News Release 14-Apr-2020

NIH/National Eye Institute

According to a recent analysis of data from two major eye disease studies, adherence to the Mediterranean diet – high in vegetables, whole grains, fish, and olive oil – correlates with higher cognitive function. Dietary factors also seem to play a role in slowing cognitive decline. Researchers at the National Eye Institute (NEI), part of the National Institutes of Health, led the analysis of data from the Age-Related Eye Disease Study (AREDS) and AREDS2. They published their results today in the journal Alzheimer’s and Dementia.

“We do not always pay attention to our diets. We need to explore how nutrition affects the brain and the eye” said Emily Chew, M.D., director of the NEI Division of Epidemiology and Clinical Applications and lead author of the studies.

The researchers examined the effects of nine components of the Mediterranean diet on cognition. The diet emphasizes consumption of whole fruits, vegetables, whole grains, nuts, legumes, fish, and olive oil, as well as reduced consumption of red meat and alcohol.

AREDS and AREDS2 assessed over years the effect of vitamins on age-related macular degeneration (AMD), which damages the light-sensitive retina. AREDS included about 4,000 participants with and without AMD, and AREDS2 included about 4,000 participants with AMD. The researchers assessed AREDS and AREDS2 participants for diet at the start of the studies. The AREDS study tested participants’ cognitive function at five years, while AREDS2 tested cognitive function in participants at baseline and again two, four, and 10 years later. The researchers used standardized tests based on the Modified Mini-Mental State Examination to evaluate cognitive function as well as other tests. They assessed diet with a questionnaire that asked participants their average consumption of each Mediterranean diet component over the previous year.

Participants with the greatest adherence to the Mediterranean diet had the lowest risk of cognitive impairment. High fish and vegetable consumption appeared to have the greatest protective effect. At 10 years, AREDS2 participants with the highest fish consumption had the slowest rate of cognitive decline.

The numerical differences in cognitive function scores between participants with the highest versus lowest adherence to a Mediterranean diet were relatively small, meaning that individuals likely won’t see a difference in daily function. But at a population level, the effects clearly show that cognition and neural health depend on diet.

The researchers also found that participants with the ApoE gene, which puts them at high risk for Alzheimer’s disease, on average had lower cognitive function scores and greater decline than those without the gene. The benefits of close adherence to a Mediterranean diet were similar for people with and without the ApoE gene, meaning that the effects of diet on cognition are independent of genetic risk for Alzheimer’s disease.

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The AREDS and AREDS2 studies were supported by the NEI Intramural Research Program and contracts NOI-EY-0-2127 (AREDS), HHS-N-260-2005-00007-C (AREDS2), and N01-EY-5-0007 (AREDS2). Additional research funds were provided by the NIH Office of Dietary Supplements, the National Center for Complementary and Integrative Health, the National Institute on Aging, the National Heart, Lung, and Blood Institute, and the National Institute of Neurological Disorders and Stroke. The AREDS trial is registered at http://www.ClinicalTrials.gov as NCT00594672. AREDS2 is registered as NCT00345176. The studies took place at the NIH Clinical Center.

Reference: Keenan TD, Agron E, Mares J, Clemons TE, van Asten F, Swaroop A, and Chew E, for the AREDS and AREDS2 research groups. “Adherence to a Mediterranean diet and cognitive function in the Age-Related Eye Disease Studies 1 & 2.” April 14, 2020. Alzheimer’s and Dementia.

NEI leads the federal government’s research on the visual system and eye diseases. NEI supports basic and clinical science programs to develop sight-saving treatments and address special needs of people with vision loss. For more information, visit https://www.nei.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit https://www.nih.gov/.

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根據最近對兩項主要眼病研究數據的分析，堅持地中海飲食（蔬菜，全穀物，魚類和橄欖油中含量較高）與更高的認知功能相關。飲食因素也似乎在減緩認知能力下降中起作用。美國國立衛生研究院下屬的美國國立眼科研究所（NEI）的研究人員領導了與年齡有關的眼病研究（AREDS）和AREDS2的數據分析。他們今天在阿爾茨海默氏症和癡呆症雜誌上發表了他們的研究結果。
“我們並不總是注意飲食。 NEI流行病學和臨床應用部主任，該研究的主要作者，醫學博士Emily Chew博士說，我們需要探索營養如何影響大腦和眼睛。

研究人員檢查了地中海飲食中九種成分對認知的影響。飲食強調食用整個水果，蔬菜，全穀物，堅果，豆類，魚和橄欖油，以及減少食用紅肉和酒精。
多年來，AREDS和AREDS2評估了維生素對與年齡有關的黃斑變性（AMD）的作用，該黃斑變性會損害光敏性視網膜。 AREDS包括大約4,000個有或沒有AMD的參與者，AREDS2包括大約4,000個有AMD的參與者。在研究開始時，研究人員評估了AREDS和AREDS2參與者的飲食。 AREDS研究在5年時測試了參與者的認知功能，而AREDS2在基線時以及2年，4年和10年後測試了參與者的認知功能。研究人員使用了基於改良的迷你精神狀態考試的標準化測試來評估認知功能以及其他測試。他們通過問卷調查了飲食，詢問參與者上一年中每種地中海飲食成分的平均消費量。

堅持地中海飲食最大的參與者認知障礙的風險最低。大量食用魚類和蔬菜似乎具有最大的保護作用。在10年時，魚類消費量最高的AREDS2參與者的認知能力下降速度最慢。
堅持地中海飲食最高與最低飲食的參與者之間認知功能評分的數值差異相對較小，這意味著個人可能不會發現其日常功能有所不同。但是從人群的角度來看，這些影響清楚地表明認知和神經健康取決於飲食。
研究人員還發現，具有ApoE基因的參與者與沒有該基因的參與者相比，平均具有較低的認知功能評分和較大的衰落，這使他們處於阿爾茨海默氏病的高風險中。無論是否患有ApoE基因，密切遵守地中海飲食的好處都是相似的，這意味著飲食對認知的影響與阿爾茨海默氏病的遺傳風險無關。