If you have high cholesterol, could you be at risk of dementia?
November 8, 2021
Alzheimer’s affects 850,000 people in the UK, with this number expected to grow to 1.5 million by the year 2040¹. It is estimated that dementia costs the NHS £26 billion per year in diagnostic tests, treatments and social care².
But beyond the facts and figures is the huge impact Alzheimer’s can have on an individual and their family once the diagnosis is given. Currently, there is no cure for dementia and prevention is the best line of defence. That is why a recent landmark research paper in The Lancet has been met with much optimism.
Published in June 2021, it demonstrated that high cholesterol levels are associated with an increased risk of developing dementia. Blood lipids, which encompass our cholesterol and triglyceride levels, are important to your health for many reasons. An elevation, or an abnormal ratio of lipids (dyslipidemia), has a known association with conditions such as heart disease, hypertension and stroke³. The research conducted shows, for the first time, a significant relationship between increased levels of blood lipids and the risk of developing dementia. The key findings of the study are discussed below, as well as the impact it could have on health services.
Dementia is an all encompassing umbrella term for many different conditions, such as Alzhemier’s disease or vascular dementia. It is associated with declining brain function, characterised by memory loss, changes in personality, mood, language skills and behaviour⁴. Risk factors for dementia can be broken down into preventable or non-preventable groups. Preventable risk factors include smoking status, obesity and alcohol intake whereas non-preventable risk factors include your genetic⁵. It’s one of the leading causes of disability and death in the world and it’s estimated that by 2050, 1 in 50 of us globally will suffer from dementia¹. Though recognised as a risk factor for cardiovascular disease, limited data has been produced to identify dyslipidemia (abnormal lipid levels) as a recognised reversible risk factor for dementia.
In the simplest terms, cholesterol is a fatty substance which is an essential part of our bodies. It’s formed from fatty acids that are absorbed through the intestine and it’s mainly made in the liver⁶.
Total cholesterol is made up of different types of cholesterol which each have varying roles and functions. The main types of cholesterol are Low Density Lipoproteins (LDL), a.k.a. “bad” cholesterol, High Density Lipoproteins (HDL), a.k.a. “good” cholesterol, and triglycerides which is the main type of fat⁷. Cholesterol is an essential building block for the body, however differences in the amounts of these cholesterols can lead to cholesterol buildup in the cardiovascular system and lead to cardiovascular disease. Though possible, buildup of cholesterol is often hard to reverse, so early detection and prevention is often best by leading an active, healthy lifestyle.
Several studies have previously looked at the relationship between lipid levels and the risk of developing dementia. The main criticism of these studies, however, has been that the length of time participants were followed-up was too short. Other studies have shown a relationship between dyslipidemia and dementia but the number of people within the study has come under scrutiny and the significance of results is debated.
The study in The Lancet showed that increased levels of LDL cholesterol were linked to an increased risk of developing dementia, particularly in those of middle age in the study. The study was produced from a number of epidemiology groups and analysed 1.8 million participants with significant follow up time⁸. Patients’ data was analysed according to LDL level and compared with the age of the patient and the follow up time of patients to see if a diagnosis of dementia was made. Other factors, including smoking, alcohol use and socioeconomic status, were also analysed and patients were then analysed for any diagnosis of dementia.
After the data was adjusted for age and other variables which may impact correlation, it was analysed for statistical significance between LDL levels and rates of dementia. Those under 65 who had higher levels of LDL measurements followed up over 10 years or more, had the highest risk of developing dementia.
In short, it can be concluded that increased LDL levels are associated with the development of dementia, and should be included as a modifiable risk factor for dementia.
What does this mean for you
Though the projected increase in Alzheimer’s and dementia can seem scary, studies like this one arm us with the knowledge to combat it.
The results of the study are important in preventative medicine and public health medicine. With the estimates of one in fifty likely being affected by dementia by 2050, it is important that healthcare professionals act to educate and empower all individuals to take a closer look at lifestyle and diet to improve lipid levels. Though the conclusions are concerning from the study there is lots people can do to control their blood lipid levels and this data should be used to implement that change.
Invoking attitude change to improve diet and lifestyle is one thing but changing behaviour over the long term is far more challenging. Many “health foods” or even healthier alternatives still remain pricey and with an estimated 14% of families in the UK experiencing food poverty it is no surprise that many people don’t have the means necessary to make and keep up these important healthcare choices⁹. It is thought that a new government initiative will encourage GPs to prescribe fruit and vegetables for patients in a bid to encourage healthier living and reduce obesity related illness in the UK¹⁰.
Individuals can empower themselves in other ways to take control of their health by making small changes over time and having regular health checks to assess weight, blood pressure and their blood lipid levels. As mentioned in the study those at highest risk are the middle aged and often this group are the most reluctant to have themselves checked out for a variety of different reasons. Simple steps, such as measuring your blood lipid levels, via a blood test may be the spark needed to make the change and see improvement in your physical and biochemical health. Information is power and the importance of knowing, not guessing about what we can do to impact our health is crucial.