Ever Wondered Why Alzheimer’s Risks Spike After Age 65?

Research published in 2015 provides crucial information about why the risk of developing Alzheimer’s increases so dramatically as people get older. Beginning at age 65, the risk of developing Alzheimer’s doubles every five years. By age 85, Alzheimer’s risk rises to 50 percent. This recent research focuses on amyloid beta, a substance that is naturally present in our brains and that is a major contributor to the plaque formations that are a key feature of Alzheimer’s.

Allan Ajifo via About Modafinil
Allan Ajifo via About Modafinil

What Is Amyloid Beta?

Amyloid beta is a naturally-occurring protein in the human brain that contains amino acids, according to Health. Neurons in the brain produce amyloid beta while they transmit messages within the brain. The amount of amyloid beta the brain produces increases along with the number of messages transmitted between neurons. In other words, the more you think, the more amyloid beta you produce.

In people with Alzheimer’s, amyloid beta sticks together to form plaques and tangles. Scientists suspect that these clusters may interfere with communication between brain cells and lead to the cognitive decline that occurs in people with Alzheimer’s.

How Does Amyloid Beta Relate to Alzheimer’s?

The 2015 study by scientists at the Washington University School of Medicine took advantage of new technology that allowed researchers to tag amino acids in the blood of 100 volunteers and then follow the movement of the amino acids within their bodies. The research showed that it took much longer for the amyloid beta to leave the brains of older people. In 80-year-olds, for example, it took more than 10 hours for the brain to clear out the amyloid beta, while previous research demonstrates that this takes only 4.5 hours for people in their 30s. Study participants ranged in age from 60 to 87.

Via National Institutes of Health
Wikimedia Commons via National Institutes of Health

The research also showed that in people who had previous evidence of plaques in their brains, the amyloid beta was more likely to create plaques. In addition, study participants whose brains flushed the amyloid beta more slowly showed an increased incidence of memory problems and other signs of Alzheimer’s.

The research revealed that the decreased speed of clearing amyloid beta from the brain very consistently corresponded with each participant’s age, but did not show any correlation with the presence or absence of plaques in each participant’s brain.

How Does This Research Help Fight Alzheimer’s?

One variable that still awaits discovery is the exact method by which the brain rids itself of amyloid beta. Scientists suspect that another substance within the brain may be able to break down the amyloid beta or that it flows from the brain into the blood or cerebral-spinal fluid. If further research can determine precisely how the brain removes amyloid beta, then it may be possible to develop treatments that accelerate this process and prevent or slow the progression of Alzheimer’s.

Via Susumu Komatsu
Via Susumu Komatsu

What Are Other Risk Factors for Alzheimer’s?

The most significant factor for developing Alzheimer’s is age, with the risk rising steeply after age 65. People who have a close relative with Alzheimer’s are also at increased risk, and there are several genes associated with a higher risk.

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Although it’s not possible to control your age and genetic makeup, there are some lifestyle choices that may help lower the risk of Alzheimer’s. Head injuries may make people more prone to developing Alzheimer’s, so placing an extra emphasis on safety can mitigate this potential risk. The Alzheimer’s Association recommends setting up your home to prevent falls and wearing a helmet while biking or participating in other sports. Consult with your doctor to optimize your cardiovascular health and help ensure that your brain gets adequate blood and oxygen.

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