Saturday, April 23, 2016

The impressive nutrition value of whole dried small fish

When I visited Japan several years ago I noticed a variety of dried small fish for sale in grocery stores and supermarkets. They came in what seemed to be vacuum-packed flat plastic bags, often dried. The packing was a bit like that of beef jerky in the USA. Since I could not read the labels, I could not tell if preservatives or things like sugar were added. Beef jerky often has sugar added to it; at least the popular brands.

I have since incorporated dried or almost dried small fish, eaten whole, into my diet. My family eats it, but they don’t seem to like it as much as I do. The easiest small fish to find for sale where I live are smelts. A previous post has a recipe (). I can easily eat 200 g of smelts, about twice as much as on the plate below; not quite dried, but almost so. The veggies are a mix of lettuce and cabbage.


As you can see from the macronutrient composition below (from Nutritiondata.com, for a 100 g portion), 200 g of smelts have about 112 g of protein, and 36 g of fat. No carbohydrates; or a very small amount of them.


Unless you misguidedly think that they will “give you cholesterol”, the macronutrient to calorie ratio of a plate with 200 g of dried (or almost dried) smelts is very good. Let us take a look at the fat content, below (from Nutritiondata.com as well), which is for 100 g of dried smelts.


The “net” omega-3 content of 200 g of dried smelts, after subtracting the omega-6 content, is approximately 4.4 g. The concept of “net” omega-3 content was discussed in a previous post ().

So, the net omega-3 content of 200 g of dried smelts is the equivalent to the net omega-3 content of about 20 fish oil softgels. (Yes, you read it right!) And you would get a lot more omega-6 from the softgels.

Not to mention the fact that isolated omega-3 and omega-6 fats tend to become oxidized much more easily than when they come in “nature’s package”.

Below is the mineral content (also from Nutritiondata.com) of a 100 g portion. Dried smelts are clearly a very good source of selenium. The significant amount of calcium comes mostly from the bones, as with many varieties of small fish that are eaten whole. Combined with the above, we could say that, overall, the nutrient content is high up there next to beef liver as a super food; a natural multivitamin, if you will.


Smelts, like many small non-predatory fish, are not a significant source of toxic metals. Many people avoid seafood because of concerns about toxic metal contamination, particularly mercury. The infamous incident that led to a major scare in that respect – in Minamata, Japan – did involve consumption of small marine animals. But it also involved years of direct and indirect exposure to very high levels of methylmercury from untreated industrial waste.

Other cases have been reported among populations consuming large amounts of whale, shark, dogfish and other relatively large marine animals with tissues compromised via biomagnification. Generally speaking, large predatory fish and predatory aquatic mammals are best avoided as food. If they are consumed, they should be consumed very sporadically.

Many people would say that a plate like the one above, with smelts and veggies, is not very appetizing. But I can really devour it quickly and go for seconds. How come? I use a special spice that enhances the natural flavor or almost any combination of “natural” foods – foods that are not engineered by humans – making them taste delicious.

This special spice is “hunger”. This spice can be your best friend, or your worst enemy.

Sunday, March 27, 2016

Subcutaneous versus visceral fat: How to tell the difference?

The photos below, from Wikipedia, show two patterns of abdominal fat deposition. The one on the left is predominantly of subcutaneous abdominal fat deposition. The one on the right is an example of visceral abdominal fat deposition, around internal organs, together with a significant amount of subcutaneous fat deposition as well.


Body fat is not an inert mass used only to store energy. Body fat can be seen as a “distributed organ”, as it secretes a number of hormones into the bloodstream. For example, it secretes leptin, which regulates hunger. It secretes adiponectin, which has many health-promoting properties. It also secretes tumor necrosis factor-alpha (more recently referred to as simply “tumor necrosis factor” in the medical literature), which promotes inflammation. Inflammation is necessary to repair damaged tissue and deal with pathogens, but too much of it does more harm than good.

How does one differentiate subcutaneous from visceral abdominal fat?

Subcutaneous abdominal fat shifts position more easily as one’s body moves. When one is standing, subcutaneous fat often tends to fold around the navel, creating a “mouth” shape. Subcutaneous fat is easier to hold in one’s hand, as shown on the left photo above. Because subcutaneous fat tends to “shift” more easily as one changes the position of the body, if you measure your waist circumference lying down and standing up, and the difference is large (a one-inch difference can be considered large), you probably have a significant amount of subcutaneous fat.

Waist circumference is a variable that reflects individual changes in body fat percentage fairly well. This is especially true as one becomes lean (e.g., around 14-17 percent or less of body fat for men, and 21-24 for women), because as that happens abdominal fat contributes to an increasingly higher proportion of total body fat. For people who are lean, a 1-inch reduction in waist circumference will frequently translate into a 2-3 percent reduction in body fat percentage. Having said that, waist circumference comparisons between individuals are often misleading. Waist-to-fat ratios tend to vary a lot among different individuals (like almost any trait). This means that someone with a 34-inch waist (measured at the navel) may have a lower body fat percentage than someone with a 33-inch waist.

Subcutaneous abdominal fat is hard to mobilize; that is, it is hard to burn through diet and exercise. This is why it is often called the “stubborn” abdominal fat. One reason for the difficulty in mobilizing subcutaneous abdominal fat is that the network of blood vessels is not as dense in the area where this type of fat occurs, as it is with visceral fat. Another reason, which is related to degree of vascularization, is that subcutaneous fat is farther away from the portal vein than visceral fat. As such, it has to travel a longer distance to reach the main “highway” that will take it to other tissues (e.g., muscle) for use as energy.

In terms of health, excess subcutaneous fat is not nearly as detrimental as excess visceral fat. Excess visceral fat typically happens together with excess subcutaneous fat; but not necessarily the other way around. For instance, sumo wrestlers frequently have excess subcutaneous fat, but little or no visceral fat. The more health-detrimental effect of excess visceral fat is probably related to its proximity to the portal vein, which amplifies the negative health effects of excessive pro-inflammatory hormone secretion. Those hormones reach a major transport “highway” rather quickly.

Even though excess subcutaneous body fat is more benign than excess visceral fat, excess body fat of any kind is unlikely to be health-promoting. From an evolutionary perspective, excess body fat impaired agile movement and decreased circulating adiponectin levels; the latter leading to a host of negative health effects. In modern humans, negative health effects may be much less pronounced with subcutaneous than visceral fat, but they will still occur.

Based on studies of isolated hunger-gatherers, it is reasonable to estimate “natural” body fat levels among our Stone Age ancestors, and thus optimal body fat levels in modern humans, to be around 6-13 percent in men and 14–20 percent in women.

If you think that being overweight probably protected some of our Stone Age ancestors during times of famine, here is one interesting factoid to consider. It will take over a month for a man weighing 150 lbs and with 10 percent body fat to die from starvation, and death will not be typically caused by too little body fat being left for use as a source of energy. In starvation, normally death will be caused by heart failure, as the body slowly breaks down muscle tissue (including heart muscle) to maintain blood glucose levels.

References:

Arner, P. (2005). Site differences in human subcutaneous adipose tissue metabolism in obesity. Aesthetic Plastic Surgery, 8(1), 13-17.

Brooks, G.A., Fahey, T.D., & Baldwin, K.M. (2005). Exercise physiology: Human bioenergetics and its applications. Boston, MA: McGraw-Hill.

Fleck, S.J., & Kraemer, W.J. (2004). Designing resistance training programs. Champaign, IL: Human Kinetics.

Taubes, G. (2007). Good calories, bad calories: Challenging the conventional wisdom on diet, weight control, and disease. New York, NY: Alfred A. Knopf.

Monday, February 29, 2016

Book review: The Eclipse of a Mind


The Eclipse of a Mind () is a 722-page book published in 1942 that describes the life of Alonzo Graves. Alonzo is also listed as the author of the book, even though the narrative is not that of a typical autobiography.

The book is an in-depth study of manic depression. Alonzo is the sufferer. He is a very intelligent college dropout journalist who narrates his lifelong struggle for mental balance. We are taken through World War I, the great Great Depression (iconic photo below: ), the various treatments of bacterial diseases prior to antibiotics, among a variety of other topics; all through Alonzo’s eyes.



This book is rather “dense”, and not very easy to read in a linear fashion – i.e., from beginning to end. Since it is annotated, with comments by various psychiatrists and medical doctors who examined and treated Alonzo, the book is fairly repetitive at points. Nevertheless, it is a fascinating read.

Alonzo delves into important historical events that many today are likely unaware of, such as the Bonus Expeditionary Force movement in the 1930s. World War I veterans had been issued paper money that they could not exchange for real money until 1945. Out-of-work veterans revolted during the Great Depression, demanding early payment. Alonzo was right in the middle of this movement, acting as a journalist and taking the side of the veterans. The ensuing stress caused a manic episode that eventually led to Alonzo's hospitalization.

Manic episodes are characterized by euphoric states and increased levels of activity. The episodes are often triggered by stress. Some people become creative and highly productive during manic states, whereas others become irritable and prone to engaging in risky behavior. Frequently manic episodes are followed by debilitating depression ().

Alonzo’s falls into manic states usually started with benign increases in work-related activity. However, as that high-energy state was maintained for various consecutive days, causing periods of very poor sleep, it often led to psychotic or near-psychotic episodes. This produced a total of five hospitalizations, all of which are described in detail in the book. The book ends with Alonzo moving to Russia, whose government ideology he admired, and never being heard of again.

One of the most interesting aspects of this book is Alonzo’s insights into other people’s mental illnesses, some of whom were manic depressive, combined with his inability to recognize the signs of his own illness. Notably, Alonzo was unable to recognize early signs, or “prodomes” (), which made it difficult for him to avoid entering manic states.

As noted earlier, this book is not an easy read. And it is an old book, copies of which are probably difficult to find today. Nevertheless, it is unique in its tell-it-all style, with detailed narratives from both the patient and doctors about a mental illness that is widespread today. Manic depression is an eminently treatable condition that tends to be highly correlated with creating intelligence ().

A frequently unrecognized reality is put forth by this book. Manic depression is not a “new” condition, even though it may be a “disease of civilization”. The levels of sustained stress found in urban societies are probably much higher than those experienced by our ancestors during most of our evolutionary history, and stress is a trigger of manic depression symptoms. The Eclipse of a Mind is a goldmine of insights into this condition.

Saturday, February 20, 2016

How much dietary protein can you store in muscle? About 15 g/d if you are a gifted bodybuilder

Let us say you are one of the gifted few who are able to put on 1 lb of pure muscle per month, or 12 lbs per year, by combining strength training with a reasonable protein intake. Let us go even further and assume that the 1 lb of muscle that we are talking about is due to muscle protein gain, not glycogen or water. This is very uncommon; one has to really be genetically gifted to achieve that.

And you do that by eating a measly 80 g of protein per day. That is little more than 0.5 g of protein per lb of body weight if you weigh 155 lbs; or 0.4 per lb if you weigh 200 lbs. At the end of the year you are much more muscular. People even think that you’ve been taking steroids; but that just came naturally. The figure below shows what happened with the 80 g of protein you consumed every day. About 15 g became muscle (that is 1 lb divided by 30) … and 65 g “disappeared”!


Is that an amazing feat? Yes, it is an amazing feat of waste, if you think that the primary role of protein is to build muscle. More than 80 percent of the protein consumed was used for something else, notably to keep your metabolic engine running.

A significant proportion of dietary protein also goes into the synthesis of albumin, to which free fatty acids bind in the blood. (Albumin is necessary for the proper use of fat as fuel.) Dietary protein is also used in the synthesis of various body tissues and hormones.

Dietary protein does not normally become body fat, but can be used in place of fat as fuel and thus allow more dietary fat to be stored. It leads to an insulin response, which causes less body fat to be released. In this sense, dietary protein has a fat-sparing effect, preventing it from being used to supply the energy needs of the body.

Nevertheless, the fat-sparing effect of protein is lower than that of another "macronutrient" – alcohol. That is, alcohol takes precedence over protein and carbohydrates for use as fuel. Protein takes precedence over carbohydrates. Neither alcohol nor protein typically becomes body fat. Carbohydrates can become body fat, but only when glycogen stores are full.

What does this mean?

As it turns out, a reasonably high protein intake seems to be quite healthy, and there is nothing wrong with the body using protein to feed its metabolism.

Having said that, one does not need enormous amounts of protein to keep or even build muscle if one is getting enough calories from other sources.

Tuesday, January 26, 2016

Wheat flour, rice and vascular diseases in the China Study II data: Article on Cliodynamics


My article on volume 6, number 2, of the journal Cliodynamics has recently been published; it is titled “Wheat flour versus rice consumption and vascular diseases: Evidence from the China Study II data” (). While this is an academic article, I think that the main body of the article is fairly easy to read. More technical readers may want to check under “Supporting material”, which is one of the links on the left, where they will find a detailed description of the data used and the results of some specialized statistical tests.

In the past I have discussed in this blog the associations with vascular diseases, in the China Study dataset, of wheat flour and rice consumption. The interest in the possible effects of wheat flour AND rice consumption comes from the fact that these foods are similar in some important respects – e.g., they tend to raise insulin levels in similar ways. But as you will see in the article, their associations with vascular diseases are clearly different, particularly when we conduct nonlinear analyses.

While I do not think that wheat flour consumption per se is particularly healthy, the results of the analysis go somewhat against the idea that wheat flour intake is the primary culprit with respect to vascular diseases. The results also go somewhat against the “insulin theory of obesity”, at least in a narrow sense, and call for a broader explanation that includes cultural elements. These points are further elaborated in the article. There is speculation in the article, and also a discussion of possible limitations.

Enjoy!

Saturday, January 2, 2016

Do prominent health gurus live longer?


Many years ago, when I started blogging about health issues, I noticed a couple of interesting patterns. The first pattern is that prominent health “gurus” often talk about having had serious health problems in their past, which they describe as having motivated them to do research on health issues – and thus become health gurus. Frequently these problems pop up before 45 years of age; this is a threshold beyond which there is a clearly noticeable increase in severity of health problems.

In fact, I remember being somewhat surprised by one such “guru” (I will not name him), who would regularly write posts saying something to the effect that “… finally, my health is now on the right track …” In other words, every few months or so this person had to deal with serious health problems, always coming up with reasonable knowledge-based solutions. The knowledge seemed to be of good quality, but this guy’s health was poor to say the least.

The second pattern, related to the above, is that prominent health gurus seem to have a below average life expectancy. The life expectancy for the general population is around 79 years of age in the USA at the time of this writing, according to the World Health Organization (). Anthony Colpo has written an interesting post about this below average life expectancy pattern among health gurus ().

To better understand and illustrate this situation to our blog’s readers, I created a dataset with 100 records, corresponding to 100 health gurus, with various variables interacting in ways that reflect the above observations. The observations are summarized as assumptions, listed later. The following variables are on a scale from 1 to 7; in real life they would have been measured retrospectively, looking back at a guru’s entire life:

- The guru's health before age 45 (BEF45).

- The guru's knowledge about health issues (KNOWL).

- The guru's health after age 45 (AFT45).

- The guru's prominence (GPROM).

Finally, the variable below is on a continuous scale of years, with an average of 79 and a standard deviation of 10. As mentioned earlier, 79 is the life expectancy for someone living in the USA at the time of this writing. The standard deviation of 10, which approximates that figure in the USA, means that approximately 68 percent of the individuals in the simulated dataset will have a life expectancy between 69 and 89. That is 79-10 and 79+10, respectively.

- The guru's age at the time of death (GAGED).

This experimental exercise with simulated data can be seen as a simulation “game”, where various variables interact to generate results that are not obvious. A widely used process to create data is known as the Monte Carlo method (), which is what we used here. I also made the following assumptions in the data creation process:

- That the poorer is the guru's health before age 45 (BEF45), the greater is the guru's knowledge about health issues (KNOWL). The reason for this is that poor health compels the person to study about health issues.

- That the poorer is the guru's health before age 45 (BEF45), the poorer is the guru's health after age 45 (AFT45). This assumes that the person has an underlying condition that causes the poor health in the first place, and that can be exacerbated by a poor diet and lifestyle.

- That the greater is the guru's knowledge about health issues (KNOWL), the better is the guru's health after age 45 (AFT45). This counteracts the effect above, and assumes that the knowledge is put to good use and contributes to improving the person’s health.

- That the greater is the guru's knowledge about health issues (KNOWL), the greater is also the guru's prominence (GPROM). In other words, a guru’s status among followers is enhanced by the guru’s knowledge.

- That the better is the guru's health after age 45 (AFT45), the higher is the guru's age at the time of death (GAGED).

A final assumption made is that the causal relationships laid out above have a small effect size (more technically, that they are associated with f-squared coefficients slightly below 0.1), meaning that random influences are not only present but also play a big role in what happens in the simulation. The causality links are summarized in the graph below, created with WarpPLS (). We also used this software to analyze the data.



Note that in our simulated data the guru's prominence (GPROM) does not directly influence the guru's age at the time of death (GAGED). Stated differently, there is no causality link between GPROM and GAGED, one way or the other, even though these two variables are likely to be correlated due to the network of causality links in which they exist. Nevertheless, it is by looking at the relationship between these two variables, GPROM and GAGED, that we can answer the question in the title of this post: Do prominent health gurus live longer?

And the answer appears to be “no” in our simulation. The plot below shows the relationship between a guru's prominence (GPROM), on the horizontal axis, and the guru's age at the time of death (GAGED), on the vertical axis. Each data point refers to a guru. On average, the greater a guru's prominence, the lower seems to be the guru’s life expectancy. Each one-point increase in prominence is associated, on average, with approximately a one-year decrease in life expectancy.



Note that there is one very prominent guru whose age at the time of death was around 95; the data point at the top-right corner (GPROM=7, GAGED~95). This happened largely by chance in our data. Nevertheless, assuming that our data somewhat reflects what could happen in real life, the followers of the guru would probably point at that longevity as being caused by the guru’s knowledge about health issues. They would likely be wrong.

Our dataset also allows us to estimate the probability that a fairly prominent guru (GPROM greater than 4, on a 1-7 scale) would have a below average life expectancy (GAGED lower than 79). That conditional probability would be approximately 60 percent.

Wednesday, December 23, 2015

You can eat a lot during the Holiday Season and gain no body fat, as long as you also eat little


The evolutionary pressures placed by periods of famine shaped the physiology of most animals, including humans, toward a design that favors asymmetric food consumption. That is, most animals are “designed” to alternate between eating little and then a lot.

Often when people hear this argument they point out the obvious. There is no evidence that our ancestors were constantly starving. This is correct, but what these folks seem to forget is that evolution responds to events that alter reproductive success rates (), even if those events are rare.

If an event causes a significant amount of death but occurs only once every year, a population will still evolve traits in response to the event. Food scarcity is one such type of event.

Since evolution is blind to complexity, adaptations to food scarcity can take all shapes and forms, including counterintuitive ones. Complicating this picture is the fact that food does not only provide us with fuel, but also with the sources of important structural components, signaling elements (e.g., hormones), and process catalysts (e.g., enzymes).

In other words, we may have traits that are health-promoting under conditions of food scarcity, but those traits are only likely to benefit our health as long as food scarcity is relatively short-term. Not eating anything for 40 days would be lethal for most people.

By "eating little" I don’t mean necessarily fasting. Given the amounts of mucus and dead cells (from normal cell turnover) passing through the digestive tract, it is very likely that we’ll be always digesting something. So eating very little within a period of 10 hours sends the body a message that is similar to the message sent by eating nothing within the same period of 10 hours.

Most of the empirical research that I've reviewed suggests that eating very little within a period of, say, 10-20 hours and then eating to satisfaction in one single meal will elicit the following responses. Protein phosphorylation underlies many of them.

- Your body will hold on to its most important nutrient reserves when you eat little, using selective autophagy to generate energy (, ). This may have powerful health-promoting properties, including the effect of triggering anti-cancer mechanisms.

- Food will taste fantastic when you feast, to such an extent that this effect will be much stronger than that associated with any spice ().

- Nutrients will be allocated more effectively when you feast, leading to a lower net gain of body fat ().

- The caloric value of food will be decreased, with a 14 percent decrease being commonly found in the literature ().

- The feast will prevent your body from down-regulating your metabolism via subclinical hypothyroidism (), which often happens when the period in which one eats little extends beyond a certain threshold (e.g., more than one week).

- Your mood will be very cheerful when you feast, potentially improving social relationships. That is, if you don’t become too grouchy during the period in which you eat little.

I recall once participating in a meeting that went from early morning to late afternoon. We had the option of taking a lunch break, or working through lunch and ending the meeting earlier. Not only was I the only person to even consider the second option, some people thought that the idea of skipping lunch was outrageous, with a few implying that they would have headaches and other problems.

When I said that I had had nothing for breakfast, a few thought that I was pushing my luck. One of my colleagues warned me that I might be damaging my health irreparably by doing those things. Well, maybe they were right on both grounds, who knows?

It is my belief that the vast majority of humans will do quite fine if they eat little or nothing for a period of 20 hours. The problem is that they need to be convinced first that they have nothing to worry about. Otherwise they may end up with a headache or worse, entirely due to psychological mechanisms ().

There is no need to eat beyond satiety when you feast. I’d recommend that you just eat to satiety, and don’t force yourself to eat more than that. If you avoid industrialized foods when you feast, that will be even better, because satiety will be achieved faster. One of the main characteristics of industrialized foods is that they promote unnatural overeating; congrats food engineers on a job well done!

If you are relatively lean, satiety will normally be achieved with less food than if you are not. Hunger intensity and duration tends to be generally associated with body weight. Except for dedicated bodybuilders and a few other athletes, body weight gain is much more strongly influenced by body fat gain than by muscle gain.