The problem with this article are statements about value of "fermentable" fiber without giving any real info about the nature of such fiber. (Except it's not digested by gut enzymes, hence "leftovers" that colonic organisms may be able to "ferment".)
There are many kinds of dietary fiber, it's actually quite a complex subject. The basic classification of "soluble" and "insoluble" is not very informative. As the article says, there are a great number of different organisms that can inhabit the "biome", each species of bacteria, fungus, virus, etc. has its own preferred substrates, and produces its own particular set of fermentation products.
I believe the research on biome activity is complicated by the vast range of variation among the organisms as well as the sorting out the beneficial or harmful effects of their activity on the host. And of course, we must not forget hosts also show a range of characteristics and are dynamically variable too.
As the article hints, research shows biome effects on many body functions, such as immune system and metabolic function. However, pinning down specifically what substrates are important to which organisms producing helpful/harmful effects is a daunting mission.
It's going to take a great deal more study before we will begin to have any clear idea about exactly which of the million different forms of fiber is going to be good (or bad) for any given health issue.
Yet people have had healthy diets long before we had science or awareness of gut microbes. Eating healthy is simple; Let's not overcomplicate it.
While reductionism is useful to learn about the constituent parts of a system, let's not forget that we don't know many things & it's ok.
In complex systems, it's important is to work with principles. Facts are nice & can be used to fine tune principles, however facts don't create a strategy.
More research is always nice, but you can get a long way with the two words I learned as a biological anthropology undergrad: dietary diversity.
Eating well isn't rocket science. Eat a wide range of foods. Then you'll very likely hit all the things you need, and not take on harmful amounts of the things you don't. Plus you'll get to enjoy the variety along the way.
As a physician I think the diversity hypothesis should really be challenged. Our guts, microbes, and even genes take a while to change. Is diversity really helpful or harmful?
When you study people that live to be very old, many of them eat the same simple things on a daily basis for decades.
As an interested layman, I've wondered about this myself. Ecosystems take a while to stabilize around local maxima. So, although diversity may prevent you from falling into any particular deficiency, it seems possible that a well balanced diet that remained stable over time would allow your flora to really dial in.
You could also be avoiding potentially harmful substances which a diverse diet might have exposed you to. That they lived into their 90s on the same diet they had in their 20's implies they skipped TV dinners, Aerosol Cheese and McDonalds along the way.
I used to be more careful what I ate, but in the last few years I started a simpler approach: about 60% of my diet is vegetable matter (bok choy, carrots, broccoli , etc. in the winter -- more squash, tomatoes, etc. in the summer).
To the point of the article: I do like fermented foods. My home made pressed cabbage being a favorite, but a local health food store features locally produced live sauerkrauts, kimchi, etc. All tasty stuff.
I think that it is pretty simple: avoid sugar, avoid processed food, and then whatever you eat enjoy it.
I think I've said this to you before, but you need to use some other word than processed. Especially if you are talking about fermented foods being good, as that is sort of a classic way of processing food.
Thanks Max, I should have made that more clear. By 'processed' I intended not eating packaged foods (cereals, frozen food, bread with lots of preservatives, etc.)
Basically, starting with fresh ingredients and cooking food yourself. In some areas, I have found inexpensive restaurants that do this. There was a vegetarian restaurant my wife and I liked in Milpitas California, about 10 miles from the Googleplex, that I would like physically moved to the town I live in :-) Seriously, you could look back in the kitchen and see lots of fresh food, food was made to order, and their prices were low.
We like to cook, but I realize that not everyone has the time to cook from fresh ingredients.
(Just like "enough vitamins", "no fat", "no trans-fat", "no cholesterol", "no carbs", "enough poly-saturated fat", "enough omega 3" seemed to be the solution before)
Anyone with background knowledge can reason for or against the article?
In general, eating the same diet as thin/healthy people will cause your microbiome to shift toward the microbiome of thin/healthy people. This is because your microbial population is largely determined by resource availability and resource type, and adaptation happens quite quickly (ie speeds not unlike those shown in http://www.youtube.com/watch?v=Pb272zsixSQ)
However, I believe it's wrong to conclude that thin/healthy people have the kind of microbiome you should be aiming for.
The microbiome you want (or rather I want) is the one my ancestor's had, just like I want the food I eat to be similar to the food my ancestor's ate. Unfortunately this is basically impossible given modern farming techniques, which remove most of the food-borne microbes found on natural crops.
> Why? Do you think your ancestors were especially healthy?
It's the null hypothesis. For me personally, it's more a bet against the modern microbiome than it is a bet for the ancestral one.
See also paleo vs margarine, no fat, no cholesterol, no carbs, enough poly-saturated fat, enough omega 3. Really paleo vs any nutrition advice that's more than 10 years old (so the science had a chance to check the claims)
IMO we don't currently know enough about nutrition or the microbiome to make a better choice than "whatever our great-great-great grandparents did"
I think it's bananas that you're advocating for historical eating and getting downvoted. The only reason we're here at all is that it worked well enough to keep people alive.
Maybe it's not "optimal" but considering that obesity, heart disease, diabetes, cancer, etc rates have all been climbing like crazy for the last 50 years and the diet has changed a lot in the last 50 years, it's not outside the realm of possibility that the change in diet is causative towards these outcomes rather than simply correlated.
And considering how long it's going to take to sort it out definitively, you might have to go most of your life making decisions based on a hunch rather than with proven science. It sucks, but that's life.
Maybe it's not "optimal" but considering that obesity, heart disease, diabetes, cancer, etc rates have all been climbing like crazy for the last 50 years
The statement you make here is a commonly made statement here on Hacker News, and I believe you are making it honestly based on the latest information you heard. Nevertheless, the statement is incorrect in large part. You are correct that rates of obesity are going up. But age-adjusted rates of heart disease, cancer, and several other diseases are steadily going down and have been going down for my whole lifetime (more than fifty years).[1] That's why the greatest increase in life expectancy in recent years in developed countries is actually coming from reduced death rates at OLD ages--the infant mortality rates in developed countries have already been very low for most of my lifetime. See an article in a series on Slate, "Why Are You Not Dead Yet? Life expectancy doubled in past 150 years. Here’s why"[2] for more background information.
>heart disease, diabetes, cancer, etc rates have all been climbing like crazy for the last 50 years
I'm not sure about that, in the past the diagnosis were really different from now so you can't really compare them.
Also the lifespan was much shorted at that time, so people had less changes to get these illnesses.
I read somewhere (I can't find it after googling extensively) that the first couple of generations of Europeans to settle in the US had a pretty long life expectancy mostly because the escaped crowded cities. Sanitation hadn't been figured out yet, but the population was so sparse the drinking water hadn't been contaminated to a considerable degree, etc.
Of course as cities were built, the life expectancy went right back down to the 35-40 years it had been previously.
You're right of course that living longer gives us the chance to get "old people's" diseases. But the majority of the gains were made from 1900 to the 1940s, the climb is much, much slower after that.
Dan, I know you like to check your facts. Age-adjusted rates of cancer have been going steadily down throughout our lifetimes. That information has been posted to Hacker News before.
Yes, the absolute number of cancer cases experienced by an individual over the course of life will increase if the individual lives longer by surviving other causes of death, as cancer is mostly a disease that takes a long time to develop. But at a given age, individuals in the developed world are at less risk than ever before to have a case of cancer, and cancer cases are less likely to have fatal outcomes than ever before.
I'm kind of baffled at the downvotes here, is this not a legitimate question or method of debate? I'm not spewing tropes or memes like on reddit. I thought here it's discouraged to downvote because you disagree as well as reddit, but it seems the intellectual levels are even lower than reddit.
Oh, I see, you downvote people other than the hivemind comments so that they never reach the levels to downvote themselves. I get it. Kinda sad and pathetic, but whatever, Internet numbers don't mean quite that much to me. It's additonally sad that I don't have any discreditation to my comment. You know you are wrong, but you downvote me anyway.
If you want an archaic microbiome, you may want to investigate the probiotic offered by General Biotics[1], featured a few times on HN. 100+ species of microbes that are both well-studied and missing from modern processed foods. I haven't tried it yet myself and I never got a response when I asked how long one has to take the supplement in order to feel results on average. It's an interesting idea and appears to be well-received by those who've tried it though.
There are many kinds of dietary fiber, it's actually quite a complex subject. The basic classification of "soluble" and "insoluble" is not very informative. As the article says, there are a great number of different organisms that can inhabit the "biome", each species of bacteria, fungus, virus, etc. has its own preferred substrates, and produces its own particular set of fermentation products.
I believe the research on biome activity is complicated by the vast range of variation among the organisms as well as the sorting out the beneficial or harmful effects of their activity on the host. And of course, we must not forget hosts also show a range of characteristics and are dynamically variable too.
As the article hints, research shows biome effects on many body functions, such as immune system and metabolic function. However, pinning down specifically what substrates are important to which organisms producing helpful/harmful effects is a daunting mission.
It's going to take a great deal more study before we will begin to have any clear idea about exactly which of the million different forms of fiber is going to be good (or bad) for any given health issue.