The Two-Year Window: What a Long Resveratrol Trial Measured in Women After Menopause (And the Curcumin Pilot That Followed)

Chapter 1

Two Years, One Group of Women

In Newcastle, on the east coast of Australia, 125 women spent two years swallowing a small capsule twice a day. For one of those years the capsule held resveratrol, the polyphenol best known from grape skins. For the other year it held nothing active at all. None of them knew which year was which.

That is an unusual amount of patience to ask of anyone. Most supplement studies run for eight or twelve weeks, and most of them measure one thing. This one ran for 24 months, and it measured thinking, blood flow to the brain, blood markers, bone and the everyday experience of life after menopause.

The women were aged 45 to 85 and all of them were past menopause. The researchers called the study RESHAW, short for Resveratrol for Healthy Ageing in Women, and its results arrived across four papers between 2020 and 2021.

In this article we walk through that trial the way its authors reported it: what the design was, what improved, how large the changes were, and what the women themselves said. Then we turn to curcumin, the golden compound from turmeric, and to the first small trials that tested it in women after menopause. You will also see exactly where the evidence stops.

Section 1

Why a Crossover Design Matters

RESHAW used what scientists call a crossover design. Instead of splitting women into a resveratrol group and a placebo group for the whole study, each woman spent 12 months on one and then 12 months on the other. Half started with resveratrol, half with placebo, and the order was decided at random.

The advantage is simple. When you compare two different groups of people, some of the difference you see can come from the people themselves: different diets, sleep, genes, starting points. When each woman is compared with herself, much of that background noise cancels out.

The cost is time. A crossover that gives each phase a full year needs two years per participant, plus the patience of everyone involved. That is part of why long crossover trials of supplements are rare, and why this one is worth reading slowly.

One group of women, two twelve-month phases: each woman became her own comparison.

Section 2

A Modest Dose, Taken Twice a Day

The dose was deliberately small: 75 mg of trans-resveratrol, taken twice a day, for a daily total of 150 mg. The resveratrol was a commercial, high-purity ingredient, and its maker publicised the results when they were published, which is worth knowing, as with any study that has an industry connection.

Why so little, when some supplements contain several times more? The design itself gives the answer: a dose that people can take comfortably, every day, for two years is a different goal from a dose meant to produce the biggest possible effect in a few weeks.

Keep that number in mind. It matters later, when we compare the trial with what is in a bottle on a shelf.

Section 3

What the Researchers Set Out to Measure

The trial was built around one main question: in women after menopause, does a daily, modest dose of resveratrol change how well they think, measured with a standard battery of memory and thinking tests?

Alongside that, the team measured how readily the blood vessels supplying the brain widen when they are asked to, using ultrasound. They also took fasting blood samples, scanned bone density, and gave the women detailed questionnaires about well-being, pain and menopausal symptoms.

This is why one trial produced four papers. The first reported the halfway point. The second reported the full two years for thinking and blood flow. The third looked at how the women felt. The fourth looked at bone. We will take them in that order.

Chapter 2

What Two Years Measured

When the code was broken and the two years were compared, the main result pointed in one direction. In the year the women took resveratrol, their overall thinking scores were better than in the year they took placebo.

The researchers summarised it as a 33% improvement in overall cognitive performance relative to placebo. That number needs a careful reading, and so we will give it one.

Section 1

Thinking Performance: A Real Effect, and a Small One

The 33% describes how much more the composite score moved on resveratrol than on placebo. It does not mean the women became a third sharper. In statistical terms, the effect sizes the authors reported were small, in the range scientists usually describe as modest.

Small is not the same as meaningless. In a long trial, a small, consistent shift in the same direction across a large group is exactly what you would expect from a gentle, everyday intervention, rather than from a drug. It is also the kind of result that is easy to exaggerate, so we will not.

What made the result more interesting was where it came from. When the team looked more closely, the women aged 65 and over gained most in verbal memory, the ability to learn and recall words and spoken information. Younger women in the study did not show the same relative gain in that area.

The trial measured both thinking and how readily the vessels supplying the brain respond.

Section 2

The First Twelve Months Already Pointed the Same Way

Before the crossover was complete, the team published an interim look at the first year, comparing the women who had started on resveratrol with those who had started on placebo. This analysis included 129 women.

Even at that stage, the resveratrol group already scored better on overall cognitive performance than the placebo group. The full two-year analysis then confirmed the direction with every woman compared with herself.

Two analyses of the same trial are not two independent trials. But when the halfway result and the final result agree, it is reassuring that the finding did not appear only once the data were sliced a particular way.

Section 3

Blood Flow to the Brain, and Fasting Insulin

The second strand of the trial was cerebrovascular responsiveness: how readily the blood vessels feeding the brain widen when they are challenged. The team measured it with ultrasound while the women breathed air with a little extra carbon dioxide, a standard way of asking those vessels to open up.

In the resveratrol year, that responsiveness improved compared with the placebo year. The authors saw it as one plausible link between the compound and the thinking results, although a trial like this cannot prove which change caused which.

The fasting blood samples added one more signal: fasting insulin was lower in the resveratrol year. That is a secondary result, measured alongside the main question rather than as its target, and we report it in that spirit.

If you read our earlier article on what polyphenol trials found in the lining of the arteries, this is the same family of compounds seen from another angle: not the arteries in general, but a specific group of women, over a much longer stretch.

Section 4

Why the Women Over 65 Stand Out

Subgroup findings always deserve caution. Split any trial into enough groups and one of them will look special by chance. Still, the pattern here is worth noticing because it fits the trial's own question: the gains in verbal memory were largest in the older women, who started from the point where memory tends to need the most support.

For a reader in her sixties or seventies, the practical message is modest and clear. In this trial, women of your age were the group in which resveratrol made the most visible difference to verbal memory over a year. That is a reason for interest, not a promise.

The compounds in this article, in one capsule pair

Resveratrol PLUS · 60 Capsules

Each two-capsule serving provides 500 mg of trans-resveratrol and 500 mg of liposomal curcumin, plus quercetin, fisetin and piperine. 60 capsules: a 30-day supply at two capsules a day.

Who it suits: adults who want both compounds from this article in one daily routine, and who plan to keep it up for months rather than weeks.

The trials in this article used resveratrol alone (150 mg a day) or curcumin alone, at different doses, and did not test this combination.

Add to cart · €84.95 →See full details

Or pass the Final Master Quiz below first: 4 out of 5 unlocks a private reader reward on this product.

🔒 LOCKED: EXCLUSIVE READER REWARD

There is a private, unadvertised reader reward waiting at the end of this article.

Read the next two chapters closely. Score at least 4 out of 5 on the Final Master Quiz at the bottom of the page and we will unlock a reward chosen for the reader who has followed a two-year trial from start to finish, together with a private code that never appears on our public pages. Your reward code works from 1 to 15 November 2026.

The answers are all in the chapters ahead…

Chapter 3

How Women Said They Felt

Numbers from a memory test are one thing. How a woman feels on an ordinary Tuesday is another. The RESHAW team asked about both, and the third paper from the trial is about the second.

During the trial the women filled in detailed questionnaires about their general well-being, bodily pain and the symptoms many women recognise from the years after menopause.

Section 1

Well-Being and Somatic Symptoms

Compared with the placebo year, the women reported better general well-being in the resveratrol year. They also reported less bodily pain and fewer somatic menopausal symptoms, the physical group of symptoms such as aches in muscles and joints, as opposed to mood or vasomotor symptoms.

These were not the main outcomes of the trial, and they came from self-report rather than a blood test or a scan. Self-report matters, though. A supplement that nudges a lab value but leaves a woman feeling no different is less interesting than one where the women themselves noticed a change, even a small one.

Well-being was measured with questionnaires the women completed throughout the two years.

Section 2

A Note on Bone

The fourth paper looked at bone. After the first 12 months, bone mineral density in the lower spine and the hip rose slightly in the resveratrol group compared with placebo. It is a single finding from a trial that was not designed around bone, so we leave it at one sentence.

Section 3

What “Secondary Outcome” Means for You

You will see the phrase secondary outcome in almost every trial report. It simply means a result the trial was not mainly designed to test. The main question gets the careful sample-size calculation; the secondary questions come along for the ride.

That has two consequences. First, secondary findings are more likely to be chance results than the main finding is, especially when many are measured. Second, they are often where the most useful hints for the next trial come from.

So the fair way to read Chapter 3 is this: the main RESHAW result was about thinking. The well-being, symptom and bone results are encouraging hints from the same carefully run trial. None of them on its own would justify a strong claim, and we are not making one.

Chapter 4

Curcumin Enters the Picture

Resveratrol had its two-year trial. Curcumin, the bright yellow compound in turmeric root, is earlier in the same journey. Its first trials in women after menopause are small and short, but they ask different questions, and that is what makes them worth knowing.

Section 1

The 2026 Pilot: Fewer Hot Flushes

In 2026, a research team in Thailand published a randomised, placebo-controlled pilot trial in 40 postmenopausal women. For 12 weeks, half took 1,000 mg of curcuminoids a day and half took a placebo.

Over those weeks, the women taking curcuminoids had about seven fewer hot flushes a week than the women on placebo. For anyone who has lived with frequent hot flushes, seven a week is not a trivial number.

It is also a pilot. Forty women, twelve weeks, one centre. Pilot trials exist to find out whether a larger trial is worth running, and this one suggests it is. It does not settle the question.

Curcumin, from turmeric root, is at an earlier stage of research in women after menopause.

Section 2

The Eight-Week Trial, and Why the Placebo Group Matters

An earlier trial from Iran tested 500 mg of curcumin twice a day for eight weeks in healthy postmenopausal women, alongside a vitamin E group and a placebo group. Neither the women nor the researchers knew who was taking what.

In the curcumin group, two blood markers fell: hs-CRP, a sensitive marker of low-grade inflammation, and MDA, a marker of oxidative stress. Those are measurements, not symptoms, but they show the compound was doing something measurable in the body.

The symptom results are where this trial teaches its most useful lesson. Menopausal symptom scores fell in every group, including placebo. Simply being in a trial, being asked about symptoms and being looked after can make people feel better.

That is exactly why we keep pointing to the comparison with placebo throughout this article. A result only counts when it is better than what the placebo group experienced, and the size of that difference is the real finding.

Section 3

What Has Not Been Tested

Here is where the evidence stops. No trial we know of has tested resveratrol and curcumin together in women after menopause. The resveratrol results come from one long trial of 150 mg a day of resveratrol alone. The curcumin results come from short trials of curcumin alone.

The doses also differ from products you can buy. Our Resveratrol PLUS provides 500 mg of trans-resveratrol and 500 mg of liposomal curcumin in a two-capsule serving, alongside quercetin, fisetin and piperine. That is more resveratrol than RESHAW used, a different form of curcumin from the pilots, and a combination no trial has studied as such.

Resveratrol PLUS combines the two compounds discussed in this article, at different doses from the trials.

So the honest position is this. If the two-year trial and the curcumin pilots interest you, a product containing both compounds is a reasonable way to take them, provided you understand that you are taking them in a different combination and at different doses from the trials. What the trials do support is the shape of the habit: one consistent daily routine, kept up for months, not a short burst.

That is the real lesson of RESHAW. The women did not take resveratrol for a fortnight and stop. They took it every day for a year, and the changes the researchers found were small, steady and visible only over time.

Complete Reference List

The two-year resveratrol trial (RESHAW)

Curcumin trials in postmenopausal women