Feb. 9, 2009 -- A new study shows that people who eat a Mediterranean-style diet are less likely to develop mild cognitive impairment, which is a stage of memory loss between typical aging and Alzheimer’s disease. Mediterranean eaters who already have mild cognitive impairment are less likely to transition into Alzheimer’s.
The Mediterranean diet consists of larger doses of fish, vegetables, legumes, fruits, cereals, and unsaturated fatty acids; low amounts of dairy products, meat, and saturated fats; and a moderate amount of alcohol.
The study was published in the Archives of Neurology. Researchers calculated a diet score for each participant in the study; the higher the score, the more of a Mediterranean diet the person ate. Participants, who were screened for cognitive impairments and interviewed at the start of the study, completed a food questionnaire near the time of study recruitment, which occurred in 1992 and 1999. Participants were all Medicare beneficiaries living in the northern part of Manhattan. At the start of the study, there were 1,393 participants with no cognitive impairments and 482 with mild cognitive impairment.
Among the 1,393 participants who started out with no cognitive impairments, 275 developed impairments during an average 4.5 year follow-up period. Those in the top one-third of Mediterranean diet scores had a 28% lower risk (compared to those in the bottom third) of developing a cognitive impairment.
Of the group of 482 who started out with mild cognitive impairment, 106 developed Alzheimer’s during an average follow-up period of 4.3 years. Again, those with a rich Mediterranean diet fared better. Those with scores in the top one-third had a 48% reduced risk of developing to Alzheimer’s than those with scores in the bottom third. The middle group had a 45% reduced risk.
This reduced risk may be because the Mediterranean diet has been linked to improvements of blood sugar levels, insulin resistance, and lower markers of inflammation, which may in turn reduce the risk of developing cognitive impairments.