If you ignore your blood sugar and cholesterol levels early in adulthood, you may miss out on opportunities to minimize your risk of developing Alzheimer’s disease down the line.
A low level of high density lipoprotein (HDL) cholesterol — the “good” kind that reduces the risk of heart disease by clearing blood vessels of fats and debris — has long been linked to an increased risk of dementia and Alzheimer’s disease in older adults. So has high blood sugar.
But much of this earlier research focused on people who had unhealthy blood levels of sugar or cholesterol in middle age. Now a study suggests that cholesterol and blood sugar levels in earlier adulthood also predicts future Alzheimer’s disease risk.
The study, published March 23 in Alzheimer’s and Dementia, followed 4,932 adults over several decades starting when they were 38 years old on average. Every four years, participants had health exams, including tests to check cholesterol and blood sugar. They also had periodic cognitive tests to check for early signs of dementia or Alzheimer’s disease.
High Triglycerides and Blood Sugar Tied to Greater Alzheimer’s Risk
People who started out with higher levels of HDL cholesterol were 13 percent less likely to develop Alzheimer’s disease by the end of the study period.
At the same time, younger adults were 34 percent more likely to develop Alzheimer’s disease when they had high triglycerides — unhealthy fats that can make blood stickier, thicker, and more likely to clot — and 12 percent more likely to have Alzheimer’s if they had high blood sugar.
“While our findings confirm other studies that linked cholesterol and glucose levels measured in blood with future risk of Alzheimer’s disease, we have shown for the first time that these associations extend much earlier in life than previously thought,” said the senior study author, Lindsay Farrer, PhD, in a statement. Dr. Farrer is the chief of biomedical genetics at Boston University School of Medicine.
Many people don’t give their cholesterol levels much thought before they reach middle age. And when they do pay attention, they tend to focus on the heart disease risk associated with elevated levels of low-density lipoprotein (LDL) cholesterol, the “bad” kind that can accumulate in blood vessels and lead to clots and heart attacks. They don’t focus as much on the potential impact of high LDL cholesterol and low HDL cholesterol on their future brain health.
This is a missed opportunity to prevent or slow age-related cognitive decline, the study team noted. That’s because adopting healthy eating and exercise habits and taking any medication needed to maintain healthy cholesterol and blood sugar levels early in adulthood can pay off decades later with a healthier brain.
Small changes can make a big difference, the study results suggest.
Each 15 milligram per deciliter (mg/dL) increase in HDL cholesterol in early adulthood was associated with a 15 percent reduction in Alzheimer’s disease risk, the study found. And every 15 mg/dL increase in blood sugars, or glucose levels, was associated with 15 percent greater chance of developing Alzheimer’s disease.
“Intervention targeting cholesterol, and glucose management starting in early adulthood, can help maximize cognitive health in later life,” Farrer said.
All the participants in the current analysis were part of the Framingham Heart Study, which was begun in 1948 to examine cardiovascular disease risk factors over multiple generations.
Farrer stated that “the unique design and mission of the Framingham Heart Study, which is a multi-generation, community-based, prospective study of health that began in 1948, allowed us to link Alzheimer’s to risk factors for heart disease and diabetes measured much earlier in life than possible in most other studies of cognitive decline and dementia.”