Ardi images from Science, Oct. 2, 2009

Very recently, a treasure trove of fossils of a new species of human ancestor was discovered in East Africa. Now known as Ardipithicus ramidus, or Ardi, this 4.4 million year old direct ancestor of ours has refined and deepened our understanding of the prehistory of health.

It is now even clearer that by then our ancestors were already omnivores because it gave them an advantage over other primate species. Their ability to walk upright as well as climb gracefully enabled them to eat a diet that varied throughout the year: fruits when they were available, insects and small animals when they could catch them, and even the few seasonal grains of grass seed before they were snatched up by insects or washed away by rain. Our ancestors set out even earlier than we suspected on an evolutionary path very different from that which led to chimps and apes.

During close examination of the fossil skeleton, it became clear that among other maladies, Ardi survived a deep infection in a foot bone, one that we would now treat with 3 months of intravenous antibiotics! Those were some hardy soles.

We can even infer that by this distant date they were a more cooperative, less combative species than are modern chimps and apes. It may very well be that pair bonding—that is, the typical human team of a single man and woman raising children–goes a whole lot further back than we previously thought.

This opens a vast new perspective on the origins and development of human intelligence, language and behavior. The males and females in Ardi’s tribe were very close in size. Cooperation was key. Effective parents were those who maximized care of a few offspring. Human couples seem to have been working together on this for a long time. Language, rather than emerging to make it easier to hunt or make war, may have developed to discuss what to do about the kids and who was going to clean the nest.

35,000 year old Stone Age Venus

Throughout most of prehistory, fat people were rare. Only in relatively recent times—from an evolutionary standpoint—did our ancestors’ skill at hunting and knowledge of which plants were edible enable them to gather such an abundance of food that a select few could enjoy the luxury of a sedentary life. When they did, the same thing happened in the Stone Age as happens now, they became obese. Some of the best evidence for this comes from primitive statues carved in stone from as long as 35,000 years ago depicting very fat, presumably fertile, and desirable females—the so-called Venus sculptures. The most recent of these was recently discovered in Germany (see link below).

Early in the Stone Age, when most people had to find their own food, life was a tale of feast or famine. In good times everyone put on a little fat, but they had to work for it.

By the late Stone Age, their skills developed to the point where a small group of hunters could support a larger tribe. This allowed them to divide up the work.  Those with with special talents—chiefs, shamans, hunters, tool makers, hide workers, and maybe even mothers–were able to pursue them and still be fed. Suplus food was the origin of the division of labor.  A powerful leader who led a large enough band might even want to keep a very healthy, well fed, fertile female or two close to home where they could engage in what they did most naturally, making healthy children.

Thus, obesity showed up in humans even before they began farming. Among the oldest carved images are figurines of very fat women dating to 35,000 years ago. The most famous of these figures, discovered in Germany and known as the Venus of Willendorf, is a tiny limestone carving of an obese young woman. The most recent is the figure above, the venus of Hohle Fels.

Why did these late Stone Age people make art depicting someone who we might now consider a candidate for stomach stapling? Because fat was beautiful. To get fat, she had to be well fed. Such a beloved wife or beautiful daughter would have led a life of comparative ease, spending her time making jewelry, ornamenting herself with flowers, bones, stones and tattoos—and eating.

Maybe these Venus  figurines are representations of the first overindulged teenager or a particularly revered fertile woman. The OctoMom or Jon and Kate of the Stone Age.  Her size was a cause of delight because fat in the Stone Age was like health insurance—energy stored for hard times. The fatter she grew, the more desirable she became. A fat woman could have many babies and breast-feed them well. As a coveted partner, she would be sought after, giving her a choice of mates. This would spread her genes and increase the number of those like her in the next generation—at least until her obesity caused health problems.

Of course, obesity was the rare exception in the Stone Age, hardly the rule. Nevertheless, hefty women were healthy women and remained attractive in most of the world until recent centuries. Witness paintings and sculptures of the Renaissance and even of the last century. Some traditional Pacific islanders, Africans, Asians and Native Americans still consider fat to be a sign of health–and admire a successful man as he grows older and fatter.

While this might not seem to square with the Western desire to be thin, remember that skinny as beautiful represents a new standard, a modern cultural phenomenon overriding an ancient biological one.  Perhaps once it became easy to get fat, being thin represented hard work—from dieting and exercise. Being thin has come to embody self-discipline, determination and even wealth. You can’t be too thin or too rich, we say. Thinness also connotes youth and vigor, strong sexual attractors. As we live longer and age more slowly, we have come to value a more youthful appearance.

Yet, despite the general idea that “thin is in,” our evolutionary imperative to be fatter still seems to be winning out.

It is remarkable how healthy most fossil teeth are.  Some paleontologists devote  their entire careers to studying the structure and functioning of ancient teeth. It helps that tooth enamel is the hardest, longest lasting substance in our bodies, leaving durable evidence of the change that human dentition has undergone as we evolved.

These fossils reveal that Stone Age teeth had a rough time of it, undergoing wear and tear as tools for cutting and grinding and chewing many hours a day. Of course, cavemen didn’t have toothbrushes, fluoridated water or dental floss. Nor did they endure school programs and television commercials admonishing them to brush twice a day and after meals.

So how did they avoid cavities, even though their tooth enamel had the same composition as ours?

The answer is diet. We know that the bacteria that rot teeth feed on sugars in our mouths. Unlike proteins and fats, which are large molecules that require the harsh conditions of our stomachs to break down, carbohydrates can be quite small and sticky. An enzyme in our saliva called amylase starts to break down starch into sugar as soon as we begin chewing. This is why carbs give us such a quick burst of energy.

Streptococcus mutans, the main bacterial culprit in tooth decay, lives in the crevices of our teeth and gums and turns sucrose, which we know as table sugar, into lactic acid which can quickly erode dental enamel. This leaves holes, or cavities, the better for more bacteria to live in.

We know from genetic studies that S. mutans has kept its current form for several million years.  And since the structure of tooth enamel hasn’t changed over that time span either, the difference must be diet.

Back when fibrous roots and bitter fruits comprised nearly all the carbohydrates in a person’s diet, bacteria in the mouth had little opportunity to produce lactic acid.  The bacteria starved and the teeth remained healthy. In contrast, our modern diet – chock full of simple carbs, starchy grains and sugary sodas – offers a veritable paradise for decay causing bacteria. It’s no surprise that dental cavities are the most widespread chronic disease of childhood in the world today, five times as common as asthma.

It’s something to chew on—another disease that the dietary changes of our advanced culture have foisted upon our ancient bodies.

http://psychcentral.com/news/archives/2006-02/s-mma021206.html

The above article was sent to me recently by a good friend, a very bright person with a PhD in Psychology. As she was reading Evolution Rx it appeared to her to contradict what I have found out about the effects of many pollutants in the environment. Her interpretation of the article led her to believe that “strandings of dolphins are linked to flame retardants in marine mammal brains.” This is a perfect example of how we are all easily misled about the effects of pollutants on our health.

The article is clearly trying to get the point across that “flame retardants” found in the brains of stranded dolphins caused them to run aground and die. “Leading scientists, physicians, and veterinarians are uncovering new links between land-based pollution and diseases in marine mammals, with implications for human health.” As that would be tragic if true, let’s look at what the research really found.

First of all the article was first published two years ago here.

http://www.seaweb.org/mediacenter/press-18February06.php

Following are a few direct quotes with italics placed by me to highlight a more scientific understanding of the findings.

“In laboratory studies and acute exposure scenarios, persistent organic pollutants have been shown to affect brain function, reproductive success, and the immune system, but there is little information on the impact of chronic, low-level exposure.” {This means if you feed animals huge amounts you can poison them, that is true of almost everything, including vitamins, as I discuss in Evolution Rx. Small amounts have no detectable effect.}

“Some suspect that declines of killer whales in Puget Sound may be linked directly to contaminated fish or increased susceptibility to stresses like vessel traffic. Similarly, adverse health effects of PCBs may explain recent observations of pseudo-hermaphroditic polar bears and bears with decreased immune function, but there is no clear evidence that would prove a cause-and-effect relationship.”

“As old chemicals are taken out of use, new ones pop up,” says Krahn. “Often we don’t know if the new substitutes will harm the ecosystem.”

Read casually, the article presents a frightening scenario of an ever more polluted ocean food chain and the threat of impact on human health. Read carefully, it is a long string of beliefs, suppositions and inferences that fail to link any human ever getting ill with these chemicals. In fact, the flame retardants have been studied extensively for more than 30 years and we still have no clear evidence that they are harmful in the kind of doses we are all exposed to.

In order to show that the flame retardants were the cause of the strandings all they needed to do was to look at the brains of some non stranded dolphins (maybe those killed accidentally by fishermen?) to see if there were lower levels. Without this kind of investigation this article is little more than fear mongering.

Evolution has prepared us, by millions of years of exposure, to be able to detoxify these and thousands of other similar threats. The same is true for our salty cousins in the sea.

As ever, I am not arguing for relaxing our vigilance about pollution. In fact, we need to be as firm as ever in enforcing measures to protect workers in the industries where large exposures to these chemicals are possible. At the same time, we all need to relax a little about these kinds of unproven beliefs that cause untallied and harmful anxiety as their only true health threat.

This is the answer I sent:
It makes almost no difference when we eat and how we combine our foods. The enzymes we need to digest most foods are present at all times in our intestines.
The different acidities are all provided for in different parts of our stomach and small intestines.
This is covered pretty well in my book Evolution Rx in the chapter on the stone age diet.
Back then people ate whatever was at hand, when it was available and didn’t know or care what they combined with what. We are the same.
Digestive illnesses have a lot of different causes but food combinations are not one of them. Obesity has only one cause: Eating too much.
We do not use up enzymes. We produce them all on a daily basis in our intestinal cells. The main reason why we would not be able to make an enzyme (a kind of protein) is if we are starving. If our diets are particularly high in certain chemicals, like lactose in milk, then we can make more of some enzymes like lactase to digest it.
We can overeat such that we don’t have enough of an enzyme. We can eat so much of one food, like sugars, that our normal amount of enzymes can’t keep up. Then the partially digested food, in this case carbs, pass on to the next part of our intestine. When too much carbohydrate appears in the large intestine, the colon, the bacteria there go to work on it, break it down and can produce a lot of gas (CO2). This is an uncomfortable condition but not really a disease.
The answer is not to take more enzymes, but to eat fewer carbs.

We can poison our liver and pancreas, with alcohol or hepatitis, to a sufficient degree that some of the liver and pancreatic enzymes aren’t present in great enough amounts. This is when digestive enzymes can be useful.
Unless you have done a lot of harm to your body you should never need to take these supplements.

What Ruins Running?

This is great article on our natural ability to run and why we have so many problems with it today.We evolved to run because of the evolutionary advantages it gave us,both after prey and away from predators. Shoes wear in our feet rather than our feet wearing in our shoes. When we think of how distorted our feet can become, as in the bound feet of the Chinese or the bunioned feet of the high heeled, it is no surprise that we suffer the sores of the slingbacks and the agony of the arrow toed.
Have you ever seen the foot of someone who has never worn shoes? Not the same creature as ours at all.

http://www.boston.com/bostonglobe/magazine/articles/2009/04/19/what_ruins_running/ ]]> http://www.evolution-rx.com/?feed=rss2&p=137 0 http://www.evolution-rx.com/?p=81 http://www.evolution-rx.com/?p=81#comments Fri, 06 Mar 2009 19:19:49 +0000 admin http://www.evolution-rx.com/wordpress/?p=81 How long have we been cooking our food? Are there advantages to a raw food diet? What do we gain from cooking, besides the chance to spice things up a bit?

We humans have been cooking our food for a very long time. While paleoanthropologists will argue just how long, especially over a good meal and a bottle of wine, the earliest evidence we have comes from what appear to be fire pits used by early man as long as 1.6 million years ago. While there are few clearly charred and chewed remains from that time, the association of fire and human settlements make it likely that such evidence will be found. Such a distant date is long before the advent of Homo sapiens and even before the geographic and genetic split that led Neanderthals off to the wilds of Europe.

Cooked food, whether it be boiled, steamed, charred or grilled is much easier to digest than raw food, especially animal flesh. Raw meat, while full of nutrients, requires an enormous amount of chewing. So do raw vegetables and grains. It has been estimated that before cooking was discovered it took almost 12 hours a day of chewing for early man to get enough calories to live. But by cooking the same foods so much more nutrition was available that the same amount of food could be assimilated in only three hours. 

That means they went from gathering and gnawing all day to having a whole lot of leisure time to pursue other tasks. Or to sleep it off.

Even if we accept a much later date for the arrival of cookery, it still appeared long before the genetic changes that we link to the development of modern man. 

From a medical perspective we are clearly adapted to cooked food. Our teeth and jaws are no longer the flat grinding platforms surrounded by huge arrays of muscle, necessary to grind all day, that we associate with primitive hominids. There are no native peoples whose diet doesn’t involve cooking. Only a handful of fringe faddists try to subsist on uncooked food alone. Cooking breaks down the proteins and cell walls of foods and makes them easier to chew, swallow and digest.  Add a few spices and a whole world of cuisine is opened up to us. Heating food also makes it safer by killing off the countless organisms, bacteria, parasites and fungi that live on and in uncooked foods.

·  Wrangham, R., Jones, J. H., Laden, G., Pilbeam, D. and Conklin-Brittain, N. L. (1999). “The raw and the stolen: Cooking and the ecology of human origins.” Current Anthropology, 40(5), 567–594. 

Here is a good article on the topic from The Economist.

These studies have led to fundamental changes in our understanding of what it means to be healthy.  We now know that many conditions thought to be abnormal are, in fact, natural abilities that helped us survive in the beautiful and hostile world of the Stone Age.  Evolutionary medicine exposes the fallacies behind long-accepted medical practices and the quackery that fosters popular health fads. 

By looking at how our ancestors lived, loved, got sick, and got well for millions of years, evolutionary medicine offers us a natural plan for living longer, healthier, and happier lives today.