A diet high in red and processed meat, refined grains and sugary drinks, which are linked to increased inflammation in the body, may increase the risk of heart disease and stroke compared to a diet full of anti-inflammatory foods, according to a study published today. The Journal of the American College of Cardiology. A separate JACC study evaluated the positive effects of eating walnuts, an anti-inflammatory food, in reducing inflammation and heart disease risk.
Chronic inflammation has been shown to play an important role in the development of heart disease and stroke. Some inflammatory biomarkers, such as interleukins, chemokines and adhesion molecules, are associated with early and late stages of atherosclerosis. Previous studies have shown that diet can affect inflammation levels, but some healthy eating patterns, such as the Mediterranean diet (high in olive oil, nuts, whole grains, fruits and vegetables, and seafood and light on dairy and red/processed meat) , showed lower concentrations of some inflammatory biomarkers and lower risk of heart disease. Less research has been done on whether long-term adherence to a proinflammatory diet is associated with increased rates of heart disease or stroke.
The researchers used men and women from the Nurses’ Health Study I and II, which began in 1986 and included up to 32 years of follow-up. After excluding participants with missing dietary information or previously diagnosed heart disease, stroke, or cancer, more than 210,000 participants were included in the analysis. Participants completed a survey every four years for dietary intake.
“Using an empirically-developed, food-based dietary index to assess the level of inflammation associated with food intake, we found that dietary patterns with higher inflammatory potential were associated with increased rates of cardiovascular disease,” said Jun Li, MD, PhD. The study is lead author and research scientist in the Department of Nutrition at Harvard TH Chan School of Public Health. “Our study is among the first to link food-based dietary inflammatory indices with long-term risk of cardiovascular disease.”
The Food-Based Proinflammatory Dietary Index is based on 18 pre-defined food groups that together show the strongest association with increases in inflammatory biomarkers. After controlling for other risk factors, such as BMI, physical activity, family history of heart disease, and multivitamin use, participants who ate a proinflammatory diet had a 46% higher risk of heart disease and a 28% higher risk of stroke, compared to those who ate an anti-inflammatory diet. Inflammatory foods
Researchers recommend eating foods high in antioxidants and fiber to help fight inflammation: green leafy vegetables (kale, spinach, cabbage, arugula), yellow vegetables (pumpkin, yellow peppers, beans, carrots), whole grains, coffee, Tea and wine. Researchers recommend limiting refined sugars and grains, fried foods, soda and processed, red and organ meats. These foods are among the major contributors to the proinflammatory dietary index.
“Better knowledge of the health protection provided by different foods and dietary patterns, particularly their anti-inflammatory properties, will provide a basis for designing even healthier dietary patterns to protect against heart disease,” said Ramon Estruch, MD, PhD, senior consultant. Department of Internal Medicine, Hospital Clinic, Barcelona, Spain, and author of an accompanying editorial comment. “When choosing foods in our diet, we must be aware of their proinflammatory and anti-inflammatory potential!”
Including walnuts in the diet reduces inflammation
In another study, researchers evaluated how including walnuts in a person’s normal diet would improve inflammatory biomarkers. Previous studies have shown that regular nut consumption is associated with lower heart disease risk and lower overall cholesterol; However, there has been limited research linking eating nuts to less inflammation in the body. A total of 634 participants were assigned either a diet without walnuts or a diet with regular walnuts (about 30-60 grams per day). After a two-year follow-up period, those who ate foods with walnuts had significantly reduced levels of inflammation in 6 out of 10 inflammatory biomarkers tested.
“The anti-inflammatory effects of long-term consumption of walnuts demonstrated in this study provide novel mechanistic insight into the benefits of walnut consumption on heart disease risk beyond cholesterol reduction,” said Montserrant Cofan, PhD, lead author of the study and a researcher at the Biomedical Research Institute of August Pi i Sanir in Barcelona, Spain.