We all know how important onions are for cooking, but their many beneficial properties are less well-known, from their anti-hypertensive and diuretic qualities to protecting the cardiovascular system.

A member of the Liliaceae family, onions are 90% water and the remaining part is carbohydrate, protein, fibre, vitamins and minerals. Thanks to their bold flavour, which can add personality to any recipe, and their great versatility when cooking, they are one of the most popular and frequently used vegetables in cooking all around the world. Whether red, white or brown, onions have the same nutritional characteristics, although each type adapts better to specific culinary uses. For example, white onions generally have a stronger flavour and are traditionally used as a base for sauces and mirepoix; while brown onions are particularly suitable for dishes that take a long time to make, such as broths, vegetable soups and stews; finally, red onions are usually more delicate and crunchy – although there are also strong-flavoured varieties – this is why they are also perfect for eating raw in sandwiches, salads and tartare dishes, but also for grilling (check out this potato salad with red onions). Read our report on Cipolla Rossa di Tropea Calabria IGP, the queen of red onions.

Used ever since ancient times as a remedy even against the flu (although there is no scientific evidence to support this belief), they are a food packed with properties that can help keep certain bodily functions balanced. For example, flavonoids give this vegetable anti-hypertensive and detoxing properties. They notably include quercetin, a flavonoid that regulates cholesterol and triglyceride levels in the blood, helping protect the cardiovascular system. Onions also enjoy digestive properties thanks to the presence of enzymes that stimulate the metabolism and, at 40 calories per 100 grams, they are particularly recommended for low-calorie diets.

However, these nutritional properties are susceptible to changes depending on the cooking method. In particular, phenolic and sulphur compounds are not heat-resistant. To keep the nutrients intact, it is therefore best to eat them raw, in rich salads or delicious side dishes, or seared, a process that will soften their strong aftertaste.

The information in this article is for general purposes only and is no substitute for an expert’s opinion. For a balanced diet suited to meet your specific needs, it is a good idea to trust the advice from a nutritionist or your doctor. 

Image: Canva