雙語閱讀：新研究發現 肚子越大腦子越小
Belly fat has long been thought to be particularly bad for your heart, but now, a new study adds more evidence to the idea that it may also be bad for your brain.
長期以來，人們都認爲腹部肥胖對心臟特別不好，但現在一項新研究提出的新證據表明，它可能還對你的大腦有害。
The study, from the United Kingdom, found that people who were obese and had a high waist-to-hip ratio (a measure of belly fat) had slightly lower brain volumes, on average, compared with people who were a healthy weight. Specifically, belly fat was linked with lower volumes of gray matter, the brain tissue that contains nerve cells.
英國的這項研究發現，肥胖者以及腰臀比（腹部脂肪衡量指標）高的人比起那些體重健康的人來說，平均的腦容量要稍微小一些。具體來說，腹部肥胖和腦灰質含量低有關。腦灰質是含有神經細胞的腦組織。
"Our research looked at a large group of people and found obesity, specifically around the middle, may be linked with brain shrinkage,” lead study author Mark Hamer, a professor at Loughborough University’s School of Sport, Exercise and Health Sciences in Leicestershire, England, said in a statement.
該研究報告的第一作者、英國萊斯特郡拉夫堡大學的運動、鍛鍊及健康科學學院的教授馬克·哈默爾在一項聲明中表示：“我們的研究調查了一大羣人，然後發現肥胖，尤其是腰腹部肥胖，可能和腦部萎縮有關。”
Lower brain volume, or brain shrinkage, has been linked with an increased risk of memory decline and dementia.
該研究指出，腦容量更小，或者說是腦部萎縮，和記憶衰退以及癡呆的風險增加有關聯。
The new findings, published Jan. 9 in the journal?Neurology, suggest that the combination of obesity (as measured by body mass index, or BMI) and a high waist-to-hip ratio may be a risk factor for brain shrinkage, the researchers said.
這些新發現1月9日發表在《神經學》期刊上。研究指出，肥胖加上高腰臀比可能是腦部萎縮的一個風險因素。研究人員通過身體質量指數來衡量一個人是否肥胖。
However, the study found only an association between belly fat and lower brain volume, and cannot prove that carrying more fat around the waist actually causes brain shrinkage. It could be that people with lower volumes of gray matter in certain brain areas are at a higher risk of obesity. Future studies are needed to tease out the reasons for the link.
不過，這項研究只是發現了腹部脂肪和腦容量小之間的關聯，並不能證明肚子上的肉會導致腦部萎縮。也可能是腦部特定區域灰質較少的人更容易肥胖。要梳理出這個關聯的前因後果，還需進行更多研究。
Dangerous fat 危險的肥肉
Belly fat, also called visceral fat, is fat that’s stored deep within the abdominal cavity. It’s tied to greater health risks than subcutaneous fat, or fat that’s stored just under the skin. Previous studies have linked visceral fat with a higher risk of heart disease (including heart attack and stroke), Type 2 diabetes, high blood pressure and premature death, according to the Mayo Clinic.
腹部脂肪也被稱爲“內臟脂肪”，是堆積在腹腔內部深處的脂肪。它們比皮下脂肪的健康風險還要高。梅奧醫學中心指出，先前的研究已經發現了內臟脂肪和更高的心臟疾病（包括心臟病發作和中風）、二型糖尿病、高血壓和早逝風險之間的關聯。
Some previous studies have also found a link between visceral fat or a high waist-to-hip ratio and lower brain volume, but these studies tended to be small and did not look at the combined effect of BMI and waist-to-hip ratio.
先前的一些研究也發現了內臟脂肪或高腰臀比和腦容量小之間的關聯，但是那些研究規模都比較小，而且也沒有考慮身體質量指數和腰臀比的混合效應。
In the new study, the researchers analyzed information from more than 9,600 people living in the United Kingdom, with an average age of 55. Participants had their BMI and waist-to-hip ratio measured, and underwent an MRI to determine their brain volumes.
在這項新研究中，研究人員分析了生活在英國的9600多名平均年齡爲55歲的參與者信息。研究人員測量了參與者的身體質量指數和腰臀比，然後通過核磁共振成像測量了他們的腦容量。
The study found that people with both a high BMI and high waist-to-hip ratio had the lowest brain volumes, compared with people who had just a high BMI (but not a high waist-to-hip ratio) and people of a healthy weight.
研究發現，和身體質量指數高但腰臀比不高的人以及體重正常的人相比，身體質量指數和腰臀比都高的人腦容量最小。
Specifically, people with both a high BMI and high waist-to-hip ratio had an average gray matter volume of 786 cubic centimeters, compared with 793 cubic centimeters for people with a high BMI but not a high waist-to-hip ratio; and 798 cubic centimeters for people of a healthy weight.
詳細來說，身體質量指數和腰臀比都高的人平均腦灰質體積爲786立方厘米，而身體質量指數高但腰臀比不高的人平均腦灰質體積爲793立方厘米，體重健康的人平均腦灰質體積爲798立方厘米。
The findings held even after researchers took into account other factors that can affect brain volume, including age, smoking and high blood pressure.
即使在研究人員考慮了年齡、吸菸和高血壓這些會影響腦容量的其他因素之後，這一發現依舊成立。
Though the study didn't look at potential mechanisms linking visceral fat and brain shrinkage, one hypothesis is that this type of fat is thought to produce inflammatory substances that may play a role in brain atrophy, the researchers said.
研究人員說，雖然本研究沒有探索內臟脂肪和腦部萎縮關聯的潛在作用機制，但是有一項假說認爲這種脂肪據說會產生炎症物質，可能會導致腦萎縮。
Dr. Gayatri Devi, a neurologist at Lenox Hill Hospital in New York, who was not involved with the study, agreed with the findings. "Brain gray matter shrinkage...seems to be associated with obesity and with increased visceral fat,” she said.
未參與該研究的紐約勒諾克斯山醫院神經學家嘉亞特里·德維醫生表示認同這一發現。她說：“腦灰質的萎縮似乎和肥胖以及內臟脂肪增多有關聯。”
"All this goes to show that good general health is very important for good brain health," Devi told Live Science.