Cholesterol-lowering statins could be increasing our risk of developing Alzheimer’s disease, dementia, and cognitive decline, especially as we get older.
The drugs reduce levels of triglycerides, a lipid or type of fat that protects the brain. Low levels of the fat double the risk of dementia, researchers from Monash University in Australia discovered when they analysed a group of 18,294 people with an average age of 75.
The volunteers were divided into four groups, based on their triglyceride levels. In the group of 1418 people with the lowest levels, 82 people—or 6 percent—were diagnosed with dementia during the six years of the study, but just 73 people—or 3 percent of the total—among the 2117 who had the highest levels developed the condition.
To reinforce their findings, the researchers also looked at a dataset of 68,000 older people in the UK, 2776 of whom developed dementia over an average of 12 years. The researchers found a consistent pattern of a 17 percent reduced risk of dementia for every doubling of triglyceride levels.
They also found that higher triglyceride levels reduced the risk of composite cognition, which includes overall function, psychomotor speed or body movement, language and memory.
Average triglyceride levels are around 150 mg/dL (milligrams per decilitre of blood), but some in the group the researchers investigated had levels as low as 62 mg/dL.
Triglycerides are the most common fat in the blood, and make up to 95 percent of dietary fats, which are the main energy source of the brain.
Statins target LDL cholesterol, the supposed ‘bad’ fat, and triglycerides, and as well as taking the drugs with extreme caution, healthy levels can also be maintained by eating a high-fat diet, the researchers say.