People with high cholesterol are at higher risk of early Alzheimer’s, study suggests
- About 200,000 have Alzheimer’s disease that started before age 65
- The early form of the disease accounts for just five to 10 percent of cases
- Four genes account for about 10 percent of the risk of early Alzheimer’s
- But a new study from Emory University found that high ‘bad’ cholesterol might raise risks regardless of genetics
High cholesterol raises the risks of early-onset Alzheimer’s disease and may even cause the devastating brain disorder, new research suggests.
A link between the more common late-onset form of Alzheimer’s and high ‘bad’ cholesterol has been established by multiple studies, but the type of disease that sets in before age 65 is not as well understood.
Now, researchers working with the Atlanta Veteran’s Affairs hospital and Emory University have found that blood cholesterol may significantly raise risks for early-onset disease – whether or not you have the dreaded ‘Alzheimer’s gene.’
The new study’s findings suggest that a healthier diet might help stave off the onset of crippling memory loss.
About 200,000 Americans have early-onset Alzheimer’s disease, and having high cholesterol may put many more at greater risk of the devastating memory disease
There are four genes that seem to raise risks for early-onset Alzheimer’s disease.
Collectively, these genes likely account for about 14 percent of the 200,000 cases of early Alzheimer’s in the US.
Well over five million Americans has Alzheimer’s, which typically strikes after age 65, but between five and 10 percent develop memory loss beginning in their 40s or 50s.
Some who inherit particularly high-risk genes for the disease may begin to lose their memories as early as in their 30s.
Like older-onset Alzheimer’s there’s no way to make an unequivocal diagnosis of younger Alzheimer’s disease until an autopsy can be conducted after death.
Tests given to diagnose the disease remain relatively subjective, treatments are minimally effective and a cure does not exist.
Scientists hope that by better understanding the disease’s root causes and risks, they can get closer to developing treatments or perhaps preventing the disease altogether.
But until gene therapies for Alzheimer’s are fully developed, there is nothing to be done about Alzheimer’s risks written into someone’s DNA.
Instead, the Emory scientists looked at a more easily changed risk factor: cholesterol.
Specifically, they focused on low-density lipoprotein (LDL) or ‘bad’ cholesterol.
They assessed blood samples and DNA from 2,125 people, 654 of whom had been diagnosed with early-onset Alzheimer’s.
About 10 percent of the participants with early-onset Alzheimer’s had a variation of the APOE gene that is closely associated with the disease.
Another three percent had at least one of three other risk genes.
But that meant that the vast majority of the group had unexplained early-onset Alzheimer’s.
A possible explanation lay in the tests for blood cholesterol levels.
The men and women with high LDL were at an elevated risk of developing Alzheimer’s at a young age, regardless of their genetic risks.
‘The big question is whether there is a causal link between cholesterol levels in the blood and Alzheimer’s disease risk,’ said Dr Thomas Wingo, neurologist and lead study author.
‘The existing data have been murky on this point. One interpretation of our current data is that LDL cholesterol does play a causal role. If that is the case, we might need to revise targets for LDC cholesterol to help reduce Alzheimer’s risk.’