One in eight Americans over the age of 60 reports worsening memory loss, raising concerns of an Alzheimer’s Disease crisis as the baby-boom generation gets older, a large government study finds. And it's bugging the youngest members of that age group the most.

Nearly 13 percent people 60 or older reported confusion or memory loss occuring more often or getting worse over the past 12 months, the Centers for Disease Control and Prevention found.

Of these people, one-third reported that confusion or memory loss interfered with their work, social activities, or ability to do household chores, the CDC found in analyzing a survey of 59,000 people in 21 states.

Because it’s the first self-reported survey of memory loss, it’s difficult to draw conclusions, said Angela Deokar, a public health adviser at the CDC.

“This is the first time we have such data,” she said, adding that future surveys would look at why people in the 60-64 age group seemed to suffer more when they did have memory loss. The survey found that 12 percent of 60 to 64-year-olds complained of confusion or memory loss, and of them,  nearly 45 percent said it interfered with daily life or work. That's worse than in the 85-and-older group -- only 38 percent of them felt the memory loss or confusion interfered with their lives.

“These findings suggest a need for future studies to examine the relationship of age and functional difficulties caused by increased confusion or memory loss,” Deokar said.

But only 35 percent of those who reported memory loss said they had discussed their symptoms with a health care provider. It's not clear whether the symptoms are just very mild, or that baby boomers are in denial.

“Some say ‘Oh, it’s just a normal part of aging.’ It’s not,” said Matthew Baumgart, senior director of public policy for the Alzheimer’s Association, which is analyzing the CDC results.

“When one in eight Americans 60-plus says they are having memory problems, then we continue to have a problem and things are not going to get better for the foreseeable future,” he said.

Even though 12.7 percent reported worsening memory loss in the previous year, that did not necessarily mean they were developing Alzheimer’s, Baumgart said, although forgetfulness is a key sign of the disease. Alzheimer’s disease, the sixth leading cause of death in the United States, is also the fastest growing threat because of the aging population.

“There is definitely a stigma surrounding this disease and 80 percent not talking to their doctor is an indication of that,” he said.

The study, which was conducted in 2011, only included the first five years of the Baby Boom generation to turn 60. “We’ve got another 15 years to come,” Baumgart said.

That will put more pressure on the system, since Alzheimer’s and dementia are probably the costliest illnesses because many patients eventually need nursing home care, he said. Most patients live four to eight year after diagnosis, but many can live for 20 more years, Baumgart said, adding that about one-third of Alzheimer’s patients live alone and are unaware of their symptoms.

“No treatments will slow the advance of the disease, but a diagnosis can allow a patient to plan for future care,” he said, stressing the importance of early detection.

Lynda Anderson, who is director of the CDC’s Healthy Aging Program, said respondents were clearly told the study was about memory loss deteriorating in the previous 12 months. “We prefaced the questions by telling them it was not about losing your keys or forgetting a face, like we all do sometimes," she said.

By Marilynn Marchione, Associated Press

Cancer and heart disease are bigger killers, but Alzheimer's is the most expensive malady in the U.S., costing families and society $157 billion to $215 billion a year, according to a new study that looked at this in unprecedented detail.

The biggest cost of Alzheimer's and other types of dementia isn't drugs or other medical treatments, but the care that's needed just to get mentally impaired people through daily life, the nonprofit RAND Corp.'s study found.

It also gives what experts say is the most reliable estimate for how many Americans have dementia — around 4.1 million. That's less than the widely cited 5.2 million estimate from the Alzheimer's Association, which comes from a study that included people with less severe impairment.

"The bottom line here is the same: Dementia is among the most costly diseases to society, and we need to address this if we're going to come to terms with the cost to the Medicare and Medicaid system," said Matthew Baumgart, senior director of public policy at the Alzheimer's Association.

Dementia's direct costs, from medicines to nursing homes, are $109 billion a year in 2010 dollars, the new RAND report found. That compares to $102 billion for heart disease and $77 billion for cancer. Informal care by family members and others pushes dementia's total even higher, depending on how that care and lost wages are valued.

"The informal care costs are substantially higher for dementia than for cancer or heart conditions," said Michael Hurd, a RAND economist who led the study. It was sponsored by the government's National Institute on Aging and will be published in Thursday's New England Journal of Medicine.

Alzheimer's is the most common form of dementia and the sixth leading cause of death in the United States. Dementia also can result from a stroke or other diseases. It is rapidly growing in prevalence as the population ages. Current treatments only temporarily ease symptoms and don't slow the disease. Patients live four to eight years on average after an Alzheimer's diagnosis, but some live 20 years. By age 80, about 75 percent of people with Alzheimer's will be in a nursing home compared with only 4 percent of the general population, the Alzheimer's group says.

"Most people have understood the enormous toll in terms of human suffering and cost," but the new comparisons to heart disease and cancer may surprise some, said Dr. Richard Hodes, director of the Institute on Aging.

"Alzheimer's disease has a burden that exceeds many of these other illnesses," especially because of how long people live with it and need care, he said.

For the new study, researchers started with about 11,000 people in a long-running government health survey of a nationally representative sample of the population. They gave 856 of these people extensive tests to determine how many had dementia, and projected that to the larger group to determine a prevalence rate — nearly 15 percent of people over age 70.

Using Medicare and other records, they tallied the cost of purchased care — nursing homes, medicines, other treatments — including out-of-pocket expenses for dementia in 2010. Next, they subtracted spending for other health conditions such as high blood pressure, diabetes or depression so they could isolate the true cost of dementia alone.

"This is an important difference" from other studies that could not determine how much health care cost was attributable just to dementia, said Dr. Kenneth Langa, a University of Michigan researcher who helped lead the work.

Even with that adjustment, dementia topped heart disease and cancer in cost, according to data on spending for those conditions from the federal Agency for Healthcare Research and Quality.

Finally, researchers factored in unpaid care using two different ways to estimate its value — foregone wages for caregivers and what the care would have cost if bought from a provider such as a home health aide. That gave a total annual cost of $41,000 to $56,000 per year for each dementia case, depending on which valuation method was used.

"They did a very careful job," and the new estimate that dementia affects about 4.1 million Americans seems the most solidly based than any before, Hodes said. The government doesn't have an official estimate but more recently has been saying "up to 5 million" cases, he said. 

The most worrisome part of the report is the trend it portends, with an aging population and fewer younger people "able to take on the informal caregiving role," Hodes said. "The best hope to change this apparent future is to find a way to intervene" and prevent Alzheimer's or change its course once it develops, he said.

A staggering 1 in 3 seniors dies with Alzheimer's disease or other types of dementia, says a new report that highlights the impact the mind-destroying disease is having on the rapidly aging population.

Dying with Alzheimer's is not the same as dying from it. But even when dementia isn't the direct cause of death, it can be the final blow — speeding someone's decline by interfering with their care for heart disease, cancer or other serious illnesses. That's the assessment of the report released Tuesday by the Alzheimer's Association, which advocates for more research and support for families afflicted by it.

"Exacerbated aging," is how Dr. Maria Carrillo, an association vice president, terms the Alzheimer's effect. "It changes any health care situation for a family."

In fact, only 30 percent of 70-year-olds who don't have Alzheimer's are expected to die before their 80th birthday. But if they do have dementia, 61 percent are expected to die, the report found.

Already, 5.2 million Americans have Alzheimer's or some other form of dementia. Those numbers will jump to 13.8 million by 2050, Tuesday's report projects. That's slightly lower than some previous estimates.

Count just the deaths directly attributed to dementia, and they're growing fast. Nearly 85,000 people died from Alzheimer's in 2011, the Centers for Disease Control and Prevention estimated in a separate report Tuesday. Those are people who had Alzheimer's listed as an underlying cause on a death certificate, perhaps because the dementia led to respiratory failure. Those numbers make Alzheimer's the sixth leading cause of death.

That death rate rose 39 percent in the past decade, even as the CDC found that deaths declined among some of the nation's other top killers — heart disease, cancer, stroke and diabetes. The reason: Alzheimer's is the only one of those leading killers to have no good treatment. Today's medications only temporarily ease some dementia symptoms.

But what's on a death certificate is only part of the story.

Consider: Severe dementia can make it difficult for people to move around or swallow properly. That increases the risk of pneumonia, one of the most commonly identified causes of death among Alzheimer's patients.

Likewise, dementia patients can forget their medications for diabetes, high blood pressure or other illnesses. They may not be able to explain they are feeling symptoms of other ailments such as infections. They're far more likely to be hospitalized than other older adults. That in turn increases their risk of death within the following year.

"You should be getting a sense of the so-called blurred distinction between deaths among people with Alzheimer's and deaths caused by Alzheimer's. It's not so clear where to draw the line," said Jennifer Weuve of Chicago's Rush University, who helped study that very question.

The Chicago Health and Aging Project tracked the health of more than 10,000 older adults over time. Weuve's team used the data to estimate how many people nationally will die with Alzheimer's this year — about 450,000, according to Tuesday's report.

That's compatible with the 1 in 3 figure the Alzheimer's Association calculates for all dementias. That number is based on a separate analysis of Medicare data that includes both Alzheimer's cases and deaths among seniors with other forms of dementia.

Last year, the Obama administration set a goal of finding effective Alzheimer's treatments by 2025, and increased research funding to help. It's not clear how the government's automatic budget cuts, which began earlier this month, will affect those plans.

But Tuesday's report calculated that health and long-term care services will total $203 billion this year, much of that paid by Medicare and Medicaid and not counting unpaid care from family and friends. That tab is expected to reach $1.2 trillion by 2050, barring a research breakthrough, the report concluded. 

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The number of Americans living with Alzheimer’s will triple in the next 40 years, which means that 13.8 million will have the mind-robbing disease by 2050, researchers projected Wednesday.

Previous estimates of what many call “the tsunami of Alzheimer’s” hitting our society as the population ages have come up with similar numbers. This latest projection is notable because it is based on an analysis of more than 10,000 people 65 and older enrolled in the Chicago Health and Aging Project since 1993.

Researchers interview the volunteers every three years to monitor the number who develop Alzheimer’s as they grow older. Census data project that as the baby boom generation ages, the number of Americans ages 65 to 84 will approximately double by 2050. At the same time, the number of those 85 and older will increase almost four-fold to a total of nearly 14 million. The study estimates that 36.6 percent of that population will suffer Alzheimer’s.

Currently an estimated 4.7 million Americans have Alzheimer's, the most common cause of dementia.

“These projections emphasize the need to find either prevention or treatment for Alzheimer’s disease dementia in order to decrease the burden of future disease on individuals, families and the medical care system,” the team at Rush Hospital in Chicago writes in the journal Neurology.

What are the chances of better treatments any time soon?  In a few words: not great. Drug companies and academic researchers are carrying out many trials and we can hope for an unexpected great success. But none is apparent.

The FDA has approved five drugs to treat Alzheimer’s. Most physicians say that in a minority of patients they relieve symptoms for a few months. But none stops the inevitable brain destruction.

Still, the drugs generated sales of $2.9 billion in 2011, according to IMS Health, a healthcare technology and information company. The best selling, Aricept from Pfizer, brought in $1.5 billion. Doctors admit that all too often they will give the patient the pills long after it is clear they have no benefit because they want to help, and families expect them to do something even if it affords no improvement.

Early diagnosis will be playing an increasing role in the effort to stop or slow down Alzheimer’s. Recent studies of people who carry gene variants that bring on Alzheimer’s at an early age found that brain changes leading to the disease began as early as 25 years before memory loss or other symptoms set in. Drug trials are now looking at people with the gene variant that predisposes them to Alzheimer’s, trying experimental drugs decades in advance to see if they can slow the process.

As part of the push for early detection, drug company Eli Lilly won approval from the FDA last April for a radioactive tracer that, used with a PET brain scan, measures the build-up of a substance called amyloid plaque that many experts believe is either the cause of Alzheimer’s or a critical marker for its progression.

The company says the product, called Amyvid, can help doctors diagnose Alzheimer’s and rule out other possible, mostly rare, causes of dementia. There is no evidence to date that it can help predict what will happen to people who do not have symptoms. The price of Amyvid, the PET scan and the doctors’ time adds up to $4,000 and federal advisers say Medicare and Medicaid should not pay for it. 

So what can a person do to reduce the risk of dementia later in life? Dozens of studies have shown that exercise is very helpful.

One of the strongest pieces of research came out Monday from the Cooper Institute in Dallas. Looking at 25 years worth of records for more than 19,000 people who visited the institute, which specializes in preventive care through fitness, it found that those most fit in their late 40s were 36 percent less likely to develop dementia in their 70s and 80s. Exercise is neither new nor glamorous. But for much disease, including Alzheimer's, it remains a strong defense.

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• Gene discovery points to possible cause for Alzheimer's

A gene mutation whose discovery was announced Wednesday triples the risk for Alzheimer’s disease.  It is a headline that might sound frightening but shouldn’t evoke fear.

The mutation in the gene called TREM2 is rare, occurring in about 1 in 150 people.  By comparison one in five people carry a form of a different gene called APO-E that also triples the risk.  One in 50 carries a form of APO-E that raises risk 13 times. APO-E’s relation to Alzheimer’s was discovered in 1993.   So in terms of public health implications, TREM2 is a small player, and is one of an ever growing list of genes implicated in Alzheimer’s

Still, the research from two teams, one headed by  Dr. Kari Stefansson at DeCode Genetics in Iceland and the other by Dr. John Hardy of University College London and both published in the New England Journal of Medicine, is critically important science that may yield clues about the causes of Alzheimer’s disease and the search for better treatments. 

TREM2 in its normal form plays a role in inflammation, the body’s response that sends white blood cells to destroy invading germs and diseased tissue.  The mutation cuts the ability to mount an inflammatory response, so it ispossible the ability to fight other diseases is tied up with the risk for Alzheimer’s.  For more than a century pathologists have noted a buildup of white blood cells in the brains of people who died from Alzheimer’s.

No one is sure what causes Alzheimer’s, which already affects more than 5 million Americans and costs the U.S, economy more than $148 billion a year, according to the Alzheimer’s Association. The numbers are projected to worsen as the baby boomer generation ages. There is no treatment and no cure.

The leading contender as the main cause of Alzheimer’s is the accumulation of plaques of protein called amyloid-beta.  It is likely that the inflammatory response is attempting to keep that buildup at bay. Last July, Stefansson’s team discovered a different gene mutation, even more rare, that actually protects against Alzheimer’s. That, too, was important science because that gene is responsible for production of amyloid-beta.  So it both supports the hypothesis about the cause and leads to ideas about how to make drugs to stop it.

Stefansson established DeCode in 1996 to find disease-causing genes in Iceland, a country with a homogenous population and national health service with excellent records.  At first it was a profit making venture, but despite an impressive record of locating genes associated with several diseases, the company was forced to declare bankruptcy in 2009.  It continues as a non-profit enterprise.  The two Alzheimer’s genes discovered in the past few months illustrate why the genetic research is so important even though it does not lead to immediate public health benefits or profits.

Follow Robert Bazell on Facebook and on Twitter @RobertBazellNBC

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Victor Rivera dances with a dementia patient Sept. 20 at the Hebrew Home at Riverdale in the Bronx borough of New York. The Hebrew Home has a program that provides care and activity overnight for dementia victims with sleep problems.

NEW YORK — Just after 10 p.m., when most people their age are going to sleep, a group of elderly folks suffering from dementia are just getting started, dancing and shaking tambourines and maracas in a raucous version of "La Bamba." 

"It's a party," says an 81-year-old woman, among dozens of patients brought to a Bronx nursing home every night for a structured series of singalongs, crafts and therapy sessions that lasts until dawn.

The program, which appears to be rare, is kind of a "night camp" for dementia victims who don't sleep at night or tend to wake up agitated or become frightened or disoriented by the fall of darkness.

It's meant to provide care and activity — lots of activity — to fill the wee hours for people with Alzheimer's and similar diseases who live at home. And it's meant to provide their caregivers — usually a son or daughter — with a treasured night's sleep.

"Without this program, my father would be lost, and I would be crazy," said Robert Garcia, whose 82-year-old father, Felix, is in the program at the Hebrew Home at Riverdale called ElderServe at Night. "He doesn't sleep. At night he's wide awake, and he needs activity."

Garcia, who lives in a Bronx apartment with his wife and three of their children, said that before his father went into the program he would wake up in the night, loudly, and keep everyone else from sleeping.

"We would all wake up, and my daughter would ask, 'Why is Grandpa screaming? Why is he so grumpy?'" Garcia said.

"Now he comes home in the morning, shows me his drawings, tells me what they did all night."

While many nursing homes offer temporary "respite care" so caregivers can catch up on sleep or go on vacation, the overnight-only program at the Hebrew Home fills a niche.

But costs are high, and such programs are rare. An official at the Alzheimer's Association said she knew of no other.

Daniel Reingold, president and CEO of the Hebrew Home, said the nonsectarian overnight program was started in 1998 because anecdotal studies found the biggest reason people gave for admitting loved ones into the nursing home was sleep deprivation of the caregiver.

"Someone with Alzheimer's can be getting up at 3 a.m., banging the pots and pans, thinking they were making dinner, even walking out of the house," Reingold said. "We heard stories of caregivers who were sleeping on mattresses across the front doorway so their loved one couldn't get out."

Most patients' care is covered by Medicaid, which pays the Hebrew Home $140 a night, plus $74 for transportation to and from home.

Dr. Robert Abrams, a geriatric psychiatrist at NewYork-Presbyterian Hospital, said sleep problems are typical in dementia and include the syndrome known as "sundowning," in which the fall of darkness causes confusion and fear. At the Hebrew Home, shades are kept closed.

Abrams says an overnight activity program like the Hebrew Home's is preferable to "fighting nature by insisting that participants try to sleep."

Ruth Drew, director of family services at the Alzheimer's Association in Chicago, said, "Many family members want to care for relatives with Alzheimer's at home, but in order to do that, the caregivers themselves have to remain healthy. You cannot stay healthy if you don't get a good night's sleep."

Many patients sleep a few hours at home during the day.

As the night passed at the Hebrew Home, other activities were offered to the 34 patients, who were in their 60s to 90s. Most moved on to a "cooking" program, where they were asked to peel and slice a banana, then add grapes and blueberries for a fruit salad.

During the slow process, the patients were asked, in English and Spanish, about colors and shapes. Several downed the fruit as it came their way, before salads could be compiled.

Other nighttime activities include walks through the nearly empty halls of the nursing home and "movie nights" with popcorn. Patients who are up to it are sometimes taken on field trips, for example to see the neighborhood's Christmas lights.

In quiet rooms, patients with more profound dementia were guided in simple puzzles like putting a peg in a hole. Others had sand or water poured over their hands to stimulate tactile sensations and perhaps reminiscences.

"They haven't been to the beach in years," said program director Deborah Messina. "Maybe it's a fond memory."

One darkened room was filled with recorded sounds of nature, a pleasant aroma and twinkly lights, all meant to provide gentle stimulation.

On occasion, a patient would nod off. There are "resting rooms" for patients who want to sleep, but half-hour naps in their chairs are more common.

"It's like a sleepover," Messina said. "It's a little bit of a party, and like a sleepover, when they come home in the morning, they haven't slept much." 

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Should a physician be held responsible if an elderly patient causes a car accident while driving?

A Los Angeles jury recently decided that Dr. Arthur Daigneault was not responsible for the wrongful death of 90-year-old William Powers, whose longtime partner, a dementia patient, drove into the path of an oncoming car, according to a report by The Los Angeles Times. The driver Lorraine Sullivan, 85, survived, but Powers died of his injuries weeks after the crash.

The Orange County, Calif. jury cleared Daigneault, but the case raises the question of whether the physician should have reported his patient -- who had suffered memory loss since 2007 and was prescribed an Alzheimer’s drug in 2009 -- to local health authorities or urged the California Department of Motor Vehicles revoke her license.

The victim’s family thought Daigneault should have done something. They sued him for wrongful death, arguing that he should have deemed the driver, a danger on the road and gotten her driver’s license yanked.

Daigneault, who had been involved in taking away driver's licenses from other patients he had seen, said that he did not think Sullivan’s condition was severe enough to warrant doing so in her case. The jury, after 30 minutes of deliberation, agreed.

Daigneault could well have been right in not reporting Sullivan. Every day there are horrible accidents that involve wrong turns, driving the wrong way and other fatal errors by drivers of all ages. But, statistics show that older drivers are more likely than younger ones to be involved in multi-vehicle crashes, particularly when turning at intersections, as Sullivan did. Drivers ages 80 and older have the 2^nd highest fatal accident rate of any age group. Only teenage drivers are more dangerous, according to Federal Highway Administration data. 

In the next 20 years, the number of elderly drivers in the United States will triple.

Should every state require doctors to report their concerns about the ability of older drivers to safely be on the road? Only a few states, including California, require or encourage doctor reporting.  Relatively few require a road test for drivers over 75. Most states do not even require a vision test for older drivers. Tennessee does not require drivers over 65 to even renew their licenses.

Defenders of the elderly’s right to drive note that there are plenty of other people out on the roads who pose huge dangers.  Reckless teenagers, novice drivers, drunks and the distracted driver contribute a great deal to the more than 90 people killed on American highways every day. The very old are, however, the biggest and fastest growing risk. And they are the ones that should be the easiest to get off the road.

States need to take this problem far more seriously and toughen their reporting laws. Doctors should put privacy on the back burner and err on the side of reporting to state motor vehicle departments when they have concerns about a demented or impaired older patient who is still driving.  So should you if you are worried about grandma or grandpa. Even if your older family member does not go to a doctor, if you think their vision is failing or their memory is badly slipping, then the right thing to do is to let officials know.

Driving is a treasured right in America. But when age takes a toll on driving skills, putting the elderly, their passengers and others on the road at grave risk, then medical providers,family and loved ones should speak up loudly -- before that next wrong turn is someone's last.

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By Kate Kelland
Reuters

LONDON - A Chinese herb called Ginkgo biloba billed by some as a potential over-the-counter wonder drug that boosts mental dexterity and sharpens the memory has been found to do nothing to prevent the onset of Alzheimer's disease.

A large scientific study of the supplement by researchers in France found that people who took twice-daily doses of Ginkgo biloba were no less likely to develop the brain-wasting disease than those given a placebo, or dummy pill.

The study, published in The Lancet Neurology journal on Thursday, suggests anyone taking the herb extract in the hope of escaping Alzheimer's is wasting their money, experts said.

"For a while it was hoped that ginkgo biloba could be the wonder drug," said Jess Smith, a spokeswoman for the Alzheimer's Society.
"However, in recent years evidence ... has repeatedly shown that it does not have any benefits in preventing the disease or slowing down symptoms."

The trial was conducted over five years and involved 2,854 people in France who were aged 70 years or older and who had already visited their doctors with concerns about their memory.

Ginkgo biloba extract - which is derived from the leaves of the Ginkgo biloba tree - was given to 1,406 patients, while the other 1,414 were given a placebo designed to have a similar taste and appearance to the Ginkgo pills.

Researchers then used standard tests to assess the patients' memory, cognitive function and dementia status.

After five years, 61 people in the ginkgo biloba group, or 4 percent, had been diagnosed with probable Alzheimer's disease, compared with 73, or 5 percent, in the placebo group.

The researchers, led by Bruno Vellas of the Hopital Casselardit in Toulouse, France, said the difference in results for the two groups was not statistically significant. The study also appeared to confirm the findings of a 2009 trial in the United States which had similar results.

Nice theory destroyed by 'ugly fact'
Vellas said that while the results suggested regular use of Ginkgo biloba did not protect the elderly from progression to Alzheimer's, more studies were needed to examine longer-term use of the herb and other potential prevention measures.

An estimated 18 million people worldwide suffer from Alzheimer's disease and as populations age, rates of the disease are expected to soar.

The fatal brain disease, which has no cure and few effective treatments, affects memory, thinking and behavior and is placing an increasingly heavy burden on societies and economies across the world.

"The fact that prevalence of this debilitating disorder is expected to quadruple by 2050 suggests that research into preventative therapies for this disease needs to receive urgent attention," Vellas said in a statement.

Edzard Ernst, a professor and former director of complementary medicine at Britain's University of Exeter, said the study's findings were important, even if they were disappointing for those who want to believe in herbal remedies.

"This is by far the largest trial of Ginkgo so far," he said in an emailed comment. "The results are disappointing and fail to show that this herbal remedy reduces the risk of Alzheimer's. Another beautiful herbal theory destroyed by an ugly fact."

Robert Bazell, NBC News

A cancer drug is turning out not to be the miraculous treatment for Alzheimer’s that many had hoped. Two papers out Wednesday in the New England Journal of Medicine warn families of Alzheimer’s victims not to seek treatment with Targretin (generic name: bexarotene). 

Last February a study from Case Western Reserve University reported that the drug rapidly cleared the clumps of protein known as beta-amyloid, the hallmark of Alzheimer’s, from the brains of mice with a version of the disease. Since the drug was already on the market, approved as a treatment for lymphoma, doctors could immediately prescribe it in so-called off-label use for Alzheimer’s. And thousands of families understandably asked.

But one mouse study does not prove that a drug is effective in humans. The drug is expensive – about $14,000 a year - and off-label use is often not covered by insurance. The drug can also bring on severe side-effects. In one paper in the Journal, Justin Lowenthal, Sara Hull and Steven Pearson of the National Institutes of Health and Massachusetts General Hospital conclude that for this drug “even if the patients are willing to take the risks for the potential benefit, the physician's answer should be no.” In the second paper Frank LaFerla of the University of California, Irvine observes “the field has been down this road before, as successes in preclinical models have thus far not translated well into the clinic.”

But the reasons for disappointment with Targretin appear to be stronger than these theoretical concerns.  Word among Alzheimer’s scientists is that no one yet has independently replicated the Case Western results in mice. In science, a single study has little value until it is repeated. It could be just a fluke or a mistake. No funding agency would support a clinical trial in humans of a potential drug unless the mouse study were confirmed.

These are not good times for potential Alzheimer’s treatments. On Monday, Pfizer announced it was abandoning its efforts to market bapineuzumab, a drug that definitely cleared amyloid plaques in people, after a second, large clinical trial found it did not make the patients noticeably better. 

The reason for this failure -- and other recent similar ones -- could be new evidence that the brain changes leading to Alzheimer’s begin decades before symptoms appear. Treatment may have to start long before there is perceptible loss of memory or other mental function. "The impending tsunami of new cases and the time required for introducing a drug to the market increase the urgency of identifying new therapeutic targets and strategies," LaFerla writes. That presents a daunting challenge, but science cannot give up trying to prevent the misery and expense from Alzheimer’s that is beginning to overwhelm us and will only get worse as the population ages.

Robert Bazell is NBC's chief science and medical correspondent. Follow him on Facebook and on Twitter @RobertBazellNBC

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The brain's abilities to reason, comprehend and remember may start to worsen as early as age 45, a new study from England suggests.

Researchers gave tests of thinking skills to about 5,100 men and 2,200 women between the ages of 45 and 70 years over a 10-year period. They found people ages 45 to 49 years experienced a notable decline in mental functioning.

" 'Senior' moments that people often joke about are true," said Dr. Gary Small, geriatric psychiatrist David Geffen School of Medicine at the University of California, Los Angeles, who was not involved with the work.

"If you follow people over time, you'll see there are structural changes that happen in the brain as they age," he said.

The study was published today (Jan. 5) in the British Medical Journal.

Healthy lifestyle may help with brain aging

Previous evidence suggests that impaired cognitive function could be  an early sign of dementia. One recent study showed cognitive performance strongly predicted a 75 percent diagnosis of Alzheimer's disease, a common form of dementia, after six years. 

About 1 in 8 older Americans have Alzheimer's disease, according to the Alzheimer's Association. They anticipate the numbers will grow each year as more and more people continue to live longer.

Though the age at which cognitive decline begins remains unknown, researchers say the new study demonstrates the importance of a healthy lifestyle, particularly paying attention to cardiovascular health, which may help stave off the effects of brain aging.

"A decline in mental function is inevitable," said Steven Ferris, a psychologist at New York University's Langone Medical Center, who was not involved with the work. "Following a healthy lifestyle can help a certain degree of mental functioning, but there requires more research to prove this."

A healthy lifestyle includes exercising, which increases blood flow to the brain, providing it with much-needed nutrients. Eating foods that are good for the heart, such as fruits, vegetables and whole grains is also important, because it could protect brain cells from age-related decline.

A faster decline among older people

Study participants were tested for memory, vocabulary, hearing and visual comprehension skills. People were given cognitive tests three times over the course of the study. The researchers took differences in education levels into account.

Researchers found that over the 10-year study, there was a 3.6 percent decline in mental reasoning scores in people who were between the ages of 45 and 49 at the study's start. There was a 9.6 percent decline in the abilities of men ages 65 to 70 years at the start, and a slightly smaller, 7.4 percent decline, in women of those ages.

Results showed that cognitive test scores declined in all categories except vocabulary, and scores declined faster in older people.

The study also demonstrated that measuring people's abilities at one point in time may not yield accurate results.

"This study follows the same people over a long period of time to see if their cognitive performance changes," said Ferris.

"And these changes are beginning earlier than what people previously thought," he said.

Pass it on: Mental functioning likely to worsen in middle-aged adults.

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