Life & Style | Health

Alzheimer’s link to cholesterol levels discovered

Study links high levels of bad cholesterol and low levels of good cholesterol to more amyloid plaque in the brain

  • By Melissa Healy
  • Published: 14:59 January 3, 2014
  • Tabloid on Saturday

Well before signs of dementia trigger a diagnosis of Alzheimer’s disease, a person’s cholesterol levels may be a bellwether of amyloid plaque build-up in the brain, a new study finds.

Long considered a reliable predictor of heart attacks and strokes, worrisome cholesterol levels may now raise concerns about dementia risk as well, prompting more aggressive use of drugs, including statins, that alter cholesterol levels.

The latest study does “not convincingly exclude the possibility” that taking statins might lower amyloid deposition, the researchers said. But neither did it show that those taking cholesterol medication were less likely to have the sticky plaques that gum up brain function. Only a larger study that gathers more of subjects’ past health history can determine what role cholesterol-lowering medication might play in protecting against Alzheimer’s disease, the authors wrote.

Published in the journal JAMA Neurology, the latest research used PET Imaging to conduct a one-time “snapshot” of the brains of 74 older patients without dementia. They looked specifically to gauge the presence and concentration of amyloid plaques in brain regions most prone to early signs of the abnormal protein build-up: the frontal cortex, lateral parietal cortex, lateral temporal cortex, posterior cingulate and precuneus.

Past research has found higher levels of amyloid deposits in the post-mortem brains of people who had worrisome cholesterol readings before their death. But this is the first to find that beta-amyloid proteins may accumulate steadily in those living with higher cholesterol, possibly resulting — should one live long enough — in dementia symptoms.

Among the subjects, with an average age of 78, having high levels of LDL-C “bad” cholesterol was closely linked to having more amyloid plaque deposits in those regions. On average, those with low levels of HDL cholesterol — the “good” cholesterol that at high levels is protective against cardiovascular disease — also had more amyloid plaque in their brains.

The researchers, from UC Berkeley, UC Davis and USC, found that other measures that physicians use to gauge a patient’s risk of heart attack or stroke — triglycerides and total cholesterol — had no clear relationship to amyloid plaques in the brain.

While none of the subjects in the study had been diagnosed with dementia, more than half suffered mild cognitive impairment — a decline in mental performance that sometimes progresses to Alzheimer’s disease. Three had been diagnosed with mild dementia.

As a group, the study’s subjects had been aggressively treated for high cholesterol, however. Their average cholesterol levels were within the optimum range set by the American Heart Association (until recently published guidelines minimised the importance of such guideposts).

Because researchers had only a one-time snapshot of subjects’ cholesterol levels as well, they were unable to discern whether lowering cholesterol with medication resulted in fewer amyloid deposits.

How cholesterol levels could affect the formation of amyloid plaques in the brain is something of a mystery. Roughly a quarter of the cholesterol in our bodies resides in our brains. Cholesterol levels there seem to affect the synthesis of beta-amyloid proteins, their clearance from the brain, and their toxicity once plaques are established.

But the central nervous system’s cholesterol is virtually walled off from that circulating throughout the rest of the body by the blood-brain barrier. So the link between circulating cholesterol levels and amyloid plaques in the brain is unknown. One possibility, recently suggested by research: oxysterols, oxidised derivatives of cholesterol that pass through the blood-brain barrier and may affect cholesterol levels throughout the body.

Your guide to the best of the weekend

Tabloid on Saturday
Lifestyle & Entertainment columnists
  • Russell Hemmings
    The Hemmings way

    Life coach Russell Hemmings on fears, anxieties and the human psyche demystified

  • Gaby Doman
    Gaby Doman: Notes to myself

    The everyday ups and downs of being a modern woman, according to this globetrotter

  • Uma Ghosh Deshpande
    The Dubai Insider

    TV personality Uma Ghosh Deshpande guides you through the city’s society gatherings and stories

  • Pratyush Sarup
    Design diary

    Dubai-based interior designer Pratyush Sarup lets us in on the world of design

  • Bharat Thakur
    Yoga for you

    Bharat Thakur guides you through practices and wisdom of this ancient science of exercising

FROM THE NETWORK

More from friday

  • WH_141024_Lambo_Huracan_STF_Stefan065
    Unhinged Huracàn meets the UAE’s maddest road

    Al Taween. Renowned for its goat s, tiny grocery shops and one of the great est mounta in roads in the world. Ripping up the newly laid tar mac? A Lamborghini Huracán. Buckle up!

  • WH_141031_mywheels_rashed (1)
    Rashed Abdulla Bin Fahad’s double impact

    Ever since he was bitten by a Mustang Cobra, Rashed couldn’t look beyond American cars. So when it came to choosing a pick-up truck and a performance saloon, the decision was easy for him

  • WH_141031_Subarub driven (6)
    Subaru WRX STI driven

    Subaru’s iconic flagship sports saloon is back, and along with all the upgrades comes a welcome price, too

  • WH_141031_SUP_Fiat 500 (2)
    Fiat 500 Cult refreshed

    Fiat’s nifty city car star has been updated for 2015 to keep pace with its small car rivals. Does it still have the magic that makes it a style icon?

  • Jonathan Castle
    Shifting opinions

    In defence of the (gasp!) continuously variable transmission...

More from Wheels

More from aquarius

More from alpha

  • gold-leaf-bath
    Inside Downtown Design

    From chic and contemporary to modern and magnificent home wares, this year's exhibition is nothing short of extraordinary

  • Noura_Main
    Highly commended finalist: Noura Al Ramahi

    Along with our three fabulous finalists, the judges decided to include a Highly Commended category as the standard of entries to our competition was so high. This goes to Noura Al Ramahi for her stunning villa in Abu Dhabi. Well done Noura – it’s beautiful!

  • IO_141020_Home of the Year awar86
    In pictures: InsideOut Home of the Year Awards

    The InsideOut Home of the Year Awards 2014 party held at the Nawwara Bar at the JW Marriott Marquis on the 20th October went with a swing! Here’s our gallery of a really great night….

  • IO_141014_Casablanca_STF_Stefan07
    InsideOut Home Of The Year finalist: Dana Jaber

    Dana Jaber’s Al Barsha villa was considered by the judges to be bold, original and eclectic. We loved her individual approach to decorating which lends interest and unexpected touches to every room

  • Main_2
    InsideOut Home Of The Year finalist: Helena Brown

    Helena Brown’s home in Umm Suqeim was a favourite with the judges because of the many personal touches, and undeniable sense of comfort and style. Her interest in Feng Shui has helped achieve a calm relaxed ambience

More from insideout