Higher intakes of fiber, total vegetables, and fruits may attenuate the risk of all-cause and cause-specific mortality: findings from a large prospective cohort study

BACKGROUND

Although studies have reported an inverse association between fruits, vegetables, and fiber consumption and all-cause and cause-specific mortality, the issue remains incompletely defined in the Middle Eastern population.

AIMS

The current study aimed to investigate the association between dietary fiber, fruit, and vegetable intake and all-cause and cause-specific mortality.

METHODS

A total of 48632 participants (mean age = 52years), 57.5% (n = 27974) women and 42.5% (n = 20658) men, were recruited from an ongoing large-scale prospective cohort study (the Golestan Cohort Study (GCS)), in the north of Iran. Using a validated semi-quantitative 116-item food questionnaire, dietary intakes were collected. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) of all-cause and cause-specific mortality were reported.

RESULTS

After approximately 14 years of follow-up, 10,774 deaths were recorded. In the fully adjusted model, compared to those in the lowest quintile of intake, those in the second and third quintiles of dietary fiber intake had a 7%-10% reduction in risk of all-cause mortality, and a 15%-17% reduction in the risk of mortality from other causes. Increasing consumption of fruits was also associated with a decreased risk of mortality for all-cause mortality by 9%-11%, and all cancer by 15-20%. Further, those in the third and fourth quintiles of vegetables intake had 11%-12% lower risk for CVD mortality.

DISCUSSION

The results from the GCS further support the current recommendations on following a healthy diet containing proper amounts of fiber, vegetables, and fruits, as health-protective dietary items.

CONCLUSIONS

Higher intake of dietary fiber, fruits, and vegetables has the potential to reduce both overall and cause-specific mortality rates. However, additional cohort studies with larger sample size and long-term follow-up durations are required to establish these findings.

Dietary quality using four dietary indices and lung cancer risk: the Golestan Cohort Study (GCS)

PURPOSE

The lung cancer incidence in Iran has increased almost ten times over the past three decades. In addition to the known causes such as smoking and certain occupational exposure, dietary quality has been suggested to play a role in lung cancer. We aim to explore the association between dietary pattern and lung cancer risk among a Middle East population.

METHODS

Data came from Golestan Cohort Study which included 48,421 participants with 136 lung cancer cases diagnosed during a median follow-up of 12 years. Multivariable Cox proportional hazards regression models were used to calculate the HRs and 95% CI of lung cancer risk by tertile of the four dietary index scores-the Health Eating Index (HEI)-2015, the Alternative Health Eating Index (AHEI)-2010, the Alternative Mediterranean Diet (AMED), and the Dietary Approach to Stop Hypertension (DASH)-Fung.

RESULTS

A higher DASH-Fung score was inversely associated with risk of lung cancer after adjusting for potential confounders (tertile three vs. tertile one: HR = 0.59 (0.38-0.93); p for trend = 0.07), and pinteraction with smoking was 0.46. Similar findings were observed among current smokers with the HEI-2015 score (tertile three vs. tertile one: HR = 0.22 (0.08-0.60): p for trend < 0.01), and pinteraction between smoking and the HEI-2015 score was 0.03.

CONCLUSION

In the GCS, consuming a diet more closely aligned with the DASH diet was associated with a reduced risk of lung cancer, which appeared to be independent of smoking status. There was also an inverse link between the HEI-2015 score and lung cancer risk among current smokers. Our finding is particularly important for the Middle East population, as diet may play an important role in cancer prevention and overall health.

Circulating plasma fatty acids and risk of pancreatic cancer: Results from the Golestan Cohort Study

BACKGROUND & AIMS

Pancreatic cancer (PC) with a dismal prognosis is considered as a fatal malignancy, attracting the scientists' attention to study its causes and pathogenesis pathways. Given the lack of enough evidence and conflicting findings about the association of PC risk with plasma fatty acids, we aimed to explore the associations of circulating plasma fatty acids with the risk of PC in a cohort study.

METHODS

From about 50,000 subjects participated in this cohort study in 2004-2008, fifty incident cases of PC were recruited and 150 controls matched by age, sex and residence place (urban/rural) were randomly selected. The plasma fatty acids composition was measured by gas chromatography with Flame Ionization Detector (GC-FID) in plasma samples collected at the baseline of cohort study. Multivariable conditional logistic regression was used to estimate OR (with 95% CI) of PC risk associated with plasma levels of fatty acids considering known potential risk factors for PC.

RESULTS

Our findings showed that total saturated fatty acids and total industrial trans fats were not associated with the risk of PC; whereas, statistically significant inverse associations were found between high plasma levels of total mono-unsaturated fatty acids (MUFAs), omega-3 and ruminant trans fatty acids with the risk of PC [OR_Q1-Q4 = 0.31 (0.11-0.89), OR _Q2-Q1 = 0.30 (0.10-0.91) and OR_Q2-Q1 = 0.15 (0.04-0.49), respectively]. Omega-6 fatty acids especially high plasma levels of Arachidonic acid was positively associated with the risk of PC [OR_Q1-Q3 = 11.07 (3.50-35.02)].

CONCLUSION

Except for the plasma circulating whole fats, the levels of different classes of fats may significantly change pancreatic cancer susceptibility. Unsaturated fatty acids including omega-3-PUFA and MUFA are considered as protective biomarkers in PC prevention. On the contrary, omega-6-fatty acids are positively associated with the risk of PC.