Alzheimer's Disease Archive

Subjective cognitive decline often appears before memory loss and other symptoms.

Recent research suggests that the brain changes leading to Alzheimer's disease begin many years before the onset of symptoms.

Most often the disease is not diagnosed until it exists in full force, so finding earlier changes in thinking or behavior may help scientists better understand this process.

Research we're watching

 Image: © Reptile8488/Getty Images

A new study published online June 21 by the journal Neuron links two common viruses to Alzheimer's disease. Based on data from three brain banks, researchers found that the brains of people with Alzheimer's disease had up to twice the levels of two viruses — herpesviruses 6A and 7 — compared with the brains of people who did not have dementia. The virus genes also appeared to have interacted with the human DNA in cells in the brain in ways that might have affected Alzheimer's disease risk.

Infection with these herpesviruses is very common. Up to 90% of people may be exposed to these viruses in childhood. They cause, among other things, a mild infection known as roseola, which produces a rash and a fever.

Here are some common warning signs of Alzheimer's disease. If you or someone you love is experiencing one or more of the following symptoms, talk to a doctor.

Trouble remembering things. At first, only short-term memory may be affected. The individual may forget an appointment or the name of a new acquaintance. She may also forget where she left things, or she may leave things in odd places (for example, putting her shoes in the microwave). Eventually, long-term memory is impaired, and the individual may not recognize family members.

News briefs

 Image: © Stockbyte/Getty Images

An observational study published online May 30, 2018, by JAMA Psychiatry found that engaging in intellectually stimulating activities, even later in life, may lower the odds of dementia. Researchers followed over 15,000 Chinese men and women in their 70s for seven years with annual assessments of health and lifestyle habits, including a variety of leisure activities. The odds of being diagnosed with dementia during the study period were 29% lower in people who challenged their brains daily with such activities as playing board games, reading, and even betting on horse racing. In contrast, less mentally demanding recreational activities (like watching TV or shopping) or social activities (like going to tea with friends) did not appear to be associated with a lower risk of dementia. Other studies have found similar evidence, but this one made a special effort to adjust for factors like better overall health that might otherwise account for the association between brain exercise and dementia.

In the journals

Anticholinergic medications used to treat bladder conditions, Parkinson's disease, and depression are associated with an increased risk of dementia, according to a large study published online April 25, 2018, by The BMJ. Anticholinergic drugs help to contract and relax muscles. They work by blocking acetylcholine, a substance that also transmits messages in the nervous system. In the study, researchers compared the medical records of 40,770 people older than 65 who were diagnosed with dementia and 283,933 seniors without.

They found that people diagnosed with dementia were up to 30% more likely to have been prescribed anticholinergic medications for Parkinson's, bladder problems, or depression. Frequently prescribed anticholinergic drugs include procyclidine (Kemadrin) for Parkinson's; tolterodine, oxybutynin, and solifenacin (Vesicare) for urological conditions like overactive bladder or incontinence; and amitriptyline, dosulepin, and paroxetine for depression. However, there was no association between dementia and anticholinergic drugs used to treat other common conditions like hay fever, travel sickness, and stomach cramps.

Stress management may reduce health problems linked to stress, which include cognitive problems and a higher risk for Alzheimer's disease and dementia.

 Image: © iMrSquid/Getty Images

It's not uncommon to feel disorganized and forgetful when you're under a lot of stress. But over the long term, stress may actually change your brain in ways that affect your memory.

Studies in both animals and people show pretty clearly that stress can affect how the brain functions, says Dr. Kerry Ressler, chief scientific officer at McLean Hospital and professor of psychiatry at Harvard Medical School. Scientists have seen changes in how the brain processes information when people experience either real-life stress or stress manufactured in a research setting. (For the latter, researchers might challenge subjects to perform a difficult task, such as counting backward from the number 1,073 by 13s while being graded.) Either type of stress seems to interfere with cognition, attention, and memory, he says.

Research we're watching

 Image: © radyreese/Getty Images

High cardiovascular fitness during middle age may lower the likelihood of dementia late in life, according to a decades-long study.

For the study, researchers asked 191 middle-aged women to ride an exercise bike until they were exhausted. They then grouped the women according to their peak cardiovascular capacity. Just 40 women met the criteria for high fitness, while 92 were in the medium category, and 59 were in the low category.

These strategies may offer greater protection.

 Image: © shapecharge/Getty Images

While there's no cure for Alzheimer's disease, ongoing research has suggested there may be ways to lower your risk.

"Much of the existing science supports how certain behavioral changes made in middle age can protect people as they grow older," says Dr. Kirk Daffner, director for the Center for Brain/Mind Medicine at Harvard-affiliated Brigham and Women's Hospital. "However, there is evidence that adopting certain healthy lifestyle habits can benefit older adults too."

In the journals

So far, research has been mixed on whether brain training programs can improve or slow memory decline. Yet a new study published online Jan. 4, 2018, by the Journal of the American Geriatrics Society found that brain training may help people with mild cognitive impairment (MCI), the stage between normal brain aging and dementia.

Researchers recruited 145 adults, average age 72, who were diagnosed with MCI. They were split into three groups. Those in one group did two hours of brain training every week for two months. The training focused on improving memory by learning new strategies to better encode information. For example, they remembered errands by associating tasks with specific locations in their home, a process called method of loci. They also practiced how to better control their attention.

Research we're watching

Drinking too much alcohol could raise the risk of developing early-onset dementia, says a study published online Feb. 20, 2018, by The Lancet Public Health.