Monday, March 31, 2008
The most dangerous fat is visceral fat, or the "beer belly". Fortunately, it's also the most responsive to lifestyle changes.
The strategies I recommend all have one thing in common: they work to restore insulin sensitivity. This will not only improve body composition, it will normalize your metabolism on a fundamental level, reducing the risk of all the common chronic diseases. I may cover these topics again in more detail at another time.
1. Carbohydrate restriction. This is by far the most effective way to improve body composition. It will even benefit people who are already profoundly insulin resistant. Eliminating grains, legumes, potatoes and sugar is the simplest and best way to do this. That includes wheat, corn, rice, beans, oats, honorary grains like buckwheat and quinoa, and especially their derivatives. Carbohydrate is not the devil, but restricting intake to moderate amounts from vegetables and fruit is ideal for someone trying to lose weight. I think starchy root vegetables, soaked or sprouted legumes and soaked, sprouted or fermented non-gluten grains are OK for people who already have a healthy body composition.
2. Exercise. Our hunter-gatherer ancestors had a word for exercise: "life". Exercise helps improve insulin sensitivity by increasing the muscles' demand for fuel. It also builds muscle mass. Any exercise is great, but the best kind is brief and intense (anaerobic). This includes sprinting and brisk weight training. It's more effective than jogging at improving muscle mass, decreasing fat mass, decreasing insulin and improving other markers of metabolic health. Chris at Conditioning Research covers this topic regularly. Traditional sports like soccer and basketball are effective because they have anaerobic and aerobic components. Even walking up stairs or down the street have measurable health benefits, however.
3. Intermittent fasting. This is very effective at improving insulin sensitivity and body composition. IF isn't starvation; it simply postpones calorie intake. Nor is it unhealthy. In fact, it's probably closely in line with the variable energy intake to which we are fundamentally adapted. My method is one 24-hour, water-only fast per week. No juice; that defeats the purpose. If you have elevated insulin like most people, it's best to get into IF gradually. Try skipping breakfast first. If you can skip breakfast and lunch, you've completed a 23-hour fast.
4. Lose the soda! Soda and other sweet foods are the enemy of body composition and general health. Fructose, found abundantly in high-fructose corn syrup, table sugar and agave nectar, seems to have a particular talent for causing insulin resistance. It's rapidly converted to fat in the liver, which is partially stored on the spot, and partially exported into the bloodstream as triglycerides. Diet soda isn't much better. It's been associated with weight gain in humans, and actually causes weight gain in rats. Normalizing insulin through carbohydrate restriction and fasting reduces cravings for sweet foods. A moderate amount of fruit is probably fine.
Thursday, March 27, 2008
They used a measure of visceral fat called the "sagittal abdominal diameter", basically the distance from the back to the belly button. In other words, the beer belly.
What we're looking at is another facet of the pervasive "disease of civilization" that rolls into town on the same truck as sugar and white flour. Weston Price described it in 14 different cultures throughout the world in Nutrition and Physical Degeneration. Diabetes, cardiovascular disease, obesity, cancer and dementia all seem to come hand-in-hand. It's hard to say exactly what the root cause is, but the chain of causality seems to pass through visceral fat and insulin signaling in many people.
Wednesday, March 26, 2008
The first article I came across showed that surgical removal of the visceral fat deposit of rats increased their lifespan. Visceral fat (VF) is the "beer belly", and consists of the perinephratic fat around the kidneys and the omental fat in front of the intestines. It doesn't include subcutaneous fat, the fat layer under the skin.
VF is tightly associated with the metabolic syndrome, the quintessential "disease of civilization" that affects 24% of Americans (NHANES III). It's defined by three or more of the following criteria: high blood pressure, large waist circumference, low HDL cholesterol, high triglycerides, and high fasting glucose. The metabolic syndrome is associated with a 3-4-fold increase in the risk of death from cardiovascular disease, and a 6-fold increase in the risk of developing type II diabetes. From a review on the metabolic syndrome (parentheses mine):
The most common alteration related to the impaired glucose metabolism with aging is the progressively increased fasting and postprandial [post-meal] plasma insulin levels, suggesting an insulin-resistant state.
This is all well and good, but who cares? What's to say VF plays any role other than as a simple marker for overweight?
The longevity paper led me to Dr. Barzilai's previous papers, which answered this question rather thoroughly. Rats raised on standard rat chow, which is a sad little compressed pellet made of grains and added nutrients, develop elevated insulin and insulin resistance with age, just like humans. Unless they don't have VF. Rats that had their VF surgically removed did not develop insulin resistance or elevated insulin with age, despite rebounding to their original total fat mass rather quickly (VF accounts for ~18% of total fat in these rats). These parameters are unaffected by removing an equal amount of subcutaneous fat, which has been shown in human liposuction patients as well.
Removing VF also improved diabetes-prone Zucker rats, which are profoundly insulin-resistant (leptin receptor loss-of-function). It kept wild-type rats just as insulin-sensitive as calorically restricted controls, which had a small amount of VF. This shows that VF isn't just a passive player; it's essential for the development of insulin resistance. It also shows, along with human studies, that insulin resistance is not an inevitable consequence of aging.
Adipose (fat) tissue is being increasingly recognized as an important endocrine (hormone-secreting) organ. It produces many different hormones that affect insulin sensitivity and appetite regulation, among other things. These hormones are collectively known as fat-derived peptides (FDPs). At least one of these FDPs, TNF-alpha, promotes insulin resistance.
Dr. Barzilai's group went on to explore the mechanism of VF contributing to insulin resistance. They increased the rate of glucose flux into the fat tissue of rats by infusing either glucose or insulin into the bloodstream. These treatments both cause increased glucose uptake by fat cells. What they saw when they dissected the rats was striking. The VF had ramped up its production of FDPs from 2- to 15-fold, while the subcutaneous fat had barely changed. Incidentally, insulin increased glucose uptake by VF twice as much as subcutaneous fat.
I'll say this again, because it's important. They forced glucose into VF cells, and those cells dramatically upregulated FDP production. And again, no visceral fat, no FDPs.
In earlier papers, he also showed that the removal of VF dramatically reduces the expression of TNF-alpha and leptin (two FDPs) in subcutaneous fat on a longer timescale, showing that VF and subcutaneous fat communicate to alter the metabolism. Again, TNF-alpha promotes insulin resistance, making it a possible link between the fat tissue and peripheral effects. VF removal had no effect on triglycerides, suggesting that they're only a marker of insulin dysfunction rather than a cause.
Now to take this research to its logical conclusion. Here's a plausible sequence of events leading up to the metabolic syndrome:
- A meal high in quickly digested carbohydrate elevates blood glucose. OR, excessive fructose causes insulin resistance in the liver which leads to high fasting glucose.
- Visceral fat responds by increasing production of FDPs.
- FDPs, directly and/or indirectly, cause insulin resistance in the liver, muscle and other tissue. Liver insulin resistance causes alterations in lipoprotein ("cholesterol") profile (more on this in another post). Fat tissue remains insulin-sensitive.
- Fat tissue (including VF) grows in size, because due to its insulin sensitivity it's taking up more than its share of glucose.
- The vicious cycle continues, with increased visceral fat size and glucose uptake increasing FDP production, which makes the liver more insulin resistant, which increases glucose production by the liver, etc.
- In the absence of lifestyle changes, the cycle only stops when the fat tissue becomes insulin-resistant, at which point you lose control over blood sugar and become diabetic.
Monday, March 24, 2008
The thing that often gets swept under the rug is that they eat lard. Traditionally, it was their primary cooking fat, and they use it liberally. Of course, they also eat the pork the lard came from.
I'm not saying lard will make you live to 100, but it certainly won't stop you...
Sunday, March 23, 2008
The best place to buy lard is at a local farmer's market. Look for pigs that have been "field-raised" or "pasture-raised", and are preferably organic. This ensures that they receive sunlight and have been treated humanely. The "organic" label by itself simply means they have been fed organic feed; the pigs will often not have had access to the outdoors. I recommend avoiding conventional (non-organic) pork at all costs, because it's profoundly inhumane and highly polluting. This is where I buy my lard.
If you don't have access to good quality local lard, there are a couple of sources on the Local Harvest website. Look for "leaf lard", which is the fat surrounding the kidneys. It's lowest in polyunsaturated oil and thus has the highest smoke point and the lowest omega-6 content. It's also practically pure fat. You will recover 90% of the pre-rendering volume from leaf lard. On to the recipe.
Ingredients and Equipment:
- Baking dish
2. Cut off any pieces of meat clinging to the fat.
3. Cut fat into small (~1-inch) cubes.
4. Place them into a non-reactive baking dish and then into the oven.
5. Over the next 2-3 hours, periodically mash the fat with a potato ricer or the back of a large spoon. The fat will gradually separate from the residual protein as a clear liquid.
6. When you are satisfied that you've separated out most of the fat, remove the baking dish from the oven and allow it to stand until it's cool enough to be safe, but warm enough to be liquid.
7. Pour through a cheesecloth into jars. Save the "cracklins", these can be eaten.
8. If you plan on using the lard for crusts, cool it as quickly as possible by placing the jars in cold water. If the lard solidifies slowly, it will have a slightly grainy texture that works less well for crusts, but is irrelevant for other purposes.
Finished lard has a long shelf life but I like to keep it in the fridge or freezer to extend it even further.
Saturday, March 22, 2008
The fatty acid profile of lard might give us a clue. A major portion of lard is monounsaturated, 40% by weight. This is the same type of fat that predominates in olive oil (73%), and which is widely recommended by mainstream nutrition experts. Another prevalent class of fat in lard is saturated, at 48%. More than one third of this saturated fat is stearic acid, which even the most hardened lipophobe will agree has a "favorable" effect on blood lipids. Then there's the 8% polyunsaturated fat, which has been the darling of mainstream heart disease research for decades due to its ability to lower blood cholesterol (for the record, I believe the polyunsaturate content is lard's least healthy feature). The omega-3:6 ratio depends on how the pig was raised, but is typically skewed more toward omega-6.
So what does that leave us with? 66% fats that we're told are heart-healthy, and 30% non-stearic saturated fats that are supposed to be unhealthy. But if you still believe saturated fats cause heart disease, check out this post, this one and this one.
Lard also contains a small amount of vitamin D. The sun is the best source of vitamin D, since your skin synthesizes it when it's exposed to UVB. But due to the low angle of the sun in winter, and the fact that many people don't spend enough time outdoors even in the summer, extra vitamin D in the diet is helpful.
I think you can see that lard's bad reputation is undeserved. It may be a legacy of the time when hydrogenated vegetable oils were competing with animal fats for the food market.
There is such a thing as unhealthy lard, however. It's the stuff you might find at the grocery store. Store-bought lard is often hydrogenated to make it more shelf-stable. It also comes from confinement-raised pork operations, which aside from being profoundly inhumane, do not allow access to the outdoors. Thus, the fat won't contain vitamin D.
In the next post, I'll talk about how to buy pasture-raised lard and render it yourself.
Wednesday, March 19, 2008
Insulin is the master hormone that orchestrates the metabolic changes that cause fat accumulation. It instructs the body to transport glucose and fat from the blood into the cells. It tells the liver to synthesize fat from sugar. It inhibits the release of fat from fat cells. There are no other hormones that have a similar range of effects.
Insulin is the "storage hormone". Don't believe me? Ask a type I diabetic. Type I diabetes happens when the pancreas no longer secretes insulin. These people are rail-thin until they are given insulin injections, at which point they often gain excess weight. Many deliberately skip injections to lose weight. Unfortunately, this has serious consequences as it allows their blood glucose to rise to dangerous levels unchecked.
If insulin is kept low, fat synthesis and storage are inhibited, and fat release from fat cells is increased. Carbohydrate is particularly effective at elevating insulin, acutely and chronically. As carbohydrate digests, it's broken down into glucose, which enters the bloodstream. The pancreas releases insulin in an attempt to keep blood glucose within a healthy range, and the storage begins. Refined carbohydrate is the worst offender, because it causes a large and rapid rise in blood glucose.
Regular overconsumption of carbohydrate causes insulin to be chronically elevated in many people [update- I no longer believe this is true. I now believe that only certain types of carbohydrate- namely wheat and sugar- cause a pathological increase in fasting insulin over time]. This comes along with "insulin resistance", whereby most or all tissues become desensitized to insulin. This is the tissues' way of saying "Stop! My energy stores are already full! I can't handle any more glucose or fat!".
Some people are able to maintain normal insulin levels (and sensitivity) in the face of a high-carbohydrate diet. This is probably partly genetic and partly environmental. Certain people, for whatever reason, have fat tissue that is prone to fat accumulation. It could be because they oversecrete insulin, or because their fat tissue is sensitive to the action of insulin, but probably both. It likely has to do with a combination of insulin resistance in non-fat tissue, and insulin sensitivity in fat tissue. Inactivity and fructose consumption (from corn syrup or sucrose) are also high on the list of suspects.
Fat tissue is typically the last to become insulin resistant because it acts as a valuable buffer to remove excess (and potentially toxic) glucose from the bloodstream. Unfortunately, simply being thin is not a reliable indicator that your body tolerates carbohydrate well. It can indicate either that all tissues are insulin-sensitive and insulin levels are low, or all tissues (including fat) are insulin resistant and insulin levels are high. The latter scenario leads to type II diabetes, pronto.
Since fat accumulation revolves around carbohydrate intake and insulin production, it makes sense that reducing carbohydrate causes weight loss. No more carbohydrate = a lot less glucose, and a lot less insulin to deal with it. This completely sidesteps the problem of insulin resistance, although that seems to respond favorably to carbohydrate restriction as well. Every time true low-carbohydrate diets are matched head-to-head with reduced-calorie, carbohydrate-rich diets, subjects lose more weight and have fewer problems with hunger on the low-carbohydrate diet. I discussed a recent study here.
The idea that you can achieve and maintain a healthy weight without cutting calories sounds too good to be true. In fact, all it represents is a return to our natural pattern of eating as human beings. It may involve breaking an addiction to carbohydrate. True hunter-gatherers eat between 0 and 35% of their calories as carbohydrate, and no refined carbohydrate [correction: a number of hunter-gatherer groups ate more than 35% carbohydrate, typically from starchy tubers]. In industrial nations, we eat approximately 50% of our calories as carbohydrate. Hunter-gatherers also exercise regularly, and don't eat Frosted Sugar Bombs for breakfast. This helps maintain good insulin sensitivity. Since we are genetically very similar to our hunter-gatherer ancestors, we would be wise to learn from their example.
Since the mid-seventies, the prevalence of overweight and obesity has increased sharply for both adults and children. Data from two NHANES surveys show that among adults aged 20–74 years the prevalence of obesity increased from 15.0% (in the 1976–1980 survey) to 32.9% (in the 2003–2004 survey).In hunter-gatherer and some semi-agricultural societies, obesity is rare. In most, it's nonexistent. Wild animals typically do not accumulate enough fat to interfere with vigorous exercise, and when they do, it's because they're about to hibernate or migrate. Wild animals also tend to have similar amounts of body fat between individuals (at a given age and sex), unlike industrialized humans. This makes me think that obesity is an unnatural effect of our current lifestyle. Whatever the cause, it's getting progressively more common.
According to self-righteous nutrition experts, we know exactly what causes overweight. It's a character flaw known as overeating. Calories in, calories out. And the cure is to eat less. The problem is, this is not supported by the evidence. First of all, overweight people often eat no more than the thin. Second, weight gain is a highly individual process. Overfeeding under controlled conditions can produce more than 3-fold differences in weight gain between individuals fed the same number of calories.
Restricting calories is also fraught with problems. Each person's metabolism has a preference for a specific body composition within the context of a particular lifestyle. If total calories are restricted without changing diet composition, the body reacts vigorously to maintain homeostasis. Energy expenditure is reduced; muscle and organ mass diminish. The psychological effects are particularly bad, as anyone can tell you who has been on a low-calorie diet. In 1944, Ancel Keys undertook a calorie restriction trial in conscientious objector "volunteers" in Minnesota. They remained on a 1,570-calorie diet that was low in fat and protein and high in carbohydrate, for 24 weeks. Hardly a draconian calorie count. Here's a quote from the study:
As starvation progressed, fewer and fewer things could stimulate the men to overt action. They described their increasing weakness, loss of ambition, narrowing of interests, depression, irritability, and loss of libido as a pattern characteristic of "growing old".Some of the men ended up suffering from neurosis and borderline psychosis before the end of the study, one culminating in self-mutilation. This is what we're being prescribed for weight loss?
There are some diet trends that have associated with rising obesity in the US. Per capita calorie consumption has increased. This increase is due to a higher consumption of carbohydrate. Total protein and fat consumption have been almost identical for the past 30 years. This period also saw increases in the consumption of unsaturated vegetable oils, hydrogenated vegetable oils and high-fructose corn syrup. It's hard to say from this association which of these factors (if any) has caused us to gain weight in the last 30 years, but it certainly isn't total fat or protein. Fortunately, we have other clues.
Monday, March 17, 2008
For those of you who haven't been reading the comments, we've been having a spirited discussion about the diet and health of hunter-gatherers here. I brought up the Kuna indians in Panama, who are immune to hypertension, live a good long time, do not gain excess weight, and seem to have less cardiovascular disease and cancer than their city-dwelling cousins.
I was hungry for more information about the Kuna lifestyle, so over the last few days, I've dug up every paper I could find on them. The first paper describing their lack of hypertension was published in 1944 and I don't have access to the full text. In 1997, a series of studies began, headed by Dr. Norman Hollenberg at Harvard. He confirmed the blood pressure findings, and collected data on their diet, lifestyle and kidney function. Here's a summary:
The Kuna are half hunter-gatherers, half agricultural. They cultivate plantains, corn, cocoa, yucca, kidney beans, and several types of fruit. They trade for sugar, salt, some processed cocoa and miscellaneous other foods. They drink 40+ oz of hot cacao/cocoa per day, some locally produced and some imported. A little-known secret: the Kuna eat an average of 3 oz of donut a week. They also fish and hunt regularly.
In the first recent study, published in 1997, the Kuna diet is described as 29% lower in fat than the average US diet (56 g/day), 23% lower in protein (12.2 g), 60% higher in cholesterol, and higher in sodium and fiber. The study doesn't specifically mention this, but the reader is left to infer that 65% of their calories come from carbohydrate. This would be from plantains, corn, yucca, sugar and beans. The fat in their diet comes almost exclusively from coconut, cocoa and fish: mostly saturated and omega-3 fats.
In the next study, the picture is beginning to change. Their staple stew, tule masi, is described as being 38% fat by calories (from coconut and fish), exceeding the American average. In the final study in 2006, Hollenberg's group used a more precise method of accounting for diet composition than was used in previous attempts. The paper doesn't report macronutrients as a percentage of calories, and I suspect the reason is that they aren't consistent with the previous papers. They have retreated from their previous position that the Kuna diet is low-fat and describe it instead as "low in animal fat", leaving plenty of room for saturated fats from coconut and cacao.
I was able to find some clues about their diet composition, however. First of all, they report the meat consumption of the Kuna at approximately 60 oz per week, mostly from fish. That's 8.6 oz per day, identical to the American average. They also reported the fat content of the cacao the Kuna produce locally and brew into their favorite 40-oz-a-day drink. It's 44.2% fat by weight. The low-fat cocoa drinks they used to calculate macronutrient totals are made from imported cocoa (cocoa is defatted cacao powder), ignoring the locally produced, full-fat cacao. If we assume half the chocolate they drank was locally produced, that's about 30 additional grams of fat a day, bringing their total fat intake to 8g above the average American. I suspect the authors chose to ignore the locally-produced cacao to lower the apparent fat intake of the Kuna, even though the paper states they drank both regularly.
By putting together the pieces from the later studies, a new picture emerges: a diet high in fish and moderate in protein, high in unprocessed fat (especially saturated and omega-3), and moderate in mostly unprocessed carbohydrate.
Here's my biased interpretation. The Kuna are healthier than their city-dwelling cousins for a number of reasons. They have a very favorable omega3:6 ratio due to seafood, wild game and relatively saturated vegetable fats. Their carbohydrate foods are mostly unprocessed and mostly from non-grain sources. They also live an outdoor life full of sunshine (vitamin D) and exercise. The chocolate may also contribute to their health, but I doubt it's a major effect. They're healthier than industrialized people because they live more naturally.
Another lesson to be learned from the Kuna and other exceptionally healthy indigenous peoples is that the human body can tolerate a fair amount of carbohydrate under the right conditions. Peter discusses another example of this, the Kitavans, on his blog. 50% carbohydrate while sitting in front of a desk all day, eating corn oil and getting no exercise = bad. 45% carbohydrate while hunting, relaxing and preparing whole, natural food in the sun all day = good.
Sunday, March 16, 2008
Most if not all dairy-eating cultures ferment their milk. Why is this? There are three main reasons. First of all, unpasteurized milk spontaneously ferments at room temperature, usually becoming delicious "clabbered milk"- whereas pasteurized milk becomes putrid under the same conditions. So fermented milk is difficult to avoid. The second, related reason, is that fermentation prolongs the life of milk in the absence of refrigeration. Fully fermented milk is stable for weeks at room temperature.
The third reason is that these cultures know cultured milk is delicious and nutritious. Fermentation with specially selected cultures of lactic acid-producing bacteria and sometimes yeast work to break milk down into a form that is more easily assimilated. They partly (or fully) digest the lactose, which can be a problem for some people, turning it into tangy lactic acid. They also partially digest casein, a protein in milk that is difficult for some to digest. And finally, the lower pH of fermented milk makes its minerals more bioavailable.
Traditionally, milk was fermented in its unpasteurized state, but raw milk is hard to find in many industrialized countries. Raw milk has its complement of enzymes intact, such as lactase and lipase, which aid in its digestion. It also contains lactose-digesting bacteria that make milk easier for some to digest, and contribute to intestinal health. These are all eliminated by pasteurization. Fortunately, fermentation restores some of the benefits of raw milk. It reintroduces lactic-acid bacteria, along with their digestive enzymes. With that in mind, here's a simple yogurt recipe:
1/2 gallon whole, raw or pasteurized, cow or goat milk (add extra cream if you wish)
Starter culture (commercial starter or 2 tbsp of your favorite live-culture yogurt)
Glass jars with lids
Cooler or yogurt maker
1. Heat the milk to 110-115 F (43 C). If the temperature exceeds 115 F, let it cool.
2. Add the starter culture. If the starter is yogurt, whisk it into the milk.
3. Pour the milk into glass jars and keep it at about 110 F for 4-10 hours. 4 hours will yield a mild yogurt, 10 will be tangy. If you don't have a yogurt maker, this is the tricky part. You can use a cooler filled with 100 F water to maintain the temperature and spike it with hot water after a few hours, or you can ferment it in your oven with the pilot light on if the temperature is in the right range.
If you want a thicker yogurt, bring the milk to 180 F (82 C) and let it cool to 110 F before adding the starter. Add fruit, honey or other flavors before fermenting. Enjoy!
As a final note, I'll mention that milk simply does not agree with some people. If you've tried raw milk and homemade yogurt, and they cause intestinal discomfort or allergies, let them go.
Saturday, March 15, 2008
1- Drive deliberately; accelerate gradually. A car uses a lot of fuel when it's accelerating rapidly.
2- Drive 55 mph on the highway. This makes a huge difference. It maximizes fuel efficiency by reducing wind resistance, which exponentially increases with speed. This reduces gas consumption by more than 20% relative to a speed of 75 mph. 60 mph is almost as good, if 55 is to slow.
3- Draft a truck. Large trucks with flat, square backs leave a massive low-pressure zone behind them, which you can exploit to save gas. At 20 feet behind a standard 18-wheeler, you will use about 27% less fuel. If that's too close, you still save 20% at 50 feet, and 11% at 100 feet. Be careful because trucks have a blind spot behind them, and some truckers do not appreciate drafting.
4- Keep your car well-maintained. Clogged filters, faulty oxygen sensors and flat tires all hurt fuel efficiency.
5- Lose the cargo. The more weight you have in your car, the more fuel is required to get it up a hill or accelerate it.
6- Turn off accessories. AC is the biggest power drain, but the fan used to circulate air also draws power.
Thursday, March 13, 2008
I actually did find two things that were palatable and not too unhealthy: canned sardines and toasted cashews. The total was $2.50, affordable even for a grad student.
The sardines were canned in "tomato sauce", which I realized later contained soybean oil. Oops. Well I suppose when you get your food at a convenience store, you have to expect such things.
The main thing that bothered me was the trash. I posted a mugshot (above) of the can, fork and plastic bag that I either trashed or recycled as a result of the meal. The total volume of trash was probably almost as much as the total volume of food.
I think if you stick to nuts, canned fish and fresh fruit, it's possible to survive a convenience store stop. And Baby Ruths. Those are healthy, right?
While I was waiting for the bus one morning, I decided I'd count cars to see how many were single-occupancy vs. two or more. I came up with a ratio of roughly 20 single-occupancy vehicles for every multiple-occupancy vehicle. The multiple-occupancy vehicles were most often work trucks, containing plumbers or construction workers going to a job.
People have to get to work. Maybe they don't have public transit where they are, or maybe they just don't feel like sitting next to smelly commuters, but for whatever reason, here in the U.S. they drive their cars.
The average American weighs about 180 lbs. Due to our love affair with SUVs, the average American car weighs over 2 tons and climbing. That means every time a person drives a single-occupancy vehicle to work, they aren't just expending the energy it takes to move 180 lbs 15 miles. They're also lugging around a hulking two-ton chunk of steel and plastic. The passenger of the average single-occupancy vehicle is only about 1/24 (4%) of the mass that's being moved to and from work. That's ridiculous!
Of course, we make up for the big weight of our cars with big engines so they can go vroom. That adds up to a lot of gasoline burned, for no clear benefit. In other words, most of us could easily be driving vehicles that perform the exact same function but burn 1/3 the gasoline. I'm not talking about space-age technology here; these vehicles are already on the market.
Why do we commute so inefficiently when better options surround us? I think there are several reasons. First of all, gasoline is dirt cheap. We have no incentive to be efficient beyond our own consciences. Even with the recent price jumps, gasoline doesn't cost much more than it ever has, if you adjust for inflation. In Europe, where high taxes mean gasoline can cost four times as much as in the US, vehicles are lighter and more efficient.
Secondly, we've always been a very car-centric society. Cars appeal to our desire for independence, power and control. A large, powerful car is a status symbol in the US. We've inherited these attitudes from previous generations and we're just beginning to question them. Are there healthier and less wasteful ways of getting to work?
There are, and many of them are very simple. The first and simplest is a carpool. If we put two average Americans in our two-ton car, all of a sudden the people are 1/12 the weight of the vehicle. With four people, the number jumps to 1/6. We've just made our vehicle almost four times as fuel efficient, per passenger! 1,000 lbs per person is still a lot of weight to be lugging around though, so let's look at some other options.
If you are on the market for a new car, fuel-efficient models abound. The new hybrid cars by Toyota and Honda are twice as efficient as their non-hybrid brethren, and not much more expensive. Some people truly need SUVs for their business, but I have good news for them too: there are now hybrid SUVs as well. That's right ladies and gentlemen, they're the most efficient gas guzzlers on the market.
Public transportation is another great option where it's available. Buses are big and heavy but they can accommodate many people.
Now let's get into the really efficient vehicles. Motorcycles and scooters weigh from 250-500 pounds, meaning that a passenger would be from 1/2 to 1/4 the total weight of the vehicle. Now we're beginning to make some sense. Certain scooters can go over 100 miles per gallon of gasoline.
An even better option is to use vehicles that don't burn gasoline at all. A bicycle weighs about 20-30 pounds, making the passenger about 9/10 of the total vehicle weight. That weight ratio might change as the average American loses some weight however. Even if you factor in the extra food you eat when you cycle regularly, it's still terribly efficient. Best of all, bikes allow us to get exercise and feel the sun for a while.
The title for the most fuel-efficient and low-tech vehicle around goes to feet. When using a pair of these, the passenger is 100% of the weight of the vehicle. You can walk until you wear them out and you still won't have burned a single molecule of gasoline. Now that's efficient.Thanks to lairdscott for the CC photo.
Monday, March 10, 2008
According to the World Health Organization, 82 out of every 100,000 French men between ages 35 and 74 died as a result of cardiovascular disease (CVD) in the year 2000. In that same year, 216 out of 100,000 men between the same ages in the U.S. succumbed to the same disease.
According to the Food and Agriculture Organization of the UN, during roughly the same time period, the average French person ate slightly more total fat and almost three times more animal fat than the average American. Animal fats came from dairy, lard, red meats, fish and poultry, and contributed to a much higher overall saturated fat intake in the French. This has been called the "French paradox", the paradox being that saturated fat is supposed to cause CVD.
Researchers have been scrambling to identify the factor that is protecting French hearts from the toxic onslaught of saturated fat. What could possibly be preventing the buttery sludge coursing through their arteries from killing them on the spot? One hypothesis is that wine is protective. Although the modern French don't actually drink much more alcohol than Americans on average, wine contains a number of molecules that are potentially protective.
One of these that has gotten a lot of attention is resveratrol, an activator of SIRT1, a deacetylase enzyme that is involved in stress resistance and lifespan regulation. But lo and behold, it turns out that there isn't enough of it in wine to be helpful. Now researchers are turning their attention to a class of molecules called procyanidins, but I suspect that this will turn up negative as well. The protective molecule is probably ethanol, but no one wants to hear that because it doesn't resolve the paradox.
As a person with a French background who has spent quite a bit of time in France, the notion of a French paradox is insulting. It implies that the French are eating an unhealthy diet, but are somehow miraculously protected by a compound they're ingesting by accident. Any French person will tell you there is no paradox. When you make a commitment to seek out the freshest, most delicious ingredients available and cook them yourself, your diet will be healthier than if you count the grams of this and that on your TV dinner.
There's more. Americans consume almost twice the amount of sugar as the average French person. I find this surprising, given the large amount of sugar I've seen on French tables, but I think it speaks to the huge amount of sugar we consume in the US. Much of it probably comes from the high-fructose corn syrup in soda. I'll save my rant about that for another time.
Another thing that stands out about French food habits is the absence of snacking. Mealtimes in France tend to be well-defined, and grazing is looked down upon. I think this is probably essential for maintaining adequate insulin sensitivity in the face of (delicious) refined carbohydrates like baguette.
And finally, the French enjoy their food more than the average nation. I wouldn't underestimate the value of this for health and overall well-being.
So what was the paradox again? I can't remember. Maybe a more parsimonious explanation of the data is that saturated fat isn't so bad after all, and enjoying wholesome food and limiting sugar is the true prescription for health.
Thanks to Gaetan Lee for the creative commons photo.
Sunday, March 9, 2008
'Ranch', '1000 Island' and other industrial monstrosities are a good way to put yourself underground in a hurry. From bottom-rung oils to artificial preservatives, they contain some of the most frightening ingredients you're likely to see in a grocery store.
Homemade salad dressing is one of the simplest, tastiest and healthiest recipes I know. If made properly, it's creamy, light and flavorful. I consider it my civic duty to spread the word about homemade salad dressing, also known as vinaigrette.
For a medium-sized salad, put two tablespoons of vinegar into your empty salad bowl. Add a pinch of salt and a tablespoon of dijon mustard. Add three tablespoons of olive oil and stir until it's creamy and homogenous. That's it! Add your salad, toss and enjoy. The tossing is essential.
I always use extra-virgin olive oil. My favorite vinegar is unpasteurized, unfiltered apple cider vinegar. You may add garlic, tarragon, mint, basil, green onions or miso to your dressing for extra flavor.
Friday, March 7, 2008
One of the things he observed was the egg-retrieving behavior of the greylag goose. When an egg rolls out of a goose's nest, it gently uses its bill to roll it back in. However, when Lorenz took an egg from the nest and placed it next to a larger round white object, the goose preferentially rolled the larger object back into its nest while ignoring the real egg. He called this larger object a superstimulus. It was an abnormally strong stimulus that was able to hijack the bird's normal behavioral pattern in a maladaptive way.
Our brains are wired to respond to the stimuli with which they evolved. For example, our natural taste preferences tell us that fruit is good. But what happens when we concentrate that sugar tenfold? We get a superstimulus. Our brains are not designed to process that amount of stimulation constructively, and it often leads to a loss of control over the will, or addiction.
It's a very similar process to drug addiction. Addictive drugs are able to plug directly into the brain's pleasure centers, stimulating them beyond their usual bounds. Food superstimuli do this less directly, by working through the body's taste reward pathways. In fact, sweet liquids are so addictive, rats prefer them to intravenous cocaine. You can't take just one hit of crack, and you can't have just one Hershey's kiss.
Our bodies are finely honed to seek out healthy food, but only in the context of what we knew when our tastes developed during evolution. If all that's available is grass-fed meat, pastured eggs, vegetables, fruit, and nuts, your appetite will naturally guide you to a healthy diet.
If you surround yourself with superstimuli such as sugars, refined grains and MSG, your body will not guide you to a healthy diet. It will take you straight into a nutritional rut because it's not adapted to dealing with unnatural foods.
Your brain is pretty simple in some ways. It has these very basic hard-wired associations, like "sweet is good" and "free glutamate is good". If your brain likes a little bit of sweet, then it really likes a lot of sweet. If it likes a little bit of glutamate from meat, then it really likes a flood of glutamate from MSG. Just like the graylag goose that prefers the big white ball over her own egg, your brain drives you to ignore normal stimuli in favor of more potent superstimuli.
This explains the partially true saying "Everything that tastes good is bad for you". Why would your body deliberately encourage you to damage your health? In our hunter-gatherer state, it didn't. In this age of processed food, our technology has outstripped our ability to adapt.
Thursday, March 6, 2008
The simplest way to make stock is to keep a "stock bag" in the freezer. Keep two plastic freezer bags (or whatever container you prefer) in the freezer, ready to accept food scraps whenever you have them. One is for vegetable scraps such as carrot peels, onion skins (not the brown part!), radish tops, etc. The other is for animal scraps such as bones, fish heads/tails, gristle, etc.
These are examples of vegetable scraps that are appropriate for stock:
These are examples of animal products that are good for stock:
Parmesan rinds (thanks Debs!)
These should not be used for stock:
Brown onion skins
Anything covered in dirt
Anything rotten or unpleasant-smelling
Celery greens, carrot greens and other bitter greens
Vegetable stock is the easiest. Take a generous amount of vegetable scraps out of your stock bag and put them in a pot full of water. Boil for one hour, then strain.
In my opinion, the best stock is made with animal bones. It's rich in minerals and gelatin, and has a full, meaty flavor. Break the bones to expose the marrow, put them in a pot full of water or a crockpot, add 2 tablespoons vinegar, and simmer for 1-20 hours. Add vegetable scraps for the last hour, then strain. Large bones from beef or lamb require long cooking to draw out their full flavor, while thinner chicken bones and fish parts require less. The vinegar helps draw the minerals out of the bones into solution.
Fish heads also make a delicious, nutritious stock. They're full of minerals (including iodine), omega-3 fats and vitamin A from the eyes. You can often get them dirt-cheap at the fish counter. Boil them for one hour with vegetable scraps and two tablespoons of vinegar, strain, pick off the meat and add it to your soup.
Wednesday, March 5, 2008
For the majority of human existence, we have been in more or less full control of food preparation. We roasted our own meat, churned our own butter, and stewed our own vegetables. Gradually, mostly over the course of the last hundred years, we have ceded this control to others.
People in industrialized nations now rely on processed food and restaurants for the majority of our diet. Our food has been outsourced, and it's killing us.
The problem is that the incentives of individuals are different from the incentives of restaurants and corporations. The individual cares about the enjoyment and healthfulness of food. The corporation and restaurant care about money. It's not a conspiracy against our health, it's just a difference of motivation.
This explains why processed food is so unhealthy. Is a food manufacturer going to use butter or dirt-cheap hydrogenated soybean oil in that cookie if you can't tell the difference?
The only reason we accept this state of affairs is we're completely disconnected from the preparation of these foods. For example, let me tell you how hydrogenated soybean oil is made. First, the oil is separated from the rest of the bean using heat and extraction with organic solvents like hexane. Then, the oil is mixed with nickel (a catalyst) and exposed to hydrogen gas at high temperatures. This causes a chemical reaction (hydrogenation) that results in trans fat, which is solid at room temperature like saturated fats. The oil is now a grayish, rancid-smelling mush. They filter out the nickel and use chemicals and heat to deodorize and bleach it, creating the final product that is ubiquitous in processed snack foods. Delicious!
If you were able to watch this whole process with your own two eyes, would you still eat hydrogenated oil? If you had to make it yourself, would you? How about if I told you eating it is associated with a dramatic increase in the risk of cardiovascular disease, insulin resistance and probably many other diseases?
It's time to re-connect ourselves with real food. It's time to reclaim food preparation.
Join me as I explore traditional methods of food preparation, one of our most valuable conduits to health and well-being.
Tuesday, March 4, 2008
Low Fat Diets More Likely To Reduce Risk Of Heart Disease Than Low Carb Diets!
This gem, courtesy of Medical News Today. I was curious so I looked up the abstract.
It was a 6-week study in the journal Hypertension where they measured a number of surrogate measures of cardiovascular disease risk, in patients eating either an Atkins-style low-carbohydrate (LC) diet or an ADA-style low-fat (LF) diet.
"Brachial artery flow-mediated dilation" and nitroglycerin-mediated dilation basically measure the ability of your arteries to dilate. The loss of the ability of vessels to dilate is associated with cardiovascular disease.
Where do I begin.
First of all, this was a 6 week study, not long enough to really say anything about cardiovascular disease risk. But nevertheless, let's look at the actual data:
The LF group lost an average of 4.3 lbs over the course of the 6 weeks. The LC group lost 5.7 lbs.
The LF group's blood pressure decreased 8/5 mm Hg (systolic/diastolic). The LC group's decreased 12/6 mm Hg.
The LF group's flow-mediated dilation increased +1.9, but was reduced in the LC group by -1.4.
There was no difference between groups in nitroglycerin-mediated vasodilation.
Here's the best part (full text only): the triglyceride/HDL ratio went from 1.2 to 1.6 in the LF group, and from 1.4 to 1.1 in the LC group. Trig/HDL ratio is the best blood lipid predictor of heart disease we have, and the lower the better.
So let me get this straight. What we're looking at is data showing that LC beat or tied LF on every relevant parameter they reported except one, and somehow that means LF diets are healthier than LC? Even though overweight and hypertension are important risk factors for cardiovascular disease? Even though trig/HDL is probably the best predictor of heart disease of any of these measures?
This article wouldn't bother me if it weren't so arrogant. If it had simply reported the facts as an interesting phenomenon, instead of tacking on a politically motivated (and incorrect) interpretation, I would have just found it interesting. But the author is bigger than his britches: "LF diets may confer greater cardiovascular protection than LC diets."
The irony isn't lost on me that the paper is published in the journal Hypertension, shows that LC diets ameliorate hypertension better than LF diets, yet somehow claims LF diets are more protective of cardiovascular disease than LC. Huh?
Unfortunately, this is typical of researchers in the diet-health field and the media that report on it.
Monday, March 3, 2008
There is a lot of confusion surrounding the role of genetics in health. It seems like every day the media have a new story about gene X or Y 'causing' obesity, diabetes or heart disease. There are some diseases that are strongly and clearly linked to a gene, such as the disease I study: spinocerebellar ataxia type 7. I do not believe that genetics are the cause of more than a slim minority of health problems however. Part of this is a semantic issue. How do you define the word 'cause'? It's a difficult question, but I'll give you an example of my reasoning and then we'll come back to it.
A classic and thoroughly studied example of genetic factors in disease can be found in the Pima indians of Arizona. Currently, this population eats a version of the American diet, high in refined and processed foods. It also has the highest prevalence of type II diabetes of any population on earth (much higher than the US average), and a very high rate of obesity. One viewpoint is that these people are genetically susceptible to obesity and diabetes, and thus their genes are the cause of their health problems.
However, if you walk across the national border to Mexico, you'll find another group of Pima indians. This population is genetically very similar to the Arizona Pima except they have low rates of obesity and diabetes. They eat a healthier, whole-foods, agriculture-based diet. Furthermore, 200 years ago, the Arizona Pima were healthy as well. So what's the cause of disease here? Strictly speaking, it's both genetics and lifestyle. Both of these factors are necessary for the health problems of the Arizona Pima. However, I think it's more helpful to think of lifestyle as the cause of disease, since that's the factor that changed.
The Pima are a useful analogy for the world in general. They are an extreme example of what has happened to many if not all modern societies. Thus, when we talk about the 'obesity gene' or the 'heart disease gene', it's misleading. It's only the 'obesity gene' in the context of a lifestyle to which we are not genetically adapted.
I do not believe that over half of paleolithic humans were overweight, or that 20% had serious blood glucose imbalances. In fact, studies of remaining populations living naturally and traditionally have shown that they are typically much healthier than industrialized humans. Yet here we are in the US, carrying the very same genes as our ancestors, sick as dogs. That's not all though: we're actually getting sicker. Obesity, diabetes, allergies and many other problems are on the rise, despite the fact that our genes haven't changed.
I conclude that genetics are only rarely the cause of disease, and that the vast majority of health problems in the US are lifestyle-related. Studies into the genetic factors that predispose us to common health problems are interesting, but they're a distraction from the real problems and the real solutions that are staring us in the face. These solutions are to promote a healthy diet, exercise, and effective stress management.
This blog will be a collection of my thoughts on health, food, the environment, science, wholesome living and whatever else captures my interest.
Maybe this will help me stop clogging up other blogs' comment pages.