ALZHEIMER'S DISEASE

The Mayo Clinic

Introduction

Alzheimer's disease is the most common cause of dementia, which is the loss of intellectual and social abilities severe enough to interfere with daily functioning. Dementia occurs in people with Alzheimer's disease because healthy brain tissue degenerates, causing a steady decline in memory and mental abilities.

About 4 million older Americans have Alzheimer's, a disease that usually develops in people age 65 or older. This number is expected to triple by the year 2050 as the population ages.

Although there's no cure for Alzheimer's disease, researchers have made progress. Treatments are available that improve the quality of life for some people with Alzheimer's. Also, more drugs are being studied, and scientists have discovered several genes associated with Alzheimer's, which may lead to new treatments to block progression of this complex disease.

In the meantime, caring for someone with Alzheimer's takes patience and a focus on the things a person can still do and enjoy. Those with Alzheimer's — as well as those who care for them — need support and affection from friends and family to cope.

Is it true that vitamin B-12 supplements can improve memory? What about in people with Alzheimer's disease?

Vitamin B-12 may improve memory in people with a proven vitamin B-12 deficiency. Poor memory may be a sign of Vitamin B-12 deficiency. In such cases, supplementing with vitamin B-12 may improve memory. However, there's no evidence that vitamin B-12 enhances memory in people with normal memory.

At this time, there's no evidence that supplementing with vitamin B-12 offers any benefit to people with Alzheimer's disease. However, some studies suggest that people with Alzheimer's disease have reduced blood levels of vitamin B-12 — and that people with reduced blood levels of vitamin B-12 are at increased risk of Alzheimer's. As a result, several large studies are under way to evaluate the potential benefit of vitamin B-12 supplementation in people with Alzheimer's

Is it true that the Mediterranean diet prevents Alzheimer's?

A study published in the Annals of Neurology in June 2006 suggests that people who eat a "Mediterranean" diet — rich in fruits, vegetables, olive oil, legumes, cereals and fish — have a lower risk of developing Alzheimer's disease.

Researchers examined the health and diet of more than 2,000 people over a four-year period. The average age of study participants was 76. None of the participants had Alzheimer's disease at the start of the study. By the end of the study, 260 participants had been diagnosed with Alzheimer's disease.

Over the course of the study, researchers evaluated how closely participants followed a published definition of the Mediterranean diet. Participants who stuck most closely to the diet were less likely to develop Alzheimer's than were participants who didn't follow the diet. Although this is an intriguing finding, more research is needed to evaluate the potential effects of diet and lifestyle on the risk of Alzheimer's disease.

An equally valid interpretation of the findings would be that people who had difficulty following a diet plan are more likely to develop Alzheimer's disease and that also makes some sense.

Alzheimer's drugs: Real benefits despite limitations

Alzheimer's still has no cure, but two different types of drugs have been found to slow the progression of the disease.

Medication can improve the quality of life for people with Alzheimer's and their caregivers. It may even delay placement in a nursing home. Unfortunately, Alzheimer's medications don't work for everyone.

Some of the most commonly used drugs work in less than half
the people tested. For those who are helped, the drugs' effects often are modest and temporary. Scientists continue to search for more effective drugs or perhaps even a vaccine that might someday
prevent Alzheimer's.

Of the two main types of drugs currently approved by the Food and Drug Administration (FDA) for use in Alzheimer's, one variety seems to work best in the earlier stages of the disease while the other is reserved for treatment of the later stages.

Early stage Alzheimer's treatments

Alzheimer's disease changes the brain in many ways. One of the changes results in a decrease in the levels of acetylcholine, a chemical messenger that is believed to be important for memory, thought and judgment.

Cholinesterase (ko-lin-ES-tur-ase) inhibitors are a type of drug that improves the effectiveness of acetylcholine either by increasing the amount of it in the brain or by strengthening the way nerve cells respond to it. These drugs appear to work best in the early to middle stages of Alzheimer's.

Types of cholinesterase inhibitors

The top three cholinesterase inhibitors seem to have similar rates of effectiveness and similar side effects — nausea, vomiting or diarrhea.

• Donepezil (Aricept). Perhaps the most popular cholinesterase inhibitor, donepezil offers a convenient once-a-day dosing not available in similar medications.
  
  This drug also appears to temporarily postpone the development of Alzheimer's in people with mild cognitive impairment (MCI), a separate memory-related condition that may precede Alzheimer's. In a recent study, magnetic resonance images show less brain shrinkage among people with MCI treated with donepezil than among people with MCI treated with a placebo. Donepezil had this effect only in people who carry a gene associated with higher risk of Alzheimer’s, however.
  
  
• Galantamine (Razadyne). Approved by the FDA in 2001, galantamine is the newest cholinesterase inhibitor on the market.
  
  
• Rivastigmine (Exelon). Rivastigmine may cause more severe gastrointestinal problems than other cholinesterase inhibitors do. Doctors typically prescribe a low dose of the drug initially and slowly increase the dosage as the body becomes accustomed to it.
  
  
• Tacrine (Cognex). Tacrine has been on the market since 1993. However, it's rarely prescribed because of serious side effects, including possible liver damage.

Later stage treatment

Memantine (Namenda) is the first drug to be approved by the FDA for treatment of moderate to severe Alzheimer's disease. It works by regulating the activity of glutamate, a messenger chemical involved in learning and memory. Its most common side effect is dizziness.

No cure yet

Until researchers find a cure — or can halt the progression of Alzheimer's— slowing the downward spiral remains the only benefit drugs can offer. But even temporary improvements in memory or thinking ability can help prolong the amount of quality time a person with Alzheimer's has with his or her family.

© 2015 TLC Magazine Online, Inc.