Researchers recently have refined grains with a higher Risk of heart disease and death. Grains such as oats, rice, barley and wheat make up around 50% of the daily caloric intake worldwide. This also applies to low- and middle-income countries, especially Africa and South Asia, according to the study authors. Whole grain products, on the other hand, tend to contain more fiber, vitamins, minerals and essential fatty acids than refined grains. Previous studies have shown that higher whole grain intake is linked to a lower risk of cardiovascular disease and death. However, no clear associations were found for refined grains.
How dangerous are refined grains to health?
To uncover such a lack of evidence, the researchers investigated the link between the intake of refined grains, whole grains and white rice with cardiovascular disease and mortality. Their results are based on data for 137,130 people aged 35 to 70 in 21 low, middle and high income countries. Participants had no history of heart disease. They took part in the prospective epidemiological study for urban and rural areas (PURE). The research team examined white rice separately from all other refined grains. This was because more than 60% of the study participants live in Asia, where rice is a staple food. At the beginning of the study, detailed information on the participants’ education, wealth, lifestyle and medical history was collected. Scientists used validated food questionnaires to assess the intake of refined grains, whole grains, and white rice.
Deaths due to cardiovascular causes or major cardiovascular events such as myocardial infarction, stroke, and heart failure were then followed over an average of 9.4 years. The researchers found that the highest category of refined grain intake (at least 350g, or about 7 servings per day) was linked to a 27% higher risk of death. There was a 33% higher risk of serious cardiovascular events compared to the lowest intake category (less than 50 g per day). A higher intake of refined grains was also linked to higher blood pressure. However, no significant associations were found between the intake of whole grain or white rice and the health risks. The results this study are likely to be robust and generally applicable to populations around the world. Reducing the amount and improving the quality of carbohydrates are therefore essential for improved health.