Alzheimer's: What you need to know

Alzheimer's is a disease that slowly causes memory impairment, behavioural changes and dementia. It affects people's ability to understand, think, remember and communicate.

Alzheimer's affects one in 20 Canadians over 65. That number rises to one in four in those over 85. Researchers say that the number of cases around the world will quadruple by 2050, because of the aging baby-boomers.

Although Alzheimer's mainly affects the elderly, it can occur even in people under 59. The disease starts to attack the brain years before any symptoms appear, so researchers are trying to find out what causes it.

In December 2006, researchers examined 2,000 proteins in the spinal fluid of 34 people who died with Alzheimer's and compared it to the spinal fluid of 34 non-demented people.

The difference was a group of 23 proteins. Testing a person's spinal fluid for this group of proteins can predict Alzheimer's with 87 percent accuracy.

There is still no cure for Alzheimer's, but in 2007 a research team found a gene that may increase the risk of the disease. They said that people with Alzheimer's have lower levels of SORL1 in their blood cells.

When SORL1 was suppressed in laboratory studies, cells made greater amounts of amyloid beta peptide (a toxic plaque). Researchers say that when the amyloid accumulates, brain cells start to die, which causes disorientation and progressive memory loss.

In a 2007 study, scientists found that a protein called soluble LRP can be used as a "sponge" to absorb the toxic plaque that causes Alzheimer's. In healthy people, soluble LRP neutralizes up to 90 percent of the amyloid beta that is circulating in the body.

When mice were injected with extra LRP, they dramatically improved learning and memory, as well as blood flow to the brain. Also, when the LRP soaked up the plaque, the brain responded by reducing levels of it.

Another study with mice found that caffeine may help. Alzheimer’s mice that were given caffeine did much better on tests measuring memory and thinking skills. Their memories improved so much that they were about the same as mice without dementia.

The onset of Alzheimer’s may be delayed by drinking fruit and vegetable juice frequently. Research from August 2006 showed that drinking a glass of freshly squeezed juice at least three times a week can dramatically reduce the symptoms of Alzheimer's.

At first, the researchers thought that the anti-oxidants in the juice might be protective, but a new study showed that it isn't the vitamins that are protective, it's the polyphenols. Protective polyphenols are found in the skin of fruits and vegetables. They disintegrate when heated, so cooking neutralizes the protective effect.

The protective effect of polyphenols probably won't stop Alzheimer's altogether, but it can reduce the chances. Other factors such as smoking, education, physical activity and fat intake may also play a role, so it's important to have a healthy lifestyle.

SOURCE: "Understanding Alzheimer's" CBC News. 6 July 2009.