In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.

Speaking more than one language may ward off three types of dementia, including the Alzheimer's disease that affected this human brain on display at the Musuem of Neuroanatomy at the University at Buffalo, in Buffalo, N.Y. DAVID DUPREY 
  
 There’s more evidence that speaking a second language can delay the onset of dementia later in life — this time in a population where even illiterate people reaped the benefits of being bilingual. 
  
 Conducted in Hyderabad, India, the largest study of its kind so far found that speaking two languages slowed the start of three types of dementia — including Alzheimer’s disease — by an average of 4.5 years. 
  
 “Being bilingual is a particularly efficient and effective type of mental training,” said Dr. Thomas H. Bak, a researcher at The University of Edinburgh and a co-author of the study published Wednesday in the journal Neurology. “In a way, I have to selectively activate one language and deactivate the other language. This switching really requires attention.” 
  
 That kind of attention keeps the brain nimble and may ward off not only Alzheimer’s disease, but other cognitive conditions such as frontotemporal dementia and vascular dementia, the new study found. 
  
 Bak is part of the team led by Dr. Suvarna Alladi, a professor of neurology at the Nizam’s Institute of Medical Sciences in Hyderabad. The researchers examined case records of 648 patients with dementia who entered a memory clinic at a Hyderabad university hospital between June 2006 and October 2012. 
  
 Slightly more than half of the patients, some 391, spoke more than one language in a place where many people grow up learning three or more languages, including Telugu and Dakkhini along with English and Hindi. 
  
 Previous studies have focused on the impact of bilingualism on dementia mostly in immigrants in Canada, which may have influenced the results, Bak said. 
  
 “It really brought up the question, is it the bilingualism or is it is being an immigrant?” he said. “They have very different lifestyles, very different diets, which can affect the outcome.” 
  
 Still, those studies also found that speaking more than one language delayed dementia by the same span of time, four to five years. 
  
 The Indian patients offered a chance to examine the issue in a society where many people are naturally multilingual and shift easily among different languages in different social settings. 
  
 “If I live in Hyderabad, I am practically always switching,” said Bak. “There will not be a day when I don’t have a chance to practice.” 
  
 The researchers found that patients who spoke a single language developed the first symptoms of dementia at age 61, versus age 65 ½ in those who were bilingual. The delay was slightly more than three years for Alzheimer’s disease, but about six years for frontotemporal dementia and about 3.7 years for vascular dementia. 
  
 In people who couldn’t read, the delay of dementia was about six years later in those who were bilingual versus those who spoke only one language — evidence that education isn’t the key in postponing problems, the researchers said. 
  
 The effect of bilingualism on dementia onset was independent of other factors including education, gender, occupation and whether patients lived in urban or rural areas, the authors said. 
  
 Speaking more than two languages didn’t appear to increase the effect, a result that surprised researchers, Bak said. Other studies have found that the more languages spoken, the greater the protection against dementia. 
  
 An outside expert who documented the first physical effects of the delay of dementia in people who speak more than one language praised the new study. 
  
 “Being able to show that immigrant status was not a factor answers one remaining question, said Dr. Tom Schweizer, a neuroscientist at St. Michael’s Hospital in Toronto, Canada, who found in 2011 that bilingual people have twice as much brain damage as those who speak one language before they show signs of Alzheimer’s disease. 
  
 “The fact that the illiterate subjects were also showing this strong effect was also novel,” he added. 
  
 It’s still not clear exactly how language acquisition triggers protection against dementia, or whether another kind of intense brain activity such as learning an instrument or doing puzzles could mimic the effect, Schweizer said. 
  
 Going forward, conducting dementia research in other non-Western cultures will be key to understanding the effect of bilingualism on dementia, the authors of the new study said. 
  
 “For me, the most important message is that you cannot do all the studies in the same place,”Bak said. “In completely different contexts, in complete different populations, we found the same effect.” 
  
 JoNel Aleccia is a senior health reporter with NBC News. Follow her on Twitter at @JoNel_Aleccia or send her an email. ||||| Speaking more than one language "stimulates your brain all the time," researcher says. 
  
 Bilingual people in a study developed dementia five years later than other people did. Other research shows mental activity has a protective effect. (Photo: Photo Disc) Story Highlights Dementia developed an average of five years later in people who spoke more than one language 
  
 The effect was seen even in illiterate people, meaning education was not the explanation 
  
 It's unclear whether learning a second language late in life would help 
  
 The latest evidence that speaking more than one language is a very good thing for our brains comes from a study finding dementia develops years later in bilingual people than in people who speak just one language. 
  
 The study, conducted in India and published Wednesday in the journal Neurology, is not the first to reach this conclusion. But it is the largest and comes with an intriguing new detail: The finding held up even in illiterate people — meaning that the possible effect is not explained by formal education. 
  
 Instead, the researchers say, there's something special about switching from one language to another in the course of routine communication — something that helps explain why bilingual people in the study developed dementia five years later than other people did. When illiterate people were compared with other illiterate people, those who could speak more than one language developed dementia six years later. 
  
 "We know from other studies that mental activity has a certain protective effect," says co-author Thomas Bak, a neurologist at the University of Edinburgh, Scotland. "Bilingualism combines a lot of different mental activities. You have to switch sounds, concepts, grammatical structures, cultural concepts. It stimulates your brain all the time." 
  
 For the study, Bak and colleagues in India reviewed medical records of 648 people with dementia who were seen in a clinic in the city of Hyderabad. 
  
 The location was key, because residents of the city, like many people in India, often speak two or three languages — typically some combination of the official language, Telugu, the Urdu dialect Dakkhini and the English increasingly used in schools, workplaces and the media, the authors write. People may speak in one language or combination at home and in neighborhoods and another at work or school, all in the course of a normal day, says co-author Suvarna Alladi, a neurologist at Nizam's Institute of Medical Sciences, Hyderabad. 
  
 "Since bilingualism is more of a norm in India, bilingualism is not a characteristic of any particular socioeconomic, geographic or religious group," she says. 
  
 More than half of the people diagnosed with dementia at the clinic were bilingual or multilingual. But the researchers found those people had developed their first symptoms, such as memory loss and confusion, at an average age of 65.6 — five years later than the average of 61.1 for people who spoke just one language. The differences were seen in several types of dementia, including Alzheimer's disease, vascular dementia (associated with poor blood flow to the brain) and frontotemporal dementia (caused by degeneration of the brain's frontal or temporal lobes). 
  
 Two previous smaller studies, conducted in Ontario, Canada, found a later onset of Alzheimer's disease in bilingual people. 
  
 But in those studies, bilingual people were largely immigrants, raising questions about whether they differed in other ways from the general population, says Brian Gold, a neuroscientist at the University of Kentucky, Lexington. The new study is more convincing, he says, "because it is studying bilingual people raised in the same country and culture." 
  
 Gold's own lab studies have found that bilingual seniors excel at certain skills, such as quickly sorting colors and shapes, and that their frontal lobes work more efficiently as they perform such tasks. 
  
 All the research taken together is more good reason, he says, to expose children to language-learning as they grow — and for bilingual families to keep using more than one language in their homes. It's still unclear, he says, whether people can boost their brains by taking up a second language later in life. 
  
 "It may never be too late," Bak says, but he agrees more research is needed. It's also unclear, Bak says, whether bilingual people fare any better than others once symptoms of dementia develop. 
  
 Read or Share this story: http://usat.ly/1hlXtvj |||||
If you could be reading this in another language, good news: You may have an extra weapon against dementia. A study in India suggests that being bilingual delays three kinds of dementia by 4.5 years on average, NBC News reports. "Being bilingual is a particularly efficient and effective type of mental training," says a co-author of the study, adding to USA Today: "You have to switch sounds, concepts, grammatical structures, cultural concepts. It stimulates your brain all the time." The study of 648 dementia patients was the largest of its kind, and India was a great place to conduct it, researchers say: There, "bilingualism is not a characteristic of any particular socioeconomic, geographic, or religious group." Speakers of one language began showing dementia signs at age 61; for the bilingual, it was 65½. For Alzheimer's specifically, the delay was three years; researchers also looked at frontotemporal and vascular dementia, which had a longer delay among bilingual subjects. The study offered another interesting detail: The benefits of bilingualism apply even if you can't read, suggesting that differences in onset age aren't dependent on education, USA Today notes.