Monday, March 30, 2009


I would consider myself pretty athletic...for the most part. I grew up playing sports and was always running around doing things as a kid. I guess I was a tomboy...still am. I was a swimmer, synchronized swimmer, fencer, diver and basketball player. I tend to pick up on things easy. Usually. Most sports. Most. Golf? Not so much.

I don't understand how people can go out there and hit balls, play the game and say it's relaxing. I wish I had a heart monitor on me to check my rate as I hit every other ball. Yes, every other. I just want to hit the crap out of it! I had to remind myself (actually, Karen had to remind me) to slow down...control the swing. I was lucky enough to have her there to coach me. She likes to remind me that she was junior all state, played for the Michigan State Women's team and too many more credentials to list here. Oh yeah, she was a instructor as well. You would think that would be enough to make me better. Well, maybe a little. It's good that she is patient with me and knows me well enough to leave me alone and not point out the fact that I missed the ball. I was kind enough not to bend the club over my knee in frustration. If you know anything about golf, you can tell right away which swing is good and which is awful.

The good news is that it was a beautiful day. I did hit a few good shots and that is what I will savor. She says that I could get better if I took the time to learn. That would mean I would need patience. I will work on that.

Thanks for a great day Karen. :)

Saturday, March 28, 2009

Preventing Tooth Decay

Meet Sir Edward Mellanby, the man who discovered vitamin D. Along with his wife, Dr. May Mellanby, he identified dietary factors that control the formation and repair of teeth and bones. He also identified the primary cause of rickets (vitamin D deficiency) and the effect of phytic acid on mineral absorption. Truly a great man! This research began in the 1910s and continued through the 1940s.

What he discovered about tooth and bone formation is profound, disarmingly simple, and largely forgotten. I remember going to the dentist as a child. He told me I had good teeth. I informed him that I tried to eat well and stay away from sweets. He explained to me that I had good teeth because of genetics, not my diet. I was skeptical at the time, and rightly so.

Tooth structure is primarily determined during growth. Well-formed teeth are highly resistant to decay, while poorly-formed teeth are cavity-prone. Drs. Mellanby demonstrated this by showing a strong correlation between tooth enamel defects and cavities in British children. The following graph is drawn from several studies he compiled in the book Nutrition and Disease (1934). "Hypoplastic" refers to enamel that's poorly formed on a microscopic level.
The graph is confusing, so don't worry if you're having a hard time interpreting it. If you look at the blue bar representing children with well-formed teeth, you can see that 77% of them have no cavities, and only 7.5% have severe cavities (a "3" on the X axis). Looking at the green bar, only 6% of children with the worst enamel structure are without cavities, while 74% have severe cavities. Enamel structure is VERY strongly related to cavity prevalence.

What determines enamel structure during growth? Drs. Mellanby identified three dominant factors:
  1. The mineral content of the diet
  2. The fat-soluble vitamin content of the diet, chiefly vitamin D
  3. The availability of minerals for absorption, determined largely by the diet's phytic acid content
Teeth and bones are a mineralized protein scaffold. Vitamin D influences the quality of the protein scaffold that's laid down, and the handling of the elements that mineralize it. For the scaffold to mineralize, the diet has to contain enough minerals, primarily calcium and phosphorus. Vitamin D allows the digestive system to absorb the minerals, but it can only absorb them if they aren't bound by phytic acid. Phytic acid is an anti-nutrient found primarily in unfermented seeds such as grains. So the process depends on getting minerals (sufficient minerals in the diet and low phytic acid) and putting them in the right place (fat-soluble vitamins).

Optimal tooth and bone formation occurs only on a diet that is sufficient in minerals, fat-soluble vitamins, and low in phytic acid
. Drs. Mellanby used dogs in their experiments, which it turns out are a good model for tooth formation in humans for a reason I'll explain later. From Nutrition and Disease:
Thus, if growing puppies are given a limited amount of separated [skim] milk together with cereals, lean meat, orange juice, and yeast (i.e., a diet containing sufficient energy value and also sufficient proteins, carbohydrates, vitamins B and C, and salts), defectively formed teeth will result. If some rich source of vitamin D be added, such as cod-liver oil or egg-yolk, the structure of the teeth will be greatly improved, while the addition of oils such as olive... leaves the teeth as badly formed as when the basal diet only is given... If, when the vitamin D intake is deficient, the cereal part of the diet is increased, or if wheat germ [high in phytic acid] replaces white flour, or, again, if oatmeal [high in phytic acid] is substituted for white flour, then the teeth tend to be worse in structure, but if, under these conditions, the calcium intake is increased, then calcification [the deposition of calcium in the teeth] is improved.
Other researchers initially disputed the Mellanbys' results because they weren't able to replicate the findings in rats. It turns out, rats produce the phytic acid-degrading enzyme phytase in their small intestine, so they can extract minerals from unfermented grains better than dogs. Humans also produce phytase, but at levels so low they don't significantly degrade phytic acid. The small intestine of rats has about 30 times the phytase activity of the human small intestine, again demonstrating that humans are not well adapted to eating grains. Our ability to extract minerals from seeds is comparable to that of dogs, which shows that the Mellanbys' results are more applicable to humans than those in rats.

Drs. Mellanby found that the same three factors determine bone quality in dogs as well, which I may discuss in another post.

Is there anything someone with fully formed enamel can do to prevent tooth decay? Drs. Mellanby showed (in humans this time) that not only can tooth decay be prevented by a good diet, it can be almost completely reversed even if it's already present. Dr. Weston Price used a similar method to reverse tooth decay as well. I'll discuss that in my next post.

Friday, March 27, 2009

First String

I am blessed with many things in my life. I am thankful for all I have and especially, I am thankful for my friends. This week, I have been visiting my long time friends in my old collage town. When I first moved here 18 years ago (GASP!), I lived on my own for a short time until I met Rose and Heide. The three of us bonded and moved in together as well as played basketball together. We are lucky that we all got along so well. We still do. I consider Rose and Heide to be my best friends, they've known me for almost 20 years, lived with me, and STILL want to hang out. It's amazing. :) Rose's dog Jake and Maggie even got along. :)

I've known Deana for several years and in the past few years, we have become really close. She even decided to go on a last minute vacation with me last May. I know we will go on a trip again soon.
It was so great to see her and meet her new girlfriend last night. Here she is with her dog, Raffie. I wish this town was closer to home. For me, this is my home away from home. I always look forward to being here and I know I will come back again soon.

Thursday, March 26, 2009

Monique Racing Tomorrow

Monique had training on the track in the morning in preparation for tomorrows sprints. The start list is out for the 200m and she will begin her Time Trial at around 3:30pm in Poland (-8hrs in CA or -7hrs in Calgary). To see the results of the race, click here

Wednesday, March 25, 2009


Lastnight, I met someone new. Actually, I met a lot of new people. I was lucky enough to be invited to one of Satyr's famous potlucks. Satyr and I have been friends online for almost a year and one day he asked me to let him know the next time I would be in town. I came to town, we met, and had a fabulous time at his home amongst his friends. Here are some pictures from the party. I am sure I will see him again. He will be at Burning Man again this year and on American Life Today next month. I am thinking of going to Burning Man for the first time this year. Hummm....what to wear?? Suggestions?

Tuesday, March 24, 2009

The Art Of Doing Nothing

Today is a beautiful day. I decided to take a tour of the park I used to work at. Years ago, I was the one sitting on the lifeguard chair nine hours a day telling people not to run, dive or do anything that wasn't allowed. Sometimes I was greeted with a "F*&K YOU LIFEGUARD!" when I enforced the rules. Sigh...the good ol' days. :)Today I was looking at it through the eyes of a visitor. I feel peaceful here. I seemed to forget to enjoy what was in my backyard.

I am amazed at how many people take advantage of a beautiful day. I believe New Yorkers have to take the award for soaking up every inch of a park. People were sunning, reading, walking, eating lunch, playing the guitar, chatting with each other, riding bikes, working out and enjoying every moment. At one point I was thinking to myself, "doesn't anyone work around here?"

I laid there for about an hour. Closed my eyes. Listened to the sounds around me. Remembered what it was like sitting in that chair all day. Besides saving an infant from drowning (mother was passed out on the grass), it was the most boring job I have ever had. The good part was playing water polo before work and being in nature.

I could learn a thing or two from the people here.

Road Trip

Maggie and I are headed up north to visit some of my closest friends in my old college town, while I lend my home to a friend for the week. I lived in this town for 7 years back in the day, so it's always nice to come for a visit. The drive was long, but with good thoughts in my head and was a piece of cake. Maggie and I will share our adventure with you as we go along.

Monday, March 23, 2009

More Thoughts on the Glycemic Index

In the last post, I reviewed the controlled trials on the effect of the glycemic index (GI) of carbohydrate foods on health. I concluded that there is not much evidence that a low GI diet is better for health than a high GI diet.

It is true that for the "average" individual the GI of carbohydrate foods can affect the glucose and insulin response somewhat, even in the context of an actual meal. If you compare two meals of very different GI, the low GI meal will cause less insulin secretion and cause less total blood glucose in the plasma over the course of the day (although the differences in blood glucose may not be large in all individuals).

But is that biologically significant? In other words, do those differences matter when it comes to health? I would argue probably not, and here's why: there's a difference between post-meal glucose and insulin surges within the normal range, and those that occur in pathological conditions such as diabetes and insulin resistance. Chronically elevated insulin is a marker of metabolic dysfunction, while post-meal insulin surges are not (although glucose surges in excess of 140 mg/dL indicate glucose intolerance). Despite what you may hear from some sectors of the low-carbohydrate community, insulin surges do not necessarily lead to insulin resistance. Just ask a Kitavan. They get 69% of their 2,200 calories per day from high-glycemic starchy tubers and fruit (380 g carbohydrate), with not much fat to slow down digestion. Yet they have low fasting insulin, very little body fat and an undetectable incidence of diabetes, heart attack and stroke. That's despite a significant elderly population on the island.

Furthermore, in the 4-month GI intervention trial I mentioned last time, they measured something called glycated hemoglobin (HbA1c). HbA1c is a measure of the amount of blood glucose that has "stuck to" hemoglobin molecules in red blood cells. It's used to determine a person's average blood glucose concentration over the course of the past few weeks. The higher your HbA1c, the poorer your blood glucose control, the higher your likelihood of having diabetes, and the higher your cardiovascular risk. The low GI group had a statistically significant drop in their HbA1c value compared to the high GI group. But the difference was only 0.06%, a change that is biologically meaningless.

OK, let's take a step back. The goal of thinking about all this is to understand what's healthy, right? Let's take a look at how carbohydrate foods are consumed by cultures that rarely suffer from obesity or metabolic disease. Cultures that rely heavily on carbohydrate generally fall into three categories: they eat cooked starchy tubers, they grind and cook their grains, or they rely on grains that become very soft when cooked. In the first category, we have Africans, South Americans, Polynesians and Melanesians (including the Kitavans). In the second, we have various Africans, Europeans (including the villagers of the Loetschental valley), Middle Easterners and South Americans. In the third category, we have Asians, Europeans (the oat-eating residents of the outer Hebrides) and South Americans (quinoa-eating Peruvians).

The pattern here is one of maximizing GI, not minimizing it. That's not because high GI foods are inherently superior, but because traditional processing techniques that maximize the digestibility of carbohydrate foods also tend to increase their GI. I believe healthy cultures around the world didn't care about the glycemic index of foods, they cared about digestibility and nutritional value.

The reason we grind grains is simple. Ground grains are digested more easily and completely (hence the higher GI).  Furthermore, ground grains are more effective than intact grains at breaking down their own phytic acid when soaked, particularly if they're allowed to ferment. This further increases their nutritional value.

The human digestive system is delicate. Cows can eat whole grass seeds and digest them using their giant four-compartment stomach that acts as a fermentation tank. Humans that eat intact grains end up donating them to the waste treatment plant. We just don't have the hardware to efficiently extract the nutrients from cooked whole rye berries, unless you're willing to chew each bite 47 times. Oats, quinoa, rice, beans and certain other starchy seeds are exceptions because they're softened sufficiently by cooking.

Grain consumption and grinding implements appear simultaneously in the archaeological record. Grinding has always been used to increase the digestibility of tough grains, even before the invention of agriculture when hunter-gatherers were gathering wild grains in the fertile crescent. Some archaeologists consider grinding implements one of the diagnostic features of a grain-based culture. Carbohydrate-based cultures have always prioritized digestibility and nutritional value over GI.

Finally, I'd like to emphasize that some people don't have a good relationship with carbohydrate. Diabetics and others with glucose intolerance should be very cautious with carbohydrate foods. The best way to know how you deal with carbohydrate is to get a blood glucose meter and use it after meals. For $70 or less, you can get a cheap meter and 50 test strips that will give you a very good idea of your glucose response to typical meals (as opposed to a glucose bomb at the doctor's office). Jenny Ruhl has a tutorial that explains the process. It's also useful to pay attention to how you feel and look with different amounts of carbohydrate in your diet.

Thursday, March 19, 2009

The Glycemic Index: A Critical Evaluation

The glycemic index (GI) is a measure of how much an individual food elevates blood sugar when it's eaten. To measure it, investigators feed a person a food that contains a fixed amount of carbohydrate, and measure their blood glucose response over time. Then they determine the area under the glucose curve and compare it to a standard food such as white bread or pure glucose.

Each food must contain the same total amount of carbohydrate, so you might have to eat a big plate of carrots to compare with a slice of bread. You end up with a number that reflects the food's ability to elevate glucose when eaten in isolation. It depends in large part on how quickly the carbohydrate is digested/absorbed, with higher numbers usually resulting from faster absorption.

The GI is a standby of modern nutritional advice. It's easy to believe in because processed foods tend to have a higher glycemic index than minimally processed foods, high blood sugar is bad, and chronically high insulin is bad. Yet many people have criticized the concept.  Why?

Blood sugar responses to a carbohydrate-containing foods vary greatly from person to person. For example, I can eat a medium potato and a big slice of white bread (roughly 60 g carbohydrate) with nothing else and only see a modest spike in my blood sugar. I barely break 100 mg/dL and I'm back at fasting glucose levels within an hour and a half. You can see a graph of this experiment here. That's what happens when you have a well-functioning pancreas and insulin-sensitive tissues. Your body shunts glucose into the tissues almost as rapidly as it enters the bloodstream. Someone with impaired glucose tolerance might have gone up to 170 mg/dL for two and a half hours on the same meal.

The other factor is that foods aren't eaten in isolation. Fat, protein, acidity and other factors slow carbohydrate absorption in the context of a normal meal, to the point where the GI of the individual foods become much less pronounced.

Researchers have conducted a number of controlled trials comparing low-GI diets to high-GI diets. I've done an informal literature review to see what the overall findings are. I'm only interested in long-term studies-- 10 weeks or longer-- and I've excluded studies using subjects with metabolic disorders such as diabetes.  

The question I'm asking with this review is, what are the health effects of a low-glycemic index diet on a healthy normal-weight or overweight person? I found a total of seven studies on PubMed in which investigators varied GI while keeping total carbohydrate about the same, for 10 weeks or longer. I'll present them out of chronological order because they flow better that way.  

One issue with this literature that I want to highlight before we proceed is that most of these studies weren't properly controlled to isolate the effects of GI independent of other factors.  Low GI foods are often whole foods with more fiber, more nutrients, and a higher satiety value per calorie than high GI foods.

Study #1. Investigators put overweight women on a 12-week diet of either high-GI or low-GI foods with an equal amount of total carbohydrate. Both were unrestricted in calories. Body composition and total food intake were the same on both diets. Despite the diet advice aimed at changing GI, the investigators found that both groups' glucose and insulin curves were the same!

Study #2. Investigators divided 129 overweight young adults into four different diet groups for 12 weeks. Diet #1: high GI, high carbohydrate (60%). Diet #2: low GI, high carbohydrate. Diet #3: high GI, high-protein (28%). Diet #4: low GI, high protein. The high-protein diets were also a bit higher in fat. Although the differences were small and mostly not statistically significant, participants on diet #3 improved the most overall in my opinion. They lost the most weight, and had the greatest decrease in fasting insulin and calculated insulin resistance. Diet #2 came out modestly ahead of diet #1 on fat loss and fasting insulin.

Study #3. At 18 months, this is by far the longest trial. Investigators assigned 203 healthy Brazilian women to either a low-GI or high-GI energy-restricted diet. The difference in GI between the two diets was substantial; the high-GI diet was supposed to be double the low-GI diet. This was accomplished by a number of differences between diets, including different types of rice and higher bean consumption in the low-GI group.  Weight loss was a meager 1/3 pound greater in the low-GI group, a difference that was not statistically significant at 18 months. Changes in estimated insulin sensitivity were not statistically significant.

Study #4. The FUNGENUT study. In this 12-week intervention, investigators divided 47 subjects with the metabolic syndrome into two diet groups. One was a high-glycemic, high-wheat group; the other was a low-glycemic, high-rye group. After 12 weeks, there was an improvement in the insulinogenic index (a marker of early insulin secretion in response to carbohydrate) in the rye group but not the wheat group. Glucose tolerance was essentially the same in both groups.

What makes this study unique is they went on to look at changes in gene expression in subcutaneous fat tissue before and after the diets. They found a decrease in the expression of stress and inflammation-related genes in the rye group, and an increase in stress and inflammation genes in the wheat group. They interpreted this as being the result of the different GIs of the two diets.

Further research will have to determine whether the result they observed is due to the glycemic differences of the two diets or something else.

Study #5. Investigators divided 18 subjects with elevated cardiovascular disease risk markers into two diets differing in their GI, for 12 weeks. The low-glycemic group lost 4 kg (statistically significant), while the high-glycemic group lost 1.5 kg (not statistically significant).  In addition, the low-GI group ended up with lower 24-hour blood glucose measurements.  This study was a bit strange because of the fact that the high-GI group started off 14 kg heavier than the low-GI group, and the way the data are reported is difficult to understand.  Perhaps these limitations, along with the study's incongruence with other controlled trails, are what inspired the authors to describe it as a pilot study.

Study #6. 45 overweight females were divided between high-GI and low-GI diets for 10 weeks. The low-GI group lost a small amount more fat than the high-GI group, but the difference wasn't significant. The low-GI group also had a 10% drop in LDL cholesterol.

Study #7. This was the second-longest trial, at 4 months. 34 subjects with impaired glucose tolerance were divided into three diet groups. Diet #1: high-carbohydrate (60%), high-GI. Diet #2: high-carbohydrate, low-GI. Diet #3: "low-carbohydrate" (49%), "high-fat" (monounsaturated from olive and canola oil). The diet #1 group lost the most weight, followed by diet #2, while diet #3 gained weight. The differences were small but statistically significant. The insulin and triglyceride response to a test meal improved in diet group #1 but not #2. The insulin response also improved in group #3. The high-GI group came out looking pretty good. 

[Update 10/2011-- please see this post for a recent example of a 6 month controlled trial including 720 participants that tested the effect of glycemic index modification on body fatness and health markers-- it is consistent with the conclusion below]

Overall, these studies do not support the idea that lowering the glycemic index of carbohydrate foods is useful for weight loss, insulin or glucose control, or anything else besides complicating your life.  I'll keep my finger on the pulse of this research as it expands, but for the time being I don't see the glycemic index per se as a significant way to combat fat gain or metabolic disease.

Meeting Strangers Online

Most of us go about our daily lives doing the same things, eating at the same restaurants, playing with the same friends. We usually don’t meet anyone new unless we step out and do something different or you rely on the same friends to do that and introduce them to you. Why are we such creatures of habit? What prevents us from meeting new people in other ways? From what I have heard from my friends, I believe it to be fear based. What if they are a psycho? What if they are going to kill me in some odd fashion? That would be too bad since I wouldn’t be able to blog about it.

When I was on the road for 120 days, I decided to branch out and meet some strangers that I met on the internet. I even stayed in their house, invited one back to a house I was staying in, slept in the backyard at another’s. In the end, I am still here to talk about it.

I am not finished meeting new people. As a matter of fact, I am going to meet another one next week. It’s in a familiar town but at an unfamiliar house with unfamiliar people. It should be an adventure! As I told a friend about it that lives in this familiar town, she said “Where the hell is this place?” “Who the hell is this person?””What the hell is going on?” That’s usually the natural reaction I get. I look forward to experiencing it and sharing it with you.

So back to the people I met while I was on the road.

The first stranger I met was Jen in Ft. Collins. We met online through a mutual blogger. We tailgated, went to red rocks, laughed, had some killer sushi, broke a bike at New Belgium Brewery, tasted Ft. Collins fine microbreweries, watched rafters, went to the lake, laughed, soaked in the spa, had the best margi, laughed some more, ate at the best breakfast spots, and who can forget the day on her motorcycle? It was the first time since high school (when I was stupid and didn’t care) that I trusted someone enough to get on the back of their bike. We became friends and she has since visited me! I am looking forward to another visit! Tell me when Jen...

While I was in Estes Park Colorado, I received an email from a man that lives in his van. There was someone who alerted him of my journey and he noticed that I was in the area so he dropped me a note. Now this time, I was a bit worried. A single guy living in a van. Hummm…. Not sure about this one. Might be a tad creepy. So, I said...OK, great! We met at Estes Park brewery and hit it off right away. After a meal, I invited him and his van to stay the night where I was. Since then we have kept in touch. We met again in Philadelphia and in California a few times. He has decided to hang up the keys to the van and settle down with his girlfriend in San Francisco. They are both wonderful people.

As I shot back across the country, Cat was another person on my stranger stop tour that I wanted to meet. As with Dave, we didn’t talk on the phone prior to meeting. I pretty much showed up at her house, backed trailie in her backyard and settled in for 5 days. We sang karaoke, we pigged out in the park, rode the Hathawaa trail, ate sushi, toured the sights, went wine tasting, toured the peach farms, and had the best people watching in her little town of Spokane. In between all of our adventures, we laughed and laughed. As with Jen and Dave, she has made the trip here to see what it’s like in California. She is returning again soon.

I would recommend taking a chance. Step out of the routine and do something you might not normally do. I will next week and I hope the trend continues. There are a few strangers out there that I am looking forward to meeting.

What have you done outside of your routine that has changed your life?

Monique is Going to the Track Cycling World Championships!

Monique just received word that she is going to the world track championships in Poland next week! Very Exciting News!! You can watch out for her on the their website here. Good Luck Monique!

Tuesday, March 17, 2009

Monique Sullivan

I am inspired by athletes. The woman rider I was referring to in my last blog is Monique Sullivan. I was lucky to be invited to watch her do a time trial at the Velodrome in California.
As a reminder, this was my first time stepping inside this type of arena. She is the reason for my palms to sweat and drive fast on the freeway. Of course there is no way I could be responsible for that so I am blaming her.

Before I met Monique, I read about her adventures on her blog. I would encourage you to do the same.

A little bit about Monique. She is a Canadian Track cyclist currently training full time in Los Angeles, California. In January, she put her engineering degree on hold at the University of Calgary to devote herself full time to her training. In 2005, at 16 yrs old, she had the fastest 500m time trial for both the Junior and Senior women at the National Championships. She has not been beat by a Canadian woman in any sprint event since. This is her 2nd year as an Elite rider and her first opportunity to compete on the World Cup circuit. In October, at her second ever World Cup, she placed 6th in the keirin competition and 11th in the Match Sprints. In January at another World Cup, she placed 9th in the Match Sprints and 12th in the keirin. At only 20, I see even more great things in store for her.

As you will read in her blog, she loves doing many different things from crafts to baking to reading and blogging, creating and sharing and taking on new challenges.

I know first hand that she makes a killer basmati rice pudding...with basil no less!
I might need the recipe for that Monique! On second thought, just let me know when you make it again. :)

Monday, March 16, 2009

The Velodrome Track

The only time I have seen racing on the Velodrome is watching it on TV during the Olympics. A few days ago, I went to see a race in person at one of two (the other in Boulder) indoor Velodrome tracks in North America.

What a rush.

Seems easy enough...but the first time I watched a racer (more on her later) go around on the track for a time trial, my hands started to sweat. When I drove home, I found myself weaving and driving fast on the freeway.

I wanna play! However, the person in charge of the track (see the woman in the blue on the track?) doesn't think I can make the corners. Humph! I'll show you! (Shaking Fist) :)

In case you wanted to know more:
Velodrome racing has been called “NASCAR on Two Wheels”. Track bikes have one gear and no brakes – the epitome of simplicity – that combined with the blazing speed, gravity-defying turns and spectacular crashes makes Velodrome racing one of the most awe-inspiring spectator sports around.

Velodromes are steeply-banked oval cycling arenas. The prefix “velo” is short for the French word “velocipede”, the bicycle’s original name. The purpose of the track’s design is to provide racers a smooth predictable surface on which to maintain the highest speed possible.

All velodromes have lines painted on the track’s surface:
The “cote d’azur” or band of blue, marks the tracks inside boundary. Racers may not ride on or below this wide band, except for emergencies or during the slow tactical maneuvering during match sprint competition.
The black “measurement line”, as the name implies, is used to measure the distance around the track.
The thin red line around the track is the “sprinters line” and it defines the sprint lane between the red line and the blue band. A leading rider in this lane is said to “own the lane” and may only be passed by a rider going over on the right.
The uppermost thin blue line is the “stayer’s line” or relief line. It marks the boundary between faster and slower traffic, with the faster riders below the line while the slower “relief” riders are above this line during Madison races.

Got it? Easy enough, right? More to come...

Sunday, March 15, 2009

Paleopathology at the Origins of Agriculture

In April of 1982, archaeologists from around the globe converged on Plattsburgh, New York for a research symposium. Their goal:
...[to use] data from human skeletal analysis and paleopathology [the study of ancient diseases] to measure the impact on human health of the Neolithic Revolution and antecedent changes in prehistoric hunter-gatherer food economies. The symposium developed out of our perception that many widely debated theories about the origins of agriculture had testable but untested implications concerning human health and nutrition and our belief that recent advances in techniques of skeletal analysis, and the recent explosive increase in data available in this field, permitted valid tests of many of these propositions.
In other words, they got together to see what happened to human health as populations adopted agriculture. They were kind enough to publish the data presented at the symposium in the book Paleopathology at the Origins of Agriculture, edited by the erudite Drs. Mark Nathan Cohen and George J. Armelagos. It appears to be out of print, but luckily I have access to an excellent university library.

There are some major limitations to studying human health by looking at bones. The most obvious is that any soft tissue pathology will have been erased by time. Nevertheless, you can learn a lot from a skeleton. Here are the main health indicators discussed in the book:
  • Mortality. Archaeologists are able to judge a person's approximate age at death, and if the number of skeletons is large enough, they can paint a rough picture of the life expectancy and infant mortality of a population.
  • General growth. Total height, bone thickness, dental crowding, and pelvic and skull shape are all indicators of relative nutrition and health. This is particularly true in a genetically stable population. Pelvic depth is sensitive to nutrition and determines the size of the birth canal in women.
  • Episodic stress. Bones and teeth carry markers of temporary "stress", most often due to starvation or malnutrition. Enamel hypoplasia, horizontal bands of thinned enamel on the teeth, is probably the most reliable marker. Harris lines, bands of increased density in long bones that may be caused by temporary growth arrest, are another type.
  • Porotic hyperostosis and cribra orbitalia. These are both skull deformities that are caused by iron deficiency anemia, and are rather creepy to look at. They're typically caused by malnutrition, but can also result from parasites.
  • Periosteal reactions. These are bone lesions resulting from infections.
  • Physical trauma, such as fractures.
  • Degenerative bone conditions, such as arthritis.
  • Isotopes and trace elements. These can sometimes yield information about the nutritional status, diet composition and diet quality of populations.
  • Dental pathology. My favorite! This category includes cavities, periodontal disease, missing teeth, abscesses, tooth wear, and excessive dental plaque.
The book presents data from 19 regions of the globe, representing Africa, Asia, the Middle East, Europe, South America, with a particular focus on North America. I'll kick things off with a fairly representative description of health in the upper Paleolithic in the Eastern Mediterranean. The term "Paleolithic" refers to the period from the invention of stone tools by hominids 2.5 million years ago, to the invention of agriculture roughly 10,000 years ago. The upper Paleolithic lasted from about 40,000 to 10,000 years ago. From page 59:
In Upper Paleolithic times nutritional health was excellent. The evidence consists of extremely tall stature from plentiful calories and protein (and some microevolutionary selection?); maximum skull base height from plentiful protein, vitamin D, and sunlight in early childhood; and very good teeth and large pelvic depth from adequate protein and vitamins in later childhood and adolescence...
Adult longevity, at 35 years for males and 30 years for females, implies fair to good general health...
There is no clear evidence for any endemic disease.
The level of skeletal (including cranial and pelvic) development Paleolithic groups exhibited has remained unmatched throughout the history of agriculture. There may be exceptions but the trend is clear. Cranial capacity was 11% higher in the upper Paleolithic. You can see the pelvic data in this table taken from Paleopathology at the Origins of Agriculture.

There's so much information in this book, the best I can do is quote pieces of the editor's summary and add a few remarks of my own. One of the most interesting things I learned from the book is that the diet of many hunter-gatherer groups changed at the end of the upper Paleolithic, foreshadowing the shift to agriculture. From pages 566-568:
During the upper Paleolithic stage, subsistence seems focused on relatively easily available foods of high nutritional value, such as large herd animals and migratory fish. Some plant foods seem to have been eaten, but they appear not to have been quantitatively important in the diet. Storage of foods appears early in many sequences, even during the Paleolithic, apparently to save seasonal surpluses for consumption during seasons of low productivity.

As hunting and gathering economies evolve during the Mesolithic [period of transition between hunting/gathering and agriculture], subsistence is expanded by exploitation of increasing numbers of species and by increasingly heavy exploitation of the more abundant and productive plant species. The inclusion of significant amounts of plant food in prehistoric diets seems to correlate with increased use of food processing tools, apparently to improve their taste and digestibility. As [Dr. Mark Nathan] Cohen suggests, there is an increasing focus through time on a few starchy plants of high productivity and storability. This process of subsistence intensification occurs even in regions where native agriculture never developed. In California, for example, as hunting-gathering populations grew, subsistence changed from an early pattern of reliance on game and varied plant resources to to one with increasing emphasis on collection of a few species of starchy seeds and nuts.

...As [Dr. Cohen] predicts, evolutionary change in prehistoric subsistence has moved in the direction of higher carrying capacity foods, not toward foods of higher-quality nutrition or greater reliability. Early nonagricultural diets appear to have been high in minerals, protein, vitamins, and trace nutrients, but relatively low in starch. In the development toward agriculture there is a growing emphasis on starchy, highly caloric food of high productivity and storability, changes that are not favorable to nutritional quality but that would have acted to increase carrying capacity, as Cohen's theory suggests.
Very interesting.

One of the interesting things I learned from the book is that Mesolithic populations, groups that were halfway between farming and hunting-gathering, were generally as healthy as hunter-gatherers: seems clear that seasonal and periodic physiological stress regularly affected most prehistoric hunting-gathering populations, as evidenced by the presence of enamel hypoplasias and Harris lines. What also seems clear is that severe and chronic stress, with high frequency of hypoplasias, infectious disease lesions, pathologies related to iron-deficiency anemia, and high mortality rates, is not characteristic of these early populations. There is no evidence of frequent, severe malnutrition, so the diet must have been adequate in calories and other nutrients most of the time. During the Mesolithic, the proportion of starch in the diet rose, to judge from the increased occurrence of certain dental diseases [with exceptions to be noted later], but not enough to create an impoverished diet... There is a possible slight tendency for Paleolithic people to be healthier and taller than Mesolithic people, but there is no apparent trend toward increasing physiological stress during the mesolithic.
Cultures that adopted intensive agriculture typically showed a marked decline in health indicators. This is particularly true of dental health, which usually became quite poor.
Stress, however, does not seem to have become common and widespread until after the development of high degrees of sedentism, population density, and reliance on intensive agriculture. At this stage in all regions the incidence of physiological stress increases greatly, and average mortality rates increase appreciably. Most of these agricultural populations have high frequencies of porotic hyperostosis and cribra orbitalia, and there is a substantial increase in the number and severity of enamel hypoplasias and pathologies associated with infectious disease. Stature in many populations appears to have been considerably lower than would be expected if genetically-determined maxima had been reached, which suggests that the growth arrests documented by pathologies were causing stunting... Incidence of carbohydrate-related tooth disease increases, apparently because subsistence by this time is characterized by a heavy emphasis on a few starchy food crops.
Infectious disease increased upon agricultural intensification:
Most [studies] conclude that infection was a more common and more serious problem for farmers than for their hunting and gathering forebears; and most suggest that this resulted from some combination of increasing sedentism, larger population aggregates, and the well-established synergism between infection and malnutrition.
There are some apparent exceptions to the trend of declining health with the adoption of intensive agriculture. In my observation, they fall into two general categories. In the first, health improves upon the transition to agriculture because the hunter-gatherer population was unhealthy to begin with. This is due to living in a marginal environment or eating a diet with a high proportion of wild plant seeds. In the second category, the culture adopted rice. Rice is associated with less of a decline in health, and in some cases an increase in overall health, than other grains such as wheat and corn. In chapter 21 of the book Ancient Health: Bioarchaeological Interpretations of the Human Past, Drs. Michelle T Douglas and Michael Pietrusewsky state that "rice appears to be less cariogenic [cavity-promoting] than other grains such as maize [corn]."

One pathology that seems to have decreased with the adoption of agriculture is arthritis. The authors speculate that it may have more to do with strenuous activity than other aspects of the lifestyle such as diet. Another interpretation is that the hunter-gatherers appeared to have a higher arthritis rate because of their longer lifespans:
The arthritis data are also complicated by the fact that the hunter-gatherers discussed commonly displayed higher average ages at death than did the farming populations from the same region. The hunter-gatherers would therefore be expected to display more arthritis as a function of age even if their workloads were comparable [to farmers].
In any case, it appears arthritis is normal for human beings and not a modern degenerative disease.

And the final word:
Taken as a whole, these indicators fairly clearly suggest an overall decline in the quality-- and probably in the length-- of human life associated with the adoption of agriculture.

Saturday, March 14, 2009


I love campfires.
I grew up camping with my family. Every summer, we would meet the same two families and camp for a week together. I have some fond memories of those days. Like waiting for people to come out of the shower only to throw sand on them and yell "Merry Christmas!" (in the middle of the summer) on a dare. Awwww, so mean I know. Horrible. Well, I think it's funny. However, that's never happened to me on my travels. Maybe it will happen now that I put it out there. Anyway...I love to sit and stare at the fire. I am a self appointed "fire poker." On my trip, some of my favorite moments were sitting and watching a fire. It's always been good therapy for me. When I felt stressed, I would grab my dog and head for the hills to camp. Maybe it's about being in nature. It's the best. So, when I bought my of the selling points was having a fire pit. Now I can enjoy a fire with my friends without planning a camping trip.

In Estes Park enjoying the fire.
Here I am with my fire poke stick.

Us being silly by the fire

With Dan in Cannon Beach

With Jo, Dan and Stu

Stacy and Dave

Mom and Allan at the Grand Canyon

I can stare for hours

Trying to chop up a palate for wood

With Heather and Karen at Doheny Beach

With Jen in Estes Park

Get outside. Go Camping. Stare at a does wonders.