The Dark Mystery of Black Olives, Ferrous Gluconate and Gluten
As you may suspect, I spend a fair portion of my time researching and investigating ingredients.
This serves several purposes; one is finding hidden gluten in foods where it may not appear obvious, especially to those new to gluten-free living.
Of course, I’ve “found” hidden gluten in some pretty unthinkable places, like my coffee cup. You can read about my last gluten oops with flavored coffee if you’re interested.
We simply can’t be too careful, can we?
That applies to scouring labels, of course, but also to choosing reliable sources of information.
This is particularly true when it comes to information about our health and the foods we eat (or avoid).
I pride myself on serving you in this area by providing my unique “Smart Nutrition Backed by Science”.
This recent reader comment on the website reminded me how important accurate information is:
“Black olives purchased in a can or jar contain gluten. The black that you see in the olive is an injected color to make them more “black”. The injected color has gluten in it!”
I didn’t approve the comment. I was afraid someone would skim the page, see the info and take it as fact.
It is false. Black olives do NOT contain gluten.
I suspect the source of this reader’s confusion is ferrous gluconate. It’s an ingredient in most black olives.
GLUconate. Like GLUten, right?
Ferrous gluconate is water soluble iron salt of gluconic acid. Gluconic acid occurs naturally in some fruits and vegetables, wine and honey.
Ferrous indicates iron. Gluconate indicates the sugar acid, as in glucose. Not gluten.
It’s an iron supplement, folks. You can get a prescription for the little black tablets from your doctor if your iron levels need a boost. (There are other forms of iron, so not every iron supplement is a gluconate, but some are.)
In addition to knowing this from a science perspective, I know it first hand; I have a genetic issue that prevents my body from storing iron. I have been on daily lifetime iron therapy for years. Learn more about Iron Deficiency Anemia here.
Of course, like many compounds, there is more than one application for ferrous gluconate.
It is used in the olive industry as a color stabilizer in black olives. It is not injected into the olives. It’s simply added to the brine in which olives are fermented.
The iron (ferrous gluconate) reacts with natural tannins in the olive skin, helping hold the rich black color and keeping it uniform.
Without it, black olives would appear chocolate brown with some color variation.
So, you got that, right?
Ferrous gluconate is not gluten. Black olives are gluten-free.
Thank goodness. Now, you can go back to enjoying those earthy little nuggets of gluten-free joy! ;)
Of course, I can’t leave it at that.
My sweet reader who asserts black olives contain gluten also says she “found out the hard way” with digestive upset and symptoms similar to having ingested gluten.
It wasn’t gluten, but science can explain what it was!
You see, according to the National Institutes of Health (NIH), digestive side effects are common with ferrous gluconate. They include heartburn, upset stomach, stomach pain, nausea, vomiting, constipation and/or diarrhea.
Keep in mind these side effects usually occur when ferrous gluconate is used as an iron supplement, not when consumed via black olives.
It is possible, however, to have an iron allergy. Signs of an allergic reaction to ferrous gluconate include hives, difficulty breathing, and facial, throat or mouth swelling. This constitutes a medical emergency and should be taken very seriously.
There’s one other thing to keep in mind when it comes to consuming ferrous gluconate.
It is derived from corn or potato acid. (Perhaps one of these was the source of my dear reader’s issues with black olives?)
For those with corn allergy or who wish to avoid corn or potato products and derivatives, no fretting!
Lindsay Olives produces ferrous gluconate free black olives (which appear a dark chocolate brown, but are no less delish!) as part of the Lindsay Naturals line. They also state on their website that all their olives are gluten-free.
(No, this is not an olive commercial. They don’t even know I’m telling you about it yet.)
There are other brands to look for, too, the next time you’re browsing the olive aisle. ;)
One last note on olives and ingredients. Olives are casein-free (dairy-free), too. The lactic acid on the ingredients list makes some people pause and wonder. It is not dairy-derived.
I’ve done the research, and shared it in my article on probiotics in June’s issue of “Food Solutions”. If you missed that one, you missed a great issue!
Alright, Honey Bunch. I think that clears up the dark mystery of black olives and gluten.
Of course, this piece did raise another question… Is ferrous gluconate derived from corn GMO-free?
Well, since about 87% of all corn in the USA is GMO, there is a very good chance it is not. And that is where we leave it until next week when we talk about GMO products and where we draw the line. Don’t miss it!!
In comments below, let me know which ingredients are you uncertain about in foods you’d like to eat, but are afraid they might contain gluten?