How yoghurt works

I came across this interesting article on how probiotic yoghurt works.

It is not about putting more "good" bacteria into your gut.  Rather it is epigenetic.  The yoghurt alters gene expression in the existing microbes in your gut, turning some function on and off.

Fascinating stuff.

How Probiotic Yogurt Works

Probiotics.....overhyped?

Maybe. I must admit I think there may be particular benefits to fermented food, but the research is still inconclusive.

The study to investigate the potential benefits of probiotics in yogurt, a patient-oriented, double-blind, cluster-randomised, placebo-controlled, clinical trial

Conclusions: Consumption of a yogurt-based drink delivering 1010 CFU of Bifidobacterium animalis ssp. lactis (B. lactis) BB-12 per day did not decrease the number of days missed of school due to an illness. Additional independent research on the potential of BB-12 to reduce illness in children needs to be conducted.

Interesting thoughts on food....

I saw this study today which - if I am reading it right - seems to indicate that - if you want to avoid a fat belly - you should eat:

• red meat ;
• vegetables;
• fruit;
• butter; and
• high-fat dairy products

and avoid

• snack foods;
• poultry;
• potatoes; and
• processed meat

BACKGROUND: Previous studies on the association between macronutrient intake and the development of abdominal obesity, which carries an increased health risk, have not shown a consistent pattern, possibly due to mixed effects of other aspects of the food intake.
OBJECTIVE: This study investigated the association between intake from 21 food and beverage groups and the subsequent 5-year difference in waist circumference.
METHODS: The study population consisted of 22,570 women and 20,126 men, aged 50 to 64 years at baseline, with complete data on baseline and follow-up waist circumference, baseline diet (192 items food frequency questionnaire), body mass index, and selected potential confounders (eg, smoking status, sport activities, and intake of alcoholic beverages). Multiple linear regression analyses were performed.
RESULTS: For women, 5-year difference in waist circumference was inversely related to intake from red meat, vegetables, fruit, butter, and high-fat dairy products, whereas intake from potatoes, processed meat, poultry, and snack foods was positively associated. For men, red meat and fruit intakes were inversely associated with 5-year difference in waist circumference, whereas snack foods intake was positively associated. Sex differences occurred for vegetables, high-fat dairy products, and processed meat.
CONCLUSIONS: The results suggest that a diet low in fruits and red meat and high in snack foods was associated with larger waist circumference gains in both sexes. Furthermore, in women a diet low in vegetables, butter, and high-fat dairy products, and high in poultry, potatoes, and processed meat were likely determinants of subsequent gain at the waist.

Fermentation (not alcholic....) of food.

Fermented food

OK, as you may have noticed this blog is often just a record of things that I come across which I find interesting - generally in the area of fitness, conditioning and diet.

Here is something I've been thinking and reading about a bit recently: the idea of fermented food - think yoghurt, kefir, sauerkraut, pickles - being uniquely healthy.

I think I first came across this idea in Sally Fallon's book Nourishing Traditions, much of which is predicated on the work of Weston Price (who made an extensive study of traditional diets in the 1930s, diets unadulterated by modern processing and diets consumed in societies where there were few of the diseases of civilisaiton). Fallon has a good article on Lacto-Fermentation if you want to learn more.

Stephan has discussed fermentation a bit on his blog:

Healthy grain-based African cultures typically soaked, ground and fermented their grains before cooking, creating a sour porridge that's nutritionally superior to unfermented grains. The bran was removed from corn and millet during processing, if possible. Legumes were always soaked prior to cooking.

These traditional food processing techniques have a very important effect on grains and legumes that brings them closer in line with the "paleolithic" foods our bodies are designed to digest. They reduce or eliminate toxins such as lectins and tannins, greatly reduce anti-nutrients such as phytic acid and protease inhibitors, and improve vitamin content and amino acid profile. Fermentation is particularly effective in this regard. One has to wonder how long it took the first agriculturalists to discover fermentation, and whether poor food preparation techniques or the exclusion of animal foods could account for their poor health.

Seth Roberts - Healthy bacteria

What has realy got me thinking about this has been some of the musings of Seth Roberts. Seth has a fascinating blog built really on his practice of self experimentation (big pdf download)

Anyway one of his recent theories is the Umami Hypothesis.

the idea that evolution shaped us to like umami taste, sour taste, and complex flavors so that we will eat more harmless-bacteria-laden food, which improves immune function. (I pompously call this the umami hypothesis.) It seemed so likely to be true that I started eating more fermented foods: miso, kimchi, yogurt, buttermilk, smelly cheese, and wine. To avoid stomach cancer and high blood pressure, I later cut back on miso, kimchi, and smelly cheese.

There have been other changes, too:

• After buying meat or fish, I don’t try to get home quickly to put it in the fridge
• I don’t worry that eggs have been in the fridge for 3 weeks
• When buying eggs and other perishables, I don’t try to get the freshest
• I don’t worry about leaving milk out

Bacteria and viruses from other humans pose a threat. This is why we find fecal matter so offensive. It’s why hand-washing by doctors matters. But I believe plant-grown and dirt-grown bacteria are harmless because the substrates are so different than conditions inside our bodies. As for meat-, fish-, and dairy-grown bacteria, I don’t think they are very dangerous. Has anyone gotten food poisoning from yogurt? I keep in mind how much stinky fish the Eskimos ate. Maybe I should do some controlled rotting experiments — leave meat at room temperature for varying lengths of time before cooking and eating it.

Also here:

My idea that we like umami tastes, sour tastes, and complex flavors so that we will eat more bacteria-laden food (which nowadays would be fermented food) is saying that we need plenty of these foods. Why else would evolution have tried so hard to make us eat them? The implication is they should be part of every diet, like Vitamin C. When someone deficient in any vitamin begins eating that vitamin, the deficiency symptoms go away very quickly, within a few weeks, usually. The changes are easy to notice. So the details of what Tucker observed - the speed and size of the improvements — support my general idea that there is a widespread deficiency here that can be easily fixed.

Rotten Fish

His theory is consistent with a lot of the ideas of Stephan and Fallon; they also line up strongly with the hygiene hypothesis.

Seth has a series of fascinating posts of this topic - fermented food - which are well worth skimming through.

Roberts also points out that Steffanson - a hero of my friends in the zero carb world - found that Eskimos would eat a lot of rotten - fermented - fish, and he himself ended up enjoying the dish:

I had become as fond of raw fish as if I had been a Japanese. I like fermented (therefore slightly acid) whale oil with my fish as well as ever I liked mixed vinegar and olive oil with a salad. But I still had two reservations against Eskimo practice; I did not eat rotten fish and I longed for salt with my meals.

There were several grades of decayed fish. The August catch had been protected by longs from animals but not from heat and was outright rotten. The September catch was mildly decayed. The October and later catches had been frozen immediately and were fresh. There was less of the August fish than of any other and, for that reason among the rest, it was a delicacy - eaten sometimes as a snack between meals, sometimes as a kind of dessert and always frozen, raw.

In midwinter it occurred to me to philosophize that in our own and foreign lands taste for a mild cheese is somewhat plebeian; it is at least a semi-truth that connoisseurs like their cheeses progressively stronger. The grading applies to meats, as in England where it is common among nobility and gentry to like game and pheasant so high that the average Midwestern American or even Englishman of a lower class, would call them rotten.

I knew of course that, while it is good form to eat decayed milk products and decayed game, it is very bad form to eat decayed fish. I knew also that the view of our populace that there are likely to be "ptomaines" in decaying fish and in the plebeian meats; but it struck me as an improbable extension of the class-consciousness that ptomaines would avoid the gentleman's food and attack that of a commoner.

These thoughts led to a summarizing query; If it is almost a mark of social distinction to be able to eat strong cheeses with a straight face and smelly birds with relish, why is it necessarily a low taste to be fond of decaying fish? On that basis of philosophy, though with several qualms, I tried the rotten fish one day, and if memory servers, like it better than my first taste of Camembert. During the next weeks I became fond of rotten fish.

Pickled Mammoths

Linking this back to the whole evolutionary fitness, palaeolithic hunter gatherer diet is this:

I came across something interesting about fermentation in the latest National Geographical. The cover story is about the discovery of a baby mammoth in Siberia. Although when found it was free of the ice it hadn’t decayed. On examination it was found that it had been “pickled” just through being in the water and thus preserved.

This was noticed by one of the researchers who noticed the pickled smell as he was doing the dissection. It reminded him of experiments that he had done to see whether primitive hunter gatherers could have preserved meat in this way. He submerged meat in a pool of water and found it was naturally pickled by the bacteria present. Hence his theory that hunters could have killed large prey (mammoths) and then preserved / fermented / pickled the meat for a long period after:

It is covered here:

Tikhonov knew that no one would be more excited by the find than Dan Fisher, an American colleague at the University of Michigan. Fisher is a soft-spoken, 59-year-old paleontologist with a bristly white beard and clear green eyes who has devoted much of the past 30 years to understanding the lives of Pleistocene mammoths and mastodons, combining fossil studies with some very hands-on experimental research.

Curious to know how Paleolithic hunters managed to store mammoth meat without spoilage, Fisher butchered a draft horse using stone tools he’d knapped himself, then cached the meat in a stock pond. Naturally preserved by microbes called lactobacilli in the water, the flesh emitted a faintly sour, pickled odour that put off scavengers even when it floated to the surface. To test its palatability, Fisher cut and ate steaks from the meat every two weeks from February until high summer, demonstrating that mammoth hunters might have stored their kills in the same way.

Also here

Based on previous experiments aimed at understanding how Paleolithic hunters stored meat from large animal kills, Fisher believes Lyuba was naturally pickled in lactic acid produced by microbes called lactobacilli. The pickling would have protected her body from decomposition, and the sour smell likely deterred scavengers.

So it is plausible that pickled meat - meat preserved through the same process of lacto fermentation that produced yoghurt or sauerkraut - is an ancient food......


What am I doing?


In the last week I have started eating some live yoghurt, kefir - when I can get it - and some genuine sauerkraut. I'll see how it goes.