Interesting Links

OK, for years now conventional wisdom has for the most part told us that 'red and processed meats' increase the risk of cancer compared to poultry.  Now some researchers claim that hot dogs have fewer carcinogens than rotisserie chicken.  They can't make up their minds because they bark up the wrong tree.  How about checking on the carcinogenicity of hot dog buns and soda pop?

Research suggests that if you want to get active, you should get a dog, not a gym membership or treadmill.  Tara Parker-Pope of the New York Times reports:

If you’re looking for the latest in home exercise equipment, you may want to consider something with four legs and a wagging tail.

Several studies now show that dogs can be powerful motivators to get people moving. Not only are dog owners more likely to take regular walks, but new research shows that dog walkers are more active over all than people who don’t have dogs.

One study even found that older people are more likely to take regular walks if the walking companion is canine rather than human.

Probably because most humans live at the fatigue-inducing effect of hyperinsulinemia.  Which reminds me, dogs, not chimps, behave most like humans (or is it, humans behave more like dogs than like chimps?).

Cooperation, attachment to people, understanding human verbal and non-verbal communications, and the ability to imitate are just a handful of the social behaviors we share with dogs. They might even think like us at times too, according to the paper, which has been accepted for publication in the journal Advances in the Study of Behavior. 

While there is no evidence to support that dogs and humans co-evolved their laundry list of shared behaviors over the past 10,000 to 20,000 years, the researchers believe adapting to the same living conditions during this period may have resulted in the similarities.

In the "duh" department, researchers announce that going on a calorie-restricted diet  will make you irritable and angry.

Research has shown that exerting self-control makes people more likely to behave aggressively toward others and people on diets are known to be irritable and quick to anger.' 

David Gal of Northwestern University and Wendy Liu of the University of California found that people who exerted self-control were more likely to prefer anger-themed movies, were more interested in looking at angry facial expressions, were more persuaded by angry arguments, and expressed more irritation at a message that used controlling language to convince them to change their exercise habits.

In one experiment for the study published in the Journal of Consumer Research, people who choose an apple instead of a chocolate bar were more likely to choose movies with anger and revenge themes than milder movies.

I think these people have the mechanism wrong.  I don't think these subjects felt angry because they exercised self-control, I think they felt angry and aggressive because they felt hungry.  Do you think those same people would be angry if they had chosen steak instead of either apples or a chocolate bar?  I doubt it.

But these researchers are stuck in the self-control model of weight management.  They think it is all about going hungry and self-discipline.  In contrast, the nature says that appetite regulation and weight management occurs spontaneously when you feed the animal its natural diet.


Nature didn't make a mistake. You don't need much aggression to go for apples.  When you choose to live on apples and go hungry, you get aggressive, because that's what you need to go out hunting for real food, i.e. meat.

On the faith front,  attending religious services apparently makes you fat.

New research finds that people who frequently attend religious services are significantly more likely to become obese by the time they reach middle age.

The study doesn't prove that attending services is fattening, nor does it explain why weight might be related to faith. Even so, the finding is surprising, especially considering that religious people tend to be in better health than others, said study author Matthew J. Feinstein, a medical student at Northwestern University in Chicago.

"It highlights a particular group that appears to be at a greater risk of becoming obese and remaining obese," he said. "It's a group that may benefit from targeted anti-obesity interventions and from obesity prevention programs."....

The researchers found that 32 percent of those who attended services the most became obese by middle age, whereas only 22 percent of those who attended services the least became obese.  Does God give girth, or what?

Levin said one possibility is that those who attend services, along with activities such as Bible study and prayer groups, could be "just sitting around passively instead of being outside engaging in physical activity."

Also, he said, "a lot of the eating traditions surrounding religion are not particularly healthy; for example, constant feasts or desserts after services or at holidays -- fried chicken, traditional kosher foods cooked in schmaltz (chicken fat), and so on."

How about those donuts served after sermons?  The pancake breakfasts used for fund raisers? 

Don't lose any sleep over it.  Researchers found that when sleep-deprived, people increase their food intake by 300 more calories per day.  Note that in the article the authors call ice cream and fast foods "high fat."  Uh, did they forget the sugar?  Just another reason to sleep like a hunter-gatherer: as much as possible, absent artificial lighting, and with family, even if only your dog.

All Low Calorie Diets Are Low(er) Carb Diets

I just posted a new article at Examiner.com

All Low Calorie Diets Are Low(er) Carb Diets

The Twinkie Diet: A Paleo Dieter Perspective

So far two people have emailed me about the “Twinkie diet” self-experiment followed by Mark Haub, Ph.D., a professor of human nutrition at Kansas State University, and reported by CNN.com.  Stephan made an excellent post on it here, which I recommend that you read.  Raj at Harder.Better.Faster.Stronger also made a useful contribution. 

My own views overlap those of Stephan and Raj. 

First, Dr. Haub limited himself to less than 1800 calories per day, while his caloric expenditure at his pre diet weight would be at least 2600 calories (see calculation below).  He described his experiment as "I'm eating to the point of need and pushing the plate or wrapper away.”    The question is, how was he determining “the point of need”?  Answer:  By calculating calories.  

Everyone agrees that anyone can lose weight by deliberately restricting caloric or food intake for a  period of time.  But who wants to meticulously count calories day after day after day?  This is not a spontaneous and therefore for most people not a sustainable way to maintain an appropriate food intake. 

As Stephan notes, the body has its own intelligence which regulates food intake without the interference of the conscious mind.  If you choose the Twinkie diet, you can lose weight as long as you consciously monitor your caloric intake and deliberately override your hunger drive.  However, if you want your body to regulate itself, you will want to eat in a way that allows you to feel satisfied and frees you of having to consciously monitor your food intake.  That would mean eating the foods to which your body is naturally adapted, and avoiding those to which it is not adapted. 

According to Dr. Haub’s Facebook page on his experiment, he lost 26.6 pounds over 10 weeks, going from 200.8 pounds and  33.4% body fat to 174.2 pounds and 24.9% body fat.  So, at the beginning he had  67 lbs fat mass and 134 lbs lean mass, and after ten weeks he had 43 lbs fat mass and 131 lbs lean mass.  Thus, he lost 24 pounds of fat, which requires the metabolism of 84000 calories over 70 days.  This means he had a caloric deficit of about 1200 calories per day.  Haub's sample diet record shows a food energy intake of about 1600 calories per day (more on this below). 

When Ancel Keys conducted the Minnesota Starvation Experiment, he “only” restricted the participants to 1800 calories daily, so 1400 calories daily for a person who requires more than 2600 is definitely starvation rations. 

As I discussed in a previous post, the Minnesota Study established that this level of caloric restriction has numerous adverse effects over time.  As reported in the Journal of Nutrition, one of the participants in this experiment, Harold Blickenstaff, "recalled the frustration of constantly thinking about food:

    I don’t know many other things in my life that I looked forward to being over with any more than this experiment. And it wasn’t so much ... because of the physical discomfort, but because it made food the most important thing in one’s life ... food became the one central and only thing really in one’s life. And life is pretty dull if that’s the only thing. I mean, if you went to a movie, you weren’t particularly interested in the love scenes, but you noticed every time they ate and what they ate. found men depression, and other effects making for many a long life not worth living.

Severe energy restriction had numerous adverse effects in the Minnesota Study:

    "They experienced dizziness, extreme tiredness, muscle soreness, hair loss, reduced coordination, and ringing in their ears. Several were forced to withdraw from their university classes because they simply didn’t have the energy or motivation to attend and concentrate."

Most people will feel something like this eating a 1400 calorie Twinkie diet.

Another interesting perspective will be gained by analyzing his sample diet. There he states an intake of 1589 calories, 222g carbohydrate, 59g fat, and 44g protein.  Since he had a 1200 calorie daily deficit calculated above, his total caloric expenditure (food intake plus fat burned from body) was about 2789 and he was severely restricting calories by 45% (i.e. consuming only 55% of required calories).  Very few people can sustain this level of caloric restriction long enough to achieve desired body composition or health outcomes.

Of that 2789 total calories burned each day, 1200 calories came from body fat and 59x9=531 calories came from food fat, so he metabolized a total of 1731 calories from fat every day, which means on that day 1731÷2789=0.62 or 62% of his calories came from fat, while only 32% of his calories came from carbohydrate and a mere 6% from protein.  In other words, metabolically he is actually on a high-fat, carbohydrate-restricted, low-protein diet.  

Some people seem surprised that he had decreases in total lipoproteins (so-called “cholesterol”) , LDL, triglycerides, and glucose, and an increase in HDL, while on this diet.  But if you maintain this level of caloric restriction, your blood fat (triglyceride) and sugar levels will be low because your starving cells are sucking every gram of usable fat and sugar from the blood.  Try eating the Twinkie diet at maintenance calories and I think you will see a very different result on blood lipids and blood sugar.

 Moreover, reductions of total “cholesterol,” LDL, triglycerides, and glucose are a well-documented effect of carbohydrate restriction or diets in which most of the calories come from fat (which is the case for most calorie-restricted diets, as Richard Nikoley has discussed in his post All Diets are High Fat Diets).

But as Raj pointed out, the changes in blood lipids reported by Haub are not particularly impressive. His LDL dropped from 153 to 123, mediocre considering he lost 27 lbs.  His HDL rose from 37 to 46, and his triglycerides dropped from 120 to 75.  His HDL still does not exceed the level of 60 considered to provide protection against heart disease.  He still has a triglyceride to HDL ratio of 1.6, slightly above the 1.5 that marks resistance to heart disease  (Triglyceride-to-HDL ratio effectively predicts mortality and CV events).

In comparison, my last blood profile showed my total lipoproteins at 231 mg/dL, my HDL at 85, and my triglycerides at 47.  Using the Friedewald equation they calculated the LDL at 138, but since I have very low triglycerides, using the Iranian formula calculator  I calculate my LDL equals 104, compared to Haub's 123, but mine was measured on a calorie-adequate diet, while his was on a deficit diet.  Haub has a trig:HDL ratio of 1.6, whereas mine is 0.55, again, mine measured while I maintained adequate caloric intake and his while he was losing body fat.  I venture that my primal diet results are much better than Haub's obtained with his Twinkie diet.

P.S.  If you like this post and want to see more like it, please consider making a small donation or a recurring subscription payment using the PayPal buttons in the right hand column.  Fighting fallacies is a full time job I love to do, but I need support to continue doing it.  Also consider sending a link to this post to all of your Facebook and other friends.  

Intermittent fasting prolongs life in mammals

Although experiments have demonstrated that caloric restriction (CR) can extend lifespan in yeasts, worms, mice, and possibly primates, few people would want to pay the price of caloric restriction to extend life. The Caloric Restriction Society has a page listing the risks of CR, which include

-chronic hunger, cravings, or food obsession
-large loss of body mass, up to 25% below normal
-loss of strength
-low body temperature
-decreased testosterone
-menstrual irregularities
-slower wound healing
-loss of emergency energy reserves

When Ancel Keys did the Minnesota Starvation Study, he restricted young men to 1800 calories daily, 20-40% below average needs -- similar to recommendations for caloric restriction for longevity. His goal was to get the men down to 25% below normal weight -- the CR society also suggests reaching 10-25% below normal weight.

As reported in the Journal of Nutrition, one of the participants in this experiment, Harold Blickenstaff, "recalled the frustration of constantly thinking about food:

I don’t know many other things in my life that I looked forward to being over with any more than this experiment. And it wasn’t so much ... because of the physical discomfort, but because it made food the most important thing in one’s life ... food became the one central and only thing really in one’s life. And life is pretty dull if that’s the only thing. I mean, if you went to a movie, you weren’t particularly interested in the love scenes, but you noticed every time they ate and what they ate. found men depression, and other effects making for many a long life not worth living.

Energy restriction had numerous adverse effects in the Minnesota Study:

"They experienced dizziness, extreme tiredness, muscle soreness, hair loss, reduced coordination, and ringing in their ears. Several were forced to withdraw from their university classes because they simply didn’t have the energy or motivation to attend and concentrate."

The subjects of the Minnesota Starvation Experiment developed all the visible signs of starvation: "sunken faces and bellies, protruding ribs, and edema-swollen legs, ankles, and faces. Other problems such as anemia, neurological deficits, and skin changes became apparent." The men lost interest in sex, and had no functional energy.

Again from the Journal of Nutrition: "The St. Paul Dispatch reported: '... the ... men on the starvation diet have lost so much physically and mentally that their ambition is gone, their will to go forward is gone, and they cannot do heavy work such as farming, mining, forestry, lifting and many other types of work necessary to rebuild war-torn Europe.'"

So, if you choose caloric restriction, you might spend more years breathing, but would you call that living? Do we have a better way?

On the CR (Caloric Restriction) Society International website FAQ page you can find this:

“Are there any other ways of retarding biological aging or extending lifespan besides CR?

None known to science at this time. .. as of this writing, there is no reliable evidence to support the notion that anything besides CR is capable of retarding biological aging or extending maximum lifespan in adult mammals. “

Yet just above this statement, on the same page, you will find this:

Studies have shown that rodents fed all they can eat [emphasis added], but fasted every two, three or four days, also have an increase in longevity, though the increase is not quite as great as that of rodents on the standard kind of CR (when implemented in mature organisms). For some people, this might be an easier way of doing CR since hunger is limited to two or three days a week.

A humane approach to life extension research would look for a method that would not entail all of the harmful side effects listed above. I personally would not want to live a long, cold, depressed, constantly hungry, food-obsessed, neutered life having insufficient strength, muscle mass, or energy for activities I enjoy, and unable to heal wounds at a normal rate.

I think intermittent fasting can give you more life to live while preserving your ability to live it.

IF extends lifespans of Wistar Rats

In 1945, Anton J Carlson and Frederick Hoelzel of the department of physiology at the University of Chicago published “Apparent Prolongation of the Life of Rats by Intermittent Fasting” in the Journal of Nutrition. This paper detailed the results of their studies in which they put adult rats on intermittent fasting schedules of 1 fast day in 2 days, 1 in 3 days, and 1 in 4 days, compared to control animals allowed to eat ad libitum.

In this study, they fed the rats in four groups, three getting one of three different omnivorous diets and one getting a vegetarian diet.

The three omnivorous diets included:
1) A basic diet consisting of 61.5% cooked and dried whole veal (including practically all of the edible parts of calves, excepting excess fat and blood), 31 % corn starch, 2% powdered yeast, 1% cod liver oil, 1.5% inorganic salt mixture and 3% veal bonemeal. This diet provided 35% protein.
2) The basic diet (#1) plus 10% finely ground alfalfa stem meal.
3) The basic diet plus 5% psyllium seed husk and 5% specially prepared kapok fiber.

The one vegetarian diet consisted of 50% whole wheat flour, 10% peanut flour, 7% lima bean flour, 7% wheat gluten flour (containing 80% gluten), 7% corn gluten meal, 7% linseed meal, 5% powdered yeast, 5% alfalfa leaf meal and 2% NaCl. This diet provided approximately 30% proteins.

Hoelzel had previously performed a study in which he found that rats fasted every other day and fed a diet low in protein on non-fast days developed peptic ulcers within about 2 weeks, but rats fed adequate protein did not develop ulcers.

All groups got lettuce trimmings daily. During feeding periods, they supplied food continuously to all groups, so rats ate ad libitum when not fasting. Fasting began at 42 days (before which all rats received identical feed) and continued until the rats died.

Table 1 of the paper shows the effects on lifespan of fasting 1 day in 2, 3, or 4 days in male and female rats.



Fasting increased the average lifespan of males by 90 days, and that of females by 23 days.

Optimum fasting interval

Upon detailed analysis of their data, Carlson and Hoelzel found that rats fasting 1 day in 4 and 1 day in 2 displayed complications by “extraneous factors” more than either control rats eating ad libitum or rats fasting 1 day in 3. Those factors included:

1) The earliest male and female deaths occurred in the groups fasted 1 day in 4, and it appeared that other rats did not fare as well fasting 1 day in 4 as in 1 day in 3. Carlson and Hoelzel suggested that “Perhaps the amount of food consumed in 3 days of feeding, with increased voracity but without proportionately increased capacity after 1 day of fasting, constituted a greater physiological overstrain than the amount of food consumed by the controls or by the rats fasted 1 day in 3.”
2) Fasting 1 day in 2 produced both a greater mortality rate and the longest-lived rats. The males and females fasted 1 day in 2 also began dying earlier than the rats fasted 1 day in 3. Carlson and Hoelzel commented: “Evidently fasting 1 day in 2 and beginning this at the age of 42 days was too much fasting for some rats. One of the females fasted 1 day in 2 apparently died of a hemorrhage from a chronic duodenal ulcer.” Fasting 1 day in 2 produced the longest-lived male and female rats, 1052 and 1073 days respectively, but the average rat did very poorly on this level of fasting.

Carlson and Hoelzel concluded that the optimum amount of fasting for the average rat in their study was 1 day in 3, or about twice weekly. This fasting frequency produced a 15% increase of average lifespan for females and 20% for males.

Of interest, in their raw data (Table 1), the average lifespan of male rats fasted 1 day in 4 did not significantly differ from those fasted 1 day in 3. Females fasted 1 day in 3 actually on average lived longer than those fasted 1 day in 2, but the reverse for males.

Another way to interpret this: Fasting 1 day in 2 produced a restriction of calories that proved too harmful for the majority of rats. Fasting 1 day in 3 or 4 produced the optimum result without daily caloric restriction.

Taking the average lifespan of 75 years in the U.S., this would mean IF twice weekly could increase the span to 86 to 90.

IF did not affect growth

Whereas 40% CR adversely affects muscle growth and mass, in this study, Carlson and Hoelzel found no or only small effects on growth or body mass in rats fasted 1 day in 4 or 1 day in 3.

Under unrestricted feeding conditions, male Wistar rats reach 450-520 g, and females reach 250-300 g.

In this study Carlson and Hoelzel compared littermates fed ad libitum to those fasted 1 day in 2, 3, or 4 days.

Using litter mate controls, male rats fasted 1 day in 4 attained body mass 91% of males fed ad libitum (413 v. 449 g), those fasted 1 day in 3 attained 85% of the mass of ad libitum males (339 v 397 g), and males fasted 1 day in 2 attained 74% of the body mass of ad libitum littermates (265 v. 356 g).

Female rats fasted 1 day in 4 attained body mass 89% of ad libitum females, those fasted 1 day in 3 attained 89% of ad libitum females, and those fasted 1 day in 2 attained body mass 85% of ad libitum females.

Again using litter mate controls, in some cases fasted rats actually had longer femurs than rats fed ad libitum, illustrating that intermittent fasting did not impair healthy tissue growth. In contrast, as stated by the CR Society's Risks Page, "Physical growth may be impaired by calorie restriction, as observed in lab animals."

Genetic controls

Carlson and Hoelzel found a large variation in response to fasting and feeding regimens. All rats were Wistar variety, and regardless of regime, 67% of all rats died between ages of 550 and 850 days, and 85% between 400 and 900 days. Further, “Some littermate rats, after having been kept from 400 to 1000 days on widely differing nutritional regimens, died within 24 hours or a few days of one another. Four of the twelve rats that lived to be over 1000 days old belonged to one of the seventeen litters.” Thus, genetic factors played a strong role in mortality.

IF influence on development of disorders leading to death

Carlson and Hoelzel also found that fasting rats had retarded development of mammary tumors, both in terms of age of onset and size of tumor, proportional to the amount of fasting. The following table from their paper displays the data.



Mammary tumors occurred in 37% of ad libitum female rats, compared to 29% of females fasted 1 day in 4 , 36% of those fasted 1 day in 3, and only 7% of those fasted 1 day in 2.

Average weight of tumors in ad libitum females equaled 193 g, versus only 67 g in rats fasted 1 day in 4 and 36 g in those fasted 1 day in 3.

Rate of tumor growth was +134 g/100 days in ad libitum rats, +48 g/100 d in rats fasted 1 day in 4, +42 g/100 d in rats fasted 1 day in 3, and +13 g/100 d in rats fasted 1 day in 2.

IF extends healthy lifespan

Carlson and Hoelzel thus showed in 1945 that intermittent fasting 1 in 3 days extends healthy lifespan of rats by 15-20% compared to ad libitum feeding, without daily food restriction (hunger), restriction of protein intake (these rats had 30-35% protein diets), impairing healthy lean tissue growth, or causing extreme loss of body mass.

It looks to me like IF offers a rational alternative to daily caloric restriction.

How insulin controls aging

Cynthia Kenyon lectures online

If you want to see Cynthia Kenyon explain how the insulin-signaling pathway controls aging -- and how we know that the insulin-signaling pathway controls aging -- you might want to take about an hour and a half to watch her lecture on the subject.

An Evolutionarily-Conserved Regulatory System for Aging

The Regulation of Aging by Signals from the Reproductive System, and, also, a Link Between Aging and Tumor Growth

In these lectures Kenyon shows that caloric restriction slows aging by regulating insulin and IGF-1 receptors. But she doesn't go for it herself; in an interview in New Scientist (I want to live forever) she says "I tried caloric restriction just for two days but I couldn't stand it, being hungry all the time."

As reported in PLOS Biology (Methuselah's Mould), she also did an experiment where she found that feeding sugar to the worms shortened their lifespans. As a consequence, she chooses to eat a low carbohydrate diet:

“I'm on a low-carb diet. I gave my worms glucose, and it shortened their lifespan. [The diet] makes sense because it keeps your insulin levels down,” she says.

She adds:

No desserts. No sweets. No potatoes. No rice. No bread. No pasta. “When I say ‘no,’ I mean ‘no, or not much,’” she notes. “Instead, eat green vegetables. Eat the fruits that aren't the sweet fruits, like melon.” Bananas? “Bananas are a little sweet.” Meat? “Meat, yes, of course. Avocados. All vegetables. Nuts. Fish. Chicken. That's what I eat. Cheese. Eggs. And one glass of red wine a day.”

In the New Scientist article interview she said:

I eat a diet that keeps my insulin levels low. So, for example, at breakfast I have bacon and eggs with tomatoes and avocados. It's bit like the Atkins diet. I don't actually know if I eat fewer calories, but I feel great and I weigh what I did in high school. I certainly wouldn't want to be hungry all the time, but I'm not, I'm never hungry.

By 2004 Kenyon had eaten a low-carb diet for two-and-a-half years. She reports very good results:

“I have a fabulous blood profile. My triglyceride level is only 30, and anything below 200 is good.....Plus, I feel better. Plus, I'm thin—I weigh what I weighed when I was in college. I feel great —you feel like you're a kid again. It's amazing.”

Kenyon feels angry about the general lack of nutritional knowledge:

“It's a little bit embarrassing to say that scientists actually don't know what you should eat…. We can target particular oncogenes, but we don't know what you should eat. Crazy,” she says.

I will second that.

Addendum:

Stephan Guyenet has an excellent discussion of What's the ideal fasting insulin level? in which he notes that Kitavans have very low fasting insulin without eating a low carbohdyrate diet. Frasseto et al also found that a paleo diet containing ~250 g carbohydrate per day from fruits and vegetables reduced fasting insulin to very low levels within just 10 days (Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet). Thus, it appears possible to eat a large amount of carbohydrate from fruits and vegetables (including tubers) and still obtain a low insulin level.

The Hungry Monkey Study

Science magazine just published a report of a 20 year study of caloric restriction in rhesus monkeys. Julie Steenhuysen wrote the Reuters report, which starts off thus:

A 20-year study of monkeys shows that a reduced-calorie diet pays off in less disease and longer life, U.S. researchers said on Thursday, a finding that could apply to humans.

They said rhesus monkeys on a strict, reduced-calorie diet were three times less likely to die from age-related diseases like heart disease, cancer and diabetes over the study period than monkeys that ate as they liked.

"We have been able to show that caloric restriction can slow the aging process in a primate species," Richard Weindruch of the University of Wisconsin in Madison, whose study appears in the journal Science, said in a statement.

"We observed that caloric restriction reduced the risk of developing an age-related disease by a factor of three and increased survival," Weindruch said.

Steenhuysen further reports:

The team found that half of the monkeys that were allowed to eat freely over the course of the 20-year study have survived, while 80 percent of the monkeys that ate 30 percent fewer calories over the same period are still alive.

While rhesus macaques have an average life span of about 27 years in captivity, the team said.

The animals that ate less had half the amount of heart disease and cancer, and there were no cases of diabetes in the low-calorie group.

Animals on a restricted diet also had more brain volume in some regions than the animals that ate freely, suggesting diet may affect brain health in aging as well.

Richard at Free the Animal has correctly pointed out that intermittent fasting without caloric restriction will very likely produce the same results. And Charles Washington at Zeroing In On Health pointed to what the scientists performing this study missed:

You’ll recall that aging is the work of advanced glycation end products, or AGE’s. AGEs can be thought of as aging accelerators. They are recognized as photosensitizers in the crystalline lens through crosslinking which has implications for cataract development. AGEs have been implicated in Alzheimer’s Disease, cardiovascular disease, and stroke. The mechanism by which AGEs induce damage is through a process called cross-linking that causes intracellular damage and apoptosis. Because AGEs are related to elevated blood sugar levels, a low calorie diet may reduce AGE body load.

Sharp readers of this blog will also recognize that if one can keep blood sugar low, this should also decrease aging. All of these maladies are included under the umbrella condition called “metabolic syndrome.” We can add obesity to that list as well. I argue that all of these conditions are merely symptoms of the metabolic disease of chronically-high insulin.

Charles goes on to remind us that

We all know that lowering calories has not been shown to reduce the symptom of obesity very well (beyond the short term), but at least in monkeys, some experts believe that lowering calories might work for that symptom, and indeed it seems to have in several species. But the astute observer will also recognize that when you lower calories, you automatically lower carbohydrates so any benefit to lowering calories may also be found with lowering carbohydrate consumption. And since low-carbohydrate diets consistently perform better in terms of obesity than low-fat, low-calorie diets, it’s safe to say that the same would be true in terms of longevity. The sad part of this is that the poor monkeys had to live their lives with less food when they could have eaten more fat and protein and just cut out the carbohydrates.

[Emphasis added.]

Yes. As Gary Taubes discussed in Good Calories Bad Calories, Ronald Kanhn and his collaborators at the Joslin Diabetes Center have already published results of their research with mice that they had genetically engineered to lack the insulin receptor on fat cells. Let me quote Gary:

With their fat tissue immune to the effect of insulin, Kahn’s mice weighed 25 percent less than normal mice. These mice remained lean, even when forced to overeat. They were simply incapable of putting on fat. As Kahn later explained, this wasn’t surprising, since fat cells require insulin for fat synthesis. If they have no receptor to detect the insulin that’s present, then no fat can accumulate. The transgenic mice lived almost 20 percent longer than normal mice.

[Emphasis Added.]

This study proved that high calorie intake does not shorten life, if the calories consumed don’t stimulate insulin receptors on fat cells. Ah, that would mean that calories from sugar and starch shorten your life, but eating fat doesn’t make you fat or shorten your life because fat does not stimulate insulin or receptors. Unfortunately, the people doing hungry monkey studies appear to have missed that memo. As Taubes notes, not even Kahn can make the logical deduction, he hopes for a drug to block insulin receptors on fat cells!

Taubes also reports the research of Cynthia Kenyon and colleagues at UCSF, who found that mutations that reduced activity in the insulin-IGF pathway in worms prolonged the worms’ lifespan significantly. Knowing that glucose stimulates that pathway, Kenyon and colleagues “began a series of experiments based on a single question: what would happened if she fed worms glucose, in addition to their preferred diet of bacteria?” Keep in mind that bacteria consist primarily of protein and fat, so a worm’s natural diet is low-carbohydrate. The results?

Kenyon added 2 percent glucose to the bacterial medium in which the worms lived, and the lifespan of the worms was reduced by a quarter.

Simple: High intake of glucose shortens life by 25 percent, via stimulating the insulin-IGF pathway. Solution? Reduce carbohydrate, not calories. Kenyon figured it couldn’t hurt to try it out herself – Taubes reports she decided to restrict her own carbohydrate intake to a bare minimum. She lost thirty pounds, and saw drops in blood pressure, triglycerides, and blood sugar, and an increase in her HDL. She’s on the way to a long life, hunger-free, while the monkeys go hungry.

This reminds me of a passage in the Histories, book 3, of Herodotus, to which Lutz refers in Life Without Bread. Herodotus (484 - c415 BCE) reported on an encounter between the king of Ethiopia and the king of Persia. The Persian king was showing the products of Persia to the Ethiopian, and:

“Finally he [the Ethiopian] came to the wine, and, having learnt the process of its manufacture, drank some and found it delicious; then, for a last question, he asked what the Persian king ate and what was the greatest age that Persians could attain. Getting in reply an account to the nature and cultivation of wheat, and hearing that the Persian king ate bread, and that people in Persia did not commonly live beyond eighty, he said he was not surprised that anyone who ate dung should die so soon, adding that Persians would doubtless die younger still, if they did not keep themselves going with that drink – and here he pointed to the wine, the one thing in which he admitted the superiority of the Persians.

“The Fish-Eaters, in their turn, asked the [Ethiopian] king how long the Ethiopians lived and what they ate, and were told that most of them lived to be a hundred and twenty, and some even more, and that they ate boiled meat and drank milk.”

[Herodotus, The Histories, book 3, trans by Aubrey De Sélincourt (New York, Penguin Books, 2003), pp 181-182.]

According to Charles, “ The federal government is funding a small study to see if some healthy normal-weight people could sustain a 25 percent calorie cut for two years and if doing so signals some changes that might, over a long enough time, reduce some age-related disease.”

I don't like this. This means some bureaucrats have decided to spend money they stole from me on a project to find the answer to a question they could get answered simply by reading GCBC or the voluminous research on caloric restriction done already to date. [BTW the "government" does not exist, what we call government consists of a gang of goons stealing money from us (taxes) and wasting it as they see fit.]

Assuming the typical caloric requirement is about 2000 calories, a 25 percent reduction would result in a 1500 calorie diet. As Taubes points out in his chapter 15 entitled “Hunger,” in October 1917, Francis Benedict, director of the Carnegie Institution of Washington’s Nutrition Laboratory “put twelve young men on diets of roughly fourteen hundred to twenty-one hundred calories a day with the intention of lowering their body weights by 10 percent in a month.”

Benedict hoped to find out whether humans could adapt to this level of caloric restriction and thrive. What happened? The men did lose weight, but they did not thrive. They complained of constant hunger, and of being constantly cold -- some found it almost impossible to stay warm regardless of amount of clothing worn. Their metabolic rates dropped by 30 percent, so that even their restricted diets now made them gain fat. They had drops in blood pressure and heart rate; they suffered from anemia, inability to concentrate, and “marked weakness” in physical activity. They had a decrease in sexual interest and expression, in some to “the point of obliteration.”

As Taubes points out in GCBC, these all are genetically conserved biologic responses to food restriction, occuring in all species so far studied, all minimizing energy output and maximizing energy retention under famine conditions, in order to extend life of the individual.

Sounds like a great way to extend life -- not. Actually, I'd call it torture. But the monkeys can't fight back.

After the experiment, the men “almost invariably over-ate.” They managed to regain all the lost weight and body fat in less than two weeks, and within another three weeks, they had gained, on average, eight pounds more. As a result, the men came out of this exercise heavier and fatter than they were when they started.

Yep, that's what happens when people restrict calories. They get fatter in the interim and the long run.

This 1917 experiment documented all the ill effects people experience from caloric restriction, and you can also find them all online by just checking out the Risks page of the Caloric Restriction Society.

So, for only $16.95 spent on Good Calories Bad Calories, or, by spending a few minutes online, or even by trying it yourself, you can find the answer to the question of whether people can sustain a 25 percent caloric restriction for two years in good health. But the goons will take millions of dollars stolen from us at gunpoint and throw it at this question to make it look like they are serving us. Bullshit.

So, the authors of this hungry monkey study appear ignorant of the research in their own field, which shows that the villain is excessive glucose, not excessive calories, and that we can get all the benefits of caloric restriction by reduction of glucose intake and insulin activity, which you can obtain without caloric restriction by two routes 1) reducing your carbohydrate intake, and 2) intermittent fasting.

So you don't have to suffer deprivation your entire life to get to "heaven," always depicted as a pleasant life without end.

You can enjoy yourself NOW. When else? You can't enjoy in the past, nor in the future, you can only enjoy NOW.

But if you did, that wouldn't work for priests and "government" authorities, including the enviro-nazis and veg-heads, who promise a future of eternal life and bliss if only you pay taxes and tithes, sacrifice your self and health, avoid meat, and obey them NOW.

If you follow your primal wisdom, they won't get a cut of your life, will they?

Addendum: More on the Hungry Monkey Study

Surprise, surprise! The "scientists" who published the hungry monkey study didn't tell the whole story. Sandy Szwarc at Junkfood Science did a lot more digging than I did and found that the media report didn't fit the facts.

Sandy reports:

1) "The lower mortality claimed among the monkeys on the calorie restricted diet were achieved only after eliminating 37% of the monkey deaths. They defined mortality as “age-associated deaths” and eliminated any cause of death they didn’t believe was associated with aging. As the supplemental data explains, 16 deaths from “non-age-associated causes were censored and their age of death used as the time variable in the regression.”"

She found in the New York Times report this nugget:

"If caloric restriction can delay aging, then there should have been significantly fewer deaths in the dieting group of monkeys than in the normally fed comparison group. But this is not the case. Though a smaller number of dieting monkeys have died, the difference is not statistically significant, the Wisconsin team reports."

No statistical difference in overall mortality between the hungry monkeys and the others.

Sandy goes on:

"The non-aging-related causes of death included monkeys who died while taking blood samples under anesthesia, from injuries or from infections, such as gastritis and endometriosis. These causes may not be aging-related as defined by the researchers, but they could realistically be adverse effects of prolonged calorie restrictions on the animals’ health, their immune system, ability to handle stress, physical agility, cognition or behavior."

2) Control monkeys were overfed by 20%. So this study compared underfed with overfed animals, not underfed with normal eating. The methods were discussed in Attenuation of Sarcopenia by Dietary Restriction in Rhesus Monkeys.

3) "Most interesting, calorie restriction doesn’t extend average lifespans in wild-derived mice, but only in certain laboratory mice bred to be adapted to specific conditions and which may not be representative of the species. “The inability of CR to extend lifespan of wild-derived mice, which were not adapted to laboratory conditions like typical laboratory mouse strains, may suggest that CR is in part an artifact of breeding animals specifically for laboratory studies,” said João Pedro de Magalhães at the Integrative Genomics of Ageing Group at the University of Liverpool."

4) The researchers have conflicts of interest.

For the full story, read Sandy's full post Calorie restrictive eating for longer life? The story we didn’t hear in the news.