Sudden cholesterol increase? It may be psychological

There are many published studies with evidence that cholesterol levels are positively associated with heart disease. In multivariate analyses the effects are usually small, but they are still there. On the other hand, there is also plenty of evidence that cholesterol is beneficial in terms of health. Here of course I am referring to the health of humans, not of the many parasites that benefit from disease.

For example, there is evidence () that cholesterol levels are negatively associated with mortality (i.e., higher cholesterol leading to lower mortality), and are positively associated with vitamin D production from skin exposure to sunlight ().

Most of the debris accumulated in atheromas are made up of macrophages, which are specialized cells that “eat” cell debris (ironically) and some pathogens. The drug market is still hot for cholesterol-lowering drugs, often presented in TV and Internet ads as effective tools to prevent formation of atheromas.

But what about macrophages? What about calcium, another big component of atheromas? If drugs were to target macrophages for atheroma prevention, drug users may experience major muscle wasting and problems with adaptive immunity, as macrophages play a key role in muscle repair and antibody formation. If drugs were to target calcium, users may experience osteoporosis.

So cholesterol is the target, because there is a “link” between cholesterol and atheroma formation. There is also a link between the number of house fires in a city and the amount of firefighting activity in the city, but we don’t see mayors announcing initiatives to reduce the number of firefighters in their cities to prevent house fires.

When we talk about variations in cholesterol, we usually mean variations in cholesterol carried by LDL particles. That is because LDL cholesterol seems to be very “sensitive” to a number of factors, including diet and disease, presenting quite a lot of sudden variation in response to changes in those factors.

LDL particles seem to be intimately involved with disease, but do not be so quick to conclude that they cause disease. Something so widespread and with so many functions in the human body could not be primarily an agent of disease that needs to be countered with statins. That makes no sense.

Looking at the totally of evidence linking cholesterol with health, it seems that cholesterol is extremely important for the human body, particularly when it is under attack. So the increases in LDL cholesterol associated with various diseases, notably heart disease, may not be because cholesterol is causing disease, but rather because cholesterol is being used to cope with disease.

LDL particles, and their content (including cholesterol), may be used by the body to cope with conditions that themselves cause heart disease, and end up being blamed in the process. The lipid hypothesis may be a classic case of reverse causation. A case in point is that of cholesterol responses to stress, particularly mental stress.

Grundy and Griffin () studied the effects of academic final examinations on serum cholesterol levels in 2 groups of medical students in the winter and spring semesters (see table below). During control periods, average cholesterol levels in the two groups were approximately 213 and 216 mg/dl. During the final examination periods, average cholesterol levels were 248 and 240 mg/dl. These measures were for winter and spring, respectively.



One could say that even the bigger increase from 213 to 248 is not that impressive in percentage terms, approximately 16 percent. However, HDL cholesterol does not go up significantly response to sustained (e.g., multi-day) stress, it actually goes down, so the increases reported can be safely assumed to be chiefly due to LDL cholesterol. For most people, LDL particles are the main carriers of cholesterol in the human body. Thus, in percentage terms, the increases in LDL cholesterol are about twice those reported for total cholesterol.

A 32-percent increase (16 x 2) in LDL cholesterol would not go unnoticed today. If one’s LDL cholesterol were to be normally 140 mg/dl, it would jump to 185 mg/dl with a 32-percent increase. It looks like the standard deviations were more than 30 in the study. (This is based on the standard errors reported, and assuming that the standard deviation equals the standard error multiplied by the square root of the sample size.) So we can guess that several people might go from 140 to 215 or more (this is LDL cholesterol, in mg/dl) in response to the stress from exams.

And the effects above were observed with young medical students, in response to the stress from exams. What about a middle-aged man or woman trying to cope with chronic mental stress for months or years, due to losing his or her job, while still having to provide for a family? Or someone who has just been promoted, and finds himself or herself overwhelmed with the new responsibilities?

Keep in mind that sustained dieting can be a major stressor for some people, particular when one gets to that point in the dieting process where he or she gets regularly into negative nitrogen balance (muscle loss). So you may have heard from people saying that, after months or years of successful dieting, their cholesterol levels are inexplicably going up. Well, this post provides one of many possible explanations for that.

The finding that cholesterol goes up with stress has been replicated many times. It has been known for a long time, with studies dating back to the 1950s. Wertlake and colleagues () observed an increase in average cholesterol levels from 214 to 238 (in mg/dl); also among medical students, in response to the mental and emotional stress of an examination week. A similar study to the one above.

Those enamored with the idea of standing up the whole day, thinking that this will make them healthy, should know that performing cognitively demanding tasks while standing up is a known stressor. It is often used in research where stress must be induced to create an experimental condition. Muldoon and colleagues () found that people performing a mental task while standing experienced an increase in serum cholesterol of approximately 22 points (in mg/dl).

What we are not adapted for is sitting down for long hours in very comfortable furniture (, ). But our anatomy clearly suggests adaptations for sitting down, particularly when engaging in activities that resemble tool-making, a hallmark of the human species. Among modern hunter-gatherers, tool-making is part of daily life, and typically it is much easier to accomplish sitting down than standing up.

Modern urbanites could be seen as engaging in activities that resemble tool-making when they produce things at work for internal or external customers, whether those things are tangible or intangible.

So, stress is associated with cholesterol levels, and particularly with LDL cholesterol levels. Diehard lipid hypothesis proponents may argue that this is how stress is associated with heart disease: stress increases cholesterol which increases heart disease. Others may argue that one of the reasons why LDL cholesterol levels are sometimes found to be associated with heart disease-related conditions, such as chronic stress, and other health conditions is that the body is using LDL cholesterol to cope with those conditions.

Specifically regarding mental stress, a third argument has been put forth by Patterson and colleagues, who claimed that stress-mediated variations in blood lipid concentrations are a secondary result of decreased plasma volume. The cause, in their interpretation, was unspecified – “vascular fluid shifts”. However, when you look at the numbers reported in their study, you still see a marked increase in LDL cholesterol, even controlling for plasma volume. And this is all in response to “10 minutes of mental arithmetic with harassment” ().

I tend to think that the view that cholesterol increases with stress because cholesterol is used by the body to cope with stress is the closest to the truth. Among other things, stress increases the body’s overall protein demand, and cholesterol is used in the synthesis of many proteins. This includes proteins used for signaling, also known as hormones.

Cholesterol also seems to be a diet marker, tending to go up in high fat diets. This is easier to explain. High fat diets increase the demand for bile production, as bile is used in the digestion of fat. Most of the cholesterol produced by the human body is used to make bile.

Read more »

Tagging along with Hadleigh HWRC to the Awards for Excellence in Recycling & Waste Management

The team from Hadeigh's HWRC, FCC Environment & Suffolk County Council with BBC's Susanna Reid

Yesterday, I had the real pleasure of tagging along with the Suffolk's Household Waste Recycling Centre team to LetsRecycle.com's Awards for Excellence in Recycling & Waste Management. 

The awards, now in their 10th year, and presented by the BBC's Susanna Reid, were held at the Landmark Hotel, London, a beautiful setting to mark the successes and excellence of the recycling and waste management industry, the kind of things that go on behind the scenes that help the UK recycle more and reduce wasted resources.

I've been singing the praises of Suffolk's recycling facilities as part of the BBC Radio Suffolk Rubbish Diet, so it was great to hear that the Hadleigh HWRC was in the running for the category of Community Amenity Site of the Year,

With composting and recycling rates that exceed 90%, Hadleigh HWRC, managed by Suffolk County Council and FCC Environment, has been identified as Suffolk ’s top performing site, with successful and effective day-to-day operations providing an enhanced service to users.

Both Suffolk County Council and FCC Environment have engaged with local third sector organisations including the Ipswich Furniture project and ‘Re-cycle’ both of which are charities that have diverted items from landfill.  Ipswich Furniture Project provides an outlet for furniture and crockery, with ‘Re-Cycle’ giving unwanted cycles a new life.  This has enabled improvements on the recycling performance within the existing site footprint and moves more of the materials up the waste hierarchy, with almost no environmental impact.

The site only has two members of staff during the week and three at weekends to manage all waste streams and maintain the high recycling rate and excellent customer service. Much of the success of the site's recycling rate is attributed to the site staff and their relationship with the public. 

But these awards always bring stiff competition and this year the team was up against the Witchford HRC, in Cambridgeshire and Witley Community Recycling Centre in Surrey.

And the winner was...... well...  sadly not the team from Hadleigh HWRC on this occasion, but another worthy winner, Witley CRC, which is part of a network of 15 facilities managed by Sita, and which has been redesigned with sustainability at its heart and strong community engagement in its development.

Ooooh, so close!  They may not have won at yesterday's event but being a finalist in the awards and one of the top performing Household Waste Recycling Centre's in the UK, Hadleigh HWRC is most definitely a winner in my eyes and it was great to chat to Mel & Terry (pictured above with Susanna Reid) about their stories of what it's like being on the ground at one of our county's facilities. The passion for what they do is so easy to see.

Once again, in a good way, it felt like I was a bit of a recycling groupie following the band, and a very successful one at that.  Seriously, when you witness how the awards' nominees are changing the future of waste, their efforts, successes and enthusiasm really does rub off.

With wide-ranging categories such as High Street Recycling Champion, Commercial Recycling Champion, Best Community Recycling Initiative and Recycling Businesses of the Year, I wonder if next year, we'll see more entries from Suffolk.  After all, from our own Greenest Suffolk awards and some of the great things coming out of the BBC Radio Suffolk Rubbish Diet, I reckon our county could offer up some stiff competition for next year's awards.

Huge thanks to Letsrecycle.com for letting me come along to support our fantastic team from Suffolk.  There were some great winners and finalists, all which can be seen either on the website or by following the updates on Twitter, using the hashtag #awardsforexcellence.

 

Read more »

Trip to South Korea: Hidden reasons for the leanness of its people

In September last year (2012) I went to South Korea to speak about nonlinear data analysis with WarpPLS (), initially for business and engineering faculty and students at Korea University in Seoul, and then as a keynote speaker at the HumanCom 2012 Conference () in Gwangju. Since Seoul is in the north part of the country, and Gwangju in the south, I had the opportunity to see quite a lot of the land and the people in this beautiful country.


(Korea University’s main entrance, Anam campus)


(In front of Korea University’s main Business School building)

Korea University is one of the most prestigious universities in South Korea. In the fields of business and engineering, it is arguably the most prestigious. It also has a solid international reputation, attracting a large number of highly qualified foreign students.

I wanted to take this opportunity and try to understand why obesity prevalence is so low in South Korea, which is a common characteristic among Southeast Asian countries, even though the caloric intake of South Koreans seems to be relatively high. Foods that are rich in carbohydrates, such as rice, are also high-calorie foods. At 4 calories per gram, carbohydrates are not as calorie-dense as fats (9 calories per gram), but they sure add up and can make one obese.

Based on my observations, explanations for the leanness that are too obvious or that focus on a particular dietary item (e.g., kimchi, green tea etc.) tend to miss the point.

Let us take for example a typical South Korean meal, like the one depicted in the photos below, which we had at a restaurant in Seoul. If you are a foreigner, this type of meal would be difficult to have without a local accompanying you, because it is not easy to make yourself understood in a traditional restaurant in South Korea speaking anything other than Korean.


(Main items of a traditional South Korean meal)


(You cook your own meal)

The meal started with thin-sliced meat (with some fat, but not much) and vegetables, with the obligatory side dishes, notably kimchi (). This part of the meal was low in calories and high in nutrients. Then we had two high-calorie low-nutrient items: noodles and rice. The rice was used in the end to soak up the broth left in the pot, so it ended adding to the nutrition value of the meal.

Because we started the meal with the low-calorie high-nutrient items, the meat and vegetables, our consumption of noodles and rice was not as high as if we had started the meal with those items. In a meal like this, a good chunk of calories would come from the carbohydrate-rich items. Still, it seems to me that we ingested plenty of calories, enough to make one fat over the long run, eating these types of meals regularly.

A side note. As I said here before, the caloric value of protein is less than the commonly listed 4 calories per gram, essentially because protein is a multi-purpose macronutrient.

In our meal, the way in which at least one of the carbohydrate-rich items was prepared possibly decreased its digestible carbohydrate content, and thus its calorie content, in a significant way. I am referring to the rice, which had been boiled, cooled and stored, way before it was re-heated and served. This likely turned some of its starch content into resistant starch (). Resistant starch is essentially treated by our digestive system as fiber.

Another factor to consider is the reduction in the glycemic load (not to be confused with glycemic index) of the rice. As I noted, the rice was used to soak up the broth from the pot. This soaking up process significantly reduces the rice’s glycemic load, because of a unique property of rice. It has an amazing capacity of absorbing liquid and swelling in the process.

This was one of several traditional Korean meals I had, and all of them followed a similar pattern in terms of the order in which the food items were consumed, and the way in which the carbohydrate-rich items were prepared. The order in which you eat foods affects your calorie intake because if you eat high nutrient-to-calorie ratio foods before, and leave the low nutrient-to-calorie ones for later, my experience is that you will eat less of the latter.

Another possible hidden reason for the low rate of obesity in South Korea is what seems to be a cultural resistance to industrialized foods, particularly among older generations; a sort of protective cultural inertia, if you will. Those foods are slowly being adopted – my visit left me with that impression – by not as quickly as in other countries. And there is overwhelming evidence that consumption of highly industrialized foods, especially those rich in refined carbohydrates and sugars, is a major cause obesity and a host of other problems.

Cultural resistance to, or cultural inertia against the adoption of, highly industrialized foods among pregnant mothers limits one’s exposure to those foods at a particularly critical time in one’s life – the 9-month gestation period in the mother’s womb. This could have a major impact on a person’s propensity to become obese or have other metabolic derangements later on in life. Some refer to this phenomenon as a classic example of modern epigenetics, whereby acquired traits appear to induce innate traits across generations.

Another reason I was excited about this trip to South Korea was my interest in table tennis. I wanted to know more about their table tennis “culture”, and how it was influenced by their general culture. China dominates modern table tennis, with such prodigies as Ma Lin, Ma Long, Wang Hao, Wang Liqin, and Zhang Jike. South Korea is not far behind; two of my all-time favorite South Korean players are Kim Taek-Soo and former Olympic champion Ryu Seung-Min.

Another side note. The best table tennis player of all time is arguably Jan-Ove Waldner (), from Sweden. I talked about him in my book on compensatory adaptation (). Waldner has been one of the few players outside China to be able to consistently beat the best Chinese players at times when they were at the top of the games, including Ma Lin ().

But, as I soon learned, as far as sports are concerned, it is not table tennis that most South Koreans are interested in these days. It is soccer.

A nice surprise during this trip was a tour in Gwangju in which we visited a studio that converted standard movies to stereoscopic three-dimensional ones (photo below). These folks were getting a lot of business, particularly from the USA, in a market that is very competitive.


(A standard-to-3D movie conversion studio in Gwangju)

Let’s get back to the health angle of the post. So there you have it, two possible “hidden” reasons for the low prevalence of obesity in South Korea, and maybe in other Southeast Asian countries. One is the way in which foods are prepared and consumed, and the other is cultural inertia. These are not very widely discussed, but future research may change that.

Read more »

Please vote for The Rubbish Diet in celebration of reaching the Brilliance in Blogging shortlist. #BiBs

Click the BiB badge to vote.

I am absolutely chuffed to bits to hear the news that The Rubbish Diet has been shortlisted in this year's Brilliance in Blogging Awards, organised by BritMums, and especially so because it's been included in the Commentary category.

This category features blogs that highlight causes, either through raising awareness or funds, and which are a force for positive change. Topics might be global, local or personal. Whatever the cause, the bloggers shortlisted in this category have been chosen for doing more than their bit, and helping others get involved too.  So to have been nominated alongside so many great bloggers is a real honour.

This news comes at a particular exciting time, having just launched the extension to this blog, i.e. The Rubbish Diet Challenge website, which finally gives people a toolkit to reduce their waste wherever they are, and properly pulls together the learning and experiences of blogging about waste over the last five years.  With over 190 online sign-ups to the challenge (and another 80 offline) in the first 10 days of what has been very much a soft launch, the new site has quickly become the official new home of The Rubbish Diet. 

And it's also become a portal for tracking localised Rubbish Diet projects that are taking place around the country, starting with Suffolk, Shropshire and very soon Powys, sharing skills and local knowledge that can help householders reduce their waste by on average 50% in just eight weeks.  With Wiltshire Wildlife Trust having successfully rolled out the Rubbish Diet as part of their waste reduction campaign and the BBC Radio Suffolk Rubbish Diet recently launched in my neck of the woods, this year feels like a real milestone.  It's no longer just me anymore and that makes me feel like doing a happy dance.

So, if you like what we're doing in helping to put waste higher up the agenda and empowering households and communities to pull-together to slim those bins, please vote for the Rubbish Diet in the Commentary category.  That really would be smashing!

And on behalf of my new team, i.e. my merry band of Bin Doctors, I'd like to thank you for your support.

Of course, should we win...  we'll be sure to recycle the celebratory Champagne bottle as well as the metal cap, the twisty wire thing, the aluminium wrapping, cork and all!

Voting closes on 12th May.

Read more »

Cabeza de Vaca: Supernaturalism and psychosomatic disorders

Andrew Weil, a major proponent of the idea of self-healing (), has repeatedly acknowledged the influence of osteopaths such as Robert C. Fulford () on him, particularly regarding his philosophy of health management. Self-healing is not about completely autonomous healing; it is about healing by stimulation of the body's self-repair processes, which in some cases can be achieved by simply reducing stress.

Interestingly, there are many reported cases of osteopaths curing people from various diseases by doing things like cranial manipulation and other forms of touching. We also have much evidence of health improvement through prescription of drugs that don’t appear to have any health benefits, which is arguably a similar phenomenon.

The number of such reported cases highlights what seems to be a reality about diseases in general, which is that they often have a psychosomatic basis. Their “cure” involves making the person affected believe that someone can cure him, a healer, with or without drugs. The healer then cures the person essentially by her power of suggestion.

Paleoanthropological evidence suggests that this healer-induced phenomenon has always been widespread among hunter-gatherer cultures, so much so that it may well have been the result of evolutionary pressures. If this is correct, how does it relate to health in our modern world?

I am very interested in hunter-gatherer cultures, and I have also been living in Texas for almost 10 years now. So it is only natural for me to try to learn more about the former hunter-gatherer groups in Texas, particularly those who lived in the area prior to the introduction of horses by the Europeans.

There are parks, museums, and other resources on the topic in various parts of Texas, which are at driving distance. Unfortunately much has been lost, as the Plains Indians of Texas (e.g., Comanches and Kiowas) who succeeded those pre-horse native groups have largely been forcibly relocated to reservations in Oklahoma.

Anthropological evidence suggests that the earliest migrations to America have occurred via the Bering Strait, initially from Siberia into Alaska, and then gradually spreading southward to most of the Americas between 13,000 and 10,000 years ago.

Much of what is known about the early Texas Indians is due to Álvar Núñez Cabeza de Vaca, a Spanish explorer who survived a shipwreck and lived among the Amerindians in and around Texas between 1528 and 1536. He later wrote a widely cited report about his experiences ().


(Cabeza de Vaca and his companions; source: Biography.com)

In Spanish, “cabeza de vaca” means, literally, “cow’s head”. This odd surname, Cabeza de Vaca, clearly had a flavor of nobility to it in Spain at the time.

You may have heard that early American Indians were uniformly of short stature, not unlike most people at the time, but certainly shorter than the average American today. Cabeza de Vaca dispels this idea with his description of the now extinct Karankawas, a description that has been born out by anthropological evidence. The male members “towered above the Spaniards”, often 6 ft or taller in height, in addition to being muscular.

The Karankawas were a distinct indigenous group that shared the same environment and similar food sources with other early groups of much lower stature. This strongly suggests a genetic basis for their high stature and muscular built, probably due to the “founder effect”, well known among population geneticists.

Cabeza de Vaca and three companions, two Spaniards and one Moroccan slave, were believed by the Amerindians to be powerful healers. This enabled them to survive among early Texas Indians for several years. Cabeza de Vaca and his colleagues at times acknowledged that they were probably curing people through what we would refer today as a powerful placebo effect.

Having said that, Cabeza de Vaca has also come to believe, at least to a certain extent, that he was indeed able to perform miraculous cures. He repeatedly stated his conviction that those cures were primarily through divine intervention, as he was a devout Christian, although there are many contradictory statements in this respect in his reports (possibly due to fear from the Spanish Inquisition). He also performed simple surgeries.

Much has been written about Cabeza de Vaca’s life among the early Indians of Texas and surrounding areas, including the report by Cabeza de Vaca himself. One of my favorites is the superb book “A Land So Strange” () by Andrés Reséndez, a professor of history at the University of California at Davis ().

The Spanish explorer’s experiences have been portrayed in the film “Cabeza de Vaca” (), which focuses primarily on the supernatural angle, with a lot of artistic license. I must admit that I was a bit disappointed with this film, as I expected it to show more about the early Indians’ culture and lifestyle. Juan Diego, the Spanish actor portraying Cabeza de Vaca, was razor thin in this film - a fairly realistic aspect of the portrayal.

It is quite possible that modern humans have an innate tendency to believe in and rely on the supernatural, a tendency that is the product of evolution. We know from early and more recent evidence from hunter-gatherer societies that supernatural beliefs help maintain group cohesion and, perhaps quite importantly, mitigate the impact that the knowledge of certain death has on the mental health of hunter-gatherers.

Homo sapiens is unique among animals in its awareness of its own mortality, which may be a byproduct of its also unique ability to make causal inferences. Supernatural beliefs among hunter-gatherers almost universally address this issue, by framing death as a threshold between this existence and the afterlife, essentially implying immortality.

Yet, supernatural beliefs seem to also have a history of exploitation, where they are used to manipulate others. Cabeza de Vaca himself implies that, at points, he and his companions took personal advantage of the beliefs in their healing powers by the various indigenous groups with which they came into contact.

Modern humans who are convinced that they have no supernatural beliefs often perceive that to be a major advantage. But there could be disadvantages. One is that they may have more difficulty dealing with psychosomatic disorders. The conscious knowledge that they are psychosomatic could possibly pale in comparison with the belief in supernatural healing, in terms of curative power. Another potential disadvantage is a greater likelihood of suffering from mental disorders.

Finally, those who are sure that they have no supernatural beliefs; are they really correct? Well, subconsciously things may be different. Perhaps a good test would be to go to a “convincing” movie (i.e., not a laughable “B-level” one; for lack of a better word) about supernatural things, such as possession or infestation by evil spirits, and see if it has any effect on you.

If the experience does have an effect on you, even a small one, couldn't this suggest that your subconscious belief in the supernatural may not be so easy to control in a conscious way? I suspect that having no supernatural beliefs is unnatural and unhealthy. In most cases it probably creates a conscious-subconscious conflict, and a fairly pessimist view of the world.

My guess is that it is better to have those beliefs, in some form or another, and be on guard against exploitation.

Read more »

The new Rubbish Diet Challenge website is now LIVE!

After much hard work from a dedicated team, the Rubbish Diet Challenge website is now live and kicking and ready as an online toolkit for anyone who wants to take the 8 week challenge to slim their bin! 

You'll find all you need, including an overview of how it works, some great diagrams and a sign-up form.  Once signed up, you'll receive a series of weekly tips, introducing different themes over the eight weeks.

So if you've been itching to take up the challenge but haven't got around to starting it yet,  there's no better time.  Do pop over to the new website and have a gander.   You can find it at www.therubbishdiet.org.uk. And if you live in Suffolk, Powys or Shropshire there are even 'Bin Doctors' on hand to tell you about their county-wide campaigns which are launching next week, offering extra assistance to help slim those bins.

Talking of which, it will come as no surprise that I'm rolling up my sleeves to help out in Suffolk, along with Kate Kelly, who took the challenge last year.  And we're getting ready to support presenter Mark Murphy, who is championing the BBC Radio Suffolk Rubbish Diet Campaign.  It's going to be HUGE and kicks off on Monday.

That's eight weeks of waste-busting fun in our own county.  We'll be covering all the latest news via a new local blog www.rubbishdietsuffolk.blogspot.com.  So, if I suddenly go all quiet here, you'll now know where to find me!

I hope you like the new website, and if you do, please tell your friends.  Here's to a very exciting new phase of The Rubbish Diet and an ENORMOUS thank you to everyone who's supported it so far.  The next few months are going to be great!

SLIMMER BINS, HERE WE COME!

__________________________________

Read more »

Dried meat: Homemade beef jerky

You can dry many types of meat, including beef, pork, goat, deer, and even some types of seafood, such as mussels. Drying meat tends to significantly increase the meat’s protein content per gram, often more than doubling it. It also helps preserve the meat, as bacteria need an aqueous environment to grow; adding salt helps further prevent bacterial growth.

Dried meat preparation and consumption was common among the Plains Indians (e.g., of the Cheyenne, Comanche, and Lakota tribes), and also a valuable trade item for them. They often ground the dried meat into a powder, mixing fat and berries with them; the result of which was pemmican. Many other hunter-gatherer cultures around the world have incorporated dried meat into their diets.

Below is a recipe for homemade beef jerky, which is very close in terms of nutrition content to the dried meat of the Plains Indians's time; that is, the time when the Plains Indians subsisted mostly on bison. Commercial beef jerky typically has a lower nutrient-to-calorie ratio, in part because sugar is added to it. The recipe is for beef jerky, but can be used to make jerky with bison meat as well.

- Cut about 3 lbs of beef muscle into thin strips (see photo below). Ideally you should buy it partially cut already, with most of the fat trimmed. Cutting with or against the grain doesn’t seem to make much difference, at least to me.

- Prepare some dry seasoning powder by mixing salt and cayenne pepper.

- Season the strips and place them on a tray with a grid on top, so that the fat that will come off the meat is captured by the tray and doesn’t drip into the oven.

- Preheat the oven to about 180 degrees Fahrenheit, and place the strips in it until you can easily pull a piece of the meat off with your fingers (see photos below, for an idea of how they would look). This should take about 1 hour or so. You will not technically be “baking” or "cooking" the meat at this temperature, although the digestibility of the final product will be comparable to that of cooked meat – i.e., greater digestibility than raw meat.

- Leave the strips in the oven until they are cold, this will dry them further.







Homemade beef jerky, prepared as above, is supposed to be eaten cold. In this sense, it could be thought of as a bit like salami, but with a higher protein-to-fat ratio. If your kids eat this on a regular basis, I suspect that their future orthodontist needs will be significantly reduced. Homemade beef jerky, like the commercial one, requires some serious chewing.

The dried strips of meat can be kept outside the fridge for a long time, but if you intend to keep them for more than a few weeks, I would suggest that you keep them in the fridge. Interestingly, adding sugar apparently increases the non-refrigerated shelf life of beef jerky even further. It doesn’t improve the flavor though, in my opinion.

This is a zero-carbohydrate food item, which may be a good choice for those who are insulin resistant or diabetic, and also for those on low-carbohydrate or just-enough-carbohydrate diets. Often I hear bodybuilders who eat multiple meals per day to say that it is hard for them to prepare high-protein snacks that they can easily carry with them. Well, beef jerky is one option.

Read more »