The Virtues of Vinegar

(We'll return to the cancer series in a few days.)



I am going to list several popular condiments:

Ketchup, mustard, mayonnaise, salsa, Worcestershire sauce, steak sauce, BBQ sauce, pickle relish, hot sauce, and The Oatmeal’s beloved Sriracha.

All of these items, with their diverse flavors and wide range of foundational ingredients, have one thing in common.

Tomatoes?  No.

Oil?  No.

Chili peppers?  Nope.

Hint: It’s VINEGAR!! (Okay, so that was more than a hint.)

It’s true: I challenge you to go to the supermarket and take a good look at the condiments. You will see vinegar listed in the ingredients in almost all of them, and that’s not even taking into account using various forms of vinegar, itself, as a condiment or critical component of salad dressing: apple cider vinegar, balsamic, red wine, champagne, sherry vinegar, and, of course, no proper fish & chips meal would be complete without a generous splash of malt vinegar to go with the newspaper-wrapped, deep-fried deliciousness.

Apart from these modern condiments, which we use on everything from hot dogs at the ballpark, to corn chips on Super Bowl Sunday, to brats at Oktoberfest (not to mention a snazzy new Sriracha beer!), vinegar has been part of traditional ethnic cuisines around the world for centuries. Of course, we can’t assume that an ingredient or culinary technique is beneficial merely because it’s been employed by many disparate groups for a very long time, but we ought to at least give that possibility some consideration. Some traditions deserve to be mothballed to history (footbinding, anyone?), but when it comes to culinary and gastronomic approaches that persist, there’s probably some good reasons lurking behind them. Perhaps the cooks of yesteryear knew something we don’t?

For a while now, I have been promising (threatening?) to write a post about my newfound love for vinegar, so here goes. And instead of writing shorter blog posts, like I have also been promising, it seems I've gone in the opposite direction with this one. It's long. But that's okay. Take your time and read it in stages if need be. It'll still be here when you get back. If you're a bored-to-death cubicle dweller and I've given you a way to kill ten minutes, you're welcome. (*Insert smiley face.*)

In poking around the interwebs for a bit, I’ve come across some very interesting things about vinegar. This humble, acidic liquid has some surprising and impressive benefits, and there’s a fairly substantial amount of research to back most of it up. (Plus common sense, which too often gets lost in the endless debates over nutritional minutia. Sometimes, there’s nothin’ better than just using your noggin to put two and two together.)

  

We will look at four properties of vinegar in our love-fest ode to this underappreciated ingredient:

1. Digestive aid
2. Antimicrobial
3. Blood sugar regulation
4. Mood booster

We’ll start with the obvious ones and work our way toward the more surprising things. 

DIGESTIVE AID

Like I said, traditional ethnic cuisines all over the world frequently include some type of vinegar and/or pickled foods with their meals: kimchi, daikon radish, sauerkraut, cortido, pickled cucumbers and relish, chutney, vinaigrette dressing, cornichons, and, of course, the freakishly pink pickled ginger that comes with sushi and sashimi. (Seriously…what’s up with that color? Last time I looked, ginger root was not pink.)

Most of the things I listed are, of course, delicious. But is that the only reason these things were consumed, or did those ancient cooks know that vinegar brings something to food besides a bright tang for the tongue?

It’s not hard to connect the dots between vinegar and better digestion. After all, what makes vinegar vinegar is acetic acid. (Molecular formula CH₃COOH.) And as we discussed way back in my series on digestion, vinegar is a digestive aid because it’s acidic. Since many forms of indigestion are actually a result of too little stomach acid, rather than too much, throwing a little extra acid down the hatch can certainly help. (Yes, you read that correctly: people with “acid reflux” usually have insufficient stomach acid, rather than an excess.) Even before anyone had ever heard of HCl, it probably wasn’t difficult to observe that when acidic foods or condiments were consumed, digestion went a little more smoothly. (Especially back in the days before Facebook and smartphones, when there wasn’t a whole lot to do after a big meal except sit around and think about how your stomach was feeling.)

You’ll notice one of the “tags” I applied to this post is “supplements.” I think we can agree that, in a way, we can consider vinegar a supplement. (If they sell HCl and digestive enzyme supplements, why not think of vinegar in the same vein?)

Now, whether the consumption of pickled foods was the cart or the horse, I’m not sure. But in thinking about it from a historical perspective, it seems likely that foods were preserved via fermentation and pickling first, and after people were eating them on a regular basis, they noticed that there were fewer incidents of digestive upset. They were probably not initially seeking a remedy for the occasional heartburn or upset stomach and experimented until they stumbled upon pickling.

I say this because pickling is a very effective food preservation technique. (It is why we have pickles, after all. Soaking in a vinegar & salt brine was a way to preserve cucumbers.) Even foods that are fermented will eventually end up “pickled.” This is why wine can “go bad” – the grape juice is, of course, fermented into alcohol, but let the alcohol keep going, and you will end up with vinegar. In fact, this is where the word “vinegar” comes from: vin aigre, or “sour wine.”

It’s the same reason there have been recalls on commercially bottled kombucha in the past—let your ‘booch ferment a little too long, and you end up with alcohol. And let that go too long, and you end up with something that smells and tastes like apple cider vinegar. (Sadly, I know this from personal experience. Yes, I still drank it, and it was still yummy.)

ANTIMICROBIAL

To distinguish between fermentation and pickling, fermented foods are generally “alive” – the enzymes and bacteria in them are alive and active. (Think of the “live and active cultures” claim you see on yogurt containers.) Pickled foods are made with vinegar, which kills microbes. In fact, the antimicrobial properties of vinegar are the reason why it’s used to preserve food—so nothing will grow in it. (Have you ever been down south and gone to a gas station and seen those scary looking jars of pickled pigs’ feet or hard boiled eggs in day-glo pink beet juice? [I’ve also seen these in rural Pennsylvania, in Amish country.] Vinegar at work.) Either way, fermentation and pickling are both food preservation techniques, and they both have their benefits.

When we think of the antimicrobial properties of vinegar, it becomes pretty interesting (or maybe confusing) that we are instructed to refrigerate (after opening) condiments that contain vinegar. After all, vinegar itself doesn’t require refrigeration. (You probably keep yours in a cabinet or pantry at home, right?) Think about it:  restaurant chains typically leave ketchup, mustard, and steak sauce on the table at all times, for customers’ convenience. They sit out all day (and all night, in the case of 24-hour places), and they don’t go bad. I will assume that they get refilled frequently from larger supplies that are refrigerated, and that if the same ketchup, mustard, etc., were sitting out for days at a time, it eventually would go bad. Still, it’s surprising, considering the vinegar content. I can only guess it’s because it’s not straight vinegar, and maybe something else in it would start to rot? (If there are any food chemists reading this, contact me!)

Before we move on to the third cool thing about vinegar, here’s a really neat bit of info you can use at your next family reunion: Y’know all those horror stories of food poisoning via picnic potato salad left out on a hot day? Guess what? It’s not the mayonnaise that goes bad; it’s the potatoes! It’s true! The mayonnaise contains enough vinegar/acid to keep the bad bugs from proliferating in it. The potatoes, on the other hand, are a bacterial amusement park. (If you happen to check out that second link, scroll down to “Keeping potato salad safe.”)

Also: vinegar’s not just for eating, y’know. Another way we take advantage of its antimicrobial action is as a household cleaner. Yep, distilled white vinegar is a very versatile and non-toxic household cleaner. (Well, not toxic to us, that is. Toxic to the microbes it kills, yes. That’s kinda the whole point.) You can spray down your counter with it, add a few splashes to your white laundry, and do lots of other nifty stuff you can learn about from this book. Some people even use apple cider vinegar as part of an all-natural hair care strategy, a.k.a. the “no 'poo” method. (No shampoo, that is.)

BLOOD SUGAR REGULATION

 

The third virtue of vinegar is its influence on blood sugar regulation. That’s right: vinegar has some fairly impressive effects when it comes to moderating postprandial glucose and insulin levels. (To all you nutrition novices out there, postprandial is a fancy word for “after a meal.”) There is a surprising amount of scientific literature available on this subject. Here is a sampling of papers I’ve read, my summaries of which will follow:

• Vinegar reduces postprandial hyperglycaemia in patients with type II diabetes when added to a high, but not to a low, glycaemic index meal.
• Examination of the antiglycemic properties of vinegar in healthy adults.
• Acetic acid suppresses the increase in disaccharidase activity that occurs during culture of caco-2 cells.
• Vinegar supplementation lowers glucose and insulin responses and increases satiety after a bread meal in healthy subjects.
• Vinegar decreases postprandial hyperglycemia in patients with type 1 diabetes.
• Vinegar co-ingestion does not improve oral glucose tolerance in patients with type 2 diabetes.
• Delayed gastric emptying rate may explain improved glycaemia in healthy subjects to a starchy meal with added vinegar.
• Effect of apple cider vinegar on delayed gastric emptying in patients with type 1 diabetes mellitus: a pilot study.
• Vinegar improves insulin sensitivity to a high-carbohydrate meal in subjects with insulin resistance or type 2 diabetes.

Do you see that list? I mean, vinegar and blood sugar regulation? Who knew?! Turns out there’s really something to it.

In planning this post, I was initially going to break down each study and share the relevant points with you, but I’ve since realized that would be overkill. (Not to mention my promise to write shorter posts, which I am obviously constitutionally incapable of doing. Exhibit A: every single post I've written since making that promise.) You have the links; you can check them out on your own if you are so inclined. (If there are any you really, really want to read, but can’t access the free full text, contact me.)

WHAT VINEGAR DOES

As all research studies do—especially those involving human beings and food—each of the studies has weaknesses. None of them are terrible, though, and I think they all provide at least some solid data to give us some useful takeaways. Taken collectively, the studies listed above included people completely free of medication, as well as some on exogenous insulin and/or oral glucose control aids; people ages 21-79; and with BMIs ranging from approximately 21-34. So we have pretty wide ranges of ages, body sizes, and medication status, which is nice, because the data weren’t limited to, say, über-healthy young people on the thinner side. The different studies employed distilled white vinegar, apple cider vinegar, raspberry vinegar, and wine vinegar (not specified as to red or white), so we also know the effects aren’t unique to one specific type. Studies used vinegar ranging from 4% to 6% acetic acid. (When you purchase a bottle of vinegar, it will specify the percentage somewhere on the label.)

Here’s the overall gist:

In type-1 diabetics, type-2 diabetics, and healthy, non-diabetic subjects, vinegar reduces postprandial blood glucose and, to a lesser extent, postprandial plasma insulin levels. 

Some of the studies tested the same individuals on different days, with the same meal, once with added vinegar and once without, while other studies had randomized groups and employed a placebo. How do you create a placebo for vinegar, you ask? Good question! (I mean, if you think about it, it should be pretty obvious when you’re eating something that has vinegar in it versus something that doesn’t.) One of the studies that used a placebo added saccharine to the vinegar to turn the sour into sweet, and the placebo was water with a little added saccharine. Both drinks were also colored to disguise things even further. (We could speculate that the saccharine might have introduced a confounding variable with regard to blood glucose & insulin, but since both the vinegar group and the placebo group ingested the saccharine, we would hope that even if it did have an effect, any difference between the two would be neutralized.)

The studies indicate that just about everyone’s blood glucose and insulin were lower with vinegar, but the type-2 diabetics generally saw less of an effect. (Meaning, their postprandial blood glucose was lower with the vinegar than without it, but the reduction wasn’t as great as was seen in non-diabetic subjects.) This is probably because diabetics will have poorer glucose management pretty much regardless, so something that helps will still help, but it’ll help to a lesser degree than for someone who’s not diabetic. So a splash of vinegar isn’t exactly powerful enough to get anyone off their metformin or insulin, but considering the devastating effects of chronic hyperglycemia and insulinemia, it certainly never hurts for a diabetic to have another weapon in their arsenal. Particularly when it’s something so readily available and inexpensive. Prescription: Go to store. Buy vinegar. Use with meals.

Yep, looks like a low GI food to me!

The effect of vinegar was different depending on the composition of the test meal(s). One of the studies showed that vinegar was more effective in lowering postprandial glucose after a high-glycemic index (GI) meal versus one with a low GI. This is probably because a meal with a lower GI would theoretically have less of an impact on blood glucose in the first place, so there’s less of an effect to be had anyway. (Note: to show you how absolutely nuts nutrition research is, the “low GI” meal consisted of whole grain bread, lettuce, and low-fat cheese. Yes, low-fat cheese. And bread. Whole grain bread, yes, but still—bread, in a meal that’s supposed to be low GI? I guess it was, compared to the high GI meal, which was instant mashed potatoes and low-fat milk. I can only guess the ethics board would never have approved a study with a low GI meal consisting of, say, a fatty pork chop and broccoli. Oy…  Anyway, according to the paper, the two meals contained the same amount of total carbohydrate, but the high GI meal had a GI of 86, while the low GI meal was 38. [Gycemic loads of 44 and 20, for high and low, respectively.]) Also: in this other study, the test meal was 300g of rice pudding, which they claimed was 110 calories, including 17g carbs. Don't ask me how they made over a half pound of rice pudding with only 17g carbs. (Maybe it was mostly water.)

In most of the studies, postprandial blood glucose reached a lower peak and came back to baseline more quickly with vinegar ingestion than without—two things that are positive. One of the studies’ subjects reported an increased degree and duration of satiety after the test meal with vinegar versus the one without. (That’s fancy-speak for saying that when vinegar was included with the test meal, the subjects felt fuller and stayed fuller for longer than when eating a meal without vinegar.) I am speculating here, but perhaps the increased satiety is connected to the aforementioned better digestion: If you are digesting and absorbing more of the nutrients in your meal, it makes sense that you’d feel more satisfied and possibly have a longer sustained feeling of satiety than if some of the nutrients were passing through as though you hadn’t even eaten them, right?

The studies that measured glucose and insulin generally showed that both of these were lower, postprandially, in the vinegar groups. This suggests that the glucose is not lower due to increased insulin. Really, it’s the reverse: insulin is probably lower because glucose is lower. Less of a spike in glucose means we need less insulin to come clear it out of the blood. (At least, in healthy people, whose blood glucose management mechanisms are working the way they’re supposed to.) So one mechanism we can rule out for how vinegar lowers blood glucose is by raising insulin.

One of the studies that made me laugh (‘cuz it was the only way not to cry) involved type-2 diabetics who did an oral glucose tolerance test (OGTT). The subjects (n=12) were age 65 (±1), HbA1c 6.6 (±0.2), BMI 29.7 (±0.8), treated with oral glucose-lowering meds. So we’ve got a relatively small study group of middle-aged, overweight, not too poorly managed type-2 diabetics. (A1c of 6.6 is by no means stellar, of course, but many diabetics have way worse!) So the OGTT involved giving these people a beverage containing 75g of glucose. (Once by itself, and, on a separate test day, with 25g of white vinegar added.) There was basically no difference in the glucose and insulin levels with or without the vinegar. WHAT A FREAKING SHOCK!! They gave DIABETICS 75 grams of LIQUID GLUCOSE, and 25 measly grams of VINEGAR (about 1.5 Tbsp) weren’t enough to make a difference in their glucose spike? I AM STUNNED! (<--Sarcasm.)

HOW VINEGAR DOES IT

It seems the blood glucose moderating effects of vinegar depend somewhat on the food matrix in which the carbohydrate is presented. Liquid form that doesn’t even need to be digested? Virtually no benefit. The GI/GL matters, and researchers also speculate the amount of fiber and the ratio of amylose to amylopectin could also be a factor. (In other words, vinegar might have more or less of an effect, depending on whether the food is, say, potatoes, versus bread, versus parsnips, versus breakfast cereal made from puffed/extruded grains. It might also have differing effects on the same food, depending on the level of processing—such as a whole, intact baked potato versus gummed up mashed potatoes that don’t even have to be chewed; or a salad of dense, unrefined wheatberries versus, say, whole wheat crackers (made from flour) that liquefy in your mouth if you mix them with saliva for a few seconds and also don’t need to be chewed. Taken as a whole, it seems like the studies point not to the total carb content of a meal, but rather, the degree to which the carbs need to be broken down in the digestive tract, that determines how much of an effect vinegar might have—if any. Add vinegar to a can of soda, good luck. But dip a chunk of bread in olive oil and lots of balsamic before your pasta dinner at the big Italian chain restaurant--and ask for extra vinegar for your salad-- and maybe there’s something to it. Not that any of you are eating pasta.)

The researchers are uncertain about the actual mechanism by which vinegar results in lower glucose & insulin. There are two main theories:

1. Delayed gastric emptying: Vinegar causes food to leave the stomach more slowly, which results in a more gradual (and lower overall) rise in postprandial blood glucose. (Supported by this study and this one.)
2. Inhibition of intestinal disaccharidases—enzymes in the small intestine that digest sugars. If these enzymes are slightly inhibited, less glucose will be absorbed into the bloodstream. (Supported by this one.)

My opinion: it’s probably a little bit of both.

MOOD BOOSTER

 

Here is where things get really interesting. I have seen discussion of this in only one other place, and I love that someone else out there “gets it.” She is Jane Plain, whose second online moniker is “Wooo,” as in “It’s the Wooo,” and she frequently talks about vinegar with respect to digestion, the gut microbiome, and perhaps most interesting to me, mood regulation. (She’s also a nurse, which suggests she knows of what she speaks. Then again, we’ve all come across MDs & RNs who are ignorant and useless, but I’ve been reading Wooo for a while now, and when it comes to the science of neurotransmitters, as well as the physiological regulation of body weight, she is the most brilliant person you’re not reading. I must give a little caveat, though: If you’ve never read Wooo before, be warned: she’s a trip. She has an…um… “interesting” way of delivering insights sometimes, but she absolutely knows what she’s talking about, and she explains things in brilliant ways you will not hear anywhere else.)

Okay, Vinegar and mood. Let’s see.

There has been a ton of talk in the ancestral health community during the last year or so on resistant starch (RS). For those of you who’ve never heard of RS, it’s a type of starch that is “resistant” to digestion by enzymes in the human gastrointestinal tract, but which the [beneficial] bacteria in the large intestine feed off of, and as a result, stay healthy and stay in sufficient numbers. The main byproduct of the colonic bacteria feasting on RS is butyric acid, a short-chain fatty acid. (Molecular formula CH3(CH₂)₂COOH. The predominant dietary source of butyric acid is butter, and dairy fat in general.) The other main byproduct of colonic bacteria feeding on RS is, not surprisingly, flatulence. (I am told this effect goes away after your body gets used to increased amounts of RS. I cannot confirm, as I have not jumped onto the RS bandwagon and have no desire to.) Resistant starch is not found in all foods that are starchy. It tends to increase with food storage—as in, there’s lots of it in cooked white rice and white potatoes that have cooled down and sat around for a bit. (It’s also in things like greenish [unripe] bananas and plantains, and straight-up starch that you can eat on a spoon, like isolated potato starch.)

There is no shortage of literature supporting the importance of healthy “gut flora” for physical and mental health. (This means the right kind of bacteria as well as the right amounts. This is why broad-spectrum antibiotics are so harmful—they kill everything in the gut, not just the bad bugs.) So if the main benefit of resistant starch is to feed the good gut bugs, and those gut bugs use most of the butyric acid they produce for themselves, I will speculate that there is a related role for vinegar, and this is possibly why I seem to have a better emotional outlook when I consume lots of vinegar. If this sounds crazy, just stay with me.

In terms of biochemical composition, vinegar is actually a fatty acid. It is the very shortest fatty acid of the short-chain fatty acids. Only 2 carbons! Remember, CH₃COOH. (Well, technically, it’s a carboxylic acid, but I once had a biochem professor confirm that we can sort of think of it as the very simplest fatty acid, so there.) So if a benefit of RS is that it eventually leads to production of a short-chain fatty acid in the gut, then there might just be something to ingesting a short-chain fatty acid in pure form (acetic acid, a.k.a. vinegar).

There is virtually no scientific literature regarding the influence of vinegar on mood and emotional health. All I could find on the interwebs were anecdotes from laypeople, and most of these people speculated that their better moods were a result of vinegar promoting better digestion. Their reasoning was, better digestion (of protein, specifically) means better liberation of amino acids like tryptophan, tyrosine, and phenylalanine, all of which are required to synthesize the “good mood” neurotransmitters, like serotonin, dopamine, epinephrine, and norepinephrine.

This makes sense to me, but I don’t buy it as the primary reason behind vinegar’s (potential) influence on mood. This is nothing but pure speculation on my part, but I am inclined to suspect it’s more related to the gut flora thing. Could be two-fold: 1) Maybe the acetic acid itself feeds some of the good bacteria; 2) Maybe, as an antimicrobial agent, vinegar is selectively killing some of the harmful bacteria and sparing the beneficial ones. I can’t say how, exactly, this might work. Like I said, I’m just thinking out loud. All I know is, I am consuming ridiculous amounts of vinegar (and have been for a while), and given that my bowel movements are going well, I have to assume the vinegar isn’t decimating the beneficial bacteria in my colon. (Sorry for TMI!) This idea intrigues me. Just think of the cost difference between prescription anti-depressants and a big ol’ gallon jug of vinegar from the warehouse store.

CARB CONTENT OF VINEGAR

Since we had a big focus on blood sugar regulation, we should probably talk about the carbohydrate content of vinegar.

Carb content of selected vinegars, per 1 Tbsp. L-R: apple cider (1g); red wine (0g); white distilled (0g); balsamic (2g).

Vinegar is pretty darn low-carb. After all, it is acidic, not sweet. Most vinegars, such as plain white (distilled), apple cider, red wine, and white wine vinegar, will have 0-1g CHO per tablespoon. Practically negligible, unless you mainline the stuff like I do, hehheh. (Again, for the novices out there, “CHO” is biochemical shorthand for carbohydrate.) The one that is a bit higher in carbs is balsamic. Your run-of-the-mill balsamic might have more like 2-3g/Tbsp. Still not all that much, especially if, in the end, the vinegar actually contributes to a lowering of postprandial blood glucose. Balsamic is “sweeter” than other vinegars, but it’s not like drinking apple juice, know what I mean? You will find that some gourmet-type (and more expensive) balsamic vinegars are much smoother on the palate and also taste sweeter. These are the ones that might have 4-5g/Tbsp. Still not really a big deal, and damn delicious. (The ones that will really be sweet and higher in CHO are the flavored/infused ones, which are incredible. The chocolate and Bordeaux cherry are AMAZING on grain-free pound cake and, odd though it sounds, good vanilla ice cream! I swear! You will thank me for this someday.)

The one to watch a little more is balsamic “glaze”—a reduction usually made by boiling balsamic vinegar until some of the water evaporates, and what you’re left with is a thick syrup. This will be a fair bit higher in carbs, maybe 8-11g/Tbsp. A little high, but not that big a deal, since you’d typically only use a small amount as a finishing touch. It is also somewhat pricey, and the fact is, you can make it at home by simmering balsamic vinegar [in a non-reactive cooking vessel] until it reduces to your desired thickness. You can save $$ by doing this with a vat of cheap-ish balsamic vinegar, like the large size they sell at TJs, but in starting with a cheaper vinegar, you might end up with a concentrated version that might not be quite as easy on the palate.

EAT IT

There are tons of ways to incorporate more vinegar into your diet. If you are not the crazy soul I am, and willing to just take a few swigs here and there, straight-up (with a tiny water chaser), you can just make lots of homemade vinaigrettes for salad dressings, or even add a splash of ACV to a cold glass of lemonade in the summer. (Just try not to have the vinegar in contact with your teeth for prolonged periods.) And, of course, balsamic vinegar is a great addition to roasted vegetables, such as this beet salad, this one, or this beet recipe with raspberry vinegar (for which you could easily substitute balsamic if you want to), these Brussels sprouts, or these red onions.

For the quickest vinaigrette ever, and something DELICIOUS over a pork chop:

Combine in a half-pint mason jar: 2-3 parts extra virgin olive oil, 1 part balsamic vinegar, and about 1-2 teaspoons mustard. (Any kind of mustard is fine—yellow, spicy brown, coarse-grain. Whatever you have on hand.) Close the lid tightly and SHAKE!  The more mustard you use, the thicker the vinaigrette will be, because the mustard is what emulsifies it. I like mine thick and very vinegar-y, so I tend to use more like 2 parts EVOO and 1 part vinegar. If you don’t have small mason jars, just use a small container with a tight lid. (You can also put everything in a bowl and use a whisk to combine by hand.)

Remember: Amy Berger, M.S., NTP, is not a physician and Tuit Nutrition, LLC, is not a medical practice. The information contained on this site is not intended to diagnose, treat, cure, or prevent any medical condition.