Archive for the 'umami hypothesis' Category

Assorted Links

Wednesday, December 18th, 2013

Assorted Links

Thursday, November 28th, 2013

Thanks to Casey Manion and Richard Sprague.

Assorted Links

Monday, May 13th, 2013

Thanks to Casey Manion and Bryan Castañeda.

Assorted Links

Sunday, May 5th, 2013

Thanks to Bryan Castañeda.

Assorted Links

Sunday, April 21st, 2013

Thanks to Dave Lull and Ashish Mukharji.

Practical Use of Our Liking For Complex Flavors

Friday, April 5th, 2013

People like complex flavors. I suppose this is why I prefer black tea to green tea. My evolutionary explanation is that this preference caused our ancestors to eat more bacteria-laden food. Bacteria make food taste more complex and bacteria-laden food are healthier than bacteria-free food.

Phil Alexander sent me a story from this book that illustrates this preference:

We entered the saloon. Not a customer was there — a very surprising fact, considering that it was New Year’s Eve. The only person in sight was the bartender who paced back and forth in front of the bar like a caged beast.

“Well, whatta you want?” he asked savagely.

“Why, we just want a little New Year’s drink,” I returned. Winterbill was too surprised to say anything.

“Mix ‘em yourself,” the bartender replied. “I’m through with the saloon business.”

“If you feel that way about it,” I said, “why don’t you sell out?”

“Well, the first guy who offers me $300 can have the works.”

Somewhat amused and thinking he must be joking, I retorted, “I’ll give you $300 — provided it includes all your stock, the cash register, and other equipment.”

“Mister, you’ve bought yourself a saloon!” he snapped. “I’ll not only include all the stock and equipment — I’ll throw in a full barrel of whiskey I’ve got in the basement.”

Winterbill now joined in the fun and began to take an inventory.

The owner took off his apron and handed it to me. “Gimme the three hundred bucks.”

I gave him the money, still believing it was a joke. He put the money into his pocket, got his hat and coat and departed. To our complete bewilderment, we found ourselves in the saloon business.

A few minutes later, our first customer came in. He evidently had not made our place his first stop. I hurriedly put the apron over my evening clothes and asked for his order.

“Martini,” he said in a thick voice.

“Martini,” I repeated to Winterbill.

“Stall him!” Winterbill whispered.

“Coming right up,” I told the customer. He didn’t mind waiting. He was at the stage where he wanted to talk and so proceeded to do.

Meanwhile Winterbill racked his brain, for he had only the vaguest idea how to mix a Martini. He finally settled upon a recipe. He put a dash of everything from the numerous bottles behind the bar into one drink. I stirred it up and handed it to the customer. We watched anxiously while he drank it down.

“That was good!” he exclaimed. “Best Martini I ever tasted. Mix me another.”

Again Winterbill started to mix.

“How do you feel?” I inquired, none too sure of the consequences.

“Me?” asked the customer. “Fine. Never felt better in my life.”

He didn’t show any bad results after the second drink, and we both were relieved. As time went on more customers came in. They ordered whiskey sours, Manhattans, and Martinis. Winterbill had just one formula and that’s what he gave them all. Nobody complained.

. . . By the time we closed that night we had taken in more than the whole outfit cost us!

Assorted Links

Thursday, April 4th, 2013

Thanks to Peter McLeod, John Batzel and Joseph Sinatra.

Earwax Transplant Story

Sunday, March 24th, 2013

I think this actually happened:

A man came to the [University of Pittsburgh] clinic with a chronic infection in his left ear. He told doctors that other doctors had tried everything: anti-fungal drops, antibiotics, and many other treatments. The Pittsburgh doctors gave him additional antibiotics. The patient came back to the clinic a week later and said he was cured. The clinic doctors told him they were glad they had helped him. He said: “You didn’t. I suffered so much after your drugs I took some earwax from my right ear and put it in my diseased left. In two days I was fine, infection cured.” . . . The good ear contained good bacteria that killed off the bad in the bad ear.

I predict that people will eventually realize that the 2005 Nobel Prize for “ulcers are caused by bacteria” was a big mistake.

Thanks to Mark Griffith.

Assorted Links

Saturday, March 16th, 2013

Thanks to Paul Nash and Adam Clemens.

Modern Food Reduced Diversity of Oral Bacteria

Wednesday, March 6th, 2013

A new paper in Nature Genetics describes research into the bacteria in ancient teeth plaque. When modern food came along, the bacteria became less diverse. One of the researchers said:

The composition of oral bacteria changed markedly with the introduction of farming, and again around 150 years ago. With the introduction of processed sugar and flour in the Industrial Revolution, we can see a dramatically decreased diversity in our oral bacteria, allowing domination by caries-causing strains.

Whether the decrease in diversity was due to (a) more sugar and flour or (b) less bacteria-laden foods is hard to say.

Again, data suggest we need bacteria to protect us against bacteria. You’d never know this from food safety laws or how freely pediatricians prescribe antibiotics. Again, it is hard to know without more research what caused this or that historical change in health (e.g., more tooth decay when sugar and flour became popular). The obvious answer (e.g., sugar causes tooth decay) might be wrong. If you believe that cavities are caused by too much sugar, the solution is to eat less sugar. What if cavities are caused by not enough bacterial diversity? Then other solutions might work better, such as eating more fermented food.

Thanks to Vic Sarjoo.

Assorted Links

Friday, March 1st, 2013
  • An Epidemic of Absence (book about allergies and autism)
  • Professor of medicine who studies medical error loses a leg due to medical error. “Despite calls to action by patient advocates and the adoption of safety programs, there is no sign that the numbers of errors, injuries and deaths [due to errors] have improved.” Nothing about consequences for the person who made the error that caused him to lose a leg.
  • Doubts about spending a huge amount of research money on a single project (brain mapping). Which has yet to produce even one useful result.
  • Cancer diagnosis innovation by somebody without a job (a 15-year-old)
  • Someone named Rob Rhinehart has greatly reduced the time and money he spends on food by drinking something he thinks contains all essential nutrients. Someone pointed out to him that he needs bacteria, which he doesn’t have. (No doubt several types of bacteria are best.) He doesn’t realize that Vitamin K has several forms. I suspect he’s getting too little omega-3. This reminds me of a man who greatly reduced how much he slept by sleeping 15 minutes every 3 hours. It didn’t work out well for him (his creativity vanished and he became bored and unhappy). In Rhinehart’s case, I can’t predict what will happen so it’s fascinating. When something goes wrong, however, I’ll be surprised if he can figure out what caused the problem.

Thanks to Amish Mukharji.

Assorted Links

Friday, January 25th, 2013

Thanks to Bryan Castañeda and Dave Lull.

Fecal Transplant Roundup

Sunday, January 20th, 2013

A new study has found that fecal transplants work better than antibiotics for clearing up a common and dangerous infection:

Such transplants cured 15 of 16 people who had recurring [= difficult-to-get-rid-of] infections with Clostridium difficile bacteria, whereas antibiotics cured only 3 of 13 and 4 of 13 patients in two comparison groups.

Clostridium difficile infections often result from antibiotic treatment. It is a big step forward for modern medicine to manage to grasp that the bacteria in our bodies protect us from infection. Here is a blog about the value of fecal transplants; here is another blog.

The comments contain many interesting details: (more…)

A Brief History of Antibiotics

Sunday, December 23rd, 2012

This excellent article by Carl Zimmer gives a brief history of the development of antibiotics. It makes the usual points that the microbes within us improve our health and killing them (with antibiotics) can have bad effects. One study found that children given antibiotics had a higher risk of developing inflammatory bowel disease (IBD) later in life. Giving antibiotics to a child younger than one year was especially dangerous — the risk of IBD increased by a factor of 6.

The article makes the minor mistake of taking seriously what researchers say about number of species:

Each of us is home to several thousand [bacterial] species. . . . My own belly button, I’ve been reliably informed, contains at least 53 species.

Counting the number of species inside us is like measuring the length of the coast of England. The more closely you look (in the case of coastlines, the shorter the ruler you use), the larger the number you will arrive at. I’d be surprised if the researchers who count bacterial species adjust for this.

What I found most interesting about the article is it says nothing about fermented foods. Apparently the connection is not so obvious.

One Reason for French Longevity: Molded Cheese

Thursday, December 20th, 2012

A new article emphasizes the benefits of cheese, especially “molded” cheese, such as Roquefort and Gorganzola. Fermentation, if that is the right word, is essential:

The advantageous properties of cheese appear dynamically during the ripening process. Cheese which has been ripened for longer has been shown to be more effective in restoration of glucose tolerance, prevention of steatosis [fat deposition inside a cell] and adipose tissue oxidative stress than short-ripened specimens. This data suggests that organic substances responsible for the health benefits of cheese emerge not merely due to mixing the ingredients required for cheese production, but rather as a result of a complex time-dependent enzymatic transformation of the cheese core controlled by probiota, temperature, humidity and possibly other factors.

Only in South Korea and Japan do people have less heart disease than in France, says the article. Readers of this blog will quickly see what South Korea, Japan, and France have in common. All of them eat much more fermented food than most people in rich countries. South Korea: kimchi. Japan: miso and pickles. France: cheese and wine.

Thanks to Peter MacLeod.

Why Do Fermented Foods Improve Health? A New Idea

Tuesday, December 11th, 2012

I became interested in the health value of fermented foods after I noticed a curious coincidence. Humans have three mysterious food preferences: for (a) sour food, (b) food with umami flavor, and (c) food with complex flavor. I realized that all three preferences made bacteria-laden food more attractive. Bacteria change sugars to acids, increasing sourness. They break down proteins, creating glutamate, which produces umami flavor. And the many chemicals they introduce into a food make its flavor more complex. After I noticed this, I came across many studies that supported the idea that fermented foods are good for health. I also found studies that suggest the bacteria in our digestive system are crucial to health.

This raised the question: What fermented foods to eat? How many? How often? To begin to answer these questions, it would help to know how bacteria in our food help us be healthy. There were two obvious answers:

1. Stimulate the immune system. The bacteria in fermented food are inherently safe: they are specialized to reproduce on/in food, which is so different than inside the human body.  But the immune system doesn’t know this. If this was one benefit of fermented food, you could study which ones to eat by measuring immune system activation. Unfortunately, that is nearly impossible.

2. Improve digestion. Many people have digestive problems and some of them are helped by fermented foods. Obviously they contain bacteria that digest food. I don’t have digestive problems so I can’t study this by figuring out which fermented foods help.

Recently, I have begun to think there is a third reason:

3. Place competition. To make us sick, outside bacteria need to stick inside us. To digest our food, the surfaces of our digestive system, such as the inside of our intestines, is much more porous than other surfaces, such as our skin. It is our digestive system, therefore, that is most vulnerable to dangerous microbes. The totally-safe microbes in fermented foods compete for sticky spots with other, more dangerous microbes. If there are plenty of safe bacteria — say, billions in a serving of yogurt — they may do a lot to protect us against the dozen or so similar dangerous bacteria we might get from touching the same surface as a sick person. I think of a wooden floor where the lumber is not quite well-fitted. If you want to protect what’s below that floor from black sand (dangerous), an excellent method would be to pour an enormous amount of white sand (safe) on the floor.

If Effect #3 (place competition) is the main reason fermented food protects us from disease, it implies that dead bacteria work as well as live bacteria (in contrast, live bacteria do not digest food, Effect #2). This might explain the potency of alcoholic beverges such as wine, where most of the bacteria are dead. It also suggests that what matters is diversity of where bacteria stick and how much they stick. It might someday be possible to feed people (non-radioactive) bacteria and learn where in the body they end up.

 

 

Bacteria are Neither Good nor Bad

Saturday, October 27th, 2012

Health experts call bacteria “good” and “bad”. Bad bacteria make us sick. Good bacteria help us digest food, and a few other things. Let me propose another view. Any bacteria (i.e., bacterial species) will make us sick if it becomes too numerous — so all bacteria are “bad”. All bacteria protect us against other bacteria — so all bacteria are “good”. The terms “good” and “bad” are misleading. It is like saying a person is inherently rich or poor. Anyone, given a lot of money, becomes rich. Anyone whose money is taken away becomes poor. Low bacterial diversity or reduction of diversity makes it more likely that one bacterial species can overwhelm its competitors, producing sickness. When this happens, to say that the species (e.g., H. pylori) that became numerous “caused” the sickness (e.g., ulcers) is to seriously misunderstand what happened and how to prevent it from happening. We are taught that our immune system protects us from infection. We should be taught that bacterial diversity does the same thing. (more…)

More Fermented Foods, Less Runny Nose?

Saturday, October 20th, 2012

As recently as four or five years ago,and for many years before that, I often had a runny nose. I went through boxes and boxes of Kleenex. I carried a handkerchief everywhere and often used it. Not because I had a cold–I almost never got colds. It was different than that. You might say I was mildly allergic to something in the air. (more…)

New Product: Cascal Fermented Soda

Friday, October 12th, 2012

This low-calorie soda (60 to 80 calories in a 12-ounce can) falls somewhere between kombucha and less-sweet sodas such as the aptly named GUS (Grown Up Soda). Its hook is the use of fermented juices as its base, resulting in a more complex flavor than sodas and sparkling waters based on plain juice.

$1.25 at Whole Foods. I’m in.

My interest in fermented foods partly derives from learning about a similar product. At a Fancy Food Show a few years ago, I learned about someone who wanted to develop a high-end non-alcoholic alternative to wine. He found he couldn’t get enough complexity without fermentation. That emphasized to me how our food preferences — in this case, a desire for complexity — push us to eat fermented foods.

The Complex Flavor of Fermented Foods

Thursday, September 27th, 2012

One of the main reasons I think we need to eat fermented foods to be healthy is that their flavors correspond neatly to the flavors we like. Fermentation of fruits and other sweet foods changes sugars to acids, making the food taste sour — and we like sour food. Fermentation of proteins produces glutamate, which produces an umami flavor — and we like umami-flavored food. With many foods, their fermentation produces many microbial byproducts, giving the food a complex flavor — and we like complex flavors.

The connection between fermentation and complex flavor is well-put in a Saveur article about fermented foods:

[As a child] I only knew Claussen and other vinegar-cured pickles, the kind you buy in jars off the supermarket shelf, and I liked them just fine. But when I finally tasted a real pickle—the kind made the old-fashioned way, fermented with nothing more than salt, water, and time—I realized what I had been missing. A vinegary pickle plows through your palate with its tartness (often in a most pleasing way), but a live-cultured, salt-cured, fermented one tells a more multifaceted story. It is sour, to be sure, but it tastes of something more, something elusive: It’s the flavor of Middle Europe captured in one bite. When I started cooking for a living, I realized that the complexity I’d tasted in that pickle is the hallmark of well-made fermented foods, which include some of my very favorite things to eat and drink: not just pickles, but aged cheeses, tangy sourdough breads, blistering kimchis, tart yogurts, winy salamis, and of course, wine itself.