Higher Carb Dieting: Pros and Cons

Posted by on February 2, 2012 160 comments

Last week’s post (Is It Good to Eat Sugar?, Jan 25, 2012) addressed what I see as the most problematic part of the thought of the health writer Ray Peat – his support for sugar consumption.

Apart from this difference, “an extreme amount of overlap is evident,” Danny Roddy notes, in our views and Peat’s. Both perspectives oppose omega-6 fats, support saturated fats, favor eating sufficient carbs to normalize metabolism, support eating nourishing foods like bone broth, and oppose eating toxic foods like wheat.

If there is another difference between our ideas and Peat’s, it’s that “Peat-atarians” often eat more carbs. Danny puts it:

Paul and Peat have similar recommendations for carbohydrate consumption. Paul’s recommendations hover around 150 grams while Peat usually recommends 180-250 grams, but he himself eats closer to ~400 grams.

So I thought it might be worth looking at the issue of overall carb consumption.

Carbs for Hypothyroidism

In Is There a Perfect Human Diet? (Jan 18, 2012) we noted that diseases can change the optimal diet. In some diseases it’s better to lower carb consumption, but in others it’s better to increase carb consumption. The example we gave is hepatitis; hepatitis B and C viruses can exploit the process of gluconeogenesis to promote their own replication, so high-carb diets which avoid gluconeogenesis tend to slow down disease progression.

Another disorder that might benefit from more carb consumption is hypothyroidism. A number of people with hypothyroidism have benefited from Peat-style carb consumption. Here is ET commenting on last week’s post:

As someone following the PHD with a good dash of Peat, I really enjoy this post and the comments. Thank you Paul….

Paul says that “I’m not persuaded that it’s a desirable thing to keep liver glycogen filled at all times, but for some health conditions it may be good to tend that way, like hypothyroidism.” Well, according to Chris Kresser, 13 of the top 50 selling US drugs are either directly or indirectly related to hypothyroidism. If going by either the low body temperature/low pulse diagnostic, and/or some kind of pattern on the serum tests (Anti-TG, TPO, TSH, free T-3, free T4, total T3, total T4), we are talking a significant proportion of the population, especially women, being hypothyroid in some form….

Many with low T3 have a conversion problem from T4 in the liver (80% of T3 is converted from T4 in the liver and kidneys – only a small portion is coming from the thyroid gland).

Is it a good idea to NOT try to fill the liver glycogen in such a pattern? For those who have lived with the consequences of low T3 (adrenaline rush, waking up in the middle of the night, fatigue, tendency to orange-yellowish color i the face etc.), and had improvements on a more Peat like diet, I do not think so.

The way to fill liver glycogen, of course, is by eating more carbs.

I’ve previously noted that increased carb consumption upregulates the levels of T3 thyroid hormone (Carbohydrates and the Thyroid, Aug 24, 2011):

T3, the most active thyroid hormone, has a strong effect on glucose utilization. T3 stimulates glucose transport into cells, and transport is the limiting factor in glucose utilization in many cell types. In hyperthyroidism, a condition of too much T3, there are very high levels of glucose utilization. Administration of T3 causes elevated rates of glycolysis regardless of insulin levels.

The body can reduce T3 levels by converting T4 into an inactive form called reverse T3 (rT3) rather than active T3. High rT3 levels with low T3 levels lead to reduced glucose transport into cells and reduced glucose utilization throughout the body.

This means that eating more carbs raises T3 levels, and eating fewer carbs lowers T3 levels.

For a hypothyroid person, then, eating more carbs is an alternative tactic for increasing thyroid hormone activity. It may provide symptomatic relief similar to that achieved by supplementing thyroid hormone directly.

Perhaps the two are complementary tactics that should be done together. Taking thyroid hormone pills will increase glucose utilization, creating a need to eat more carbs. A mix of the two tactics may be optimal.

UPDATE: Mario points out that most cases of hypothyroidism in advanced countries are due to Hashimoto’s, an autoimmune disease probably triggered by infections or gut dysbiosis, and eating more carbs will tend to flare any gut dysbiosis and thus aggravate the thyroiditis. Meanwhile, supplemental thyroid hormone tends to reduce antibody activity.

Carbs for Mood

Another interesting comment came from Jim Jozwiak:

Paul, this discussion gets to the crux of what I do not understand about the Perfect Health Diet. You are speaking as if refilling liver glycogen is a good thing, and it undoubtedly is, because mood is so much better when there is sufficient liver glycogen because then the brain is confident of its power supply. Also, you acknowledge that safe starch would eventually replenish liver glycogen after muscle glycogen is topped off. So why not eat enough starch to replenish liver glycogen? It is not so difficult to figure out how much that would be. Have some sugar, feel what replenished liver glycogen is like, then titrate safe starch gradually meal-by-meal to get the same effect. When I do it, and I am not an athlete, I get 260 grams of non-fiber carb per day, which is considerably more than you usually recommend. Have you tried this experiment and found the result unsatisfactory in some way?

Jim has experimented to find the amount of carbs that optimize his mood, and found it to be 260 g (1040 calories). On a 2400 calorie diet, typical for men, this would be 43% carbs.

If Peat typically recommends 180 to 250 g carbs, as Danny says, then on a 2000 calorie reference diet that would be 36% to 50% carbs.

Those numbers are strikingly similar to another statistic: The amount of carbs people actually eat in every country of the world.

Here is a scatter plot of carb consumption vs per capita income by country. Dietary data comes from the FAO, income is represented by GDP per capita from the IMF:

At low incomes people eat mainly carbs, because the agricultural staples like wheat, rice, corn, and sorghum provide the cheapest calories.

As incomes rise, carb consumption falls, but it seems to approach an asymptote slightly below 50% carbs. The lowest carb consumption was France at 45%, followed by Spain, Australia, Samoa, Switzerland, Iceland, Italy, Austria, Belgium, and Netherlands.

We can guess that if money were no object, and people could eat whatever they liked, most people would select a carb intake between 40% and 50%.

This is precisely the range which Jim found optimized his mood.

The Longevity vs Fertility and Athleticism Trade-off

I won’t enumerate studies here, but animal studies indicate that higher carb and protein intakes promote fertility and athleticism, while restriction of carbohydrate and protein promotes longevity.

In our book, we calculate the daily glucose requirements of the human body at around 600 to 800 calories, or 30% to 40% of energy on a 2000-calorie diet.

So a 30-40% carb diet is a neutral diet, which probably places minimal stress on the body.

A 40-50% diet is a carb-overfed diet, which probably promotes fertility and athleticism.

A 20-30% diet is a mildly carb-restricted diet, which probably promotes longevity.

Do we see diminished longevity with higher carb consumption in human epidemiological data? I think so.

It’s useful to compare European countries, since they are genetically and culturally similar. There is a correlation between carbohydrate intake and longevity. Here is a list of life expectancy among 46 European countries. Neglecting little countries like Monaco, San Marino, and Andorra, that are not in my carb database, the countries with the longest life expectancy are also the ones with the lowest carb consumption: Italy first, France second, Spain third, Switzerland fourth, and Iceland sixth are all countries with carb intake below 50%. Sweden, at 50.8% carbs, placed fifth in longevity.

Did Evolution Hardwire a Preference for Carbs?

We know that the brain has an innate food reward system which tries to get people to eat a certain diet. What carbohydrate intake is it likely to select for?

Experiments on the food preferences of insects and rodents give us clues. The paper “Macronutrient balance and lifespan,” by Simpson and Raubenheimer, cited some time ago by Dennis Mangan, summarizes evidence from animals for the influence of macronutrients on lifespan. A good example is the fruit fly; protein has the dominant effect on lifespan, with low protein favoring longevity and high protein favoring fertility. The flies eat so as to maximize fertility:

The response surface for lifetime egg production peaked at a higher protein content than supported maximal lifespan (1:4 P:C, Figure 1A). This demonstrates that the flies could not maximize both lifespan and egg production rate on a single diet, and raises the interesting question of what the flies themselves prioritized – extending lifespan or maximizing lifetime egg production. Lee et al. [3] answered this by offering one of 9 complementary food choices in the form of separate yeast and sugar solutions differing in concentration. The flies mixed a diet such that they converged upon a nutrient intake trajectory of 1:4 P:C, thereby maximizing lifetime egg production and paying the price of a diminished lifespan.

This seems to be the evolutionary preference in mammals as well as flies. When unlimited food is available, animals tend to overfeed slightly on carb and protein, sacrificing lifespan for increased fertility and athleticism.

Jim reported improved mood on a 43% carb diet. Is it due to the filling of liver glycogen raising metabolism? Due to a sensation of enhanced fertility, libido, and athleticism? Or simply due to greater satisfaction of the brain’s reward system?

Yet another factor may also be involved.

Might Stress Be Mistaken for Enhanced Energy?

Peat favors sucrose as a carb source, which is why Danny Roddy recommended orange juice and Travis Culp soda. I argued in last week’s post that it would be better to eat a starchier diet so that the carb breakdown would be at least 70% glucose, less than 30% fructose and galactose.

Eating a higher-carb diet fills up liver glycogen, removing the most rapid fructose disposal pathway. This makes a high-carb sucrose-based diet rather stressful for the body; it has to dispose of fructose rapidly to avoid toxicity, but has limited ability to do so.

We can see the stressfulness of sucrose by its effects on the “fight-or-flight” stress hormones adrenaline (epinephrine) and noradrenaline (norepinephrine). Here is a study that fed high-fat, high-starch, and high-sucrose diets for 14 days to healthy non-obese subjects, and measured the hormonal response [1; full text]. This paper was discussed by the blog Proline (hat tip: Vladimir Heiskanen). The results:


On high-fat and high-starch diets, adrenaline and noradrenaline levels are low; they are consistently elevated — almost doubled — on the high-sucrose diet.

This makes sense; as Wikipedia notes,

epinephrine and norepinephrine are stress hormones that underly the fight-or-flight response; they increase heart rate, trigger the release of glucose from energy stores, and increase blood flow to skeletal muscle.

These hormones trigger the release of glucose from liver glycogen, thus freeing up room for fructose disposal.

Note that this result contradicts an assertion by Danny Roddy:

I consider the ability to refill glycogen (minimizing adrenaline & cortisol release) to be an important factor in health.

Refilling glycogen is not the same thing as minimizing adrenaline release. The requirement to dispose of fructose may trigger adrenaline release.

The reason I bring this up is not to renew the starch vs sugar discussion; but rather to ask if this “fight-or-flight” response to sugar consumption may not be partially responsible for the perceived mood and energy improvements on a Peat-style diet.

Indeed, one of the peculiar aspects of Ray Peat’s health advice is his recommendation to increase pulse rates well above normal levels. In his article on hypothyroidism, Peat states:

Healthy and intelligent groups of people have been found to have an average resting pulse rate of 85/minute, while less healthy groups average close to 70/minute.

I would have thought 60 beats per minute was normal, and when I was more athletic my pulse was typically 48 beats per minute.

One of the effects of adrenaline and noradrenaline is to speed up the pulse rate. If Peat really does eat 400 g of carbs per day, predominantly from sucrose, then he may be achieving his high pulse rate from an “adrenaline rush” that helps dispose of an excess of fructose.

If, indeed, this is a source of improved sense of well-being on Peat-style diets, it may be a double-edged sword. Chronic stimulation of the “fight-or-flight” hormones to aid in fructose disposal may have long-run negative consequences.

UPDATE: I’m reminded of this video, showing the adrenaline-promoting effects of sucrose consumption:


Starch would not have had the same effect, and would surely be healthier in the long run.

Summary

It is possible that higher carb intake may increase thyroid hormone levels, fertility, and athleticism, and enhance mood in some people. These gains do not come without cost. Notably, they probably involve a sacrifice of longevity.

If the benefits of higher carb intake are sought, it is best to achieve them by eating starches primarily, not sugar.

Conclusion

In our book, we recommend a slightly low-carb diet of 20-30% of calories. If we were re-writing the book now, we would probably be a bit less specific about what carb intake is best. Rather, we would say that a carb intake around 30-40% is neutral and fully meets the body’s actual glucose needs; and discuss the pros and cons of deviating from this neutral carb intake in either direction.

For most people, I believe a slightly carb-restricted intake of 20-30% of calories is optimal. Most people are not currently seeking to have children or engaging in athletic competition. There is good reason to believe that mild carb restriction maximizes lifespan, and most people desire long life. As we’ve noted, supercentenarians generally eat low-carb, high-fat diets.

But the spirit of our book is to educate, and let everyone design the diet that is best for them. And there is room for difference of opinion about the optimal carb intake.

References

[1] Raben A et al. Replacement of dietary fat by sucrose or starch: effects on 14 d ad libitum energy intake, energy expenditure and body weight in formerly obese and never-obese subjects. Int J Obes Relat Metab Disord. 1997 Oct;21(10):846-59. http://pmid.us/9347402. Full text: http://www.nature.com/ijo/journal/v21/n10/pdf/0800494a.pdf.

Around the Web; Why I Blog Edition

Posted by on January 29, 2012 51 comments

[1] Why I Blog: A few weeks ago Joan asked my advice for her sister, who has suffered from eczema for over 40 years:

My 59 year old sister has Chronic Fatigue Syndrome…. Since her teens she has had from time to time small scaly patches that resolve with omega-6 supplementation…. At the present time she is taking 2 tablespoons of organic cold-pressed safflower oil 4X a day to control it. If she misses a dose her arms and face rapidly develop eczema which in a short time opens up and oozes.

As it happens, the primary symptom of an omega-6 deficiency is eczema. We discuss this in the book on p 55:

In humans, the main symptom of an omega-6 deficiency is a dry scaly skin rash. In the 1940s and 1950s, it was common to feed infants a fat-free milk formula – skim milk with sugar.  After some months, these infants developed eczema which could be cured by providing lard, which is about 10% PUFA.

Why was she becoming omega-6 deficient despite eating 8 tbsp (120 ml) a day of safflower oil? If omega-6 is deficient the body won’t consume it for energy. But omega-6 (and omega-3) fats are also destroyed by oxidation; our book discusses this on pp 65-67. Controlled oxidation of the longer 20-carbon omega-6 fatty acids to eicosanoids is exploited by the body as a signal of infections and stimulant of immune activity. Uncontrolled oxidation turns omega-6 fats into dangerous aldehydes.

To destroy 100 ml of safflower oil per day requires a huge level of oxidative stress. It indicates some sort of infection, and a severe deficiency of antioxidants. So I advised supplementation with zinc, copper, selenium, vitamin C, vitamin E and glutathione, as well as vitamins D, A, and K2 which help fight infections.

This week Joan gave us an update:

Hi Paul,

You will remember 12 days ago I asked you about my sister who has CFS and was taking 100 mls a day of safflower oil to keep eczema under control….

Your advice was spot on and the results have been miraculous. She started supplementation with zinc, copper, selenium, vitamins C, E, D and K and NAC. Within 24 hours her eczema was much improved and she began reducing the safflower oil. Now 10 days later she is down to 10 mls of safflower oil and is confident she can discontinue it completely in a few days. Her eczema has completely cleared and her skin is looking good.

Not only that, but some of her CFS symptoms have improved. Her constant headache is not as severe, irregular heartbeat episodes have almost completely stopped and she is tolerating slightly more physical activity. Needless to say she is absolutely delighted and wants me to pass on her deepest gratitude to you. Her words are, “It’s a miracle”. Once again Proverbs 13:12 springs to mind. “Hope deferred makes the heart sick, but a longing fulfilled is a tree of life.” Her sense of despair and resignation has gone and you have given her hope of a better future. Words seem inadequate to express thanks for that.

Congratulations, Joan’s sister! And thank you, Joan, for passing on your sister’s results. It made my day. And that’s why we blog – to try to develop and share knowledge of dietary and nutritional healing methods that, without our work, would be overlooked, leaving people to suffer needlessly.

[2] Vigilance is the Price of Liberty: Steve Cooksey, Diabetes Warrior, is being threatened by the North Carolina Board of Dietitians for giving dietary advice without a license. His crimes can be seen on this notice from the official investigation review:

If people are writing you with diabetic specific questions and you are responding you are no longer just providing information – you are counseling – you need a license to provide this service.

Here you are giving this person advice based on what she has said to you…. Counseling/advising requires a license.

You guided her (for her friend) to your meal plan – indirectly you conducted an assessment and provided advice/nutritional counseling.

The director of the Board of Dietitians consoled him: “even IF convicted, it would only be a misdemeanor.” Steve is looking for an attorney.

Of course, laws like this would make it illegal for me to respond to questions too. “Miracles” like that of Joan’s sister would be outlawed, in the hope that a few politically connected dietitians might make a few more dollars.

And it doesn’t end with licensing. The licensees get subject to standards of practice and have to conform or risk loss of their livelihood. Their ability to innovate is stifled; in time bureaucraticized medicine can sap even their will or ability to serve patients.

All of us should be outraged at these corrupt attempts to deprive us of freedom of speech, and of freedom to enter a profession as entrepreneurs with innovative approaches.

[3] Music to Read By: Rhapsody in Blue, played by piano and tap shoes:

[4] Interesting Items this Week:

Friend of the blog Allan Balliett is up and running with his Biodynamics Now podcast at www.bdnow.org. He’s kicked off the podcast with two star guests: Joel Salatin, self-described “Christian-libertarian-environmentalist-capitalist-lunatic-Farmer,” and Sally Fallon Morell, leader of the Weston A Price Foundation. An interview with Dr Thomas Cowan, author of The Fourfold Path to Healing and a Weston Price Foundation affiliated doctor, is coming up soon; visit Allan’s blog to leave questions for Dr Cowan.

Via Allan’s interview, I learned that Sally Fallon has fulfilled a dream. She owns a farm and is making cheeses.

We were very happy to see our diet mentioned in the Sunday, Jan 22, 2012 US Wellness Meats newsletter. GrasslandBeef.com, of course, is a great source of PHD-compatible food.

Chris Kresser has a new podcast: Why It’s So Hard To Lose Weight – And Keep It Off.

Prof Dr Andro compares BPA, soy, and corn oil: which is the best endocrine disruptor?

Via Russ Farris, a new paper suggests that high levels of vitamin D increase inflammation and raise CRP.

Dan’s Plan credits bacon with saving the life of a 4 year old boy.

Chris Masterjohn says zinc defends against AGE production, and that vitamins A and D protect against autoimmune disease.

Michael Ellsberg explains how he overcame bipolar disorder.

Gary Taubes has an update. His colleague Peter Attia is blogging at “The War on Insulin” and they are starting an “insurgency” to wage this war. Meanwhile, a medical student at Virginia Commonwealth, Larry Istrail, has started the Ancestral Weight Loss Registry.

Seth Roberts defends personal science.

It pays to have a good marriage: an 85-year-old woman beat off a moose attack on her 82-year-old husband.

Future Pundit gives us an interesting fact about autism: the twin with the smaller birth weight is more likely to become autistic.

Iodide heart scans confirm that it’s risky to suddenly increase iodine intake: people who take a high dose of iodine for imaging studies are more likely to develop thyroid disease in subsequent years. Iodine is good for us, but protect your thyroid by starting low, combining it with selenium, and increasing the dose very slowly.

A testimonial at robbwolf.com: Paleo works better than immune suppression for ulcerative colitis.

Homeopathy for nematodes? Drinking 0.01 proof alcohol is sufficient to extend the lifespan of worms.

A mystery illness is afflicting upstate New York teens. Video at the link. Erin Brockovich is involved.

Jamie Scott continues his series on the adipogenic nature of omega-6 fats.

Emily Deans reports that Lactobacillus rhamnosus knows how to control our mood.

CarbSane reports that saturated fat is more likely than polyunsaturated fat to induce gestational diabetes.

Stephan Guyenet adds a nail to the coffin of the insulin-obesity hypothesis, but Peter Dobromylskyj pulls one out: he shows that adipose tissue needs insulin receptors if hypothalamic damage is to be obesogenic in mice.

Via Shari Bambino on Facebook, it seems you can’t trust cheap supermarket olive oil. Much of it is soybean oil mixed with low-grade olive-pomace oil.

Mat Lalonde critiques evolutionary arguments for Paleo, but some of his counter-arguments are just as flawed as the views he criticizes.

Steve Phinney and Rick Johnson discuss ketogenic diets.

[5] Cute animal:

Via naked capitalism.

[6] Dr Mercola finds our dietary advice helpful: The “safe starches” debate is still making converts:

After trying both approaches, my experience suggests that Dr. Jaminet’s position is more clinically relevant….

When I eliminated all my grains and starchy vegetables, I actually experienced some negative effects. My energy levels declined considerably, and my cholesterol, which is normally about 150, rose to over 200. It appears I was suffering a glucose deficiency and this can trigger lipoprotein abnormalities. It also seemed to worsen my kidney function. So, while carbohydrate restriction is a miracle move for most people, like most good things in life, you can overdo it.

This information really underscores how important glucose is as a nutrient, and some people can’t manufacture glucose from protein as well as others, so they need SOME starches in their diet or else they will suffer from metabolic stress….

My experience now shows me that I need to have some source of non-vegetable carbs. I still seek to avoid nearly all grains, except for rice and potatoes. I typically limit my total carbohydrate calories to about 25 percent of total daily intake, and my protein to about 15 percent, with the additional 60 percent coming from healthful fats like butter, egg yolks, avocados, coconut oil, nuts and animal fat.

However, that is what works for me. You must listen to YOUR body and perform your own experiment. The bottom line is how your body responds, and you’re the ONLY one who can determine that.

On Facebook, A.b. Dada noted health improvements when adding rice and potatoes to a too-low-carb diet:

I added back white potatoes and even white rice based on Dr. Harris’ advice and definitely feel better (less orthostatic hypotension) — plus I’m actually slimmer than I’ve ever been, yet my muscles are much stronger.

Low carb for 12 years before this year!

There were a lot of nice comments on the “Is It Good to Eat Sugar?” post, including good ones from ET and Jim Jozwiak that I’ll probably discuss this coming week.

[7] More cute animals: From the BBC, “That’s Life,” 1986:

[8] Shou-Ching’s Photo Art:

[9] Weekly Video: Jazz concert:

Is It Good to Eat Sugar?

Posted by on January 25, 2012 188 comments

A few “Peat-atarians” – followers of the iconoclastic health writer Ray Peat – have accused us of being too skeptical of fructose. They think we should promote sugar consumption.

Here’s Travis Culp:

I think fructose is only conditionally problematic and that the consumption of it alongside glucose at a time of low liver glycogen is highly advantageous. In fact, I would go so far as to say that (somewhat slowly) drinking a can of soda upon waking (as disgusting as that is) would not result in any real glycation, insulin resistance, elevated TGs etc…. I think it’s beneficial to eat something really sugary upon waking …

Here’s Danny Roddy:

Peat has stated that … fructose … “powerfully” refills glycogen …

I would consider the ability to refill glycogen (minimizing adrenaline & cortisol release) to be an important factor in health …

It’s true that the ability to refill glycogen is essential for health; some genetic glycogen storage disorders are fatal in early childhood. But everyone who lacks a glycogen storage disorder has the ability to refill glycogen from multiple sources. In addition to fructose, glucose sugars and starches refill glycogen, as does milk sugar (a compound of glucose and galactose).

So the question is which combination of dietary sugars (a) is best at refilling glycogen and (b) makes the healthiest diet, all things considered?

Sugar Composition of the Diets

Both Danny and Travis framed their arguments as criticisms of our diet. They are really arguing that a Peat-style sugary diet is healthier than a PHD-style moderate-starch diet.

So before going further, let’s look at the sugar content of the diets we’re comparing.

First, note that PHD is not a zero-fructose diet. As an examination of the PHD Food Plate shows, PHD includes many fructose-containing plant foods – fruits, berries, and vegetables such as beets, onions, carrots, and squashes – plus “pleasure foods” like chocolate.

Also, PHD is not a zero-dairy diet, so for many practitioners it will include some milk sugars which are half galactose and half glucose.

In my diet personally, probably about 55% of carb calories come from starches, 30% from fruits, berries, and sugary vegetables, and 15% from dairy products such as yogurt. In terms of simple sugars, this translates to about 77% glucose, 15% fructose, and 8% galactose.

Not every Perfect Health Dieter will have the same sugar proportions; there is no obligation to consume dairy, and the relative proportions of starchy and sugary plants will vary according to taste. But let’s take mine as characteristic PHD proportions.

In a Peat-style diet, in contrast, the breakdown of sugars is near 50% glucose and 50% fructose.

So we aren’t comparing fructose against glucose, but a 77% glucose 15% fructose diet against a 50% glucose 50% fructose diet.

Why the Focus on Refilling Glycogen?

Why do the defenders of sugar focus on its ability to refill glycogen?

The reason is that fructose is treated by the body as a poison. Dietary fructose is shunted to the liver for disposal by conversion to glycogen, fat, lactate, or pyruvate.

Fructose is treated like a poison because it is dangerous. High doses of fructose have observable harmful effects even in short-term studies. Fructose does no good to the liver while it’s there, in fact fructose combined with polyunsaturated fats very effectively creates liver disease. Fructose in any other organ does harm; for instance, fructose promotes cancer growth.

Given fructose’s rapid disposal, any benefits from fructose have to be attributable to the glycogen or other products it is turned into. If fat, lactate, or pyruvate (a glucose product) provided benefits, dietary fats or starches would do the same, without the risk of fructose toxicity or fats getting stuck in the liver due to choline and methionine deficiency. So if fructose is to have benefits, it has to be via glycogen.

Here, then, is the challenge Peat-atarians face. Fructose has many proven harms. It has only one possible benefit: its ability to help re-fill liver glycogen. Peat-atarians have to show two things:

  1. That a diet with Peat-like sugar proportions – roughly 50% fructose, 50% glucose –is better than a diet with PHD-like sugar proportions – 15% fructose, 8% galactose, 77% glucose – at refilling liver glycogen.
  2. That better re-filling of liver glycogen improves the healthfulness of the diet.

How Do Sugars Perform at Refilling Glycogen?

Danny provides no citations for his claim that fructose “powerfully” refills glycogen. But Danny’s commenters help him out.

Daz, drawing upon a New York Times report, offers two studies [1] [2]. Cliff offers several more [3] [4]. Let’s see what these tell us.

The first study, “Fructose and galactose enhance postexercise human liver glycogen synthesis” [1], looks at athletes depleted of liver glycogen by intense cycling, and assessed the effectiveness of three sugar drinks at replenishing liver glycogen. The three drinks were:

  • 2/3 maltodextrin, 1/3 fructose;
  • 2/3 maltodextrin, 1/3 glucose;
  • 2/3 maltodextrin, 1/3 galactose.

Maltodextrin digests to glucose, so all three drinks are majority glucose. The athletes drink 275 calories of these drinks per hour for 6.5 hours after exercise. Galactose is non-toxic, but like fructose tends to be taken up by the liver.

Liver glycogen was measured every two hours with carbon-13 magnetic resonance imaging. Here were the results:

So 67% glucose / 33% galactose did the best, 67% glucose 33% fructose was close behind, and 100% glucose lagged.

Why does the 100% glucose drink underperform? One reason is that fructose and galactose, but not glucose, are preferentially targeted to the liver:

A factor of potentially larger magnitude in enhancing liver glycogen synthesis is the differential postabsorptive fates of fructose and glucose. Glucose is a relatively poor direct substrate for liver glycogen synthesis (24,27). Much of it is released from the liver into the systemic circulation to be stored as muscle glycogen (3,7). In contrast, fructose is primarily taken up by the liver … [1]

The second paper, “Superior endurance performance with ingestion of multiple transportable carbohydrates” [2], did not measure liver glycogen replenishment; instead, it gave its cyclists sugary drinks every 15 minutes throughout an intense 2-hr cycling test, and compared performance. Three different drinks were used: a 67% glucose 33% fructose drink, a 100% glucose drink, and a water-only control group. Performance was best with the 67% glucose 33% fructose drink, intermediate with the glucose drink, and worst with the water drink. The results suggest that the 67% glucose 33% fructose drink was better for liver glycogen replenishment, and that liver glycogen replenishment aided the cyclists’ performance.

The third paper, “Effect of different post-exercise sugar diets on the rate of muscle glycogen synthesis” [3], isn’t available to me electronically, so we’ll have to work from the abstract. It looked at muscle glycogen, measured using biopsies (ouch!), rather than liver glycogen.

It first assessed the effect of different amounts of glucose. It found that 0.7 g/kg body weight of glucose given every 2 hours would maximize the rate of muscle glycogen synthesis. For an 80 kg man, that works out to 56 g or 224 calories of glucose per two-hour period, or 112 calories per hour. Above this amount, the rate of muscle glycogen synthesis is unchanged.

It then compared three formulations at this same 0.7 g/kg body weight dose: 100% glucose, 100% sucrose (50% glucose, 50% fructose), and 100% fructose. Muscle glycogen synthesis rates were:

  • 5.8 mmol/kg/hr with 100% glucose
  • 6.2 mmol/kg/hr with 50% glucose, 50% fructose
  • 3.2 mmol/kg/hr with 100% fructose

If we fit a quadratic curve to these points, it predicts a peak rate of glycogen synthesis with 70% glucose, 30% fructose:

Athletes Agree: More Glucose Than Fructose

Of course, endurance athletes know that it’s beneficial to replenish glycogen during endurance events like marathons and triathlons.

Some authorities, including Tim Noakes, an exercise physiologist who has run over 70 marathons, believe that liver glycogen rather than muscle glycogen is the gating factor in marathon performance. From “The Science of Carbohydrate Loading” by David Peterson:

Remember also that muscle glycogen is committed to be used by muscle and cannot assist in maintaining blood sugar levels. Therefore should no additional carbohydrate be ingested during prolonged exercise, the task of maintaining blood glucose levels rests firmly on the liver’s glycogen stores and gluconeogenesis (the manufacturing of glucose from plasma amino acids). Oxidation of blood glucose at 70-80% VO2 max is about 1.0 g/min or about 60 g/hour. Therefore it can be predicted that even with full glycogen stores, a less conditioned athlete’s liver will be depleted of its carbohydrate within an hour and three quarters of continuous moderate intensity exercise. (Interestingly, the daily carbohydrate requirements of the brain and nervous system alone are enough to deplete the liver glycogen stores within 24 hours.) Once liver glycogen levels begin to drop and exercise continues the body becomes increasingly hypoglycemic (low blood sugar) mainly because blood glucose is depleted faster than it is replaced by gluconeogenesis. Professor Tim Noakes considers liver glycogen depletion and subsequent hypoglycemia to be the primary factors affecting fatigue and performance during extended duration races and especially in instances where muscle glycogen levels are low as well.

So marathoners and other endurance athletes will want to replenish liver glycogen as rapidly as possible during a race. What mix of sugars do they use?

The popular product is carbohydrate gels that can be swallowed at the same time water is taken. Here are the top carbohydrate gels sold on Amazon:

So the sugar mix ranges from 67% glucose to 100% glucose. No product uses 50% fructose.

Presumably, athletes have done a great deal of personal experimentation and know that these ratios do, indeed, optimize the speed of glycogen replenishment.

When athletes have no need for speed, as when they are carb loading before a marathon, then they eat starches like pasta and bread, not sugar. So to maximize total glycogen status, regardless of speed of filling, a carb mix close to 100% glucose works just fine.

Glycemic Control

The fourth paper, “Acute fructose administration decreases the glycemic response to an oral glucose tolerance test in normal adults” [4], is about how a bit of fructose affects the glycemic response to an oral glucose tolerance test.

It showed that a 9% fructose 91% glucose test (7.5 g fructose, 75 g glucose) produced a lower glucose area under the curve and higher insulin response than a 100% glucose test. Here’s the glucose response:

In general higher insulin and lower glucose is healthier than the reverse, so this is considered an improvement.

Summary of the Data

What these papers show is:

  • Glycogen replenishment proceeds the fastest with a mix of sugars consisting of about 70% glucose and 30% fructose or galactose.
  • Although this wasn’t tested, we can guess that a mix of fructose and galactose would be more effective than fructose alone, since it seems that utilizing multiple carbohydrate pathways is what drives the speedier glycogen replenishment. So the fastest glycogen replenishment might occur with something like 70% glucose 15% fructose 15% galactose.
  • Muscle glycogen replenishment is maximized with a carbohydrate intake of 100 calories per hour.
  • Athletes agree with the research, using carb gel packs that contain typically 30-40 g carbs with a composition of 67% to 100% glucose, 0% to 33% fructose.
  • Glycemic response to a large dose of carbohydrate may be improved by eating a 9% fructose 91% glucose mix.

From these data, I infer that for glycogen replenishment in liver or muscle, a PHD-style carb mix of 77% glucose, 15% fructose, 8% galactose is probably equal or superior to a Peat-style carb mix of 50% glucose, 50% fructose.

Conclusion

For athletes in the midst of a race, or in need of rapid recovery for a second race on the same day, speedy glycogen replenishment may be the endpoint to optimize. If so, they should eat a sugar drink composed of roughly 70% glucose and 30% fructose and galactose.

This is closer to PHD diet ratios than to Danny Roddy’s recommendation of orange juice or Travis Culp’s recommendation of soda!

But for others, speed of glycogen replenishment is hardly likely to be the parameter to optimize. There are unlikely to be significant benefits for non-athletes from replenishing glycogen 6.5% faster, as was found in the muscle glycogen study [3].

Speedier glycogen replenishment is almost the only known benefit to fructose consumption. It’s possible that low fructose doses, about 9% of carb calories (perhaps 2-3% of total calories), may improve glycemic control. This is a lower fructose fraction than is found in PHD, and far below the fructose fraction recommended by Danny and Travis.

Given the known risks of fructose consumption, especially with chronic intake at high doses or in conjunction with polyunsaturated fats, it seems prudent to err on the low side. It seems to me that the Peat-atarians have failed to provide any evidence at all in favor of a higher fructose intake than is provided by the fruits, berries, and sugary vegetables recommended by the Perfect Health Diet, save for athletes in the midst of a race or post-race recovery.

References

[1] Décombaz J et al. Fructose and galactose enhance postexercise human liver glycogen synthesis. Med Sci Sports Exerc. 2011 Oct;43(10):1964-71. http://pmid.us/21407126.

[2] Currell K, Jeukendrup AE. Superior endurance performance with ingestion of multiple transportable carbohydrates. Med Sci Sports Exerc. 2008 Feb;40(2):275-81. http://pmid.us/18202575.

[3] Blom PC et al. Effect of different post-exercise sugar diets on the rate of muscle glycogen synthesis. Med Sci Sports Exerc. 1987 Oct;19(5):491-6. http://pmid.us/3316904.

[4] Moore MC et al. Acute fructose administration decreases the glycemic response to an oral glucose tolerance test in normal adults. J Clin Endocrinol Metab. 2000 Dec;85(12):4515-9. http://pmid.us/11134101.

Around the Web; Congratulations Naomi Edition

Posted by on January 21, 2012 52 comments

I had a great time talking to Sean Croxton on his Underground Wellness radio show Thursday night; check out the show here. I’m excited to be participating in Sean’s upcoming “Paleo Summit.” And it was nice to see that Miriam Knight of New Consciousness Review put our chat on Youtube.

Shou-Ching and I pleased to be blogging at Psychology Today. We join some great writers there, including Dr. Emily Deans and Dr. Kurt Harris, and are looking forward to introducing our ideas to a new audience.

[1] Reader Results: I’m always excited when readers report results. Here are a few from this week.

Naomi has recovered from longstanding digestive troubles:

Hi Paul, I have incredible news, my food intolerances are gone!! I just returned from a trip to India and Nepal, and while on the trip discovered I could eat anything with no reaction. If you recall from my questions in the Q&A section, I had severe histamine intolerance and fructose intolerance. After doing GAPS + buckwheat (but no ferments) for 7-8 months last year, I got worse, but after adding rice, via PHD and supplementing Vit C and D last fall, I felt a lot better, but still had the severe intolerances. I took ivermectin in early December after my stool test indicated the parasite strongyloides, but there was no noticeable change. For the trip to India, my doctor recommended artemisinin, 200 mg 2 x a day for prevention of malaria. I started it 2 weeks before the trip and had 3 days of mild die-off. It took about 2 weeks before I realized I could eat anything. Now that I am home, I cannot wait to add ferments or many of the simple things like tomatoes that I could not tolerate before.

I definitely credit PHD as well as your thinking about infection and parasites for helping me. Thank you so much.

I’m very happy for Naomi. Her case is also a capsule summary of our strategy for healing disease; disease is caused by bad diets and infections, so the strategy is to fix the diet, diagnose pathogens, and then optimize diet for that type of pathogen and take antimicrobial medicines as appropriate. Sometimes diagnosis is impossible, and it is worthwhile to just experiment with antimicrobial medicines. Artemisinin is known to work against protozoa such as plasmodium which causes malaria and trematode worms which cause schistosomiasis; perhaps it also works against the nematode worm strongyloides, or perhaps the stool test got her pathogen wrong. In any case, congratulations Naomi!

Naomi’s failure on GAPS recalls an observation I made in my Weston A Price Foundation Wise Traditions talk, which was discussed a bit on the Internet afterward. Natasha Campbell-McBride’s GAPS diet is a great approach, generally speaking, for bacterial dysbiosis of the gut, but isn’t necessarily optimal for infections with eukaryotic pathogens like fungi, protozoa, and parasitic worms. No one diet is perfect for every gut problem – as we wrote this week, “All healthy persons are alike; each unhealthy person is unhealthy in his own way.”

Helena reports:

Hi Paul, Thank you again! You helped my mom who has suffered with chronic constipation for 60 plus years. She had taken Senna for decades. I read your post about using Magnesium Citrate instead. It works like a charm and she is no longer taking toxic Senna. Thank you!

Think about this: Helena’s mom was magnesium deficient for 60 years, suffered constipation as a result, and never got the problem diagnosed or fixed. This says something about how easy it is to be magnesium deficient in today’s world, and how unaware people are about the need for key nutrients.

Finally, Ole reported his progress:

Here is a short summary of my time on the PHD: I have been on the PHD diet for over a year now. (I bought the draft version in September 2010). My health has improved a lot. I have lost about 25kg and I’m now about 87kg (i’m 185cm tall). I’m probably healthier than an average person on just about any performance metric.

On his blog Ole shared “before” (2010) and “midway through” (summer 2011) photos:

[2] Music to read by: Via Craig Newmark, here is They Might Be Giants covering “Tubthumping” by Chumbawumba at A.V. Club:


They Might Be Giants covers Chumbawamba

[3] Interesting Items This Week:

In the book and the post What Makes a Supercentenarian? (Aug 18, 2010) we discuss supercentenarian diets, and find they’re almost always Perfect Health Diet compatible. Dr. Daniel Chong, a naturopathic doctor and primary care physician in Portland Oregon who recommends our diet, reports another example: the oldest woman in the world, age 121, eats “grilled meat, monkey, fish, manioc (a root vegetable), and banana porridge. She does not eat salt, sugar, or any processed foods.”

Jamie Scott compiles evidence against omega-6 fats. All of Jamie’s posts are good, but this one is really good.

At RobbWolf.com, Roman Sasik, Ph.D., argues that chlorella may be dangerous, because it carries giant viruses and is rich in LPS to which chronic exposure is dangerous. CarbSane objects to stevia, xylitol, and erythritol.

Dan’s Plan has a nice discussion of Paula Deen’s decision to treat diabetes with drugs, not diet.

Peter Dobromylskyj of Hyperlipid comments on Stephan Guyenet’s recent paper: Peter argues that injury to the hypothalamus increases adipose insulin sensitivity leading to a free fatty acid deficiency, after which obesity is an adaptation that normalizes free fatty acid levels.

Matt Stone argues the case for ice cream: “[I]ce cream is not only healthy, but far healthier than most human breast milk.” Of course, it’s not an either-or situation.

Seth Roberts comments on Tara Parker-Pope’s “The Fat Trap”: Its defects were what it didn’t say.

Are GMO foods safe? Brian Cormack Carr quotes from our book’s discussion of why genetically modified foods can be unsafe and need to be screened for safety. Elsewhere, Emily Willingham in Slate supports GMO foods against a critique by Ari LeVaux in the Atlantic. Unfortunately, LeVaux doesn’t seem to know much biology and cites unlikely mechanisms, such as miRNA, for potential harm from GMO foods. (Monsanto responds with a nice commentary on the Zhang et al. paper we commented on earlier.) Neither article states precisely what safety testing is currently being done on GMO foods. What is needed is careful testing for the levels of all natural plant toxins. Is this being done? I don’t know.

Prof Dr Andro calls a high-fat diet “exercise in a pill.”

John J. Ray reports that men over 6 feet tall have a 24% lower risk of heart failure.

LymeMD:  “Idiopathic means the doctor is an idiot and the patient is pathological.”

A student revolt may mean the end of “healthy” food in the Los Angeles schools: “The complaints have been heard … and dishes like quinoa salads and brown rice cutlets are out.”

The Economist (hat tip: Brad) and The Scientist report on a new paper showing that exercise may improve health by inducing autophagy. Here’s the Pubmed abstract. What’s exciting about the research is that exercise induces autophagy not just in muscles and the heart, but in organs like the liver and pancreas. This gives us a mechanism by which exercise will be therapeutic for diabetes and metabolic syndrome.

Joshua Newman makes a powerful case for exercise.

Richard Fernandez ponders whether the FDA is on the side of the microbes.

Conrad’s Dairy Farm finds that it’s good business to give their cows waterbeds. Here’s a video:

[4] Some items I may do posts on: First, two critiques of our diet:

  • Travis Culp complains that we like butter too much; it’s the Pastoral Diet.
  • Danny Roddy complains that we don’t like sugar enough; it’s a Fructose-Deficient Diet.

I started writing a response but it’s too long for inclusion in this Around the Web.

Second, Dr Emily Deans has an important post: Tylenol and Autism? Paul Whiteley contributes a good comment to the post. Moms, don’t give your kids acetaminophen (paracetamol), and I wouldn’t take it during pregnancy either.

Third, Chris Kresser did an outstanding post on GERD, arguing that GERD is an inflammatory disease characterized by autoimmune attacks on the esophagus. I’ve been meaning to do a post or series on acid reflux and this fills in one of the missing pieces.

[5] Cute animal: Via Kamal Patel and reddit.com, a Galapagos Island seal:

[6] Scary animal?: Those who have read the verso page of our book may have noticed that our niece, Seo Jung, did a few illustrations. Here’s a recent drawing she made:

[6] Notable comments this week:

Dr. Ricardo de Souza Pereira left a comment telling us how to buy his Protexid supplement for acid reflux. Michael Eades once blogged about this supplement.

Lucas Tafur notes that ketogenic diets suppress leukocyte chemotaxis and phagocytosis, and increase vulnerability to tuberculosis and staph infections.

Rhonda W of the National Starch Company reflects on the benefits of resistant starch, a fiber found in starchy foods. She favors cornstarch, we favor safe starches like potatoes as a source of resistant starch.

Mehlinda provides us with a student video I found fascinating. It turns out many supermarket potatoes are sprayed with Bud Nip, a herbicide and sprout suppressant:

[7] Not the Weekly Video:

Via Yoni Freedhoff, who claims he almost got his bride to process to the Imperial Death March.

[8] Shou-Ching’s Photo Art: I disagree with this one:

[9] Weekly Video:

Via John Durant.