If you are over 60, you have probably had a routine blood test that checked your haemoglobin levels. For years, doctors have known that low haemoglobin (a condition called anaemia) can make you feel tired, weak, and foggy headed. But new research suggests the stakes might be much higher than just daily fatigue.
I recently reviewed a major study published in JAMA Network Open that found a strong link between anaemia and the biological markers of Alzheimer’s disease. As someone who follows post reproductive health closely, I believe these findings could change how we think about preventing dementia.
What the Study Found
Researchers followed 2,282 adults over the age of 60 for nearly a decade (an average of 9.3 years). None of them had dementia at the start of the study. They wanted to see if having anaemia changed their risk of developing dementia later on.
The results were striking:
- Higher Alzheimer’s Biomarkers: People with anaemia had significantly higher levels of Alzheimer’s-related proteins in their blood.
- Increased Dementia Risk: Overall, having anaemia was associated with a 66% higher risk of developing dementia compared to those with normal haemoglobin levels.
- A “Double Hit” Effect: The risk was most severe for individuals who had both anaemia and elevated Alzheimer’s biomarkers. In some of these groups, the risk of dementia was more than three times higher than normal.
Why might this Happen?
The study authors suggest a biological pathway called cerebral hypoxia – essentially, a lack of oxygen reaching the brain. Haemoglobin is the protein in your red blood cells that carries oxygen. When you are anaemic, you have fewer of these oxygen carriers, which may starve brain cells of the energy they need to survive. Over time, this low-oxygen state might accelerate the accumulation of damaging proteins like tau, speeding up neurodegeneration.
What this means for you and your family
This is not a reason to panic, but it is a powerful reason to be proactive. Here is my takeaway from this data:
- Anaemia is modifiable. Unlike your genetics or your age, anaemia can often be treated. Causes range from iron or vitamin B12 deficiencies to chronic inflammation or kidney disease.
- Ask your doctor for a simple blood test. If you are over 60, or caring for someone who is, make sure a full blood count (FBC) is part of your annual physical. Do not dismiss mild anaemia as “just part of getting older.”
- Treat the root cause. If you are diagnosed with anaemia, work with your doctor to find out why. Treating the underlying cause (e.g., taking iron supplements, adjusting diet, or managing a chronic condition) might do more than just boost your energy—it could potentially lower your long-term risk of cognitive decline.
The Bottom line
We have long known that a healthy heart supports a healthy brain. This study suggests that healthy blood is just as critical. While more research is needed to prove that treating anaemia directly prevents Alzheimer’s, the evidence is compelling enough to act. A simple blood test today could be a powerful step toward protecting your memory tomorrow.
