alzheimer s disease ( ad ) is a progressive and the most prominent old - age debilitating disease which had a notable epidemic growth in recent years . according to statistical analyses
, it is estimated that the number of people suffering from ad will double every twenty years ; and by 2050 , the number of sufferers from ad in the world would reach 115 million ( 1 , 2 ) .
one - eighth of people aged 65 and older and half of people aged 85 and older were diagnosed with ad , approximately ; its death toll from 2000 to 2008 has increased by 66% ( 3 ) .
the costs for this disease are so high that one percent of global gdp is spent on ad s consequences ( 4 ) .
diagnosed patient with ad usually dies after 5 to 7 years ( 2 ) . in iranian traditional medicine ( itm )
manuscripts , diseases in which forgetfulness is the main symptom are categorized under nesyan label . in itm manuscripts ,
one of the types of nesyan which originates from coldness and dryness of the brain has the same symptoms as ad . forgetting recent events and remembering old happenings , cognitive disturbance , problems in constant talking ( language disability ) , and insomnia are of its most important signs ( 5 , 6 ) which are similar to ad s according to nincds - adrda criterion ( 7 ) .
itm takes nourishment as one of the six pillars of health ( 8 , 9 ) ; therefore , itm manuscripts have dedicated a considerable part of their content to nutritional recommendations . in the first volume of canon of medicine , avicenna ( 970 - 1051 a.d . ) , the great persian scholar , described those in detail ( 10 ) .
he urged elderly people not to take foods producing black bile ( sowd ) such as lentil , eggplant , beef , dried meat , and salted foods ; and phlegmatic foods such as fish , watermelon , melon , and cucumber .
on the other hand , taking milk , shirberenj ( an iranian dish consists of milk , rice , sugar , and rosewater ) , honey milk , and milk with ginger are recommended .
apart from preventive recommendations , nutritional therapeutic recommendations are included to boost medication and shorten illness - period ; and nesyan is no exception .
muhammad ibn zakariy rz ( rhazes ) ( 865 - 925 a.d . ) , another great persian scholar , in his book  al - hawi  recommended to have poultry ( such as chicken , dull - yellow partridge , hoopoe , pheasant , and sparrow meat ) , their brains , and yolks for people affected to nesyan . at the same time
the patients were prohibited from having beef , mutton , goat meat , camel meat , and rabbit meat because they produce black bile ; and fish as well for producing phlegm ( balgham ) . moreover , having nuts such as almond , hazelnut , coconut , and walnut were recommended ( 12 ) .
it is worth mentioning that some other persian scholars such as aghili korasani and chishti had the same idea as rhazes ( 5 , 6 ) .
there have been remarkable either observational or experimental studies on the role of diet and nutrients in prevention and treatment of dementia , especially ad .
studies on effects of different kinds of fat such as saturated fatty - acids ( sfa ) , unsaturated fatty - acids ( ufa ) , and cholesterol on ad have been conducted recently .
unsaturated fatty - acids and cholesterol play an important role in the brain ; 60 percent of dry weight of the brain is consisted of fat which 20% of it is of unsatu - rated fatty - acids ( 13 ) .
although the brain is only 2% of the total body mass , it carries 25% of cholesterol of the whole body ( 14 ) . in the light of
the fact that most of the brain is consisted of fat and it uses nutrients as other organs , types and amounts of fat consumption could be vitally important in the brain s health .
studying multi - nutrient diets ( instead of one or more nutrients ) has a notable importance .
one of the multi - nutrient diets which have been frequently studied is the mediterranean diet ( table 1 ) ( 15 ) .
studies have shown that it has preventive effect on ad ( 16 , 17 ) .
taking types of fat into consideration , this diet has a great deal of ufas and lesser amounts of sfas and cholesterol .
ufas positive impact has been reported in several other researches ( 18 ) . while the results of studies on therapeutic role of ufas ( especially omega-3 ) on ad are controversial ( 19 , 20 ) , ufas
multi - nutrient diets like the mediterranean diet which contains high levels of ufas have abated the incidence of ad ( 16 , 17 ) ; the abatement is 13% according to sofi et al .
study on the relationship between the mediterranean diet and health status in 2008 ( 17 ) . about cholesterol
, it plays a vital role in cell membranes , yet its functions in neurons are more prominent .
cholesterol is amassed within lipid rafts in the neuronal cell membrane and is involved in the formation and maintenance of synaptic connections ( 21 ) . several studies on the effect of cholesterol on ad had ambiguous results . according to the importance of diets
especially fats - in ad , this study attempted to analyze the fat content of itm recommended diet for nesyan ( itm equivalent of alzheimer s disease ) . since traditional physicians used to recommend distinctive diets based on their own clinical experiences , analyzing these diets would eventuate in new nutritional regimen to improve ad sufferers quality of life .
in order to study the traditional recommended diet for nesyan , itm prominent books including al - hawi ( rhazes , 10th century ) , canon of medicine ( avicenna , 11th century ) , zakhire - ye - khawrazmshahi ( jorjani , 12th century ) , kholasat - ul - hekma ( aqilikhorasani , 18th century ) , and exir - e - azam ( chishti , 19th century ) were searched for recommended and abstinent foods and diets traditionally prescribed for patients afflicted by senescence and/or nesyan ( 5 , 8 , 11 , 12 , 22 ) . to quantify the results ,
the content of fatty components of each food ( including polyunsatu - rated ( pufa ) , monounsaturated ( mufa ) , and saturated fatty acids ( sfa ) and also cholesterol ) were extracted from the database of the department of agriculture of the usa ( usda ) ( 23 ) .
the content of fatty elements per 100 gr of each recommended food was compared with that of the abstinences and statistically analyzed by mann - whitney test via spss ( version 16 ) .
about the diet , the sum of the nutrients of recommended and abstinent diets for daily consumption was also measured .
ad dietary recommendations and abstinences which currently published in medical journals were also searched via scopus .
finally , traditional and new dietary suggestions were compared with each other and the results presented as tables and figures .
the results show that the recommended foods ( presented in the first column of table 2 ) are fattier than the abstinent ones ( presented in the first column of table 3 ) ( p<0.001 ) .
there are also meaningful differences between unsaturated fatty acids ( p<0.001 ) , saturated fatty acids ( p<0.001 ) , and cholesterol ( p<0.05 ) of recommended foods and abstinent foods ( fig .
these foods form recommended and abstinent diets for nesyan . this recommended diet is fattier than the abstinent diet ( 4.5 times ) ( see the last row of table 2 and 3 ) ; polyunsaturated fatty acids of recommended diet
it is the same story for monounsaturated fatty acids and cholesterol ( 11 and 1.4 times more than abstinent diet , respectively ) ( fig .
2 ) . fatty components in 100 gr of each food traditionally recommended or forbidden for people afflicted by nesyan . *
error bars indicate sem comparison between nutritional factors of recommended and abstinent diet in nesyan the results of searching scopus database show that recent studies emphasize on diets with high amounts of unsaturated fatty acids for ad sufferers .
a considerable number of papers but not all of them - emphasizes on probable positive role of cholesterol on ad .
nutritional factors of daily diet recommended for patients affected with nesyan in iranian traditional medicine .
the last row of the table presents the amounts of nutrients in daily recommended diet nutritional factors of daily diet forbidden for patients affected with nesyan in iranian traditional medicine .
the last row of the table presents the amounts of nutrients in daily abstinent diet .
iranian traditional medicine has nutritional recommendations to help curing nesyan ( ad equivalent in traditional medicine ) . in this study , evaluating the ingredients of the recommended foods highlights that it is ufas - rich because of having nuts .
the types of meat in the recommendations are mostly poultry ( chicken , pheasant , and sparrow ) ; their remark is their greater amount of cholesterol compared to the abstinences .
some recent studies substantiate that cholesterol is a boost to improve memory function ( 24 , 25 ) .
when cholesterol is consumed with ufas , it will turn into hdl ( 26 , 27 ) . in 2004 ,
reitz and colleagues have concluded that there is no connection between serum cholesterol level and ad ( 28 ) .
however , some other studies have shown that the higher the serum cholesterol level in the elderly , the better memory functions ( 24 , 25 ) .
some studies also have shown the decline in serum total cholesterol levels is associated with increased dementia risk ( 29 , 30 ) .
furthermore , in a cohort study conducted on 1130 people ( published 2010 ) , reitz et al .
conclude that high hdl levels in elderly individuals may be associated with a decreased rate of ad ( 31 ) .
prior to reitz , singh - manoux and colleagues ( 2008 ) indicated that a low level of hdl could be considered as a risk factor of memory dysfunction ( 32 ) .
bear in mind , there has been no study on hdl destructive effect on ad , so far ( 33 ) .
therefore , prescribing more amounts of cholesterol along with ufas in itm is in accordance with recent studies . on the other side ,
recent studies have shown that cholesterol and all of its precursors in cerebrospinal fluid ( csf ) and its precursorslanosterol , lathosterol , and desmosterol in plasma abate in ad sufferers ( 34 , 35 ) . in 2010 , klsch et al . determined csf and plasma levels of cholesterol and its precursors in ad diagnosed people compared to those of healthy individuals .
the results showed that csf levels of cholesterol and all of its precursors and also plasma levels of two of the precursors named lanosterol and lathosterol are lower in ad diagnosed people than those of healthy individuals ( 34 ) .
sato et al . showed in 2012 that plasma levels of desmosterol , another precursor of cholesterol , are also lower in alzheimer s sufferers than the levels in healthy ones ( 35 ) .
this casts doubt whether the cholesterol reducing agents have preventive effect on ad or not .
there are some studies highlighting that cholesterol reducing agents such as statins are ineffective on ad incidence ( 36 , 37 ) . in a prospective study conducted by zandi et al .
( 2005 ) on 5000 elderly people in the usa , the relationship between statins consumption and the onset of dementia or ad has been violated ( 36 ) . along the lines of zandi
s study , mcguinness and colleagues ( 2009 ) co - evaluated two randomized double blind clinical trials containing 26 thousand participants which resulted that there is no relationship between statins consumption and the risk of ad incidence ( 37 ) .
also , reduction in serum total cholesterol could be considered as a risk factor of dementia in the elderly ( 29 , 30 ) .
there are other ingredients in the abstinences which are not considerable in having fats and cholesterol .
pumpkin , lettuce , melon , garlic , onion , cabbage , beans , broad beans , and mushroom are of its examples .
according to iranian cuisine in the past , there were foods in itm that have no place in eating habit nowadays ; so there is not much information about them .
hoopoe , lark , dull - yellow partridge meat and their brain are of the examples .
this diet contains high amounts of unsaturated fatty acids and cholesterol to boost treatment of nesyan ( traditional equivalent of alzheimer disease ) .
according to new scientific findings , this kind of diet could be useful as a complementary therapy of alzheimer disease .
ethical issues ( including plagiarism , informed consent , misconduct , data fabrication and/or falsification , double publication and/or submission , redundancy , etc . ) have been completely observed by the authors .
 abstractbackgrounddietary notifications have been introduced recently for alzheimer disease ( ad ) . in iranian old medical manuscripts , there are some nutritional recommendations related to nesyan ( ad equivalent ) . 
 the aim of this article was to compare dietary recommendations of iranian traditional medicine ( itm ) with novel medical outcomes.methods1 ) searching for dietary recommendations and abstinences described in itm credible manuscripts ; 2 ) extracting fatty components of itm diet according to the database of the department of agriculture of the usa ; 3 ) statistical analysis of fatty elements of traditionally recommended foods via mann - whitney test in comparison with elements of the abstinent ones ; 4 ) searching for ad dietary recommendations and abstinences which currently published in medical journals ; 5 ) comparing traditional and new dietary suggestions with each other.results1 ) traditionally recommended foods are fattier than abstinent ones ( p<0.001 ) . 
 there are meaningful differences between unsaturated fatty acids ( ufas ) ( p<0.001 ) , saturated fatty acids ( p<0.001 ) , and cholesterol ( p<0.05 ) of recommended foods and abstinent ones . 
 2 ) traditionally recommended diet is also fattier than the abstinent diet ( 4.5 times ) ; ufas of the recommended diet is 11 times more than that of the abstinent one ; it is the same story for cholesterol ( 1.4 times ) ; 3 ) recent studies show that diets with high amounts of ufas have positive effects on ad ; a considerable number of papers emphasizes on probable positive role of cholesterol on ad ; 4 ) traditional recommended diet is in agreement with recent studies.conclusionitm recommended diet which is full of unsaturated fatty acids and cholesterol can be utilized for complementary treatment of ad . 