The Effects of Onions on Cholesterol & Blood Sugar
It's obvious that onions are more than a garnish in the United States; the National Onion Association reports that Americans eat 20 pounds of onions per capita each year. Whether you enjoy the strong flavor of raw onions or their sweetness once caramelized, you may not realize that onions also have a history of therapeutic use. Their effects on both cholesterol and blood sugar have been the focus of scientific study, but solid conclusions are still elusive.
Onions belong to the same biological category as garlic, leeks and chives. They are grown throughout the world, although they are thought to be native to Europe and Asia. Onions' healing power can be traced to the 17th century, when New World explorer Pere Marquette ate them to prevent starvation. Onions' sulfur content gives them their characteristic odor and may play a role in their health benefits.
- Onions belong to the same biological category as garlic, leeks and chives.
- Onions' sulfur content gives them their characteristic odor and may play a role in their health benefits.
Carbohydrates and Fiber in Onions
Onions contain the antioxidant called quercetin. Quercetin intake is associated with decreasing heart risks such as arterial hardening, high blood pressure and heart attack. Cholesterol accumulation contributes to clogging and hardening of the arteries. Cholesterol also is a major component of gallstones. Findings published in June 2009 in the "British Journal of Nutrition" revealed that both raw and heated onions reduced cholesterol gallstone development up to 39 percent, although the study was conducted on mice. Much of the research on onions' efficacy has been done on animals, so it's unclear how effective they may be in reducing cholesterol in humans.
- Onions contain the antioxidant called quercetin.
- Cholesterol also is a major component of gallstones.
Research on how onions affect blood sugar in humans has been more extensive. The sulfur compound called allyl propyl disulphide may increase insulin production and lower blood glucose levels. An October 2010 preliminary study published in the journal "Environmental Health Insights" found that red onion was effective at reducing blood sugar in people with diabetes. Glucose readings in type 1 and type 2 diabetics fell and remained lowered for four hours after eating. More research is needed, but these findings suggest that onion could be helpful in diabetes management.
- Research on how onions affect blood sugar in humans has been more extensive.
- An October 2010 preliminary study published in the journal "Environmental Health Insights" found that red onion was effective at reducing blood sugar in people with diabetes.
Benefits From Purple Onion Tea
Onions are a popular food throughout the world and are generally safe. Like most things that can be consumed, however, side effects exist. This is particularly a concern if you're consuming large amounts of onions daily. Symptoms associated with heartburn may worsen if you already have this condition. You may be at higher risk for an allergic reaction, such as itchy eyes and a skin rash, if you have asthma. Much of the scientific evidence regarding onions' benefits for cholesterol, blood sugar and other health concerns are still inconclusive, so don't stop taking any medications your doctor prescribes.
- Onions are a popular food throughout the world and are generally safe.
- Much of the scientific evidence regarding onions' benefits for cholesterol, blood sugar and other health concerns are still inconclusive, so don't stop taking any medications your doctor prescribes.
Carbohydrates and Fiber in Onions
Benefits From Purple Onion Tea
How to Eat Raw Onions for a Cold and Stuffy Nose
The Vitamin C in Onions
Garlic and Gallstones
Onion & Garlic for Asthma Relief
What Peppers Are Good for Lowering Cholesterol?
Does a Cut-Up Onion Clear Sinuses?
Which Fruits Lower Triglycerides?
How to Boil Onions for Soup
- "British Journal of Nutrition"; Dietary Garlic and Onion Reduce the Incidence of Atherogenic Diet-induced Cholesterol Gallstones in Experimental Mice; S Vidyashankar, et al.; June 2009
- "Environmental Health Insights"; Preliminary Study of the Clinical Hypoglycemic Effects of Allium cepa (Red Onion) in Type 1 and Type 2 Diabetic Patients; Imad M. Taj Eldin, et al.; October 2010
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- Cooking with onions without crying. University of Nebraska-Lincoln. Updated 2020.
- What is the low FODMAP diet?. Academy of Nutrition and Dietetics. Updated 2019.
- Onions. RxList. Updated 2019.
- Shock CC, Cheatham NE, Harden JL, Mahony, AC, Shock BM. Types of onions and varieties. Oregon State University. College of Agricultural Sciences. Updated 2020.
- Dowdy S. Stored properly Vidalia onions can still be around this winter. University of Georgia. College of Agriculture and Environmental Science. Updated 2019.
Previously working for the North Carolina Community College System, Rachel Morgan has been a freelance writer and editor for over six years. She has a bachelor's degree in public health as well as a master's degree in English.