Causes and Risk Factors
Introduction
Age
Family history and genetics
Other risk factors
Introduction
While scientists know Alzheimer's disease involves the progressive failure of brain cells, why this happens is still not known. However, they have identified certain risk factors that increase the likelihood of developing Alzheimer's.
Age
The greatest known risk factor for Alzheimer's is increasing age. Of Americans aged 65 and over, 1 in 8 has Alzheimer’s, and nearly half of people aged 85 and older have the disease.
Family history and genetics
Another risk factor is family history. Research has shown that those who have a parent, brother or sister with Alzheimer's are more likely to develop the disease. The risk increases if more than one family member has the illness. When diseases tend to run in families, either heredity (genetics) or environmental factors, or both, may play a role.
Scientists have identified one gene that increases the risk for Alzheimer's but does not guarantee an individual will develop the disease. Research has also revealed certain rare genes that virtually guarantee an individual will develop Alzheimer's. These genes have been found in only a few hundred extended families worldwide and account for less than five percent of all cases of Alzheimer's.
Other risk factors
Most experts believe that the majority of Alzheimer's disease occurs as a result of complex interactions among genes and other risk factors. Age, family history and heredity are all risk factors we can’t change. Now, research is beginning to reveal clues about other risk factors we may be able to influence through general lifestyle and wellness choices and effective management of other health conditions.
Head trauma: There may be a strong link between serious head injury and future risk of Alzheimer’s, especially when trauma occurs repeatedly or involves loss of consciousness. Protect your brain by buckling your seat belt, wearing your helmet when participating in sports, and "fall-proofing" your home.
Heart-head connection: Growing evidence links brain health to heart health. Your brain is nourished by one of your body’s richest networks of blood vessels. Every heartbeat pumps about 20 to 25 percent of your blood to your head, where brain cells use at least 20 percent of the food and oxygen your blood carries.
The risk of developing Alzheimer’s or vascular dementia appears to be increased by many conditions that damage the heart or blood vessels. These include high blood pressure, heart disease, stroke, diabetes and high cholesterol. Work with your doctor to monitor your heart health and treat any problems that arise.
General healthy aging: Other lines of evidence suggest that strategies for overall healthy aging may help keep your brain as well as your body fit. These strategies may even offer some protection against developing Alzheimer’s or related disorders. Try to keep your weight within recommended guidelines, avoid tobacco and excess alcohol, stay socially connected, and exercise both your body and mind.
Next: Stages
簡介
年齡
家族病史和基因
其他風險因素
簡介
儘管科學家知道阿滋海默症與腦細胞的逐漸衰竭有關,而這為什麼會發生仍不清楚。但他們已經確定了會增加患阿滋海默症的可能性的某些風險因素。
年齡
已知患阿滋海默症的最大風險因素是年齡的增長。在 65 歲及以上的美國人中,8 人中有一個患阿滋海默症,85 歲及以上的美國人中幾乎有一半患有該疾病。
家族病史和基因
另一個風險因素是家庭病史。研究已表明,有父母,兄弟或姐妹患阿滋海默症的人患該疾病的可能性更高。如果有多個家庭成員患該疾病,則該風險會增加。此疾病有在家族成員中發生的傾向,或與遺傳(基因),環境因素有關。
科學家已確定了一個會增加阿滋海默症患病風險的基因,但並不保證具有該基因的人一定會患該疾病。研究發現,幾乎可確定具有某些罕見基因的人會患阿滋海默症。這些基因是在全球僅幾百個家族中發現的,占所有阿滋海默症的不到 5%。
其他風險因素
大多數專家認為,阿滋海默症大部分是由於基因與其他風險因素之間複雜的相互作用導致的。年齡,家族病史和遺傳均是我們無法改變的風險因素。現在透過研究,我們開始認識到,透過一般生活方式和健康選擇,以及對其他健康情況的有效管理,我們或許能夠影響其他風險因素。
頭部創傷: 頭部受傷與未來患阿滋海默症的風險之間可能存在強大的關聯,尤其是在常常發生頭部創傷或涉及到失去意識時。可透過繫上安全帶,在參加體育運動時戴上頭盔以及在家中安裝「防跌倒」裝置,保護您的大腦。
心臟與頭部的關聯: 越來越多的證據證明大腦健康與心臟健康之間存在關聯。大腦是由身體最豐富的血管網絡提供補給。每次心跳會將約 20% 至 25% 的血液泵入頭部,在頭部中腦細胞至少使用 20% 的血液攜帶的食物和氧。
心臟或血管受損的許多情況似乎增加了患阿滋海默症或血管型失智症的風險。這些包括高血壓,心臟疾病,中風,糖尿病和高膽固醇。與您的醫生共同監控您的心臟健康並治療出現的任何問題。
一般正常的老化: 其他一系列證據顯示,整體正常的老化的策略可協助使您的大腦和身體保持良好狀態。這些策略甚至可在某種程度上預防患阿滋海默症或相關疾病。儘量按照建議的指導原則保持體重,請勿吸煙和過度飲酒,經常參加社群活動,以及鍛煉身體和智力。
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