However, while the study establishes a connection, it does not definitively prove that higher triglyceride levels prevent dementia.
Triglycerides, classified as fatty acids and the most common form of fat in the bloodstream, contribute significantly to dietary fats, serving as the brain’s primary energy source.
Dr. Zhen Zhou, a study author from Monash University in Melbourne, Australia, suggests that “higher triglyceride levels might reflect better overall health and lifestyle practices that act as protective factors against dementia. Our findings propose that triglyceride levels could serve as a valuable predictor for dementia risk and cognitive decline among older populations.”
The research, employing health care data, identified 18,294 participants from one cohort with an average age of 75 who had not received a prior Alzheimer’s disease or dementia diagnosis. These participants were monitored for an average of six years, during which 823 individuals developed dementia.
The study analysed participants’ annual measurements of total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL), and high-density lipoprotein cholesterol (HDL). Subsequently, participants were categorised into four groups based on their fasting triglyceride levels. For the entire cohort, the average triglyceride level stood at 106 milligrams per deciliter (mg/dL). In adults, a typical or healthy triglyceride level is under 150 mg/dL.
When adjusting for variables that could impact dementia risk, including educational background and cholesterol-lowering treatments, researchers discovered that each doubling of triglyceride levels correlated with an 18% reduced risk of developing dementia.
The lowest triglyceride group featured levels below 62 mg/dL. The second group reported levels between 63 and 106 mg/dL and was 15% less likely to develop dementia compared to the lowest group. The third group, with levels between 107 and 186 mg/dL, showed a 24% reduced risk of dementia compared to the lowest group. The fourth group, with levels of 187 mg/dL or higher, demonstrated a 36% lower risk of developing dementia in comparison to the lowest group.
In the lowest triglyceride group, consisting of 1,416 individuals, 6% developed dementia, while in the second group comprising 7,449 people, 5% developed dementia. The third group, with 7,312 individuals, witnessed 4% of its members developing dementia. The fourth group included 2,117 individuals, with 3% of them developing dementia.
The study’s results were also validated in another dataset encompassing 68,200 older people from the U.K., where a 17% reduced risk of dementia was observed with each doubling of triglyceride levels, despite the average monitoring period extending over 12 years. Researchers also noted that higher triglycerides were associated with a slower decline in composite cognition, reflecting combined results from tests evaluating global function, psychomotor speed, language, executive function, and memory over time.
The study has its limitations, as it exclusively examined individuals aged 65 and older with no initial cognitive issues, rendering the findings less applicable to other populations. The study does, however, set the stage for further investigations into the potential of specific components within triglycerides to promote better cognitive function, with the hope of developing new preventative strategies.