たばこは心も体もむしばみ、老化現象を早めるー② [健康・医療お役立ち情報]
①からの続き
「喫煙と精神的退化との間の関連性を説明できる幾つかの要因が考えられると研究チームは話している。
まず第１に、喫煙が心臓、肺や血管などに影響を与えることと関連していることだ。喫煙は血管疾患の危険性を増大させるため、脳がベストの状態で機能するのに必要な血液、酸素、そして栄養素などを脳に送り込むという身体活動が制限されてしまうことになる。
心臓血管病との違いを見れば、女性よりも男性の方に喫煙と認識力低下の関連が多く見ららることの説明がつくかもしれないとカルフォルニァ大学アルツハイマー病センター長のCharles DeCarli医師は話している。
「男性は女性よりも７０歳ぐらいまでは、心臓病や脳卒中にかかる危険性が高いが、これには生活スタイルが関係しており、この年齢層の男性は女性よりもタバコを吸う頻度が高いのです。」とDeCarli医師は話している。」
「マイアミ医科大学精神科Philip Harvey教授は、タバコの中毒性が脳に損傷を与えていて、脳内に蓄積されているニコチンの分子が注意力、集中力や記憶力などの機能をつかさどる脳受容体(brain receptor)にぴったりくっついて離れないのですと話している。
「そうなるとこうした受容体の働きが機能しなくなり、機能低下に陥ってしまうことになる。しかし、このことは長期にわたって危険な状態になるということではなくて、受容体の働きをリセットしょうとする可逆過程なのです。」とHarvey医師は話している。
長期にわたる喫煙が精神機能に与える影響については、あまり問題視されてはいないようだが、これは喫煙者が認知症にかかる前に、他の健康上の問題(病気など)で死亡することが多いからなのであると調査チームは語っている。」
Smoking Slows Memory, Reasoning in Middle-Aged Men
New evidence suggests that smoking isn't only bad for the body but can also take a toll on the mind.
A study published today in the Archives of General Psychiatry linked smoking to faster, more dramatic age-related mental decline in men.
Researchers from University College in London studied more than 5,000 men and 2,000 women from Britain's long-running Whitehall II study, which has surveyed the health of thousands of British civil service employees.
The researchers studied each participant's performance on tests of memory, verbal skills and reasoning over a period of 10 years, beginning when the participants were about 56 years old. They found that men who smoked showed a greater decline in these mental functions than those who had never smoked.
Smoking seemed to speed up the cognitive aging process, making men function mentally as if they were 10 years older, said Severine Sabia, the study's lead author.
"For example, a 50-year-old male smoker shows a similar cognitive decline as a 60-year-old male never-smoker," she said.
The brain changes weren't necessarily permanent. Men who stopped smoking more than 10 years before the tests performed as well as those who had never smoked. But men who kicked the smoking habit less than 10 years before the cognitive tests began didn't do much better than the men who'd kept smoking.
While smoking seemed to drain men's brains, the researchers didn't find a similar connection between smoking and declining mental function in women. Sabia said that could be because women in this age group smoked less than men do, or that there were simply fewer women in the study.
Researchers said there are several factors that could explain the connection between smoking and mental decline. One reason could lie in the way smoking affects the heart, lungs and blood vessels. Because smoking ups the risk of vascular disease, it could limit the body's ability to deliver the blood, oxygen and nutrients the brain needs to function at its best.
Dr. Charles DeCarli, director of the Alzheimer's Disease Center at the University of California at Davis, said differences in cardiovascular disease may also explain why the study found that men showed more cognitive decline linked to smoking than women did.
"Men have more heart disease and greater stroke risk than women do up until about age 70 or so. Part of that is related to lifestyle," DeCarli said. "Men of this age group often smoked more than women did."
Philip Harvey, a professor of psychiatry at the University of Miami School of Medicine, said the addictive nature of cigarettes may also take a toll on the brain, noting that molecules of nicotine in the brain latch onto the same brain receptors involved in attention, concentration and memory.
"That just may lead to a disregulation of those receptors, it may make them function less well," Harvey said. "But that could mean that rather than some kind of long-term damage, it's a reversible process that may involve resetting the receptors."
The study's authors said that smoking's long-term effects on mental function are probably underestimated, since smokers are more likely to die of other health problems before they have the chance to develop dementia.
(abc News 2012/02/06)
「タバコと精神機能との関連性」
「喫煙と精神的退化との間の関連性を説明できる幾つかの要因が考えられると研究チームは話している。
まず第１に、喫煙が心臓、肺や血管などに影響を与えることと関連していることだ。喫煙は血管疾患の危険性を増大させるため、脳がベストの状態で機能するのに必要な血液、酸素、そして栄養素などを脳に送り込むという身体活動が制限されてしまうことになる。
心臓血管病との違いを見れば、女性よりも男性の方に喫煙と認識力低下の関連が多く見ららることの説明がつくかもしれないとカルフォルニァ大学アルツハイマー病センター長のCharles DeCarli医師は話している。
「男性は女性よりも７０歳ぐらいまでは、心臓病や脳卒中にかかる危険性が高いが、これには生活スタイルが関係しており、この年齢層の男性は女性よりもタバコを吸う頻度が高いのです。」とDeCarli医師は話している。」
タバコの中毒性が脳に損傷を与える
「マイアミ医科大学精神科Philip Harvey教授は、タバコの中毒性が脳に損傷を与えていて、脳内に蓄積されているニコチンの分子が注意力、集中力や記憶力などの機能をつかさどる脳受容体(brain receptor)にぴったりくっついて離れないのですと話している。
「そうなるとこうした受容体の働きが機能しなくなり、機能低下に陥ってしまうことになる。しかし、このことは長期にわたって危険な状態になるということではなくて、受容体の働きをリセットしょうとする可逆過程なのです。」とHarvey医師は話している。
長期にわたる喫煙が精神機能に与える影響については、あまり問題視されてはいないようだが、これは喫煙者が認知症にかかる前に、他の健康上の問題(病気など)で死亡することが多いからなのであると調査チームは語っている。」
Smoking Slows Memory, Reasoning in Middle-Aged Men
New evidence suggests that smoking isn't only bad for the body but can also take a toll on the mind.
A study published today in the Archives of General Psychiatry linked smoking to faster, more dramatic age-related mental decline in men.
Researchers from University College in London studied more than 5,000 men and 2,000 women from Britain's long-running Whitehall II study, which has surveyed the health of thousands of British civil service employees.
The researchers studied each participant's performance on tests of memory, verbal skills and reasoning over a period of 10 years, beginning when the participants were about 56 years old. They found that men who smoked showed a greater decline in these mental functions than those who had never smoked.
Smoking seemed to speed up the cognitive aging process, making men function mentally as if they were 10 years older, said Severine Sabia, the study's lead author.
"For example, a 50-year-old male smoker shows a similar cognitive decline as a 60-year-old male never-smoker," she said.
The brain changes weren't necessarily permanent. Men who stopped smoking more than 10 years before the tests performed as well as those who had never smoked. But men who kicked the smoking habit less than 10 years before the cognitive tests began didn't do much better than the men who'd kept smoking.
While smoking seemed to drain men's brains, the researchers didn't find a similar connection between smoking and declining mental function in women. Sabia said that could be because women in this age group smoked less than men do, or that there were simply fewer women in the study.
Researchers said there are several factors that could explain the connection between smoking and mental decline. One reason could lie in the way smoking affects the heart, lungs and blood vessels. Because smoking ups the risk of vascular disease, it could limit the body's ability to deliver the blood, oxygen and nutrients the brain needs to function at its best.
Dr. Charles DeCarli, director of the Alzheimer's Disease Center at the University of California at Davis, said differences in cardiovascular disease may also explain why the study found that men showed more cognitive decline linked to smoking than women did.
"Men have more heart disease and greater stroke risk than women do up until about age 70 or so. Part of that is related to lifestyle," DeCarli said. "Men of this age group often smoked more than women did."
Philip Harvey, a professor of psychiatry at the University of Miami School of Medicine, said the addictive nature of cigarettes may also take a toll on the brain, noting that molecules of nicotine in the brain latch onto the same brain receptors involved in attention, concentration and memory.
"That just may lead to a disregulation of those receptors, it may make them function less well," Harvey said. "But that could mean that rather than some kind of long-term damage, it's a reversible process that may involve resetting the receptors."
The study's authors said that smoking's long-term effects on mental function are probably underestimated, since smokers are more likely to die of other health problems before they have the chance to develop dementia.
(abc News 2012/02/06)
2012-02-13 13:02
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