What have randomized, controlled human trials found about the ways we can benefit—or not benefit—from eating onions?
Onions can be a good source of antioxidants, which, interestingly, are concentrated in the outer layers under the papery skin. White onions, for example, contain more than ten times the antioxidants in the outer layer compared to the inner core. Unfortunately, many people discard the highly nutritious outer layers, “thereby losing an important part of the antioxidant content.” In general, yellow onions have more antioxidants than white onions. Red onions beat them both, based on three different antioxidant testing methods, as seen at 0:39 in my video Do Onions Benefit Testosterone, Osteoporosis, Allergies, and Cancer?
While red onions are actually a little better, yellow and white onions are no slouches, containing high levels of antioxidants. We know they are nutritious, but are there any clinical benefits to eating onions? There are all kinds of articles in the medical literature that talk about miraculous benefits, but where are these claims based?
For example, there is a review that purports to have evidence that testosterone levels in men are improved by onions, but the researchers were referring to a similar study of the effects of onion juice after testicular maturation in rats. Who cares what happens after a rat’s testicle is rotated 720 degrees counterclockwise? (Except for a mouse.) You don’t know what happens to people until you test people. It was only then that it was discovered that onion extract does not seem to affect men’s testosterone.
What about bone health? Apparently, older white women who ate onions at least once a day had 5% more bone density than women who ate onions more than once a month. Now, 5% may not sound like much, but that improvement in bone density could mean a reduction in hip fracture risk of more than 20% if, indeed, it is cause and effect.
Taking onions every day for four weeks caused a big bump in the bones. This could lead to a safe, effective, and cost-effective way to treat osteoporosis in mice—you guessed it. Another rat study!
Great progress has been made in treating osteoporosis with drugs, but they have the potential to have serious side effects, so scientists have focused their attention on natural remedies. In one study, researchers chose people to drink onion juice or a placebo onion juice for 8 weeks. The improvement was marked by a marker of bone health; However, they did not actually follow the participants long enough to compare osteoporosis rates.
Do shallots show anti-allergic activity or provide any therapeutic effects to relieve a runny nose? Sixteen patients were randomly assigned to the antihistamine group or the group that received antihistamines and capsules containing dried shallot powder. It seems that the shallot group did better after four weeks, but there was no significant difference in the total number of symptoms between the two groups. So, another #onionfail.
How about testing the effects of eating fresh yellow onions to try to reduce the toxic effects of a chemotherapy drug called doxorubicin in breast cancer patients? Unfortunately, no significant benefit has been found in reducing damage to the liver or heart. But eating fresh yellow onions was found to help reduce high blood sugar levels and insulin resistance in breast cancer patients during doxorubicin-based chemotherapy. The drug is not only toxic to the liver and heart—it may contribute to insulin resistance.
Therefore, researchers conducted a randomized, triple-blind, controlled clinical trial in which patients ate a whole onion a day or a third of an onion a day for eight weeks. What’s going on? The high-dose onion group experienced a significant decrease in blood sugar and insulin resistance compared to the low-dose group. Levels went up in the low dose group but down in the high dose group, as you can see below and at 4:28 in mine video.
So, make onion your friend. What’s the worst that could happen—a little onion breath and body odor?
Doctor’s Note
What else can we do about breast cancer? See related posts below.
