Spain has launched one of the world’s largest clinical trials on moderate alcohol consumption, recruiting 10,000 volunteers to help scientists understand its long-term effects on health.

Known as the UNATI study (University of Navarra Alumni Trialist Initiative), the trial is designed as a randomized controlled clinical study that will follow participants for four years to assess how moderate alcohol consumption compares with abstinence in terms of major health risks.

The project has received funding from the European Research Council and is coordinated by researchers at the University of Navarra along with partners across Spain. More than 500 healthcare professionals, including doctors, dietitians, and psychologists, are involved in the follow-up and support of participants.

Who Can Join

To take part, volunteers must:

• Be between approximately 50 and 75 years old (men aged 50–70, women aged 55–75)

• Live in Spain

• Currently consume between 3 and 40 alcoholic drinks per week

Teetotallers or people with medical conditions that make alcohol unsafe are not eligible, as the study focuses on regular, moderate drinkers.

What Participants Will Do

Participants will be randomly divided into two groups:

• One group will receive guidance promoting moderate alcohol consumption, defined as no more than 7 drinks per week for women and 14 drinks per week for men, ideally as red wine with meals and spread throughout the week.

• The other group will be advised to reduce or abstain from alcohol entirely.

All volunteers will undergo annual medical check-ups, quarterly guidance sessions, and regular online surveys on lifestyle and health. Both groups receive ongoing dietary and health support, including coaching and check-ins during the four-year period.

Why This Study Matters

Despite decades of research on alcohol, public health experts remain divided on whether moderate consumption—especially of wine—has benefits, risks, or is neutral for long-term health. Many previous studies on the topic have been observational, meaning they can’t prove cause and effect.

UNATI is one of the first large randomized trials designed to provide strong evidence on whether moderate alcohol intake is genuinely associated with outcomes like:

• Heart disease and cardiovascular events

• Cancer

• Type 2 diabetes

• Cognitive decline and dementia

• Overall mortality and quality of life

Lead researchers hope these results will influence future public health guidelines worldwide.

What’s Next

Recruitment is ongoing, and as of late 2025 thousands of participants had already signed up. Final results are expected by the end of the study period, around late 2028 at the earliest.

For those who qualify and are interested, the official volunteer registration remains open through the UNATI website.