July 11, 2023 – Around 10% of people over 65 in the United States have anemia, or a shortage of iron in their blood. This is an important statistic, because researchers now believe that anemia may have a significant connection to Alzheimer's disease, or AD.
A new Chinese study of over 300,000 people found that anemia was linked to a 56% higher risk of dementia. What’s more, a new study from the University of Kansas found that iron can become “sequestered” in the brains of Alzheimer’s patients, creating a deficiency that could then make the disease get worse faster.
According to the Cleveland Clinic, having iron-deficiency anemia means that your body doesn’t have enough iron to make hemoglobin, a substance in your red blood cells to send oxygen through your system. It develops when your body uses up iron faster than it can be made, or when iron flow starts to slow down. Losing blood through internal bleeding, heavy menstruation, or frequent blood tests can cause iron-deficiency anemia. Pregnancy, breastfeeding, bone marrow diseases, autoimmune conditions, and not getting proper nutrition can all contribute as well. In fact, not eating enough is often how older people develop the condition.
There are a number of ways anemia could harm the brain and speed up cognitive dysfunction.
“Alzheimer’s disease results in the death of nerve cells with deterioration of memory, thinking skills, and changes in behavior and personality,” said Allison B. Reiss, MD, an associate professor of medicine at NYU Long Island School of Medicine in Mineola, NY, and a member of the Alzheimer’s Foundation of America’s Medical, Scientific and Memory Screening Advisory Board. “Lack of iron can interfere with processes in the brain that affect neurotransmitters and the formation of myelin, a protein that forms a protective layer of insulation around nerves.”
The Alzheimer’s Association lists being age 65 or older, having a family history of Alzheimer’s, having a head injury, or having poor heart health as major risk factors for the disease. Yet anyone can have anemia, and everyone should think in terms of Alzheimer’s prevention. Here’s everything you need to know about anemia and Alzheimer’s, and the connection between the two.
What Are the Symptoms of Alzheimer’s Disease?
According to the National Institute on Aging, signs of the disease can occur in three distinct stages.
Mild Alzheimer's symptoms may include:
- Memory loss
- Poor decision-making
- Loss of motivation
- Not knowing where you are
- Taking a long time to finish familiar tasks
- Asking questions over and over
- Forgetting new information
- Problems handling finances
- A hard time solving problems
- Getting lost
- Changes in mood or personality
- Getting anxious or behaving aggressively
Moderate Alzheimer’s symptoms may include:
- Increasing confusion and memory difficulties
- Withdrawing from friends and family
- Trouble learning, speaking, reading, writing, and doing math
- Problems with logic and concentration
- Changes in sleeping
- A hard time dealing with new situations
- Not recognizing familiar people
- Having delusions, hallucinations, paranoia, or behaving in inappropriate ways
- Being restless, upset, or having crying spells
- Saying the same thing over and over, or moving repetitively
- Muscle twitches
Severe Alzheimer’s symptoms may include:
- Not being able to communicate
- Not being aware of where you are or what you have recently done.
- Loss of appetite or loss of weight
- Problems with feet, skin, or teeth
- Trouble swallowing
- Making sounds like moans, grunts, or groans
- Sleeping more
- Having seizures
- Losing bowel and bladder control
What Are the Symptoms of Anemia?
According to the Mayo Clinic, symptoms of iron-deficiency anemia include:
- Major fatigue and weakness
- Skin that’s pale
- Feeling lightheaded or weak, or having headaches
- Chest pain, feeling short of breath, or feeling like your heart’s beating fast
- Cold extremities or brittle nails
- A swollen, painful tongue
- Craving unusual things to eat, like ice
- Losing your appetite
How Is Anemia Linked to Alzheimer’s?
One established theory is because of iron's essential function in providing the brain with oxygen, if iron is low, this could cause brain decline.
“The brain relies on good blood circulation to receive nutrition and oxygen. Nerve cells have a high requirement for oxygen. If a person has severe anemia, their red blood cells may not be carrying sufficient oxygen to the brain, and this will cause hypoxia (not enough oxygen for tissues) and damage the brain, especially if the hypoxia continues over a long period," said Reiss. "If a person already has dementia of any type, AD, or early stages such as mild cognitive impairment, anemia can make the symptoms worse and accelerate the destructive process. Anemia can cause changes to small blood vessels in the brain that compromise the ability of oxygen to reach all structures.”And other factors can be at play, too.
“Anemia also reduces cerebral metabolism of glucose, the mechanism for energy production in the brain, and poor metabolism in the brain is a known feature of AD,” Reiss said.
Inflammatory molecules in some types of anemia could also make Alzheimer's get worse faster.
“The connection of anemia to Alzheimer’s is not necessarily the anemia itself, but rather the inflammation it can cause,” said Kyle Womack, MD, a professor of neurology in the Division of Aging and Dementia at Washington University School of medicine in St. Louis. “Anemia may not start the cascade that causes Alzheimer’s, but could be involved with the impairment.”
Certain types of iron deficiency, such as anemia of inflammation, can stop your body from using stored iron to make healthy red blood cells.
If You Have Anemia, Should You Get Screened for Alzheimer’s?
Israeli researchers reported that the more severe anemia an elderly person has, the higher the risk of dementia and a decline in thinking skills. Still, this study points out that mild cases of anemia should be caught so that treatment might reverse dementia risk.
“If a patient has anemia, and that person – or more commonly, a family member of that person – notices their behavior seems to be a little off, it’s important to tell that person’s [doctor]," Womack said. “Very often, a person with Alzheimer’s will not know their behavior is changing. In such a case, anemia could be acute, so it’s very important not to completely put blinders on about this – you need to act promptly.”
Getting a full physical workup is vital, and cardiac testing should be an essential part of an evaluation. “Heart health and brain health are very much intertwined, and anemia can cause a lot of damage to the heart and cardiovascular system which, in turn, can be unhealthy for the brain and lead to worsening of dementia,” said Reiss.
A patient should also be tested to find out if, and/or how, they are losing blood.
The good news: Treatment for anemia can be easy. Your doctor can revamp your diet so you’re eating iron-rich foods such as more meat, fish, poultry, leafy greens, beans, yeast-filled bread products, and iron-enriched cereal, pasta, and bread. Iron supplements can also make a big difference in correcting anemia, and potentially stopping cognitive damage.
As Reiss sums it up: “While there is no cure for AD, treating anemia and implementing lifestyle changes to optimize brain health may be helpful.”