***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The Minnesota Coronary Survey was a 4.5-year , open enrollment , single end-time , double-blind , r and omized clinical trial that was conducted In six Minnesota state mental hospitals and one nursing home . It Involved 4393 Institutionalized men and 4664 Institutionalized women . The trial compared the effects of a 39 % fat control diet ( 18 % saturated fat , 5 % polyunsaturated fat , 16 % monounsaturated fat , 446 mg dietary cholesterol per day ) with a 38 % fat treatment diet ( 9 % saturated fat , 15 % polyunsaturated fat , 14 % monounsaturated fat , 166 mg dietary cholesterol per day ) on serum cholesterol levels and the Incidence of myocardlal Infa rct ions , sudden deaths , and all-cause mortality . The mean duration of time on the diets was 384 days , with 1568 subjects consuming the diet for over 2 years . The mean serum cholesterol level In the pre-admission period was 207 mg/dl , falling to 175 mg/dl in the treatment group and 203 mg/dl In the control group . For the entire study population , no differences between the treatment and control groups were observed for cardiovascular events , cardiovascular deaths , or total mortality . A favorable trend for all these end-points occurred In some younger age groups Restriction of energy intake ( ER ) , without malnutrition of essential nutrients , has repeatedly been demonstrated to increase longevity in rodents . In the antioxidant theory of aging the lack of balance between the generation of free radicals and free radical scavenging was thought to be a main causal agent , in the aging process . From this point of view the antiaging effect induced by ER might be due to the lower rate of free-radical production and related damage induced by a lower metabolic rate . The antiaging effects of ER might also occur in humans . This study explored the effects of a 10-week moderately energy-restricted diet ( 80 % of habitual ) in 24 non-obese middle-aged men ( 16 ER subjects , 8 controls ) on resting metabolic rate ( RMR ) and indicators of the primary antioxidant defense system , oxidative stress and genotoxicity . RMR decreased significantly in both groups , even when adjustments were made for the change in body composition . The increase in blood vitamin C concentration correlated with the increase in urinary 8-hydroxydeoxyguanosine ( 80HdG ) excretion . The change in urinary 80HdG excretion also correlated with the change in RMR per kg fat-free mass . No differences between groups were found for changes in indicators of genotoxicity , erythrocyte catalase , glutathione peroxidase and superoxide dismutase activity and in plasma vitamin E , A or beta-carotene concentrations . We conclude that 10 weeks of moderate ER did not affect indicators of antioxidative capacity , oxidative stress and genotoxicity of humans . Since subjects were not in energy balance at the end of the study , no conclusions can be made with respect to long-term effects Dietary adherence to four different fat-modified diets was examined in 160 subjects by determining the fatty acid composition of serum cholesterol esters ( CEs ) and erythrocyte ( ER ) and platelet ( PT ) membranes in addition to food records . Subjects were r and omly assigned to one of the following diet groups : 1 ) high-sat--35/14:104 ( % of energy from total/saturated : monounsaturated : polyunsaturated fatty acids in the actual diet ) 2 ) AHA ( American Heart Association ) type--32/10:8:8 3 ) monoene-enriched--34/11:11:5 , or 4 ) low-fat--30/12:8:3 for 6 mo . Decreases in the proportions of palmitic acid in CEs were found in the AHA-type and monoene-enriched-diet groups . An increased proportion of linoleic acid in CEs was found in the AHA-type group . The differences in the proportions of palmitic acid in CEs and linoleic and palmitoleic acids in PTs were significant in the AHA-type and monoene-enriched-diet groups compared with the high-sat group . An increase in alpha-linolenic acid in CEs was an indicator of the use of low erucic acid rapeseed oil , which was the main source of monoenes in the monoene-enriched-diet group Two groups of patients with non-insulin-dependent diabetes mellitus ( NIDDM ) , with dietary advice r  and  omized between a low-carbohydrate ( LC ) diet and a modified-fat ( MF ) diet , were followed to determine the effect of diet on phospholipid fatty acid composition of platelets and on development of retinopathy in the 7 years following diagnosis . There was a tendency for retinopathy to occur more frequently in those r and omized to the LC diet . This difference was not statistically significant , and fatty acid composition of platelets did not differ significantly in those with and without retinopathy . Linoleic acid values from platelet phospholipid fatty acids were significantly higher in NIDDM on an MF diet compared with an LC diet . There was no difference between the two dietary subgroups with respect to platelet arachidonic acid , but this was lower in the whole diabetic population when compared with non-diabetics . The arachidonic acid values correlated with neither glycosylated haemoglobin nor mean glycaemia . Significant correlation between the fatty acid values for platelets and plasma cholesterol esters was found only for 16:0 THE National Diet-Heart Study which was supported by the National Heart Institute , has been completed , and the final report appears as a supplement to CIRCULATION . This was a large double-blind , 2-year study on the effects of diet on blood cholesterol levels in both free-living and closed population s. The relevance of such a study originated in our minds as a result of a study we conducted for 10 months with 55 volunteer couples using commercially prepared , fat-modified foods .  These foods were low in saturated fat and relatively high in polyunsaturated oils . Individual diet instruction was not given . The average reduction in serum cholesterol was 14%.1 The general principles on which it was design ed have already been presented.2 Its great importance lies in the demonstration that adequate techniques have now been developed for large experimental studies using volunteers . This is the first study of its kind in which so complex and important a factor as diet was controlled double-blind in a freeliving population . Centers were established in Baltimore , Minneapolis-St . Paul , Oakl and , Chicago , and Boston , where studies of free-living Diet enriched with polyunsaturated fat may increase the susceptibility of LDL to oxidation . Therefore the effects of two low-fat diets on plasma lipid peroxides in free-living mildly hypercholesterolaemic men ( n = 37 ) were investigated in a r and omized single-blind 28-week study . Composition of the diets were ( 1 ) American Heart Association ( AHA ) type 32/10:8:8 ( indicating percentages of energy from total fat/saturated fat : monoenes : polyenes in actual diet ) ; ( 2 ) low-fat 30/12:8:3 . The subjects kept 3-day dietary records five times during the study to estimate the intake of nutrients .  Plasma lipid peroxides were measured photometrically as the thiobarbituric-acid reactive substances ( TBARS ) . Levels of serum vitamin E during the study were also determined . Mean change ( + /- SD ) in serum low density lipoprotein ( LDL ) cholesterol was similar in both groups ( -0.32 + /- 0.76 vs -0.32 + /- 0.87 mmol/l ) ( AHA type vs low-fat ) . Level of TBARS decreased ( P < 0.05 ) during the AHA type diet ( -8.4 + /- 37.1 % ) ( mean + /- SD ) and increased ( P = 0.228 ) during the low-fat diet ( + 8.7 + /- 27.0 % ) from 0 to 6 months . The mean intake of total active tocopherols was greater ( 14.7 + /- 3.7 mg ) during the AHA type diet compared to the low-fat diet ( 7.8 + /- 2.1 mg ) . Serum vitamin E to LDL cholesterol ratio increased from 8.9 + /- 2.9 to 9.6 + /- 2.4 nmol/mmol ( 0 vs 6 months ) ( P = 0.07 ) during the AHA type diet and from 8.6 + /- 2.6 to 9.3 + /- 2.4 nmol/mmol ( P = 0.159 ) during the low-fat diet . ( ABSTRACT TRUNCATED AT 250 WORDS BACKGROUND The " Mediterranean " diet and statin treatment have both independently been shown to improve survival and reduce the risk of cardiovascular events in patients with ischemic heart disease ( IHD ) , but no studies have evaluated the effect of this combination on endothelial function . We therefore sought to evaluate the effect of the combination dietary intervention and lipid-lowering treatment on brachial vasoreactivity . METHODS A total of 131 consecutive patients with documented IHD and a serum cholesterol level > or = 5 mmol/L ( 193 mg/dL ) were r and omized to receive Mediterranean dietary advice ( n = 68 ) or no specific dietary advice ( n = 63 ) . Endothelial function was assessed at baseline and after 12 months with noninvasive ultrasound scanning vessel-wall tracking of brachial artery flow-mediated vasodilatation ( FMD ) . All patients started statin treatment with Fluvastatin ( 40 mg once daily ) at baseline . RESULTS A total of 115 patients completed the study . At baseline , FMD was 4.30 % + /- 4.89 % in the control group versus 4.32 % + /- 6.15 % in the intervention group ( P = not significant ) . After 12 months of follow-up , FMD was significantly higher in the intervention group ( control group 5.72 % + /- 4.87 % vs intervention group 8.62 % + /- 6.60 % , P < .01 ) . This was accompanied by a larger intake of fatty fish and a significant decrease in triglyceride levels . In multivariate analysis , r and omization status was a significant predictor of FMD after adjustment for classic cardiovascular risk factors and vessel size ( P = .02 ; beta = -2.66 [ -4.91 ; -0.41 ] ) . CONCLUSION Dietary intervention with the Mediterranean diet and statin treatment improve FMD in the brachial artery in patients with IHD and hypercholesterolemia to a greater degree than statin treatment alone One hundred and forty nine diabetic patients were ophthalmologically assessed seven years after r and omisation to a low carbohydrate or modified fat diet ( rich in linoleic acid ) .  Glycaemic control , regardless of the type of diet , was a major determinant of the development of retinopathy . Poorly controlled patients ( haemoglobin A1c greater than 8 % ) with low levels of linoleic acid in cholesterol ester had a significantly greater frequency of retinopathy than well controlled patients or patients with similarly unsatisfactory control but higher levels of linoleic acid . The findings support an earlier suggestion that linoleic acid might protect against diabetic retinopathy Fat in the diet has been associated with increased breast cancer risk . In this study , blood sample s were obtained from 21 women at high risk for breast cancer who had been r and omly assigned to either a nonintervention diet or a low-fat diet .  Oxidative damage was examined in the DNA from nucleated peripheral blood cells . The levels of oxidized thymine , specifically 5-hydroxymethyluracil , were threefold higher in the nonintervention diet group than in the low-fat diet group . Without regard to diet arm , there also was a significant linear relationship between daily total fat intake and 5-hydroxymethyluracil level . These results suggest that oxidative damage to DNA may be a marker of dietary fat intake . In addition , oxidative DNA damage may be a mechanistic link between fat in the diet and cancer risk , since such damage is associated with the process of tumor promotion The study deals with 412 men , aged 30 to 64 years , r and omized 1 to 2 years after a first myocardial infa rct ion . For the experimental group a diet low in saturated fats and cholesterol , and high in polyunsaturated fats was recommended . After 5 years , as reported previously , the incidence of fatal and nonfatal myocardial reinfa rct ion was found to be significantly reduced . “ Sudden death ” was uninfluenced . Major coronary heart disease ( CHD ) relapses , including fatal and nonfatal events ( MI ) , were significantly reduced ( P = 0.05).After 11 years , death from all causes had occurred in 101 of the original dieters and 108 controls . A significantly reduced myocardial infa rct ion mortality in the original diet group was found ( 32 versus 57 , P = 0.004 ) . The total number of coronary deaths ( fatal myoc 
    Output:
    
Trials where participants were involved for more than 2 years showed significant reductions in the rate of cardiovascular events and a suggestion of protection from total mortality .
The degree of protection from cardiovascular events appeared similar in high and low risk groups , but was statistically significant only in the former .
REVIEW ER 'S CONCLUSIONS The findings are suggestive of a small but potentially important reduction in cardiovascular risk in trials longer than two years .