Experts are still trying to fully understand the cause or causes of Alzheimer's disease. In the meantime, it's helpful to understand the hallmarks of Alzheimer's -- plaques and tangles -- and the risk factors that affect a person's likelihood of developing the disease (Hill).

Alzheimer's disease is characterized by a build-up of proteins in the brain. Though this cannot be measured in a living person, extensive autopsy studies have revealed this phenomenon. The build-up manifests in two ways: Plaques -- deposits of the protein accumulate in the spaces between nerve cells. Tangles -- deposits of the protein that accumulate inside of nerve cells.

Scientists are still studying how plaques and tangles are related to Alzheimer's disease. One theory is that they block nerve cells' ability to communicate with each other, making it difficult for the cells to survive (Hill).

Autopsies have shown that most people develop some plaques and tangles as they age, but people with Alzheimer's develop far more than those who do not develop the disease. Scientists still don't know why some people develop so many compared to others. However, several risk factors for Alzheimer's disease have been uncovered (Hill).

Advancing age is the number one risk factor for developing Alzheimer's disease. One out of eight people over the age of 65 has Alzheimer's disease, and almost one out of every two people over the age of 85 has Alzheimer's. The probability of being diagnosed with Alzheimer's nearly doubles every five years after age 65 (Hill).

Family history is another factor. People who have a parent or sibling that developed Alzheimer's disease are two to three times more likely to develop the disease than...

If more than one close relative has been affected, the risk increases even more.
Scientists have identified two kinds of genes that are associated with this familial risk factor. The first is thought to be a "risk gene," ApoE 4, that increases the likelihood of developing Alzheimer's, but does not guarantee it. In addition to ApoE 4, scientists think there could be up to a dozen more risk genes yet to be discovered (Hill).

Prevention

When discussing the prevention of Alzheimer's, it's important to remember that there is no "vaccine" against the disease, nor is it guaranteed that prevention strategies will work. Still, scientific evidence indicates that how we live our lives really does make a difference in how likely we are to develop Alzheimer's or a related dementia. Prevention involves making healthy lifestyle choices in four areas: Diet and Nutrition, Physical Exercise, Mental Exercise, and Social Interaction (Hill).

Conclusion

While there is no cure for Alzheimer's disease and no proven treatment to slow its progression, it is possible to relieve some of the symptoms and sometimes slow progression. By managing the disease life can be easier for the patient and family.

Bibliography

Hill, Carrie. "What Causes Alzheimer's Disease?" 4 Mar 2009. about.com. 5 May 2009 .

"history." n.d. alzheimers.factsforhealth.org. 8 May 2009 .

"Living With Alzheimer's." n.d. alzheimerstreatment.org. 8 May 2009 .

Plontz, Michael. "A Brief History of Alzheimer's Disease." n.d. caregiver.com. 8 May 2009 .

Stephens, Laura. "Alzheimer's Disease ." 5 Dec 2007 . psychologytoday. 8 May 2009 .