Declining sense of smell may be an early sign of Alzheimer’s disease

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Our sense of smell is more than just a way to enjoy food or detect dangers like fire. It turns out that changes in the ability to smell might be an early warning sign of cognitive decline, including conditions like Alzheimer’s disease and dementia.

Researchers at the University of Chicago Medicine have discovered that a gradual loss of smell could predict future memory problems and brain changes associated with these diseases.

In their study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, the team found that smell tests could be an effective tool for spotting early signs of cognitive impairment.

Alzheimer’s is a serious condition affecting more than 6 million Americans.

It typically begins with memory loss and can progress to more severe symptoms like confusion, mood swings, and trouble with daily tasks. Early detection is key to managing the disease and potentially slowing its progress.

The research team used data from the Memory and Aging Project (MAP), a long-term study focusing on aging and diseases that affect the brain.

Each year, participants were tested on their ability to identify specific smells, along with assessments of their cognitive abilities and signs of dementia.

By studying this data, the researchers found that people who experienced a rapid decline in their sense of smell, even while their cognitive abilities were still normal, were more likely to show signs of Alzheimer’s later.

This included smaller gray matter in parts of the brain linked to smell and memory, lower cognitive performance, and a higher risk of developing dementia.

Interestingly, the decline in smell was found to be a risk factor for Alzheimer’s similar to carrying a specific gene called APOE-e4, which is known to increase the likelihood of developing the disease.

This finding suggests that smell loss could be as important a predictor as genetics when it comes to detecting Alzheimer’s early.

The researchers hope to further their studies by examining brain tissue for markers of Alzheimer’s and determining if smell tests can reliably be used as an early detection method.

They also want to explore whether people from different racial and ethnic backgrounds experience similar connections between smell loss and cognitive decline, as this study primarily included participants from one population.

This is not the first time the sense of smell has been linked to overall health. In earlier studies, researchers found that older adults who lost their sense of smell entirely were three times more likely to die within five years than those who retained it.

This loss of smell turned out to be an even stronger indicator of death than conditions like heart failure, lung disease, or cancer.

For those concerned about brain health, it’s worth exploring lifestyle changes that might help. Studies suggest that a Mediterranean diet, rich in fruits, vegetables, and healthy fats, can protect brain health. Additionally, research shows that blueberry supplements might help prevent cognitive decline.

Other research has connected Alzheimer’s risk to vitamin D deficiency and blood pressure issues, especially at night. By addressing these factors, it may be possible to reduce the risk of developing dementia.

In summary, the ability to smell could be more closely tied to brain health than many of us realize. This research opens the door to using smell tests as an easy, non-invasive way to detect Alzheimer’s earlier, giving doctors and patients more time to manage the disease before symptoms become severe.

If you care about Alzheimer’s disease, please read studies about the protective power of dietary antioxidants against Alzheimer’s, and eating habits linked to higher Alzheimer’s risk.

For more information about brain health, please see recent studies that oral cannabis extract may help reduce Alzheimer’s symptoms, and Vitamin E may help prevent Parkinson’s disease.

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