Research shows that compounds called flavonoid reduces the preliminary risk of heart disease. We should eat foods that are rich in flavonoid compound. Onion is one among them.
An Institute of Food Research team focused on one of the compounds, quercetin, which is found in tea, onions, apples and red wine. Those foods were shown to help prevent the chronic inflammation which can lead to thickening of the arteries.
The research found that, in the case of one inflammatory process, a lower dose of the compounds – achievable by eating 100g to 200g of onions – actually had a bigger impact.