Dementia affects more than 55 million people worldwide, with no cure yet in sight. However, a major study published in The Lancet journal reveals that many cases of dementia could potentially be prevented or delayed by addressing various risk factors. These risk factors include smoking, air pollution, and high cholesterol, among others.

Dementia is a debilitating condition that progressively robs people of their memories, cognitive abilities, language, and independence. Alzheimer’s disease is the most common cause of dementia, but there are other diseases that can also lead to this condition.

The Lancet study, conducted by an international team of researchers, builds on previous research and highlights the significant potential for preventing dementia. Here are some of the study’s key points:

1. Risk Factors Identified:
- Previous Findings: The 2020 report identified 12 risk factors linked to 40% of dementia cases. These included lower levels of education, hearing problems, high blood pressure, smoking, obesity, depression, physical inactivity, diabetes, excessive drinking, traumatic brain injury, air pollution, and social isolation.
- New Additions: The latest update adds two more risk factors: vision loss and high cholesterol.

2. Potential for Prevention:
- The study suggests that nearly half of dementia cases could theoretically be prevented by eliminating these 14 risk factors.
- Addressing these factors could significantly reduce the burden of dementia worldwide.

While the potential for prevention is high, there are several challenges:

1. Complexity of Risk Factors:
- It’s difficult to separate the risk factors from each other. For example, depression and social isolation can be linked, as can smoking and high blood pressure.
- Some risk factors might be symptoms rather than causes of dementia. For instance, depression could be a result of early dementia rather than a cause.

2. Societal and Genetic Influences:
- Many risk factors are societal issues that are challenging to address fully, such as access to education and socioeconomic conditions.
- Genetics also play a significant role, and some factors are beyond individual control.

3. Existing Public Health Efforts:
- Public health programs already aim to reduce some of these risk factors, like smoking and high blood pressure. However, the extent to which further reduction is possible remains uncertain.

The study outlines various recommendations, both personal and governmental, to address these risk factors:

1. Personal Actions:
- Healthier Lifestyle Choices: Quitting smoking, reducing alcohol intake, and maintaining a healthy weight.
- Physical and Mental Activity: Engaging in regular physical exercise and mental activities to keep the brain active.
- Healthcare Management: Managing conditions like diabetes and high blood pressure effectively.

2. Governmental Actions:
- Education and Awareness: Improving access to education and raising awareness about dementia and its risk factors.
- Public Health Initiatives: Enhancing public health programs to address air pollution, promote healthy lifestyles, and support mental health.

Despite the focus on prevention, research continues into treatments for dementia. Two Alzheimer’s treatments, Biogen’s lecanemab and Eli Lilly’s donanemab, have recently been approved in the United States. These drugs target the build-up of proteins considered to play a key role in the disease’s progression. However, their benefits are modest, they have severe side effects, and they are often very expensive. The European Union has been more cautious, with its medicine watchdog recently refusing to approve lecanemab and still considering donanemab.

Experts have welcomed the study’s focus on prevention but caution against overestimating its potential impact. Charles Marshall, a neurologist at Queen Mary University of London, emphasizes the difficulty of completely eliminating any risk factors, noting that existing public health programs already target smoking and hypertension. Tara Spires-Jones, a neuroscientist at the University of Edinburgh, stresses the importance of not blaming individuals with dementia for their condition, pointing out that many factors, including genetics and childhood opportunities for education, are beyond individual control.

While the quest for a cure for dementia continues, the potential for prevention through addressing risk factors offers hope. By focusing on both personal and societal measures, it is possible to reduce the incidence of dementia and improve the quality of life for millions of people worldwide. However, it’s essential to approach prevention with a nuanced understanding of the complexities involved and the limits of current public health initiatives.