November 02, 2020
3 min read
This study was supported by grants from the NIH. Li reports she received grants from the National Institute of Diabetes and Digestive and Kidney Diseases and the Boston Nutrition Obesity Research Center. Please see the study for the other authors’ relevant financial disclosures. Estruch and the other authors of the editorial report no relevant financial disclosures.
High intake of proinflammatory foods such as red or processed meats and refined carbohydrates was associated with a 38% increased risk for CVD and a poor lipid profile, researchers reported.
“Using an empirically developed, food-based dietary index to evaluate levels of inflammation induced by diet, we found that a higher inflammatory potential of habitual dietary patterns was associated with an increased incidence of total CVD, CHD and stroke in U.S. men and women,” Jun Li, MD, PhD, research scientist in departments of nutrition and epidemiology at Harvard T.H. Chan School of Public Health, and colleagues wrote.
“Diet plays an important role in CVD development, and the underlying mechanisms are suggested to partially involve modulation of inflammation,” the researchers wrote. “Our study is among the first to link a food-based dietary inflammatory index with CVD incidence.”
For this analysis, published in the Journal of the American College of Cardiology, researchers administered food frequency questionnaires every 4 years to 74,578 women from the Nurses’ Health Study (NHS), 91,656 women from the NHSII and 43,911 men from the Health Professionals Follow-up Study. They evaluated the inflammatory potential of the participants’ diet using a food-based empirical dietary inflammatory pattern score. All participants were free from CVD at baseline.
Overall, investigators reviewed 5,291,518 person-years of follow-up and noted 15,837 cases of CVD. These incidents included 9,794 cases of CHD and 6,174 strokes.
Individuals were stratified into quintiles based on the median empirical dietary inflammatory pattern (EDIP) score, quintile 1 being the lowest and 5 being the highest.
“EDIP shares only a few dietary components with other indices (thus explaining their modest correlations) and has a greater emphasis on unique foods associated with inflammation,” the researchers wrote. “For instance, it recommends higher intakes of green leafy vegetables, yellow vegetables, whole grains, coffee, tea and wine, which are rich in anti-inflammatory compounds (eg, vitamins, carotenoids, flavonoids and fiber). It also limits intakes of the proinflammatory refined grains and restricts processed, red and organ meat (vs. others that limit total red/processed meat).”
Increased risk for CVD
Individuals in higher quintiles were more likely to report elevated BMI, lower physical activity and have a family history of CHD.
After adjustment for use of anti-inflammatory medications and CVD risk factors, researchers found that participants in the highest quintile for dietary inflammatory potential, indicated by EDIP scores, experienced increased risk for CVD (HR = 1.38; 95% CI, 1.31-1.46), CHD (HR = 1.46; 95% CI, 1.36-1.56) and stroke (HR = 1.28; 95% CI, 1.17-1.39) compared with those in the lowest quintile.
The findings were consistent for between sexes and cohorts (P for difference = .98).
Moreover, the association between dietary proinflammatory consumption and CVD risk was robust even after adjustment for alcohol consumption, pack-years of smoking, lipid-lowering or antihypertensive medications or sodium intake and BP.
Poorer lipid profile
In a secondary analysis, researchers observed a positive association between EDIP score and levels of systemic inflammatory biomarkers such as C-reactive protein, interleukin-6 and tumor necrosis factor receptor 2 (P < .001).
Additionally, investigators found a strong positive association between dietary proinflammatory consumption and levels of tumor necrosis factor receptor 1, soluble intercellular adhesion molecule-1 and leptin and an inverse association with levels of adiponectin (P < .001).
“When examining the cardioprotective mechanisms of anti-inflammatory foods, we should recall that most proinflammatory cytokines that increase with the inflammatory diet or decrease ensuing walnut consumption are involved in the formation of atheroma plaque,” Ramon Estruch, MD, PhD, senior consultant of in the department of internal medicine at Hospital Clínic de Barcelona, Spain, and colleagues wrote in a related editorial. “Like-wise, some dietary patterns and key foods (olive oil, nuts, fruit, vegetables and wine) have pleiotropic immunomodulatory effects on interleukins (ILs), chemokines and adhesion molecules that are associated with the early and late stages of atherosclerosis, including those related to atheroma plaque instability (eg, metalloproteinase-9 and IL-10, -13 and -18).”