研究表明，身體中部脂肪過多與大腦體積較小有關(guān)

研究表明，身體中部脂肪過多與大腦體積較小有關(guān)

If you're too heavy, especially around your middle, you probably have shrunken gray matter volume in your brain, according to a study published Wednesday in the journal Neurology. Gray matter contains most of your brain's 100 billion nerve cells, while white matter is filled with nerve fibers that connect the brain regions.

根據(jù)周三發(fā)表在《神經(jīng)學》雜志上的一項研究，如果你太胖了，特別是在你的腰部，你的大腦中灰質(zhì)的體積可能會縮小。灰質(zhì)包含了大腦1000億個神經(jīng)細胞中的大部分，而白質(zhì)則充滿了連接大腦各區(qū)域的神經(jīng)纖維。

"Previous studies have shown associations between gray matter atrophy and risk of developing dementia," study author Mark Hamer, a professor of exercise as medicine at Loughborough University in England, wrote in an email.

“之前的研究已經(jīng)表明，灰質(zhì)萎縮與患癡呆癥的風險之間存在關(guān)聯(lián)，”研究報告作者、英國拉夫堡大學運動醫(yī)學教授馬克·哈默在電子郵件中寫道。

Obesity linked to reduced brain volume in four regions

肥胖與四個區(qū)域的腦容量減少有關(guān)

The study of 9.652 middle-age people in the UK measured body mass index (BMI) and waist-to-hip ratio. BMI is a formula involving a person's weight and height; a BMI score between 18.5 and 24.9 is considered healthy, while above 30 is considered obese. Similarly, the waist-to-hip ratio is scored, and a high score -- above 0.90 for men and above 0.85 for women -- means a person has central obesity, or a bigger belly than hips.

這項研究調(diào)查了9652名英國中年人，測量了他們的身體質(zhì)量指數(shù)(BMI)和腰臀比。BMI是一個包含一個人的體重和身高的公式;BMI指數(shù)在18.5到24.9之間被認為是健康的，超過30被認為是肥胖的。同樣地，腰臀比也會被計算在內(nèi)，如果男性的腰臀比高于0.90.女性的腰臀比高于0.85.那么這個人就屬于中樞性肥胖，也就是腹部比臀部大。

Based on these criteria, nearly one in five of the study participants was found to be obese. Hamer and his co-researchers also used an MRI to scan participants' brain volume. The researchers factored in age, physical activity, smoking and high blood pressure, all of which might lead to reduced volume.

根據(jù)這些標準，近五分之一的研究參與者被發(fā)現(xiàn)患有肥胖癥。哈默和他的同事們還用核磁共振掃描了參與者的腦容量。研究人員將年齡、體育活動、吸煙和高血壓都考慮在內(nèi)，所有這些因素都可能導致體重下降。

What did they find? People with higher numbers on both BMI and waist-to-hip ratio had the lowest gray matter volume. "The reductions in brain size increase in a linear fashion as fat around the middle grew larger," Hamer wrote.

他們發(fā)現(xiàn)了什么?BMI和腰臀比較高的人灰質(zhì)體積最低。哈默寫道:“隨著腰部脂肪的增加，大腦體積的縮小呈線性增長。”

"It's unclear if abnormalities in brain structure lead to obesity or if obesity leads to these changes in the brain," Hamer said.

“目前還不清楚是大腦結(jié)構(gòu)異常導致了肥胖，還是肥胖導致了大腦的這些變化，”哈默說。

Potential causes of lower brain volume

腦容量下降的潛在原因

Cara Bohon, an assistant professor in the Department of Psychiatry and Behavioral Sciences at the Stanford University School of Medicine, wrote in an email that the study's findings are "not particularly new or surprising."

斯坦福大學醫(yī)學院精神病學和行為科學系的助理教授卡拉·博洪在一封電子郵件中寫道，這項研究的發(fā)現(xiàn)“并不特別新，也不令人驚訝”。

The study's strength is its size with "a sample of almost 10.000 individuals," wrote Bohon, who was not involved in this research. Previous studies had come to similar conclusions, but few participants were involved, so scientists could not feel confident in the results, she explained.

這項研究的優(yōu)勢在于它的規(guī)模，“樣本幾乎有1萬人，”博洪寫道，他沒有參與這項研究。她解釋說，之前的研究也得出了類似的結(jié)論，但參與者很少，所以科學家對結(jié)果沒有信心。

"One particularly interesting finding is that, among individuals with obesity, those with greater waist to hip ratio (a marker of visceral fat around the abdomen), showed even lower gray matter volume," Bohon said. This connection between reduced brain volume and abdominal fat could suggest that inflammation and vascular factors may be at work.

博洪說:“一個特別有趣的發(fā)現(xiàn)是，在肥胖人群中，腰臀比(腹部周圍內(nèi)臟脂肪的標志)越高，灰質(zhì)體積越小。”腦容量減少和腹部脂肪之間的這種聯(lián)系可能表明炎癥和血管因素可能在起作用。

Future research should explore inflammation, nutrition and vascular health to better understand potential links between brain health and obesity, she said. Bohon's own research suggests that weight loss can reverse brain changes, as it showed that when people lost weight, whether a lot or a little, brain volume improved.

她說，未來的研究應該探索炎癥、營養(yǎng)和血管健康，以更好地了解大腦健康和肥胖之間的潛在聯(lián)系。博洪自己的研究表明，減肥可以逆轉(zhuǎn)大腦的變化，因為它表明當人們減重時，無論減重是多還是少，大腦容量都會增加。