Dietary proteins and protein sources and risk of death: the Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND: Previous studies investigating protein intake in relation to mortality have provided conflicting results. OBJECTIVE: We investigated the associations of dietary protein and protein sources with risk of disease death in the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study. METHODS: The study population consisted of 2641 Finnish men, aged 42-60 y at baseline in 1984-1989. We estimated protein intakes with 4-d dietary records at baseline and collected data on disease deaths from the national Causes of Death Register. Cox proportional hazards regression models were used to estimate HRs and 95% CIs. RESULTS: During the average follow-up of 22.3 y, we observed 1225 deaths due to disease. Higher intakes of total protein and animal protein had borderline statistically significant associations with increased mortality risk: multivariable-adjusted HR (95% CI) in the highest compared with the lowest quartile for total protein intake = 1.17 (0.99, 1.39; P-trend across quartiles = 0.07) and for animal protein intake = 1.13 (0.95, 1.35; P-trend = 0.04). Higher animal-to-plant protein ratio (extreme-quartile HR = 1.23; 95% CI: 1.02, 1.49; P-trend = 0.01) and higher meat intake (extreme-quartile HR = 1.23; 95% CI: 1.04, 1.47; P-trend = 0.01) were associated with increased mortality. When evaluated based on disease history at baseline, the association of total protein with mortality appeared more evident among those with a history of type 2 diabetes, cardiovascular disease, or cancer (n = 1094) compared with those without disease history (n = 1547) (P-interaction = 0.05 or 0.07, depending on the model). Intakes of fish, eggs, dairy, or plant protein sources were not associated with mortality. CONCLUSIONS: Higher ratio of animal to plant protein in diet and higher meat intake were associated with increased mortality risk. Higher total protein intake appeared to be associated with mortality mainly among those with a predisposing disease. This trial was registered at clinicaltrials.gov as NCT03221127.

Intake of fermented and non-fermented dairy products and risk of incident CHD: the Kuopio Ischaemic Heart Disease Risk Factor Study.

Recent dairy product studies have suggested that fermented rather than non-fermented dairy products might provide benefits on cardiovascular health, but the evidence is inconclusive. Therefore, we investigated whether fermented and non-fermented dairy products have distinct associations with the risk of incident CHD in a population with high dairy product intake. The present study included a total of 1981 men, aged 42-60 years, from the Kuopio Ischaemic Heart Disease Risk Factor Study, with no CHD at baseline. Dietary intakes were assessed with instructed 4-d food records. We used Cox's proportional hazards regression model to estimate the associations with the risk of CHD. Fatal and non-fatal CHD events were ascertained from national registries. During a mean follow-up of 20·1 years, 472 CHD events were recorded. Median intakes were 105 g/d for fermented (87 % low-fat products) and 466 g/d for non-fermented dairy products (60 % low-fat products). After adjusting for potential confounders, those in the highest (v. lowest) intake quartile of fermented dairy products had 27 % (95 % CI 5, 44; P-trend=0·02) lower risk of CHD. In contrast, those in the highest intake quartile of non-fermented dairy products had 52 % (95 % CI 13, 104; P-trend=0·003) higher risk of CHD. When analysed based on fat content, low-fat (<3·5 % fat) fermented dairy product intake was associated with lower risk (hazard ratio in the highest quartile=0·74; 95 % CI 0·57, 0·97; P-trend=0·03), but high-fat fermented dairy and low-fat or high-fat non-fermented dairy products had no association. These results suggest that fermented and non-fermented dairy products can have opposite associations with the risk of CHD.

Intake of Different Dietary Proteins and Risk of Heart Failure in Men: The Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND: Animal and plant protein intakes have indicated opposite associations with cardiovascular mortality risk. Whether dietary proteins are associated with risk of heart failure (HF) is unclear. Thus, we examined the associations of proteins from different food sources with risk of HF. METHODS AND RESULTS: The study included 2441 men aged 42 to 60 years at the baseline examinations in 1984 to 1989 in the Kuopio Ischaemic Heart Disease Risk Factor Study. Protein intakes at baseline were assessed with 4-day dietary records. Data on incident HF cases were obtained from national registers. HF risk according to protein intake was estimated by Cox proportional hazard ratios. During the mean follow-up of 22.2 years, 334 incident HF cases occurred. Higher intake of total protein indicated a trend toward increased risk of HF (multivariable-adjusted hazard ratio in the highest versus lowest quartile=1.33; 95% confidence interval: 0.95-1.85; P-trend=0.05). The associations between specific types and sources of protein with incident HF were consistent with this overall finding although not all associations reached statistical significance. For example, the hazard ratio in the highest versus lowest quartile was 1.43 (95% confidence interval: 1.00-2.03; P-trend=0.07) for total animal protein and 1.17 (95% confidence interval: 0.72-1.91; P-trend=0.35) for total plant protein. CONCLUSIONS: In middle-aged men, higher protein intake was marginally associated with increased risk of HF. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03221127.

Intake of different dietary proteins and risk of type 2 diabetes in men: the Kuopio Ischaemic Heart Disease Risk Factor Study.

The roles of different dietary proteins in the aetiology of type 2 diabetes (T2D) remain unclear. We investigated the associations of dietary proteins with the risk of incident T2D in Finnish men from the prospective Kuopio Ischaemic Heart Disease Risk Factor Study. The study included 2332 men aged 42-60 years at the baseline examinations in 1984-1989. Protein intakes were calculated from 4-d dietary records. Incident T2D was determined by self-administered questionnaires, fasting blood glucose measurements, 2-h oral glucose tolerance tests, and with national registers. The multivariable-adjusted risk of T2D on the basis of protein intakes was compared by the Cox proportional hazard ratios (HR). During the mean follow-up of 19·3 years, 432 incident T2D cases were identified. Total, animal, meat or dairy product protein intakes were not associated with risk of T2D when the potential confounders were accounted for. Plant (multivariable-adjusted extreme-quartile HR 0·65; 95 % CI 0·42, 1·00; P trend 0·04) and egg (HR 0·67; 95 % CI 0·44, 1·00; P trend 0·03) protein intakes were associated with a decreased risk of T2D. Adjustments for BMI, plasma glucose and serum insulin slightly attenuated associations. Replacing 1 % energy from carbohydrates with energy from protein was associated with a 5 % (95 % CI 0, 11) increased risk of T2D, but adjustment for fibre intake attenuated the association. Replacing 1 % of energy from animal protein with energy from plant protein was associated with 18 % (95 % CI 0, 32) decreased risk of T2D. This association remained after adjusting for BMI. In conclusion, favouring plant and egg proteins appeared to be beneficial in preventing T2D.

Association of dietary cholesterol and egg intakes with the risk of incident dementia or Alzheimer disease: the Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND: There is little information about the associations of intakes of cholesterol and eggs, a major source of dietary cholesterol, with the risk of cognitive decline in general populations or in carriers of apolipoprotein E ɛ4 (APO-E4), a major risk factor for dementia. OBJECTIVE: We investigated the associations of cholesterol and egg intakes with incident dementia, Alzheimer disease (AD), and cognitive performance in middle-aged and older men from Eastern Finland. DESIGN: A total of 2497 dementia-free men, aged 42-60 y in 1984-1989 at the baseline examinations of the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study, were included in the study. Information on the apolipoprotein E (Apo-E) phenotype was available for 1259 men. Data on cognitive performance tests at the 4-y re-examinations were available for 480 men. Dietary intakes were assessed with the use of 4-d food records at baseline. Dementia and AD diagnoses were based on Finnish health registers. Cox regression and ANCOVA were used for the analyses. RESULTS: During the 21.9-y follow-up, 337 men were diagnosed with dementia, and 266 men were diagnosed with AD. Neither cholesterol nor egg intake was associated with a higher risk of incident dementia or AD. For example, when evaluated continuously, each intake of 100 mg cholesterol/d was associated with a multivariable-adjusted HR of 0.90 (95% CI: 0.79, 1.02) for incident dementia, and each additional 0.5 egg (27 g)/d was associated with an HR of 0.89 (95% CI: 0.78, 1.01). However, egg intake was associated with better performance on neuropsychological tests of the frontal lobe and executive functioning, the Trail Making Test, and the Verbal Fluency Test. The Apo-E4 phenotype did not modify the associations of cholesterol or egg intake (P-interactions > 0.11). CONCLUSIONS: Neither cholesterol nor egg intake is associated with an increased risk of incident dementia or AD in Eastern Finnish men. Instead, moderate egg intake may have a beneficial association with certain areas of cognitive performance.

Associations of egg and cholesterol intakes with carotid intima-media thickness and risk of incident coronary artery disease according to apolipoprotein E phenotype in men: the Kuopio Ischaemic Heart Disease Risk Factor Study.

BACKGROUND: In general populations, the effects of dietary cholesterol on blood cholesterol concentrations are modest. However, the relation is stronger in those with an ɛ4 allele in the apolipoprotein E gene (APOE). There is little information on the association between cholesterol intake and the risk of coronary artery disease (CAD) among those with the ApoE4 phenotype. OBJECTIVE: We investigated the associations of intakes of cholesterol and eggs, a major source of dietary cholesterol, with carotid intima-media thickness and the risk of incident CAD in middle-aged and older men from eastern Finland. DESIGN: The study included 1032 men aged 42-60 y in 1984-1989 at the baseline examinations of the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study. Data on common carotid artery intima-media thickness (CCA-IMT) were available for 846 men. Dietary intakes were assessed with 4-d food records. Associations with incident CAD and baseline CCA-IMT were analyzed by using Cox regression and ANCOVA, respectively. RESULTS: The ApoE4 phenotype was found in 32.5% of the men. During the average follow-up of 20.8 y, 230 CAD events occurred. Egg or cholesterol intakes were not associated with the risk of CAD. Each 1 additional egg (55 g)/d was associated with a multivariable-adjusted HR of 1.17 (95% CI: 0.85, 1.61) in the ApoE4 noncarriers and an HR of 0.93 (95% CI: 0.50, 1.72) in the ApoE4 carriers (P-interaction = 0.34). Each 100-mg/d higher cholesterol intake was associated with an HR of 1.04 (95% CI: 0.89, 1.22) in the ApoE4 noncarriers and an HR of 0.95 (95% CI: 0.73, 1.25) in the ApoE4 carriers (P-interaction = 0.81). Egg or cholesterol intakes were also not associated with increased CCA-IMT. CONCLUSION: Egg or cholesterol intakes were not associated with increased CAD risk, even in ApoE4 carriers (i.e., in highly susceptible individuals).