Want to Live Longer? Get a Dog 想長壽？快養狗

維多利亞·拉尼德文 劉春伶 劉建穩譯

The benefits that come with owning a dog are clear—physical activity， support， companionship—but owning a dog could literally be saving your life. 養狗的好處不言而喻——活動身體，得到支持，相依為伴——而且養狗真的可以救命。

Dog ownership is associated with a reduced risk for cardiovascular disease and death， finds a new Swedish study published in the journal Scientific Reports.

For people living alone， owning a dog can decrease their risk of death by 33% and their risk of cardiovascular related death by 36%， when compared to single individuals without a pet， according to the study. Chances of a heart attack were also found to be 11% lower.

Multi-person household owners also saw benefits， though to a lesser extent. Risk of death among these dog owners fell by 11% and their chances of cardiovascular death were 15% lower. But their risk of a heart attack was not reduced by owning a dog.

“A very interesting finding in our study was that dog ownership was especially prominent as a protective factor in persons living alone， which is a group reported previously to be at higher risk of cardiovascular disease and death than those living in a multi-person household，” said Mwenya Mubanga， an author on the study and PhD student at Uppsala University.

As a single dog owner， an individual is the sole person walking and interacting with their pet as opposed to married couples or households with children， which may contribute to greater protection from cardiovascular disease and death， said the study.

Owners of hunting breeds， including terriers， retrievers， and scent hounds， are most protected from cardiovascular disease and death. However， owning any dog will reduce an owners risk of death， just to different extents， said Tove Fall， senior author of the study and Associate Professor in Epidemiology at Uppsala University.

The study looked at over 3.4 million Swedish individuals between the ages of 40 and 80 sampled from a national database and the Swedish Twin Registry over a 12-year study period.

“We know that dog owners in general have a higher level of physical activity， which could be one explanation to the observed results，” said Fall. This includes taking the dog out for a walk in any weather condition.

The findings also suggest increased social well-being and immune system development as additional reasons why dog ownership offers protection against cardiovascular disease and death.

One factor behind this may be because dogs bring dirt into homes and they lick you， which could impact your microbiome—the bacteria that live in your gut—and thus your health.

“It may encourage owners to improve their social life， and that in itself will reduce their stress level， which we know absolutely is a primary cause for cardiovascular disease and cardiac events，” said Dr. Rachel Bond， Associate Director of Womens Heart Health at Lenox Hill Hospital in New York City， who was not involved in the research.

More to be revealed

Fall believes that while their study provides strong evidence for the health benefits of dogs， their work is not done yet， since it does not answer why dogs achieve these results or why specific breeds seem to offer more protection.

Bond commented that owners of hunting breeds may be getting more exercise because these dogs are more active as opposed to small dogs who do not require as much exercise.

There are also other factors that still need to be considered， such as the owners personality and general physical health and activity.

“It is hard to say if there truly is a causal effect. This study in particular， excluded patients with heart disease in general， and we know that disabled people may be less likely to own a dog so that really raises the question if owning a dog leads to heart health or it is merely a marker for people who are more likely to have good heart health，” said Dr. Bond.

While Bond may not prescribe a dog as treatment for a patient， she said that she will not discourage owning or buying one， or expressing the benefits of owning one.

Benefits beyond Sweden

While the research was carried out in Sweden， Fall does believe it may also apply to other countries， including the US， since popular breeds and peoples attitudes toward dog care are similar.

However， some factors that may affect the results are the differences in climate and socio-economic backgrounds， noted Fall.

“We have a colder climate so we have indoor dogs where owners take their dogs out for a walk. In warmer climates， they could keep them in the yard and wont have to actively take them for a walk，” said Fall.

“I think it would be hard to take the data from Sweden and apply it to the US since we have a more diverse population. More studies should be obtained in the United States，” said Bond.

瑞典一項新研究發現，養狗可以降低心血管疾病的患病與死亡風險。該研究報告發表于《科學報告》雜志。

根據這項研究，同沒養寵物的獨居人士相比，養狗的獨居人士死亡風險降低33%，心血管疾病引起的死亡風險降低36%，此外，心臟病發作幾率降低11%。

非獨居人士養狗也有益處，只是程度較小。此類養狗人士的死亡風險降低11%，心血管疾病引起的死亡幾率降低15%。但養狗并沒有降低他們心臟病發作的幾率。

該研究報告的作者之一、烏普薩拉大學博士生姆韋尼婭·穆班加說：“我們研究中有個特別有意思的發現，即養狗對獨居人士的保護作用特別明顯，先前有報告說，獨居人士患上心血管疾病和死亡的風險都高于非獨居人士。”

該研究指出，相對于已婚夫婦或有孩子的家庭，對單身養狗人士來說，與狗狗散步和交流都須一力承擔，這或許幫助他們更能免于心血管疾病和死亡。

養獵犬，包括?犬、尋回犬和嗅覺獵犬等品種的人，能夠得到最好的保護，免于血管疾病和死亡。不過，養任何種類的狗都會降低養狗人士的死亡風險，只是程度有所不同。該項研究報告的主要作者、烏普薩拉大學流行病學副教授托弗·法爾如是說。

該研究歷時12年，樣本來自國家數據庫和瑞典雙胞胎統計所，樣本容量為超340萬瑞典人，年齡在40至80歲之間。

法爾說：“我們知道，一般來講，養狗人士體力活動較多，這可能用以解釋觀察到的結果。”體力活動包括，不論何種天氣，養狗人士都會出去遛狗。

研究結果還顯示，養狗之所以能預防心血管疾病和死亡，還在于其可以提高社會幸福感，增強免疫系統。

這背后一個因素，可能是因為寵物狗把塵土帶到家里，還會舔主人，這樣可能影響其腸道菌群——生活在腸道里的各種細菌——進而對其健康產生影響。

“養狗可促進養狗人士改善社交生活，社交本身會減少壓力，而壓力絕對是導致心血管疾病和心臟病的一大原因。”紐約市萊諾克斯希爾醫院女性心臟健康中心副主任蕾切爾·邦德醫生說道，她沒有參與這項研究。

更多有待揭示

法爾認為，盡管他們的研究為養狗有益于健康提供了有力證據，但是他們的工作尚未完成，因為其研究并未解答為什么養狗有這樣的功效，或者為什么養特定品種的狗似乎效果更明顯。

邦德認為，養獵犬的人士可得到更多的鍛煉，因為獵犬更好動，而小型犬活動量沒這么大。

此外還要考慮其他因素，比如，養狗人士的性格，以及他們的整體健康狀況和體力活動等。

邦德醫生說：“很難說是否真的存在因果關系。尤其是這項研究，它并未普遍涉及心臟病患者，而且殘疾人士養狗的可能性較小，所以，人們確實會問：是養狗帶來心臟健康，還是養狗只是那些更可能擁有健康心臟人士的一個特征。”

盡管邦德可能不會建議患者養狗治病，但她說她并不反對他們養狗或者準備養狗，也不反對說說養狗的好處。

受益的不只是瑞典

盡管這項研究是在瑞典展開，但法爾教授堅信，研究成果或許也適用于包括美國在內的其他國家，因為各國常見犬種以及人們對養狗的態度是差不多的。

然而，法爾指出，各國氣候差異、社會經濟背景不同等因素，或對研究結果產生影響。

法爾表示：“瑞典氣候偏冷，所以我們在室內養狗，主人遛狗要出門。在比較暖和的地區，人們可以在院子里養狗，就無需經常外出遛狗。”

邦德說：“我認為，美國人口更加多元化，很難將瑞典的數據運用到美國。應當在美國進行更多的相關研究。”

（譯者單位：武漢輕工大學外國語學院）