Intake of Boiled Potato in Relation to Cardiovascular Disease Risk Factors in a Large Norwegian Cohort: The HUNT Study

Potato Consumption and All-Cause and Cardiovascular Disease Mortality - A Long-Term Follow-Up of a Norwegian Cohort

BACKGROUND

Potatoes are a staple food in many traditional cuisines, yet their impact on long-term risk of cardiovascular disease (CVD) and mortality is unclear, hampering evidence-based dietary guidelines.

OBJECTIVES

This study aimed to examine the association between potato consumption and all-cause and CVD-specific death over a substantial follow-up period within a cohort predominantly consuming boiled potatoes.

METHODS

Adults from 3 Norwegian counties were invited to 3 health screenings in 1974-1988 (>80% attendance). Dietary data were collected using semiquantitative food frequency questionnaires at each screening to categorize weekly potato consumption (≤6, 7-13, or ≥14 potatoes/wk) and calculate daily cumulative mean intakes (grams/day). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression to estimate HRs and 95% CIs for the association between potato consumption and risk of death from all causes, CVD, ischemic heart disease (IHD), and acute myocardial infarction (AMI).

RESULTS

Among 77,297 participants with a mean baseline age of 41.1 y (range: 18.0-63.9 y), we observed 27,848 deaths, including 9072 deaths due to CVD, over a median follow-up of 33.5 y. Participants who consumed ≥14 potatoes/wk had a lower risk of all-cause death compared with those consuming ≤6 potatoes/wk (HR: 0.88; 95% CI: 0.84, 0.93). Potato consumption was associated with a minor, inverse risk of death due to CVD, IHD, and AMI. In continuous analyses of cumulative intakes, each 100 g/d increment was associated with 4% lower risk of death from all causes (HR: 0.96; 95% CI: 0.94, 0.98), CVD (HR: 0.96; 95% CI: 0.93, 0.99), IHD (HR: 0.96; 95% CI: 0.91, 1.00), and AMI (HR: 0.96, 95% CI: 0.91, 1.01).

CONCLUSIONS

In this cohort with a generally high consumption of predominantly boiled potatoes, we find modest, inverse associations between potato consumption and death from all causes, CVD, and IHD.

Potato consumption is not associated with cardiometabolic health outcomes in Framingham Offspring Study adults

Some consider potatoes to be unhealthy vegetables that may contribute to adverse cardiometabolic health outcomes. We evaluated the association between potato consumption (including fried and non-fried types) and three key cardiometabolic outcomes among middle-aged and older adults in the Framingham Offspring Study. We included 2523 subjects ≥30 years of age with available dietary data from 3-d food records. Cox-proportional hazards models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for hypertension, type 2 diabetes or impaired fasting glucose (T2DM/IFG), and elevated triglycerides, adjusting for anthropometric, demographic and lifestyle factors. In the present study, 36 % of potatoes consumed were baked, 28 % fried, 14 % mashed, 9 % boiled and the rest cooked in other ways. Overall, higher total potato intake (≥4 v. <1 cup-equivalents/week) was not associated with risks of T2DM/IFG (HR 0⋅97, 95 % CI 0⋅81, 1⋅15), hypertension (HR 0⋅95; 95 % CI 0⋅80, 1⋅12) or elevated triglycerides (HR 0⋅99, 95 % CI 0⋅86, 1⋅13). Stratified analyses were used to evaluate effect modification by physical activity levels and red meat consumption, and in those analyses, there were no adverse effects of potato intake. However, when combined with higher levels of physical activity, greater consumption of fried potatoes was associated with a 24 % lower risk (95 % CI 0⋅60, 0⋅96) of T2DM/IFG, and in combination with lower red meat consumption, higher fried potato intake was associated with a 26 % lower risk (95 % CI 0⋅56, 0⋅99) of elevated triglycerides. In this prospective cohort, there was no adverse association between fried or non-fried potato consumption and risks of T2DM/IFG, hypertension or elevated triglycerides.

Cooking Methods and Their Relationship with Anthropometrics and Cardiovascular Risk Factors among Older Spanish Adults

Food consumption has a prominent role in the occurrence of cardiometabolic diseases, however, little is known about the specific influence of cooking methods. This study examined the association between cooking methods and anthropometrics, cardiovascular risk factors, and cardiac damage biomarkers in older adults. Data were taken from 2476 individuals aged ≥65 from the Seniors-ENRICA 2 cohort in Spain and recruited between 2015 and 2017. Eight cooking methods (raw, boiling, roasting, pan-frying, frying, toasting, sautéing, and stewing) were assessed using a face-to-face validated dietary history. Study associations were summarized as adjusted percentage differences (PDs) in anthropometrics, cardiovascular risk factors, and cardiac damage biomarkers between extreme sex-specific quintiles ((5th − 1st/1st) × 100) of food consumed with each cooking method, estimated using marginal effects from generalized linear models. After adjusting for potential confounders, including diet quality, PDs corresponding to raw food consumption were −13.4% (p-trend: <0.001) for weight, −12.9% (p-trend: <0.001) for body mass index (BMI), −14.8% (p-trend: <0.001) for triglycerides, and −13.6% (p-trend: <0.115) for insulin. PDs for boiled food consumption were −13.3% (p-trend: <0.001) for weight, −10.0% (p-trend: <0.001) for BMI, and −20.5% (p-trend: <0.001) for insulin. PDs for roasted food consumption were −11.1 (p-trend: <0.001) for weight and −23.3% (p-trend: <0.001) for insulin. PDs for pan-fried food consumption were −18.7% (p-trend: <0.019) for insulin, −15.3% (p-trend: <0.094) for pro-B-type natriuretic peptide amino-terminal, and −10.9% (p-trend: <0.295) for troponin T. No relevant differences were observed for blood pressure nor for other cooking methods. Raw food consumption along with boiling, roasting, and pan-frying were associated with healthier cardiovascular profiles, mainly due to lower weight and insulin levels. Future experimental research should test the effectiveness of these cooking methods for cardiovascular prevention in older adults.

Frequency of Boiled Potato Consumption and All-Cause and Cardiovascular Disease Mortality in the Prospective Population-Based HUNT Study

Few studies have assessed the association between potato consumption and mortality, especially cardiovascular disease (CVD) mortality. Our objective was to investigate the association between consumption of boiled potatoes and all-cause and CVD mortality in a Norwegian population. We used data from the population based HUNT3 study in Norway, with data on boiled potato consumption frequency in 2006–2008 from 49,926 males and females aged 20 years or above. All-cause and CVD mortality were identified during 10 years follow-up through the national Cause of Death Registry, which is virtually complete. We used Cox regression to estimate hazard ratio (HR) with a 95% confidence interval (CI) for death controlling for potential confounders, and conducted additional analyses stratified by sex, body mass index (BMI) ±25 kg/m², and age ±65 years. There were 4,084 deaths and 1,284 of these were due to CVD. Frequency of boiled potato consumption was not associated with all-cause mortality, nor with CVD mortality. Compared to those individuals who consumed boiled potatoes less than once weekly, those who reported to consume boiled potatoes 1–3 times per week had an adjusted HR (95% CI) of 1.12 (0.89, 1.41) for all-cause mortality and 1.20 (0.78, 1.86) for CVD mortality. Individuals who consumed boiled potatoes 4–6 times per week had HRs of 0.97 (0.78, 1.21) and 1.03 (0.68, 1.55), for all-cause and CVD mortality, respectively, whereas those who consumed boiled potatoes more than once daily had HRs of 1.04 (0.83, 1.29) and 1.09 (0.73, 1.63) for all-cause and CVD mortality, respectively. There was no evidence of differential associations for males vs. females, nor between people with BMI ± 25 kg/m². The associations between frequency of boiled potato consumption and all-cause mortality showed different patterns between those younger vs. older than 65 years, with a tendency of increased risk only in the oldest age group. In conclusion, frequency of consumption of boiled potatoes was not associated with all-cause or CVD mortality in the HUNT population in Norway.