每天食用鳄梨可提高超重,肥胖人群的注意力 Study: Daily avocado consumption improves attention in persons with overweight, obesity

News Release 10-Mar-2020

University of Illinois at Urbana-Champaign, News Bureau

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IMAGE: An avocado a day improves the ability to focus attention for overweight or obese adults, Illinois researchers found in a new study. view more  Credit: Graphic by Michael Vincent

An avocado a day improves the ability to focus attention for overweight or obese adults, Illinois researchers found in a new study.

CHAMPAIGN, Ill. — A diet including daily avocado consumption improves the ability to focus attention in adults whose measurements of height and weight are categorized as overweight or obese, a new randomized control trial found.

Researchers at the University of Illinois at Urbana-Champaign conducted the 12-week study, published in the International Journal of Psychophysiology.

“Previous work has shown that individuals with overweight and obesity are at higher risk for cognitive decline and dementia in older age,” said kinesiology and community health professor Naiman Khan, who led the study. “We are interested in whether dietary approaches may have benefits for cognitive health, especially in midlife.”

The Hass Avocado Board and the U.S. Department of Agriculture’s National Institute of Food and Agriculture supported this work.

Avocados are high in lutein, a dietary component associated with cognitive benefits. Though avocado consumption’s benefits have been studied in older adults and children, no randomized controlled trials had studied its cognitive effects on adults with overweight or obesity, despite 70% of the American adult population falling into that category, said graduate student Caitlyn Edwards, the first author of the study.

In the new study, the researchers provided 12 weeks of daily meals to 84 adults with overweight or obesity. The meals were identical in calories and macronutrients, but one group’s meals included a fresh avocado every day, while the control group had no avocado in their meals.

At the beginning and end of the study, the participants completed three cognitive tests to measure attention and inhibition. In addition, the researchers measured lutein levels in the participants’ serum and in their retinas, which is associated with the lutein concentration in the brain.

They found that the participants whose diets included avocados improved their performance on one of the cognitive tests, called the Flanker task, which measures attentional inhibition – the ability to maintain focus on the task at hand even in the face of distraction. However, there was no difference in the other two cognitive tests.

“It could be that nutrients in avocados have a specific action in the brain that supports the ability to do this task in particular, or they could be more beneficial for certain cognitive abilities over others,” Khan said. “It’s also possible that with a longer study or different tests, we could see other effects. Other studies have found broader effects in other populations, so it is interesting to see a more specific benefit for this population.”

Another unexpected finding was that, while the participants who ate avocados had higher levels of lutein at the end of the study, the changes in lutein levels were not correlated with their cognitive changes.

“Avocados also are high in fiber and monounsaturated fats. It is possible that these other nutrients may have played a role in the cognitive effects we saw, but we focused on the lutein in our analyses,” Edwards said. “Future analyses may focus on other nutrients found in avocados, or avocado consumption’s impact on other measures such as weight status, inflammation and potential changes in the microbiome.”

Although this study focused on avocados, other dietary sources of lutein, fiber and unsaturated fats – such as green leafy vegetables or eggs – also have potential cognitive and health benefits. The researchers say their study shows that small dietary changes, such as eating avocados, can have measurable impacts on cognitive performance, even when other health behaviors remain the same.

“Our mission is to give people options. There are multiple ways people can eat to optimize brain health,” Khan said. “What we’re learning is that avocados may be one of those fruits that may be neuroprotective in certain ways. This work provides some evidence behind one option people have from a plethora of healthful foods that we can consume.”

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Editor’s notes: To reach Naiman Khan, email [email protected].

The paper “Effects of 12-week avocado consumption on cognitive function among adults with overweight and obesity” is available online. DOI: 10.1016/j.ijpsycho.2019.12.006

伊利诺伊州的研究人员在一项新研究中发现,每天鳄梨可提高将注意力集中在超重或肥胖成年人身上的能力。

一项新的随机对照试验发现,每日食用鳄梨的饮食可以提高成年人的注意力集中能力,这些成年人的身高和体重测量结果被归类为超重或肥胖。

伊利诺伊大学香槟分校的研究人员进行了为期12周的研究,该研究发表在《国际心理生理学杂志》上。

“以前的工作表明,超重和肥胖的人在较高的年龄中更容易出现认知能力下降和痴呆症,”负责这项研究的运动学和社区健康教授奈曼·汗说。 “我们对饮食方法是否可能对认知健康特别是中年人的认知健康有益。”

哈斯牛油果委员会和美国农业部国家粮食与农业研究所都支持这项工作。

鳄梨叶黄素含量高,叶黄素是一种与认知功能相关的饮食成分。研究生凯特琳·爱德华兹(Caitlyn Edwards)表示,尽管鳄梨食用的益处已在老年人和儿童中进行了研究,但没有随机对照试验研究其对超重或肥胖成年人的认知作用,尽管美国成年人口中有70%属于此类人群。该研究的作者。

在这项新研究中,研究人员为84名超重或肥胖的成年人提供了12周的每日进餐。膳食中的卡路里和大量营养素相同,但是一组膳食中每天都包含新鲜的鳄梨,而对照组的膳食中没有鳄梨。

在研究的开始和结束时,参与者完成了三个认知测试以测量注意力和抑制力。此外,研究人员测量了参与者血清和视网膜中叶黄素的水平,这与大脑中叶黄素的浓度有关。

他们发现,饮食中包括鳄梨的参与者在一项名为“侧卫任务”的认知测试中改善了他们的表现,该任务测量注意抑制–即使面对分心时也能够保持专注于手头任务的能力。但是,其他两个认知测验没有差异。

汗说:“鳄梨中的营养物质可能在大脑中具有特定的作用,从而特别支持完成这项任务的能力,或者它们对某些认知能力的影响可能超过其他物质。” “通过更长的研究或不同的测试,我们还可能看到其他效果。其他研究发现,在其他人群中产生了更广泛的影响,因此有趣的是,该人群获得了更具体的收益。”

另一个出乎意料的发现是,尽管在研究结束时吃鳄梨的参与者叶黄素水平较高,但叶黄素水平的变化与他们的认知变化无关。

鳄梨的纤维和单不饱和脂肪含量也很高。这些其他营养素可能在我们看到的认知作用中发挥了作用,但我们在分析中着重于叶黄素。”爱德华兹说。 “未来的分析可能会集中在鳄梨中发现的其他营养物质,或者鳄梨食用量对其他指标的影响,例如体重状况,炎症和微生物组的潜在变化。”

尽管这项研究的重点是鳄梨,但叶黄素,纤维和不饱和脂肪的其他饮食来源(例如绿叶蔬菜或鸡蛋)也具有潜在的认知和健康益处。研究人员说,他们的研究表明,即使其他健康行为保持不变,小的饮食变化(例如吃鳄梨)也可能对认知能力产生可测量的影响。

“我们的使命是为人们提供选择。人们可以通过多种饮食来优化大脑健康。” “我们正在学习的是,鳄梨可能是在某些方面可能具有神经保护作用的水果之一。这项工作提供了一些证据,表明人们可以从我们可以食用的多种健康食品中获得一种选择。”

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