People who consume more inflammation-promoting foods are at increased risk of cardiovascular disease (CVD), new findings show. Adults in the top quintile based on their diet's proinflammatory potential had higher incidences of CVD, coronary heart disease (CHD) and stroke compared to those in the bottom quintile, Dr. Frank B. Hu of Brigham and Women's Hospital and Harvard Medical School in Boston and colleagues found. "Reducing the inflammatory potential of diets may provide an effective strategy for CVD prevention," they conclude in the Journal of the American College of Cardiology (JACC). The investigators developed and validated an empirical dietary inflammatory pattern (EDIP) score, based on intake of 18 food groups associated with levels of inflammatory markers. Proinflammatory food groups include red meat, processed meat, organ meat, refined carbohydrates and sweetened beverages, while anti-inflammatory foods include green leafy vegetables, dark yellow vegetables, whole grains, fruit, tea, coffee and wine. In the new study, Dr. Hu and his team compared EDIP score to CVD risk in 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. Over nearly 5.3 million person-years of follow-up, 15,837 new cases of CVD were documented, including 9,794 cases of CHD and 6,174 strokes. After accounting for use of anti-inflammatory drugs and CVD risk factors, the authors found that study participants in the top vs. bottom quintile based on EDIP score had a 38% higher risk of CVD, a 46% higher risk of CHD and a 28% higher risk of stroke (all P<0.001). Analysis of a subset of study participants showed an association between higher EDIP and higher plasma triglycerides, lower high-density lipoprotein cholesterol, and a small decrease in total cholesterol. "Our study suggests that modulation of chronic inflammation may be a potential mechanism linking dietary patterns with CVD. Future studies are warranted to replicate our findings, to confirm the causal relationship, and to examine the detailed inflammatory mechanisms through which diet/specific foods are associated with CVD risk," Dr. Hu and colleagues conclude. A research letter also published in JACC found 324 healthy elders randomized to consume 30 to 60 grams of walnuts a day (about 15% of total energy) had reduced concentrations of six out of 10 inflammatory biomarkers at two years compared to their peers who didn't eat walnuts. "Eating walnuts is scientifically proven to lower LDL-C, and now it is encouraging that it can also lower inflammation, another risk factor for CVD," Dr. Sujatha Rajaram, a professor at the Center for Nutrition and Healthy Lifestyle at Loma Linda University, in California, told Reuters Health by email. The center is running the ongoing Walnuts And Healthy Aging study with Hospital Clinic in Barcelona. "Patients look for simple messages or small changes that they can make to their diet that can benefit them. Including walnuts in their usual diet is a simple message that physicians can suggest to their patients that either have high cholesterol or other CVD risk factors or have a family history of CVD," he added. The California Walnut Commission (CWC) helped fund the study. Dr. Rajaram reports receiving institutional research funding from the CWC, and other study authors report financial relationships with the group. "By being the largest and longest nut trial to date, this study had enough power to overcome the limitations of previous studies that assessed the effects of nuts on inflammation with inconclusive results," Dr. Ramon Estruch of the Instituto de Salud Carlos III in Madrid and colleagues write in an editorial accompanying the studies. "Regular consumption of walnuts, like that of other nuts, has been consistently linked to reduced CVD outcomes in prospective studies and to cholesterol lowering in RCTs." The editorialists conclude: "A better knowledge of the mechanisms of health protection by the different foods and dietary patterns, mainly their anti-inflammatory properties as gleaned from the 2 reports editorialized here, should provide the basis for designing healthier dietary patterns and upgrading their protective effects against CVD." Dr. Hu was not available for an interview by press time. —Anne Harding Source
