There are now many ways to determine biological age, the most prevalent of which are epigenetic clocks and combinations of normal blood biomarkers such as the phenotypic age clock. In all cases, the idea is to identify specific measurable changes that correlate with age, and then develop an algorithm that combines the measures to produce an age as the output. Whether a given clock actually reflects all of the processes of aging, and what exactly is being measured under the hood, are questions that have yet to be satisfactorily answered. It has been noted that in all of the established biological age measures, people with a higher biological age than chronological age also exhibit a higher risk of age-related disease. This is the case here, for another novel measure of biological age that is derived from a combination of simple biomarkers.
In order to measure biological age and the link to disease, the researchers used data from the UK Biobank. They studied a cohort of 325,000 people who were all between 40 and 70 years old at the time of the first measurement. Biological age was calculated using 18 biomarkers, including blood lipids, blood sugar, blood pressure, lung function, and BMI. The researchers then investigated the relationship between these biomarkers and the risk of developing neurodegenerative diseases such as dementia, stroke, ALS, and Parkinson's disease within a nine-year period.
When compared to actual, chronological age, high biological age was linked to a significantly increased risk of dementia, especially vascular dementia, and ischemic stroke, (i.e. blood clot in the brain). "If a person's biological age is five years higher than their actual age, the person has a 40 per cent higher risk of developing vascular dementia or suffering a stroke." The results are particularly interesting because the study included such a large group of people. This makes it possible to break down the material into smaller pieces and capture less common diagnoses such as ALS. The risk of developing ALS also increases with higher biological age. However, no such risk increase was seen for Parkinson's disease.