Dementia risk may increase with high cholesterol, vision loss: Study

Dementia, a term used for multiple medical conditions like Alzheimer’s disease, affects our memory, and thinking. It also has an impact on our ability to perform activities every day. Ageing is the most significant risk factor for dementia, as our cognitive functions naturally decline as we grow older. There are other risk factors like diabetes, obesity and smoking as well. Now, high cholesterol and untreated vision loss have joined the list of dementia risk factors, according to a new study. Make sure your cholesterol is in control, and take care of your eyes to prevent the development of dementia, which is a degenerative condition and gets worse over time.

What is dementia?

Dementia is a deeply transformative condition that affects the mind, altering how a person thinks, remembers, and interacts with people around them. It is not a single disease, but an umbrella term encompassing various disorders characterised by a progressive decline in cognitive abilities, explains psychologist Dr Rituparna Ghosh.

Dementia encompasses conditions like Alzheimer’s disease, vascular dementia, and Lewy body dementia, which all impact the brain. Over 55 million people in the world have dementia, with Alzheimer’s disease being the most common form, according to the World Health Organization. It may contribute to 60 to 70 percent of dementia cases across the globe.

Study on the risk factors for dementia

In 2020, hearing loss, less education, obesity, hypertension, smoking, diabetes, depression, physical inactivity, excess alcohol consumption, social isolation, traumatic brain injury, and air pollution were found to be dementia risk factors in a study published in The Lancet.

In a fresh report published in The Lancet in July 2024, untreated vision loss and high LDL or low-density lipoprotein cholesterol have been mentioned as risk factors for dementia. About 7 percent of dementia cases were linked to high levels of LDL or bad cholesterol. As for untreated vision problems, they contribute to two percent of dementia cases. Apart from identifying the risk factors, researchers suggested that efforts to prevent the development of dementia can start as early as childhood. It could be a step toward reducing dementia cases by nearly half.

Connection between cholesterol and vision loss with dementia risk

LDL cholesterol, often dubbed as the bad cholesterol, gets collected in the walls of blood vessels. This, in turn, raises the chances of a heart attack or stroke. High LDL cholesterol contributes to the buildup of plaques in the arteries, including those supplying the brain. This can impede blood flow, depriving the brain of essential nutrients and oxygen, shares Dr Ghosh. The brain’s ability to function properly gets jeopardised, which can accelerate cognitive decline and increase the risk of dementia.

Our eyes are also intricately connected to brain function. Visual impairment forces the brain to work harder to interpret visual information, which in turn increases the cognitive load. Also, poor vision can lead to decreased physical activity and social isolation, both of which are important for maintaining cognitive health. For example, a person with deteriorating vision might become less active or withdraw from social interactions, leading to further cognitive decline.

How to reduce the risk of dementia?

Considering the new findings, you need to manage cholesterol and support eye health first. Here’s what to do:

1. Diet

Embrace a heart-healthy diet rich in vegetables, whole grains, fruits and lean proteins. Incorporate foods high in omega-3 fatty acids, like salmon and walnuts, which can help lower cholesterol levels. Reducing intake of saturated and trans fats that are found in many ultra-processed foods and fried items can prevent cholesterol levels from rising, says the expert.

2. Exercise

Engage in regular physical activity to help manage cholesterol levels and support overall cardiovascular health. Your total cholesterol should be below 5 millimoles per litre (mmol/L), as per the UK’s National Health Service. Take out at least 150 minutes to do moderate exercise each week . You can go for brisk walking, swimming or cycling. Exercise improves blood circulation, helps maintain a healthy weight, and reduces the risk of chronic diseases that can exacerbate dementia risk, says Dr Ghosh.

3. Medication

For some people, lifestyle changes alone may not suffice. Medications such as statins can help manage cholesterol levels effectively, but consult with a doctor to determine the best approach and monitor the impact of the medications on your health.

4. Regular eye exams

Schedule eye exams at least once a year to detect and address vision problems early. Conditions like glaucoma, macular degeneration, or diabetic retinopathy can be managed more effectively when identified early. Regular check-ups ensure that any vision issues are promptly addressed, preserving both visual and cognitive health.

5. Corrective lenses

Use prescribed glasses or contact lenses to correct your vision problems. Clear vision reduces cognitive strain and supports optimal brain function. It’s essential to follow your eye doctor’s recommendations to ensure that your vision aids are effective and comfortable.

6. Protective measures

Protect your eyes from harmful ultraviolet rays and ensure proper lighting in your room to prevent further vision deterioration. Simple measures, such as wearing sunglasses outdoors and using adequate lighting for reading, can help maintain eye health and reduce visual strain.

7. Healthy lifestyle

Incorporate a diet rich in antioxidants and nutrients essential for eye health, such as vitamins A, C, and E, and minerals like zinc. A balanced diet can be great for your eye health and can help prevent age-related vision problems apart from dementia.

To reduce dementia risk, you should also engage in activities that challenge your brain. Spend some time reading, or learning new skills. Also, stay socially active to maintain cognitive function and emotional health, says the expert. Managing conditions such as diabetes, and hypertension are also important for your brain.

High cholesterol and untreated vision loss may increase the chances of developing dementia, but these health problems can be prevented. Adopt healthy practices to enhance your overall well-being and reduce the risk of developing dementia.