Statement on biomarkers for early detection of Alzheimer’s disease in Chile

Foto de la mano de una p levantando un tubo de una serie de muestras de sangre.
MICARE Director Claudia Miranda was one of the signatories to this statement by the Transdisciplinary Network on Aging of Universidad de Chile regarding the dissemination and implementation of a technology that uses a blood sample to detect Alzheimer’s disease up to 10 years before it develops.

Read here the original statement published by Universidad de Chile.

In view of the dissemination and implementation of a technology that uses a blood sample to detect Alzheimer’s disease up to 10 years before it develops, representatives of the Transdisciplinary Network on Aging of the Universidad de Chile and researchers from other institutions express their concern about the actual usefulness of this test and other biomarkers that are still being researched.

The launch of a blood test that could predict Alzheimer’s dementia at least 10 years in advance has recently been mentioned in the national media.

We, the undersigned, believe that this news should be taken with caution and without losing sight of the available scientific evidence.

Neurodegenerative dementias are a series of diseases that cause a slow and progressive deterioration of brain functions that at some point will generate an impact such that people require the assistance of others to function in daily life. The most common cause of dementia is Alzheimer’s disease, which is characterized from the neuropathological point of view by the deposition in the brain of two molecules, beta-amyloid and Tau, and neuronal death. In a research context, these molecules have been measured in blood, cerebrospinal fluid, and through neuroimaging examinations as a biomarker for the presence of Alzheimer’s disease.

One of the main challenges of international research is identifying biomarkers to predict the risk of developing Alzheimer’s type dementia in people without clinical symptoms of dementia.

It is, however, essential to clarify several aspects:

At present, no biomarker has been shown to predict the likelihood of developing Alzheimer’s dementia. Thus, no clinical guideline or international recommendation proposes to study asymptomatic or non-demented individuals with biomarkers to predict their risk of developing dementia.

Biomarker studies are performed exclusively in the context of research protocols to establish their real clinical utility.

Behavior will not change after a positive test, which can also have a negative effect on mental health.

Although we do not have biomarkers to predict the risk of developing Alzheimer’s dementia, research has shown that the risk of developing dementia can be reduced. Dementias are a group of potentially preventable diseases, or at least to a certain extent, through healthy lifestyle habits. These recommendations are the same for everybody and do not depend on the presence or absence of a biomarker. On the contrary, interpreting the presence of such a biomarker as the possibility of experiencing a future event, such as dementia, could even have an iatrogenic effect on people’s mental health.

We believe that the population should be offered suitably validated diagnostic tests that provide clinically useful information. It is essential to further investigate whether biomarkers could predict the risk of developing Alzheimer’s type dementia before proposing them as a diagnostic test to the population at large.

Dementias, and in particular dementia due to Alzheimer’s disease, are among the most feared diseases in the population. To profit from that fear by proposing to predict Alzheimer’s disease in people over 40 years old is highly questionable.

The answer to the question about the risk of dementia is to educate about prevention and communicate that there are currently no tests that can eliminate this uncertainty.

We urge all national and scientific bodies to follow international guidelines and limit the use of biomarkers to research protocols or highly specific cases, where it could generate effective behavioural changes.

We believe it is crucial to bear in mind that one of the ethical principles of medicine is, first, to do no harm, so proposing onerous tests to predict the risk of dementia without adequate evidence not only makes people incur excessive expense but also damages their trust in medical science and clinical research.

Finally, we believe it is important for the scientific and medical community and the media to disseminate health news with sound scientific backing.

Petition signers:

Tomás León R.

Memory Clinic Psychiatrist and Neuropsychiatrist Hosp. del Salvador

Atlantic Fellow for Equity in Brain Health Global Brain Health Institute

Andrea Slachevsky

Neurologist, PhD.

Memory and Neuropsychiatry Clinic, Salvador Hospital, and University of Chile School of Medicine

Center for Geroscience, Mental Health and Metabolism (GERO)

Department of Neurology, Clínica Alemana, Santiago

Gabriel Martínez Fuentes

Geriatrician, PhD

Angela Nervi Nattero


Alejandra Pinto Henríquez

Clinical Psychologist

Memory Unit

Salvador Hospital

Patricia Alegría Figueroa

Neuropsychologist, Clínica Alemana

President of the Alzheimer Chile Corporation

Adriana López Ravest


Jorge González Hernández


Teresita Ramos Franco


Claudia Miranda Castillo

Psychologist, PhD, Associate Professor, Andrés Bello University

Director, Millennium Institute for Caregiving Research (MICARE)

María Ignacia Balocchi


Susana Rojas Caroca

Clinical Psychologist

Master in Clinical Psychology, PUC

María Isabel Behrens

Neurologist, PhD

Daniela González Astorga


Alejandra Flores



Paola Cabezas A


Memory Unit, Salvador Hospital

Daniel Jiménez Fernández


East Department of Neurological Sciences, University of Chile

Tahina Chang


Mario Ociel Moya

Anthropologist, PhD.

INTA, University of Chile.

Benjamín Suárez

Tenured Professor

Disciplinary Physiology and Biophysics Program, ICBM

School of Medicine

University of Chile

Natalia Castillo Núñez

Occupational Therapist, Master in Health Sciences Education.

Academic, Department of Occupational Therapy and Occupational Science, University of Chile.

Ignacio Gallardo Navarro

Academic Psychology FACSO U de Chile

Bárbara Angel Badillo

PhD. Assistant Professor

Public Nutrition Unit

INTA, University of Chile

Alejandra Fuentes-García

Assistant Professor

School of Public Health

School of Medicine

University of Chile

Marco Cornejo Ovalle

Surgeon-Dentist. Doctor of Public Health

Assistant Professor, School of Dentistry

University of Chile

Carolina Delgado Derio


Associate Professor

Department of Neuroscience

University of Chile Clinical Hospital

Nicole Rogers Castillo

Neurologist, PhD

Mijal Martínez Trajtmann

Psychologist, studying a Master’s Degree in Psychogerontology

Marcela Farías Vergara


Assistant Professor, School of Dentistry

University of Chile

Andrea Pizarro


Assistant Professor, School of Dentistry

University of Chile

Javiera Gajardo Arias


San Pablo Hospital, Coquimbo/ Catholic University of the North

Jaime Labrin Carrasco


Los Ángeles Hospital

Fernando Molt Cancino


Coquimbo Hospital/ U. Católica del Norte.

Felipe Alzola Bendicho


César Morales

Neurologist, Arica

Carolina Leal Werner


Jorge Matamala Saavedra

Neurologist, Chillán

Rodolfo Vergara Quinchagual


Arauco Health Service

Rafael Aránguiz


Inger Psychogeriatric Unit

Benjamín Chacana

President of Coprad (Professional Corporation for Alzheimer’s and other Dementias)

Rodrigo Salinas


Paola Morales Retamales

Neurobiologist, PhD.

Associate Professor, Dept. of Neurosciences, Molecular & Clinical Pharmacology Program, ICBM

School of Medicine, University of Chile

Claudia Duran-Aniotz


Director of Coprad (Professional Corporation for Alzheimer’s and other Dementias)

Co-Director of BrainLat. Adolfo Ibañez University

Paulina Arriagada


Romy Von Benhardi

MD, PhD in neurosciences

Claudio Martínez


René Meza Flores


Coordinator of the Memory Unit, Talca Regional Hospital

Professor of Neurology at Maule University

MINSAL Neurology Advisory Member

Patricia Flores


Teresa Castillo


Dr. Hernan Henriquez Aravena Hospital, Temuco

Kimunche Community Support Center for People with Dementia

La Frontera University

David Sáez


Associate Professor

School of Medicine, University of Chile

Gustav Rohde


Cognitive Disorders Unit, Department of Neurology

Gustavo Fricke Hospital

Valparaíso University

María José Angel


INGER Psychogeriatric Unit

Rafael Aránguiz


Psychogeriatric Unit. INGER

María Angélica Silva


Gabriel Cea


Tenured Professor, School of Medicine

Ramiro Zepeda


Arturo Martínez

Neurologist, San Felipe

Rodrigo Guerrero Torrealba


Jorge Ibáñez Piña


Lorena Montecino Ramos


Rodolfo Vergara Quinchagual

Neurologist – Arauco Health Service

Silvia Oliva Castillo


Juan Almeida

Neurologist, Padre Hurtado Hospital

Wilhelm Uslar Nawrath


UC-CHRISTUS Health Network

Herminda Martín Hospital, Chillán

Mónica Nivelo Clavijo

Physician, Master in Public Health

Academic, Department of PHC and Family Health, School of Medicine, University of Chile.

Cristo Vive CESFAM. SSMN

Patricio Sandoval R.


Department of Neurology, School of Medicine, Catholic University of Chile