- Chronic low-grade inflammation in the body linked to several diseases including heart disease.
- A diet that increases inflammation within the body could increase risk of first heart attack
- Optimization and switching to healthier diet is critical to reducing heart attack risk.
A diet that increases levels of inflammation within the body is considered unhealthy and could increase the risk of heart attack according to a prospective case-control study undertaken in two population-based cohorts of the Northern Sweden Health and Disease Study (NSHDS).
Aim of the StudyThe authors of the study believe that diet plays a far more critical role in deciding the heart health than we think. They aim to establish the role of a pro-inflammatory diet in increasing the risk of a first heart attack in the current long-term prospective case-control study.
Details of the StudyThe current study was a prospective case-control study from the Northern Sweden Health and Disease Study (NSHDS).
The NSHDS consists of 2 population cohorts namely the Västerbotten Intervention Programme (VIP) and the Northern Sweden Monitoring Trends and Determinants in Cardiovascular Disease (MONICA). Both are ongoing projects involved in the collection and maintenance of health history and lifestyle data from the population in Northern Sweden.
- The study population from both cohorts together included nearly 100,000 participants ranging from 25 years to 75 years.
- The participants under VIP and MONICA programs, during their visits to the health centers had been given a validated food frequency questionnaire (FFQ) to fill regarding the details of food intake and dietary habits.
- The current study team analyzed data collected over 20 years from 1986-2006.
- The primary end-point was the occurrence of confirmed first heart attack (myocardial infarction), both fatal as well as non-fatal during the same period. Cases were identified by linkage of the NSHDS database to various disease registries such as diabetes and heart disease.
- The research team identified 1389 (1057 men and 332 women) confirmed cases of first heart attack and compared their data and dietary inflammatory index (DII) scores with over 5000 age and sex matched controls.
Findings of the StudyFrom the data, dietary inflammatory index (DII) scores of both groups were calculated and relationship to first heart attack risk was estimated. DII scores ranged between −4.16 (most anti-inflammatory) to +5.04 (most pro-inflammatory), with a mean in the control group of 0.89 (1.66) in men and 1.08 (1.59) in women.
- Males with the highest DII scores (most pro-inflammatory diet), showed a significantly greater risk of first heart attack compared to men with the lowest DII scores.
- Interestingly, there was no association between DII scores and heart attack risk in women.
- There was no significant relation between DII and body mass index (BMI) in men, but obese (BMI >30) women were found to have higher DII scores.
- Persons with higher DII scores were more likely to have lesser education, higher smoking rates, were more likely to be sedentary and in men, was associated with higher serum total cholesterol concentrations and higher systolic blood pressure than individuals with lower DII scores.
What is Dietary Inflammatory Index?Based on an extensive review of the scientific literature and publications, 45 food parameters have been identified and the inflammatory potential of each parameter is estimated depending on it increased (+1) decreased (-1) or displayed no effect (0) in increasing the blood levels of a defined set of inflammatory bio-markers (IL-1β, IL-4, IL-6, IL-10, TNF-α and C-reactive protein).
For each parameter, data was collected from around the world that helped to arrive at global mean intakes and standard deviations. From these values, the final DII score for each food parameter was calculated.
The DII score could vary from −8.87 (most anti-inflammatory to +7.98 (most pro- inflammatory).
Relationship Between DII and Heart Disease
- Various scientific studies have established the role of inflammation in the evolution of atherosclerosis, an important change seen within blood vessels that increases the risk of heart attack and stroke.
- Prior studies have also established that chronic low-grade systemic inflammation increased the risk of heart disease. These observations have been supported by diagnostic imaging as well as measurement of inflammatory bio-markers in the blood.
Pro-inflammatory and Anti-inflammatory FoodsIn general, a refined or processed diet high in sugar and fat promotes inflammation. A fiber rich diet, low in fat and sugar has been found to be associated with lower levels systemic inflammation, and a low heart disease risk.
|Inflammatory Foods (Avoid)||Anti-inflammatory foods (Eat more of these)|
|White bread and bakery products||Fruits - berries, cherries, oranges, apples, and pears|
|Red meat (steaks and burgers)||Green and leafy vegetables - Kale, spinach, cabbage|
|Processed meat (sausages hotdogs)||Nuts - almonds, walnuts|
|Fried foods eg French fries||Fish - tuna, salmon, mackerel, sardines|
|Sweetened beverages, soda||Tomatoes|
|Margarine lard and vegetable shortening||Olive oil|
- Dietary Inflammatory Index and Incidence of Cardiovascular Disease in the SUN Cohort - (http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0135221)