If you're middle-aged and your memory's not what it used to be, check the bathroom scale, researchers warned, suggesting overweight people tend to score more poorly on tests of memory than their thinner peers do.

The findings suggest that a heavier weight in middle age may mean a higher risk of dementia later in life.

Reporting in the journal Neurology, the researchers speculated that higher rates ofcardiovascular diseaseor diabetes might help explain the link. But it's also possible that substances produced by fat cells, such as the hormone leptin, have direct effects on the brain.

The study compared mental abilities to body mass index (BMI), a measurement of weight in relation to height used to define overweight and obesity. A BMI of 25 or more indicates overweight, and 30 or more is obese.

The study also investigated the relationships between BMI and cognitive function in 2,223 healthy men and women between the ages of 32 and 62 in France through the use of four cognitive tests.

The study found a higher BMI was associated with lower cognitive test scores. Results from a test involving word memory recall show people with a BMI of 20 remembered an average of nine out of 16 words, while people with a BMI of 30 remembered an average of seven out of 16 words.

研究人員提醒，如果你已步入中年，發(fā)現(xiàn)自己的記憶力不如從前，那么你得小心體重了。研究表明，超重的人記憶測(cè)試的得分要比較瘦的人低。

研究發(fā)現(xiàn)，體重偏大的中年人今后患老年癡呆癥的可能性較大。

研究報(bào)告在《神經(jīng)學(xué)》期刊上發(fā)表，研究人員推斷，心血管疾病及糖尿病的高發(fā)現(xiàn)象可以解釋其中的原因。此外，脂肪細(xì)胞所產(chǎn)生的物質(zhì)，如瘦體激素，對(duì)大腦有直接影響。

此項(xiàng)研究將調(diào)查對(duì)象的智力與體重指數(shù)進(jìn)行了對(duì)比。體重指數(shù)指的是身高和體重之間的比例，主要用來(lái)衡量一個(gè)人是否偏胖或肥胖。體重指數(shù)為25或25以上的人偏胖，達(dá)到30或30以上的人則為肥胖。

研究人員還對(duì)體重指數(shù)和認(rèn)知功能間的關(guān)系進(jìn)行了研究，他們?cè)诜▏?guó)對(duì)2223位年齡在32歲至62歲間的健康男女進(jìn)行了認(rèn)知測(cè)試。

研究發(fā)現(xiàn)，體重指數(shù)越大，認(rèn)知測(cè)試的得分越低。其中一項(xiàng)"單詞記憶"的測(cè)試結(jié)果表明，在16個(gè)單詞中，體重指數(shù)為20的人平均能記住9個(gè)，而體重指數(shù)為30的人平均只能記住7個(gè)。