Onions have been used in food for more than 3,000 years, and the vegetable was one of the earliest plants to be cultivated.
Yet, many people do not realize that nutritional values that are associated with onions, particularly when it comes to red onion’s nutritional benefits.
In fact, many people assume that red and white onions are essentially the same, or that the only difference between these two types of onion is their taste.
That isn’t true though, and red onions are a valuable and healthy addition to any kitchen.
In fact, they offer more health benefits than white onions.
Additionally, red onion can make a tasty addition to food and is easy to include in the diet, even for people who don’t particularly like the taste.
Onions also have the benefit of being exceptionally easy to store and transport.
The Red in Red Onions
The biggest difference between red and white onions is their colors.
The red comes from a group of compounds called anthocyanins.
Anthocyanins are pigment compounds and are responsible for blue, purple and red pigmentation in plants. They are also a prominent type of flavonoid.
These compounds are challenging to study, but at the same time, they offer a lot of potential for human health (1). One issue with the compounds is that they are relatively unstable, which makes them difficult to isolate and to purify (2).
This is a key reason that getting anthocyanins through food, such as from red onions, is so important.
These pigments are interesting, because they may play a key functional role, helping to contribute to the health of consumers (3).
Nutritional Elements of Red Onions
Red onion’s nutritional benefits are derived from a number of different chemicals, particularly a class of chemicals known as flavonoids.
One of these is the bioflavonoid quercetin, which is a highly effective antioxidant, helping to reverse many of the damaging impacts that can be caused by free radicals.
Antioxidants have been linked to significant health benefits, particularly as free radical activity has been linked to some of the negative elements of aging (4).
There are many different foods and compounds that have been associated with antioxidant activity, but the antioxidant levels of red onions are particularly significant (5).
Traditional medicine has also involved the use of red onion in combating gastrointestinal issues, suggesting that the compounds in the vegetable may help with stomach issues (6).
Recent research has also focused on the role that red onion may play in the treatment of type I and type II diabetes.
One study considered the outcome of red onion supplementation on people with each type of diabetes.
The study found that red onion was able to produce hypoglycemic effects, meaning that red onion may be an effective supplement for the management of diabetes (7).
The flavonoids in red onions have been strongly linked to a number of substantial health benefits.
This includes a reduction in the risk of cardiovascular disease as well as some types of cancer (8).
Likewise, there has been considerable evidence that red onion extracts have antimicrobial properties (9), which suggests that red onion may help the immune system.
This has important implications in our busy and stressful modern environment where our immune system is often strained and it can be easy to get sick.
The chemicals in red onions have also been associated with an antimutagenic action.
This term refers to the ability to limit the occurrence of mutations. This provides the compounds with the ability to reduce the risk of cancer (10).
Researchers have suggested that foods containing flavonoids may be a novel strategy for preventing cancer within the population (11).
As the prevalence of cancer continues to increase and the disease remains challenging to combat, any approach that can help to reduce the risk of cancer is certainly worth trying.
This strategy has significant benefits, particularly as red onions and other foods containing flavonoids are so widely available.
This speaks a lot about the advantages of red onions as this vegetable contains a large amount of flavonoids (12).
An additional nutritional aspect of red onions is that they have a high level of chromium. This is a trace mineral that has been positively associated with control of glucose levels.
This can make consumption of red onion particularly important for people who have problems with glucose control.
People who eat foods low in chromium can sometimes suffer from chromium deficiency.
This has multiple possible consequences, including potentially impairing control of blood sugar, and increasing the risk of type 2 diabetes as well as cardiovascular disease.
There are even some indications that a high level of chromium deficiency may act to make weight loss significantly more challenging.
Finally, red onions contain significant levels of vitamin B6 and vitamin C. Both of these vitamins are important to human health.
Eating half an onion per day might seem a little difficult, but it isn’t necessary to consume this much for most of the health benefits of red onions.
Furthermore, there is a range of different ways that red onions can be consumed, including raw in salads and sandwiches, as well as cooked in many of the dishes that white onion is used in.
For people who don’t like the way that red onions taste, or don’t like raw onions, one good trick is to include it in meals that have rich red sauces.
Many people simply replace white onions with red onions in any meal.
This can create some different tastes in food, but this isn’t necessarily a bad thing.
Sometimes variations in flavor can make food seem much more interesting, and it is certainly worthwhile when red onions offer so many significant health benefits.
When it comes to working with red onions, one of the most important aspects is ensuring the greatest health benefits.
A key way of doing this is to be careful in peeling onions. In red onions, most of the flavonoids are located in the outer layer of the onion.
Excessive peeling can significantly reduce the amount of flavonoids present, which in turn reduces the health benefits.
Like most produce, it is important to pick healthy onions.
For red onions, this involves choosing onions that are round, with dry outer skins and that look like they are clean.
Onions should be avoided if they are sprouting, have any indications of mold, have dark patches or have soft spots, these factors are an indication that the onion is decaying.
If you choose onions that show no signs of decay, then they will last longer and be fresher when they are used.
Finally, red onions should be stored in a dark and well-ventilated area, and kept away from sources of heat.
A dark cool cupboard is usually a good choice.
After all, you want to keep them in a good condition so you can enjoy them.