"A team of Spanish scientists made a striking announcement 15 years ago: they were seeking thousands of volunteers among the employees of Banco Santander in Madrid: researchers wanted to study them in depth for decades, in order to understand the onset of cardiovascular disease in healthy people."

Is there a project like this one can join in the US? I've always wanted to contribute to a biomedical study.

"Cohort study" is the broader term for this type of work. For heart disease, the Framingham Heart Study (in Framingham MA) is a foundational one in the US.

It's not really something you can go looking to volunteer for though, someone has to be putting together a cohort study (which is a big expensive long term project) on a group that you happen to be part of, and you can agree to participate in it.

https://en.wikipedia.org/wiki/Framingham_Heart_Study

I use this one - https://heh.eurekaplatform.org/pages/landing. I'm filling a large form every 6 months for them. Seems they focus on long term studies.

You could look for specific studies on clinialtrials.gov. Its a database of trials in the US and also around the world. In the US I'm not sure of the status of such studies about budget cuts to NIH.

I myself was on 1 year study post organ transplant for impact of whole grain plant based diet. They educate you initially on the diet and then monitor your weight and blood tests over the year.