Onions contain a significant amount of flavonoids. However, this content is depleted if the skin is peeled or cut into slices. Moreover, cooking methods also affect flavonoid content. Boiling reduces flavonoid content while microwaving has less impact. Fryng, however, results in the greatest loss of flavonoids.
In vitro antioxidant activity
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Studies have demonstrated that the flavonoids in onions exhibit potent antioxidant activity. The antioxidant activity of onions was characterized by a dose-response relationship. The higher the concentration of onion extract, the greater its antioxidant activity. In vitro tests showed that onion flavonoids produced an increase in reduction force compared to BHT.
It has been suggested that phenolics, which are the compounds responsible for plant antioxidant activity, may be beneficial to the human body. Onion extracts were able to enhance antioxidant activity in mice fed with a diet high in fat. Although these results are preliminary, they suggest that dietary onions may have important applications as natural antioxidant agents in high-fat diets.
Effects on hepatic and renal function
Effects of onions on hepatic function and renal function were studied in two flocks of mature breeder geese. A sudden increase in mortality was observed in both groups. The necropsy of the dead birds revealed a pale epicardium, swelling of the liver and spleen, and accumulation of sanguinous fluid. Hepatocytes also showed vacuolation and hemosiderin.
In the animal model, the effects of onion and garlic on the liver were studied. The results showed that dietary intake of garlic and onions alleviated the symptoms of hyperlipidemia and steatosis. The two oils also had an anti-inflammatory effect.
Effects on eosinophil and lymphocyte counts
A study in mice found that topical application of onion extract significantly reduced inflammatory cytokine levels and serum IgE levels. It also reduced the levels of IL-5, IL-10, IFN-g, and IL-13. These results suggest that onions may have anti-inflammatory and anti-allergenic properties. Further, these compounds also reduced IL-13 and IL-4.
Onions are a potent source of flavonoids, which have anti-inflammatory properties. In addition, onions contain steroid saponins and sapogenins, such as b-chlorogenin. In addition, onion extracts can inhibit the inflammatory response in cells by inhibiting the activity of certain genes.
Effects on blood sugar
A new study shows that onions may have beneficial effects on blood sugar levels and can help people with diabetes. Researchers conducted studies on rats to test the effectiveness of onion-based diets and found that onions reduced blood glucose levels by 50%. The findings were presented at the 97th annual meeting of the Endocrine Society in San Diego, California, on August 25.
Onions contain several anti-diabetic compounds that regulate blood sugar levels. These substances are called quercetin and sulfur compounds. Because of their low GL and GI, onions can be a great choice for people with diabetes, because they do not cause a spike in blood sugar levels. However, before incorporating onions into your diet, it's important to consult with your doctor.
Effects on weight
Onions contain phytochemicals, which are natural compounds that interact with the human body to provide health benefits. These compounds are called flavonoids, and they may help to lower the risk of type 2 diabetes, cardiovascular disease, and Parkinson's disease. One important flavonoid in onions is quercetin. This compound increases good cholesterol levels and may boost overall health.
In a recent study, subjects were given nine grams of quercetin-rich onion powder every day, while maintaining their normal diet and exercise. The study found that subjects with low HDL cholesterol had less visceral fat and improved liver function. Other studies have found that onions may help prevent obesity, reduce the symptoms of bladder infections, promote prostate health, and lower blood pressure. Furthermore, some evidence suggests that onions may have anti-cancer properties.
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