How Much Vinegar Every Day?

Consuming vinegar with a meal reduces the spike in blood sugar, insulin, and triglycerides, and it appears to work particularly well in those who are insulin resistant and on their way to type 2 diabetes. No wonder the consumption of vinegar with meals was used as a folk medicine for the treatment of diabetes before diabetes drugs were invented.

Many cultures have taken advantage of this fact by mixing vinegar with high glycemic foods. For example, in Japan, they use vinegar in rice to make sushi, and, in the Mediterranean, they dip bread into balsamic vinegar. Throughout Europe, a variety of sourdough breads can lower both blood sugar and insulin spikes. You can get the same effect by adding vinegar to boiled white potatoes then cooling them to make potato salad.

Adding vinegar to white bread doesn’t just lower blood sugar and insulin responses—it increases satiety, or the feeling of being full after a meal. As you can see in my video Optimal Vinegar Dose, a study found that if you eat three slices of white bread, it may fill you up a little, but in less than two hours, you’re hungrier than when you began eating. If you eat that same amount of bread with some vinegar, though, you feel twice as full and, even two hours later, still feel nearly just as full as if you had just eaten the three pieces of bread plain. But this remarkable increase and prolongation of satiety took nearly two tablespoons of vinegar. That’s a lot of vinegar. What’s the minimum amount?

It turns out that even just two teaspoons of vinegar with a meal can significantly decrease the blood sugar spike of a refined carb meal, a bagel and juice, for instance. You could easily add two teaspoons of vinaigrette to a little side salad or two teaspoons of vinegar to some tea with lemon. Or even better you could scrap the bagel with juice and just have some oatmeal with berries instead.

What if you consume vinegar every day for months? Researchers at Arizona State University randomized pre-diabetics to take daily either a bottle of an apple cider vinegar drink—a half bottle at lunch, and the remaining half at dinner—or an apple cider vinegar tablet, which was pretty much considered to be a placebo control: While the bottled drink contained two tablespoons of vinegar, the two tablets only contained about one third of a teaspoon. So in effect, the study was comparing about 40 spoonfuls of vinegar a week to 2 spoonfuls for 12 weeks.

What happened? On the vinegar drink, fasting blood sugars dropped by 16 points within one week. How significant is a drop of 16 points? Well this simple dietary tweak of a tablespoon of vinegar twice a day worked better than the leading drugs like Glucophage and Avandia. “This effect of vinegar is particularly noteworthy when comparing the cost, access, and toxicities” associated with pharmaceutical medications. So the vinegar is safer, cheaper, and more effective. This could explain why it’s been used medicinally since antiquity. Interestingly, even the tiny amount of vinegar in pill form seemed to help a bit. That’s astonishing. And, no: The study was not funded by a vinegar company.

What about long-term vinegar use in those with full-blown diabetes? To investigate this, researchers randomized subjects into one of three groups. One group took two tablespoons of vinegar twice a day, with lunch and supper. Another group ate two dill pickles a day, which each contained about a half tablespoon’s worth of vinegar. A third group took one vinegar pill twice a day, each containing only one sixteenth of a teaspoon’s worth of vinegar. I wasn’t surprised that the small dose in the pill didn’t work, but neither did the pickles. Maybe one tablespoon a day isn’t enough for diabetics? Regardless, the  vinegar did work. This was all the more impressive because the diabetics were mostly well controlled on medication and still saw an additional benefit from the vinegar.


Make sure to check out my other videos on vinegar’s benefits:

This vinegar effect seems a little too good to be true. There have to be some downsides, right? I cover the caveats in Vinegar Mechanisms and Side Effects.

There are a few other foods found to improve blood sugar levels:

The best approach, of course, is a diet full of healthy foods:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Sip Smoothies Slowly

A famous study in 2000 compared the impact of soda versus jelly beans. Researchers had people add 28 extra spoonfuls of sugar to their daily diet in the form of jelly beans or soda. Then, they measured how many calories participants ate over the rest of the day to see if their bodies would compensate for all that extra sugar. For the jelly bean group, their bodies registered all the extra calories from the handfuls of jelly beans and they ended up eating less of everything else throughout the day. So, they ate pretty much the same number of calories before and after adding the jelly beans to their diet. But, for the soda group, despite all the added calories from the cans of pop they were drinking every day, they kept eating about the same amount. No wonder they gained weight after a month of drinking soda. Their bodies didn’t seem to recognize the extra calories when they were in liquid form and therefore didn’t compensate by reducing their appetite for the rest of the day.

What if we drink a smoothie for breakfast instead of eating a solid meal? Will our body think we skipped breakfast and make us so ravenous at lunch we’d eat more than we normally would and end up gaining weight? To answer this, we first have to determine if this solid versus liquid calorie effect is real. Soda and jelly beans don’t just differ by physical form; they have different ingredients. That’s a problem with a lot of these kinds of studies: They use dissimilar foods.

Take, for example, the study comparing liquid to solid breakfasts in my video Liquid Calories: Do Smoothies Lead to Weight Gain?. Researchers gave participants breakfasts of either fruit juices and skim milk or oatmeal with blueberries and apples. Not so surprisingly, study subjects were less hungry after the oatmeal. But, that may not be a solid versus liquid effect, as the breakfasts were comprised of completely different foods.

To test for a solid versus liquid effect, you’d have to use the exact same foods in two different forms. Finally, a study did just that. Researchers looked at what happens if you have a fruit salad with raw apples, apricots, and bananas with three cups of water to drink versus blending the fruit with two of the cups of water to make a smoothie and then just drinking the third cup of water. It’s the identical meal—one in solid form and one in smoothie form. What happened? People felt significantly less full after the smoothie, although it was the same amount of food and fiber. In smoothie form, it didn’t fill people up as much as eating fruit au natural.

Originally, we thought it was due to the lack of chewing. The act of chewing itself may be an I’ve-eaten-enough signal that you don’t get just by drinking. Researchers had people chew either 10 or 35 times per mouthful and eat pasta until they felt comfortably full. Those forced to chew 35 times per bite ended up eating about a third of a cup less pasta than those who only chewed 10 times per bite. So there we have it: We had the proof of solid versus liquid effect and the mechanism. But, as so often happens in science, just when we have everything neatly wrapped up with a bow, a paradox arises.

In this case, the great soup paradox.

Pureed, blended soup—essentially a hot, green smoothie of blended vegetables—is more satiating than the same veggies in solid form. The same meal in liquid form was more filling than in solid form. So, it can’t be the chewing that has the satiating effect. In fact, there doesn’t appear to be a solid versus liquid effect at all since cold smoothies appear to be less filling, but hot smoothies appear to be more filling. They are so filling that when people have soup as a first course, they eat so much less of the main course, that they eat fewer calories overall, even when you add in the soup calories.

How can we explain this paradox? Maybe pureed fruit is less filling than solid, but pureed vegetables are more filling? To test this, Purdue University researchers used apple soup. They mixed about a cup of apple juice with two cups of applesauce, liquefied it in a blender, and heated it up. If you have people eat three actual apples, they started out pretty hungry, but, within 15 minutes of eating the apples, they were hardly hungry at all. Drinking three cups of apple juice didn’t cut hunger much, but what about the apple soup, which was pretty much just hot apple juice with applesauce mixed in? The apple soup cut hunger almost as much as the whole apples, even more than an hour later. It even beat out whole apples for decreasing overall calorie intake for the day.

What’s so special about soup? What does eating soup have in common with prolonged chewing that differentiates it from smoothie drinking? Time. It took about twice as long to chew 35 times. And think about how long it takes to eat a bowl of soup compared to drinking a smoothie. Eating slower reduces calorie intake.

Alternatively, maybe we just imagine soup to be filling, so it’s like a placebo effect. Feelings like hunger and fullness are subjective. People tend to report hunger more in accordance with how many calories they think something has rather than the actual caloric content. If you study people with no short-term memory, like the character in the movie Memento who couldn’t remember what happened more than a minute ago, they can overdose on food because they forgot they just ate, which shows what poor judges we are of our own hunger. It’s not just subjective effects, either. In a famous study called Mind Over Milkshakes, people were offered two different milkshakes, one described as indulgent, “decadence you deserve,” and the other a sensible, “guilt-free satisfaction.” People have different hormonal responses to them even though they were being fooled and given the exact same milkshake.

Finally, maybe it was just because the soup was hot, and warmer foods may be more satiating? How do we figure out if the solution to the soup mystery was time, thought, or temperature? If only the study we discussed earlier that had subjects eat either a fruit salad with three cups of water or drink the same exact foods in smoothie form had a third group—a liquid eating group, too. Well, it did!

Researchers also offered the fruit smoothie in a bowl to be eaten cold with a spoon. (Very un-soup-like.) So, if it were thought or temperature, the fullness rating would be down by the liquid drinking. However, if it was just the slowed eating rate that made soup as filling as solid food, then the fullness rating would be up closer to the solid eating rating—and it was exactly as high. The only real reason smoothies aren’t as filling is because we gulp them down, but if we sip them slowly over time, they can be just as filling as if we ate the fruits and veggies solid.

Wow, that study thought of everything. You don’t know the half of it! They also wanted to see if it would work with high-fat smoothies too. So, what, almond butter or walnuts? No, they used a liquefied fat smoothie of steamed pork belly.

I guess maybe  sometimes smoothies can suppress your appetite 🙂

I have a whole series of videos on smoothies: Are Green Smoothies Good for You?, Are Green Smoothies Bad for You?, Green Smoothies: What Does the Science Say?, and The Downside of Green Smoothies.

For videos on weight gain, see Do Fruit & Nut Bars Cause Weight Gain?, Does Chocolate Cause Weight Gain?, Nuts and Obesity: The Weight of Evidence, and How Diet Soda Can Make Us Gain Weight. 

For weight loss, check out How Much Exercise to Sustain Weight Loss, Brown Fat: Losing Weight Through Thermogenesis, Boosting Brown Fat Through Diet, Eating More to Weigh Less, and Can Morbid Obesity Be Reversed Through Diet?

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

What Animal Protein Does in Your Colon

There’s a take-off of the industry slogan, “Beef: It’s What’s For Dinner” – “Beef: It’s What’s Rotting in Your Colon.” I saw this on a shirt once with some friends and I was such the party pooper—no pun intended—explaining to everyone that meat is fully digested in the small intestine, and never makes it down into the colon. It’s no fun hanging out with biology geeks.

But I was wrong!

It’s been estimated that with a typical Western diet, up to 12 grams of protein can escape digestion, and when it reaches the colon, it can be turned into toxic substances like ammonia. This degradation of undigested protein in the colon is called putrefaction; so, a little meat can actually end up putrefying in our colon. The problem is that some of the by-products of this putrefaction process can be toxic.

It’s generally accepted that carbohydrate fermentation—the fiber and resistant starches that reach our colon—results in beneficial effects because of the generation of short-chain fatty acids like butyrate, whereas protein fermentation is considered detrimental. Protein fermentation mainly occurs in the lower end of colon and results in the production of potentially toxic metabolites. That may be why colorectal cancer and ulcerative colitis tend to happen lower down—because that’s where the protein is putrefying.

Probably the simplest strategy to reduce the potential harm of protein fermentation is to reduce dietary protein intake. But the accumulation of these toxic by-products of protein metabolism may be attenuated by the fermentation of undigested plant matter. In my video, Bowel Wars: Hydrogen Sulfide vs. Butyrate, you can see that a study out of Australia showed that if you give people foods containing resistant starch, you can block the accumulation of potentially harmful by-products of protein metabolism. Resistant starch is resistant to small intestine digestion; and so, it makes it down to our colon where it can feed our good bacteria. Resistant starch is found in cooked beans, split peas, chickpeas, lentils, raw oatmeal, and cooled cooked pasta (like macaroni salad). Apparently, the more starch that ends up in the colon, the less ammonia that is produced.

Of course, there’s protein in plants too. The difference is that animal proteins tend to have more sulfur-containing amino acids like methionine, which can be turned into hydrogen sulfide in our colon. Hydrogen sulfide is the rotten egg gas that may play a role in the development of the inflammatory bowel disease, ulcerative colitis (see Preventing Ulcerative Colitis with Diet).

The toxic effects of hydrogen sulfide appear to be a result of blocking the ability of the cells lining our colon from utilizing butyrate, which is what our good bacteria make from the fiber and resistant starch we eat. It’s like this constant battle in our colon between the bad metabolites of protein, hydrogen sulfide, and the good metabolites of carbohydrates, butyrate. Using human colon samples, researchers were able to show that the adverse effects of sulfide could be reversed by butyrate. So, we can either cut down on meat, eat more plants, or both.

There are two ways hydrogen sulfide can be produced, though. It’s mainly present in our large intestine as a result of the breakdown of sulfur-containing proteins, but the rotten egg gas can also be generated from inorganic sulfur preservatives like sulfites and sulfur dioxide.

Sulfur dioxide is used as a preservative in dried fruit, and sulfites are added to wines. We can avoid sulfur additives by reading labels or by just choosing organic, since they’re forbidden from organic fruits and beverages by law.

More than 35 years ago, studies started implicating sulfur dioxide preservatives in the exacerbation of asthma. This so-called “sulfite-sensitivity” seems to affect only about 1 in 2,000 people; so, I recommended those with asthma avoid it, but otherwise I considered the preservative harmless. I am now not so sure, and advise people to avoid it when possible.

Cabbage family vegetables naturally have some sulfur compounds, but thankfully, after following more than a hundred thousand women for over 25 years, researchers concluded cruciferous vegetables were not associated with elevated colitis risk.

Because of animal protein and processed food intake, the standard American diet may contain five or six times more sulfur than a diet centered around unprocessed plant foods. This may help explain the rarity of inflammatory bowel disease among those eating traditional whole food, plant-based diets.

How could companies just add things like sulfur dioxide to foods without adequate safety testing? See Who Determines if Food Additives are Safe? For other additives that may be a problem, see Titanium Dioxide & Inflammatory Bowel Disease and Is Carrageenan Safe?

More on this epic fermentation battle in our gut in Stool pH and Colon Cancer.

Does the sulfur-containing amino acid methionine sound familiar? You may remember it from such hits as Starving Cancer with Methionine Restriction and Methionine Restriction as a Life Extension Strategy.

These short-chain fatty acids released by our good bacteria when we eat fiber and resistant starches are what may be behind the second meal effect: Beans and the Second Meal Effect.

I mentioned ulcerative colitis. What about the other inflammatory bowel disease, Crohn’s?  See Preventing Crohn’s Disease With Diet and Dietary Treatment of Crohn’s Disease.

 In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: