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7 Myths About Alzheimer's Disease

What not to believe about Alzheimer's disease.

3. Myth: Only old people get Alzheimer’s.

It is true that age is the biggest risk factor for Alzheimer’s disease: One out of eight people 65 and older have it.

But there is such a thing as early-onset Alzheimer's disease, which starts before age 65. It's rare, accounting for only 5% to 10% of all U.S. Alzheimer's cases -- about 200,000 people. 

“People can get it in their 20s, although typical [for early onset] is in the 40s and 50s,” Ringman says.

Early-onset Alzheimer's disease often has a strong genetic link.

4. Myth: Alzheimer’s is all about genetics.

There are gene mutations that are linked to Alzheimer's. But there's more to Alzheimer's disease than having a rogue gene.

Take the APOE gene, for example. It has several variations, including one that is linked to greater risk of getting Alzheimer's disease. But not everyone with that APOE variation gets Alzheimer's, and not everyone with Alzheimer's has that APOE variation. And that's just one of several genes linked to Alzheimer's risk.

So clearly, genetics isn't everything.

Usually, Galvin says, there is a strong family history with people of every generation getting it at same age. “But, generally [genetics] are not a very large risk factor,” he says.

Researchers are hunting for more genetic clues. Meanwhile, keep this in mind: There is not one Alzheimer's gene that seals your fate, and the biggest risk factor for Alzheimer’s, by far, is aging.

5. Myth: Depression causes Alzheimer's disease.

Depression can be an early sign of Alzheimer’s disease, but it's not proven to cause Alzheimer's disease.

Depression is common. It affects nearly 15 million Americans, including 6.5 million people aged 65 or older.

But not everyone who is depressed gets Alzheimer's disease. The exact link between the two conditions isn't clear.

The degree of the depression may matter. “The kind of depression that precedes Alzheimer’s disease is milder, whereas people with depression [without Alzheimer’s] tend to be more severely affected. A suicidal Alzheimer’s patient is extremely rare,” Ringman says.

6. Myth: Dementia is the same as Alzheimer’s disease.

Dementia is an umbrella term used to describe a loss of memory caused by changes in the brain. Alzheimer’s is the most common form of dementia, but it’s not the only one.

“Everyone with Alzheimer’s disease has dementia but not everyone with dementia has Alzheimer’s disease,” Galvin says.

There are more than 70 different causes of dementia, including strokes, Parkinson’s disease, Lewy body dementia, and Pick’s disease.

7. Myth: Dietary supplements protect the brain.

There is no good evidence showing that dietary supplements prevent Alzheimer’s.

“At least in the supplements and vitamins and minerals that have been vigorously tested, they have uniformly failed to show any benefit,” Galvin says.

The dietary supplements most tested include fish oil, ginkgo biloba, and high-dose vitamins. Other supplements have not been as thoroughly tested for brain-protecting power.

Always tell your doctor about any supplements you're taking or any memory problems you're having.

Reviewed on January 31, 2011

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