Currently, there are upwards of six million people in the United States alone living with Alzheimer’s disease. As some researchers work to determine the exact cause of this neurodegenerative disease, others work to determine what factors might reduce the risk of developing Alzheimer’s disease. According to an article in Neuroscience News, one such study explored the association between Alzheimer’s development and flu vaccinations. 

The Research

The study, published in the Journal of Alzheimer’s Disease, sought to understand how flu vaccines could increase, decrease, or otherwise impact Alzheimer’s risk. Two years prior to this study, a research team from UTHealth Houston found a possible link between flu vaccines and a reduced risk. So they decided to keep evaluating it. In the more current study, the researchers evaluated data from 935,887 individuals aged 65+ who had been vaccinated against the flu, and 935,887 individuals who had not. 

Over a 4-year period, researchers continued to evaluate the health of these groups. They found that about 47,730 individuals (5.1%) who had received the flu vaccine had developed Alzheimer’s. Alternately, 79,550 (8.5%) of those who had not received the flu vaccine had developed this disease. After further examination, the researchers found that a single flu vaccine reduced the risk of developing this disease by 40%; researchers believe that the protectiveness only increases for those who receive a vaccine each year. 

While this research is interesting, there is much more research to be done – including the potential underlying mechanisms which could make this possible, whether the vaccine has any impact on disease progression, and whether it is specifically the flu vaccine that affects this. Other research has shown that other vaccines also offer protective qualities against Alzheimer’s. Therefore, while this research shows a correlation, more research is needed to determine how vaccines may stimulate or affect the immune system, which in turn may affect disease progression or development. 

About Alzheimer’s Disease

Alzheimer’s disease is a progressive neurodegenerative disorder in which brain cells degenerate and die. Doctors are unsure of the underlying cause of this disorder. However, a mixture of genetics, environmental factors, and lifestyle choices are believed to play a role. Risk factors include being older in age, being female, having past head trauma, poor sleeping or exercise patterns, or a family history of Alzheimer’s. The early signs may include forgetfulness, such as an inability to remember conversations or recent events. Memory loss will increase as the disease progresses. Additional symptoms, characteristics, and complications can (but do not always) include:

• Worsening memory loss
• Changes in mood, personality, and behavior 
• Depression or apathy
• Loss of inhibitions 
• Jumbled speech
• Appetite loss
• Difficulty thinking and concentrating
• Aspiration (complication)
• Pneumonia (complication)
• Bedsores (complication)
• Malnutrition or dehydration (complication)