from Argentina's Rosario National University and CONICET — the country's premier scientific research council — has published findings that will resonate with anyone familiar with South American drinking culture. Their study, published in the Journal of Bone Metabolism in May 2025, examined 300 postmenopausal women and found that those who habitually drink yerba mate have significantly stronger bones than those who don't — with an osteoporosis diagnosis rate nearly three times lower, and half the rate of fragility fractures. [1]

What Is Osteoporosis, and Why Does It Matter So Much?

Before diving into the study, it helps to understand what osteoporosis actually is — and why scientists are so eager to find ways to prevent it. Your bones are not static structures. They are living tissue, constantly being broken down and rebuilt by two types of specialized cells: osteoclasts, which dissolve old bone, and osteoblasts, which build new bone. In healthy adults, these two processes are roughly in balance. But after menopause, the loss of estrogen tips the scales decisively in favor of the osteoclasts. Bone gets broken down faster than it can be rebuilt, and over time, the skeleton becomes porous and fragile.

The clinical term for this is osteoporosis — literally 'porous bones.' The condition typically causes no symptoms until a bone breaks, often from a fall that wouldn't have caused a fracture in a younger person. The most dangerous fractures occur at the hip, spine, and wrist. Spinal compression fractures can cause chronic pain and loss of height; hip fractures can be life-threatening, especially in elderly patients who may never fully recover their mobility. [2]

The Study: Who, Where, and How

The research was led by Dr. Lucas R. Brun and Dr. María Lorena Brance from the Bone Biology Laboratory at Rosario National University's School of Medicine, in collaboration with researchers from CONICET, the Fundación Escuela de Medicina Nuclear (FUESMEN) in Mendoza, and the Universidad del Magdalena in Colombia. The team studied 300 postmenopausal women in Argentina, dividing them into two groups: 153 women who regularly drink yerba mate and 147 who do not. [1]

What makes this study technically notable is the imaging method. While all women received standard dual-energy X-ray absorptiometry (DXA) scans — the same bone density test your doctor might order — the researchers went a step further. They used a specialized software called 3D-Shaper, which reconstructs a three-dimensional model of the bone from the standard DXA image. This allowed them to separately analyze two distinct types of bone that are critical to understand.

Cortical vs. Trabecular Bone: A Quick Anatomy Lesson

Imagine sawing a long bone in half. The hard, dense outer shell that you see is cortical bone — it makes up about 80% of the skeleton's total mass and provides structural strength. But inside that shell is trabecular bone, a spongy, honeycomb-like network of thin struts called trabeculae. Though it represents only about 20% of bone mass, trabecular bone has an enormous surface area and is metabolically far more active than cortical bone. This means it responds faster to both good and bad influences — including hormonal changes after menopause.

Standard DXA scans measure areal bone mineral density — essentially a two-dimensional projection that mixes cortical and trabecular bone together. The 3D-DXA technique used in this study separates the two, which is important because interventions that improve cortical bone might not affect trabecular bone, and vice versa. By measuring both, the researchers could determine whether yerba mate's apparent bone-protective effect operates across the full architecture of the skeleton. [1]

The Results: Striking Differences

The two groups were well-matched: there was no significant difference in either age (p=0.746) or body mass index (p=0.329), meaning the researchers were comparing like with like. The results were unambiguous. [1]

Every bone parameter measured — total hip BMD, integral volumetric BMD, cortical surface BMD, and trabecular BMD — was significantly higher in the yerba mate group, all with p-values below 0.0001. In clinical terms, a p-value below 0.05 is generally considered statistically significant; p<0.0001 means there is less than a 1-in-10,000 probability that the observed difference is due to random chance. [1]

The clinical outcomes were equally striking. Only 3.3% of yerba mate drinkers received a DXA-based osteoporosis diagnosis, compared to 10.9% of non-drinkers — a more than threefold difference. The odds ratio of 0.276 means that yerba mate drinkers had roughly one-quarter the odds of being diagnosed with osteoporosis. Similarly, only 5.9% of mate drinkers reported a history of low-impact fractures (fractures caused by forces that would not normally break healthy bone), compared to 12.9% of non-drinkers. [1]

The 3D Finding: Both Bone Types Are Protected

Perhaps the most significant finding was that both cortical and trabecular bone compartments showed higher density in the yerba mate group. This matters because the two bone types degrade differently in osteoporosis and respond differently to treatment. For example, some osteoporosis drugs primarily preserve cortical bone while having limited effect on trabecular architecture. The fact that yerba mate consumption was associated with across-the-board improvements suggests a systemic mechanism rather than a targeted effect on one bone type.

The regression analysis reinforced this conclusion. In both mate drinkers and non-drinkers, bone density correlated positively with BMI (heavier women tend to have denser bones) and negatively with age (older women lose bone density). But at every BMI and every age, the mate-drinking group had higher bone density than the non-drinking group. The slope of the relationship was the same — meaning mate doesn't change how fast you lose bone with age — but the 'starting point' was uniformly higher. Think of it as two parallel lines on a graph, one consistently elevated above the other. [1]

Why Might Yerba Mate Protect Bones? Four Possible Mechanisms

The study is observational, meaning it shows association, not causation. The researchers did not randomly assign women to drink or avoid yerba mate and then track their bone density over decades — a study design that would be prohibitively expensive and logistically challenging. But the biological plausibility of a yerba mate-bone connection is supported by several lines of evidence.

First, yerba mate is exceptionally rich in polyphenols — particularly chlorogenic acids and caffeoylquinic acid derivatives. These compounds are potent antioxidants and anti-inflammatory agents. This is relevant because chronic low-grade inflammation — sometimes called 'inflammaging' — is a major driver of osteoclast activation, the process that breaks down bone. By dampening systemic inflammation, polyphenols could theoretically slow the rate of bone resorption. Previous research has established that Ilex paraguariensis extracts demonstrate significant anti-inflammatory properties in both cell culture and animal studies. [5]

Second, yerba mate contains meaningful amounts of minerals relevant to bone metabolism. These include manganese (essential for bone formation), magnesium (required for calcium absorption and bone crystal structure), potassium (which helps reduce calcium loss through urine), and zinc (a cofactor for enzymes involved in bone formation). While no single cup of mate provides therapeutic doses of these minerals, the habitual, daily pattern of consumption — which in Argentine culture often means drinking mate throughout the day — creates a cumulative intake that may meaningfully supplement dietary mineral needs.

Third, some researchers have proposed that the saponins found in yerba mate may directly influence osteoblast and osteoclast activity. Saponins are a class of naturally occurring compounds that have demonstrated bone-protective effects in studies of other plants, though this mechanism remains less well characterized in yerba mate specifically.

Fourth, there is the caffeine question. Yerba mate contains significant caffeine — roughly 80-100 mg per typical serving. High caffeine intake has been associated in some studies with increased urinary calcium excretion, which could theoretically weaken bones. However, the evidence on moderate caffeine consumption (200-400 mg/day) is far from clear-cut, and several large meta-analyses have found no significant relationship between moderate caffeine intake and fracture risk when calcium intake is adequate. This study's findings add to the evidence that whatever calciuretic effect caffeine might have in mate is apparently overwhelmed by the beverage's other bone-protective constituents.

Our study provides novel insights into yerba mate consumption and bone health in postmenopausal women. We confirm its positive association with BMD and demonstrate, for the first time, that both cortical and trabecular compartments contribute to this effect. Our findings also suggest a potential protective role of yerba mate against osteoporosis and fragility fractures.

How This Fits Into Earlier Research

This is not the first study to examine the yerba mate-bone relationship. In 2012, researchers including Dr. Fernando Daniel Saraví — who is also a co-author of the new study — published work in Bone showing that postmenopausal mate drinkers in Argentina had higher lumbar spine and femoral neck BMD than non-drinkers. That earlier study used standard 2D DXA imaging and had a similar observational design. [3]

The 2025 study advances the field in two key ways. First, by using 3D-DXA modeling, it disaggregates the cortical and trabecular contributions to bone density — something the 2012 study could not do. Second, it documents clinical outcomes (osteoporosis diagnoses and fracture rates) in addition to bone density measurements, providing a bridge from imaging findings to real-world health consequences.

It is also worth noting that the research team spans multiple institutions across Argentina and Colombia, and that the lead institution — Rosario National University — houses a dedicated Bone Biology Laboratory that has been studying bone metabolism for decades. This is not an isolated finding from an unfamiliar laboratory; it is the product of a research program with a long track record in the field.

Limitations: What the Study Cannot Tell Us

Several important caveats apply, and honest science reporting requires stating them clearly.

First, this is a cross-sectional observational study — a snapshot in time, not a longitudinal experiment. Women who drink yerba mate daily may differ from non-drinkers in other ways that affect bone health: different diets, different physical activity patterns, different genetic backgrounds, or even different sun exposure (which influences vitamin D levels). Although the researchers controlled for age and BMI, other unmeasured confounders could partially explain the observed differences.

Second, the sample size of 300 women, while adequate for detecting the reported effect sizes, is modest. Larger studies — ideally multi-center, longitudinal cohorts that follow women for years before and after menopause — would provide stronger evidence. The gold standard would be a randomized controlled trial, though assigning women to drink or abstain from mate for years raises practical and ethical challenges.

Third, the study was conducted in Argentina, where yerba mate preparation follows specific cultural practices (hot water infusion in a gourd, consumed throughout the day). Whether the same effects would apply to different preparation methods — cold-brewed tereré, ready-to-drink canned products, or mate tea bags — remains unknown.

Fourth, any balanced assessment of yerba mate must acknowledge the thermal risk documented in other research. Drinking very hot beverages of any kind — including mate consumed at temperatures above 65°C — has been classified by the International Agency for Research on Cancer (IARC) as 'probably carcinogenic to humans' for esophageal cancer. This risk relates to temperature, not to yerba mate specifically, and modern health guidance recommends allowing hot beverages to cool before drinking.

What This Means for You

It would be premature to call yerba mate a treatment or prevention for osteoporosis. The evidence is observational and, while increasingly consistent across studies, has not yet reached the level of proof that would justify a clinical recommendation. No one should replace prescribed osteoporosis medication with yerba mate based on this research.

That said, for women already concerned about bone health — particularly those approaching or past menopause — the emerging evidence positions yerba mate as a dietary factor worth considering alongside well-established bone-protective habits like weight-bearing exercise, adequate calcium and vitamin D intake, and avoiding smoking. If you are already a mate drinker, this research provides reassurance that the habit may carry skeletal benefits beyond its well-known stimulant properties. If you are curious about starting, the data suggests that habitual, daily consumption — not occasional sipping — is associated with the observed benefits.

The broader significance may be for the nutrition research community. Yerba mate has long been studied primarily for its antioxidant properties and its effects on metabolic markers like blood sugar and cholesterol. The bone density findings open a new and somewhat unexpected research direction — one that the Argentine research team has been pursuing steadily for over a decade. If their work continues to hold up under larger, more rigorous study designs, it could add a meaningful chapter to the story of how traditional dietary practices, shaped over centuries, sometimes turn out to encode biological wisdom that modern science is only beginning to quantify.

The Bottom Line

A team of Argentine and Colombian researchers has published the most technologically sophisticated study to date on yerba mate and bone health. Using 3D bone imaging that standard clinical scans cannot provide, they found that postmenopausal women who drink mate daily have denser bones across both cortical and trabecular compartments, a three-times-lower rate of osteoporosis diagnosis, and half the rate of fragility fractures. The study does not prove that yerba mate directly causes stronger bones — but combined with earlier research, it builds a compelling case that the world's most popular caffeine source you've probably never heard of may carry benefits that extend from the teacup all the way down to the skeleton.