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Around the Web; Memorial Day Edition

Our prayers for the people of Joplin, Missouri and the victims of recent tornados.

Here are things that caught my eye this week:

[1] Interesting posts: Don’t miss Stephan Guyenet’s podcast with Chris Kresser, which I’ll comment on this week. Also, Stephan explains what “food reward” is.

Emily Deans discusses the influence of dirt on health; Stabby thinks he has a dirt deficiency.

Dennis Mangan notes that BCAA supplements may extend lifespan. At Robb Wolf’s blog, Amber Karnes reports an autistic child improving on Paleo. Matt Stone and Danny Roddy have been summarizing Ray Peat. Chris Highcock reports that sprinting up stairs may be the best exercise.

Mike the Mad Biologist recalls a lucky episode of serendipity in science. Craig Newmark thinks the Greeks have the most talent.

Don Matesz reports some lore from Chinese medicine:

[T]he Chinese medical view [holds] that sugar has yin effects, where yin stands for the overlapping sensory characteristics cool, calm/quiet, soft, and moist.  According to Chinese medicine, this makes sugar a medication for excessive yang conditions characterized by heat, agitation, tension, and dryness; but because it has relatively extreme characteristics, long term regular use of large amounts will create an excessively yin condition, i.e. excessive coolness, lassitude, weakness/impotence, and moisture (e.g. watery phlegm accumulation, excessive salivation), and a generally deficient condition.  Chinese dietary principles classify whole food starches as more desirable, more balanced foods–having a balance of yin and yang characteristics making them suitable for use as staple foods.

The yang condition sounds like that produced by low-carb ketogenic dieting (high body temperature, dry mucosal membranes) and the yin condition like that produced by high-carb dieting. The Chinese lore is consistent with our view that starches are better than sugars, and that eating some starch is desirable to avoid excessive ketosis which would promote fungal infections. Fungal infections are “hot” diseases in Chinese medicine.

This reminds me of an oldie but goodie, Chris Kresser’s explanation of Chinese medicine: qi is oxygen, meridians are vessels, and acupuncture points are neurovascular nodes.

Andrew Badenoch of evolvify.com argues that vegans are hotter. I refute him thus: Ms. Julianne Taylor.

Finally, John Durant offers a video of cheetah cubs playing:

[2] A song to read by:

[3] Why we don’t recommend high-dose niacin: A clinical trial of high-dose niacin for heart disease had to be stopped early this week, because it didn’t reduce heart attacks and increased strokes.

We have always counseled against supplementing niacin. Our reasoning is that niacin has both good and bad effects, but the primary good effect (raising HDL) can be achieved by dietary means via occasional ketogenic dieting without the ill effects (promotion of bacterial infections). See the book or How to Raise HDL, April 20, 2011, for more.

Thanks to Erik for mentioning the study. As I noted in my reply, strokes are strongly linked to bacterial infections of the vasculature, so it’s not a surprise that niacin would increase stroke risk. It’s also possible the statins administered with the niacin undermined its benefits.

[4] Gimme shelter:

[5] H. Pylori can cause Parkinson’s in mice: New results.

[6] Compelling scientific discovery of the week: If you have migraines and drink too much alcohol, caffeine can help you recover from a hangover.

[7] Nanny state chronicles: Denmark has banned Vegemite (Marmite) because it has too many vitamins. John J. Ray counters: “Australians have unusually long lifespans. Which is entirely due to Vegemite, of course!”

[8] I hate when that happens: Truck driver blows up like a balloon:

A New Zealand truck driver said he is “lucky to be alive” after an air hose became lodged in his buttocks and blew him up “like a balloon.”…

McCormack was rescued by coworkers and taken to an intensive care unit at a Whakatane hospital. He said it took nearly three days for his body to deflate to normal size.

Farting and burping is the therapy:

[9] Is that precipitation infectious?: Hail is full of bacteria. No word on whether they’re probiotic.

[10] They’re getting more human all the time: Scientists have discovered a bacterium that lives on coffee.

[11] Northern Lights: Photographer Stephane Vetter captures an aurora reflected off Jökulsárlón, Iceland’s largest glacial lake:

[12] Why I went to MIT: “At MIT, everyone is eccentric”.

[13] Shou-Ching’s photo art:

[14] Heroism and grief in the Joplin Tornado: This is a heartrending video, but love should be honored even – or especially – when it meets with misfortune:

Via Eric Falkenstein.

[15] Gaudeamus Igitur (“Therefore let us rejoice”): Via Danielle Ofri in the New York Times, a poem called “Gaudeamus Igitur,” by John Stone, a cardiologist from Atlanta. This poem was delivered as a commencement address to a class of Emory medical students, and gives a doctor’s view of life. One stanza:

For this is the end of examinations
For this is the beginning of testing
For Death will give the final examination
and everyone will pass.

[16] Science done the old-fashioned way: We’ve learned as much from personal experience with disease as from reading the journals – and personally-acquired knowledge is more likely to be novel and therefore scientifically significant. Brain researcher Jill Bolte Taylor got a research opportunity few brain scientists would wish for: She had a massive stroke, and watched as her brain functions — motion, speech, self-awareness — shut down one by one; and then in recovery she became inspired.

“How many brain scientists have been able to study the brain from the inside out? I’ve gotten as much out of this experience of losing my left mind as I have in my entire academic career.”

Here’s her story:

Around the Web; It’s Anthropology Week!

Here’s what caught my eye this week:

[1] Interesting posts this week: Paleo Pepper has compiled an online encyclopedia: the top 120 Paleo blog posts. Richard Nikoley asks: is optimality in diet a fool’s errand? He takes the view that individuals have an optimum, but not humanity. Via Seth Roberts, a fascinating story of how even doctors cannot get good care out of today’s medical system: How modern medicine killed my brother.

Also from Seth, his “morning faces therapy” has produced a great result for a man with bipolar disorder. We believe that “circadian rhythm therapies,” and bio-rhythm restoring techniques generally, are an underappreciated therapy. See, for instance, Intermittent Fasting as a Therapy for Hypothyroidism (Dec 1, 2010) and Seth Roberts and Circadian Therapy (Mar 22, 2011).

Emily Deans offers up a surprising danger of smoking pot – fungal infections of the lung:

[S]moked joints could easily be adulterated with natural fungi that grow into big nasty (and deadly) fungus balls in the lung.  I saw a case of this fungus ball in medical school in a patient immunosuppresed with HIV who also happened to smoke a lot of pot.  It could have been from other sources, of course, but my attendings assured me they had seen it several times in AIDS patients who were heavy pot users.  It’s not a pleasant way to go, and the treatments are horrible.

In a more controversial post, Emily argues that greater dopamine in the male brain creates “Genius and Madness,” while the lower dopamine feminine brain promotes sociability and social stability. But I wonder if a world led by “Generation XX” is really going to be more stable.

Mark’s Daily Apple notes that city living can be a brain drain. It certainly is for Shou-Ching and I; our nightmare would be living in New York City. Curiously I didn’t have the same sense of oppression in Tokyo, a much more open city. Boston is better than New York but we would prefer the country.

Robert Krulwich discusses the “loneliest plant in the world”: a male tree that can’t find a mate, as it is the only known surviving member of its species. Scientific American discusses how gut bacteria shape the brain. Chris Kresser suggests ways to keep your brain from aging.

Finally, if you’ve never seen a deer eat a bird, and would like to, Bix has you covered.

[2] Music to read exercise by:

The video can’t be embedded but is great. I wonder if the gymnastics were influenced by Parkour?

[3] My Favorite Posts This Week: The best posts this week were by Melissa McEwen of Hunt Gather Love, who has been running a series on “The Human Colon in Evolution.” All posts are great – I loved today’s (part 5) because it was new to me, and part 4 because it argues our “safe starches” are great foods for the gut – but they’re all outstanding:

[4] Human origins elucidated:

An important paper on human origins came out this week. “A Revised Root for the Human Y Chromosomal Phylogenetic Tree: The Origin of Patrilineal Diversity in Africa” used Y-chromosomes to trace the male “Adam” back to 142,000 years ago and northwest Africa, in what is now the Sahara but was then an open woodland environment. This is significant for many reasons, but one is that this region had easy communications with the Middle East along the Mediterranean coast and supports the possibility that interbreeding between Neanderthals and Africans, with significant back-migration into Africa proper, may have been an important process in the evolution of modern humans. Dienekes (here and here) and Razib Khan comment.

JS Stanton at gnolls.org had a nice essay. I don’t agree with everything in it; in particular, JS underestimates the violence of Paleolithic society. The work of Lawrence Keeley is helpful in this regard:

In browsing the comments to JS’s post I saw a link to a weird book by Danny Vendramini called Them and Us. A video by the author presents his case: Neanderthals were chimp-like super-predators and predation and rape by Neanderthals killed all the dumb humans, until the smarter humans figured out how to kill all the Neanderthals. Here’s how Vendramini imagines the Neanderthals:

There is plenty of evidence indicating that this view of the Neanderthals is wrong. I will just note that the fraction of Neanderthal genes in present-day humans is of the same order of magnitude as the level of mixing African-Americans and European-Americans have achieved in 200 years – this despite 30,000 years of selection which will have tended to work against survival of most Neanderthal genes. The idea that such extensive mixing came about through rape conducted by radically different species in perpetual warfare is, I think, totally untenable. There must have been extensive voluntary interbreeding.

Curiously, the Vendramini view recapitulates one of the earliest hypotheses about Neanderthals. This talk by Carl Zimmer shows that (at 2:40) in 1909 leading anthropologists shared Vendramini’s view of the Neanderthals, whereas today they seem — ahem — considerably more attractive:

[5] We’re glad it’s helping! Chris Kresser on Twitter:

I’ve been having some success w/modified ketogenic diet a la Paul Jaminet w/50g CHO, 6 TBS MCT oil 5g leucine.

This method of producing ketosis is much healthier than the zero-carb low-protein diets sometimes used.

UPDATE: It’s mood disorders generally, and depression specifically, that the ketogenic diet has been helping with.

[6] More on Food Deserts: Beth Mazur of Weight Maven has written of the significance of “food deserts” in the obesity epidemic. Basically, where fresh whole foods are difficult to buy, obesity rates are high.

Now the USDA has a cool interactive map showing the locations of food deserts:

Via Razib Khan

[7] Did monkeys keep pets?:

Via Yves Smith.

[8] Our book on sale: I know of at least one store that offers our book for sale: The Grainery in Baraboo, Wisconsin. Their web site has a great line from Thomas Edison:

“The doctors of the future will give no medicine , but intrest their patients in care of the human frame, diet and the cause and prevention of disease.” — Thomas A. Edison

The proprietor of The Grainery, John Kessenich, spoke recently on “Eating for Perfect Health” and might have used some of our ideas. If you happen to find yourself in Baraboo, check out The Grainery and ask John for health tips!

[9] Why the Kindle version isn’t available: I have too much brain.

[10] Primal Fashion Week: No, this is definitely not Paleo re-enactment. I doubt Neanderthal women ever wore a Sperm Coat or paired it with a Heart Tube Hat.

Personally I would prefer a cheetah skin.

[11] Low-dose naltrexone is great for Crohn’s: On my editorial calendar is a discussion of the role of endorphins and enkephalins in immunity, and the opportunity to increase their levels and circadian variability and thus modulate immunity through low-dose naltrexone (LDN), with beneficial effects against certain diseases.

While I dither, clinical studies of LDN are progressing. This week, a report came out on LDN for Crohn’s disease:

Eighty-eight percent of those treated with naltrexone had at least a 70-point decline in Crohn’s Disease Activity Index scores compared to 40 percent of placebo-treated patients.

[12] Shou-Ching’s Photo-Art:

© 2011 Shou-Ching Jaminet.

[13] Not the weekly video: Ducks Against the Wind:

Via erp, who says, “It’s getting harder and harder to keep your ducks in a row!”

[14] Weekly video: Marriage is health-improving and life-extending, especially for men, so I consider this (done in moderation!) an exemplary health practice:

Via Orrin Judd

How to Raise HDL

In the earlier two posts of this series (HDL and Immunity, April 12; HDL: Higher is Good, But is Highest Best?, April 14), we established that HDL is central to the immunity and toxin clearance, and that it’s probably desirable to have more of it than our body’s natural levels, since we are in a more pathogen-and-toxin-rich environment than the Paleolithic and evolution hasn’t caught up to the situation.

The question is: how?

Disease Can Upregulate HDL

Chris Kresser left two great comments (here and here):

I tend to view HDL >85 or 90 in the presence of other inflammatory or immunological markers as a potential sign of infection or immune dysregulation.

I don’t have the reference handy, but I came across a study associating elevated HDL and CRP (occurring together) with INCREASED risk of heart disease….

I frequently see HDL >100 in patients with several other markers of inflammation, such as elevated CRP, ferritin, WBC, monocytes, etc.

Yes, indeed; as one review of HDL and heart attacks states, “many patients who experience a clinical event have normal, or even high, levels of HDL cholesterol.” [1]

Heart attacks result from a high burden of infected atherosclerotic lesions. When the body is fighting infections, it upregulates its defense mechanisms, including HDL.

Mario added a great comment along this line:

This could explain why runners have higher levels of HDL: to fight infections that abound among them!

And, the fact that pathogen-fighting HDL particles do not go back to the liver can explain why the half-life of HDL in runners is much higher than in sedentaries http://www.ncbi.nlm.nih.gov/pubmed/6748208.

These facts lead us toward one possible strategy for raising HDL: swallow a lot of pathogens!

Our Strategy: Benign Hormetic Stress

But this isn’t likely be desirable. Higher HDL may do some good, but the pathogens are likely to do a lot more harm.

So we have to look at tactics for raising HDL that do more good than harm. I think it’s useful to classify tactics in three groups:

  • Beneficial Methods. These methods have no known toxicity, but cause the body to increase HDL levels – perhaps because of an association with danger in our evolutionary past.
  • Mildly Toxic, Plausibly Beneficial Methods. These methods have some toxicity, but there is a plausible case to be made that the toxicity is innocuous or insignificant, so that the benefits of higher HDL will outweigh the harms.
  • Damaging Methods. Intentionally swallowing HDL-increasing pathogens or toxins is probably a bad strategy most of the time, and should be avoided.

I’ll look at tactics one by one.

Coconut Oil-Induced Ketosis

One of the most powerful, and probably also benign, ways to raise HDL is intermittent fasting or ketogenic dieting, with ketosis enhanced by the use of coconut oil or MCT (medium-chain triglyceride) oil.

Ketosis stimulates the ketone receptor GPR109A, which strongly induces HDL synthesis. GPR109A is better known as the receptor on which niacin acts to raise HDL, but its physiological ligand was not known until recently when it was found to be the ketone beta-hydroxy-butyrate. [2] It looks like any time a human goes into ketosis, HDL is upregulated.

Why we evolved a mechanism to increase HDL during ketosis is not known. However, it’s easy to imagine plausible stories. Ketosis would have been a frequent event in the Paleolithic, since most hunter-gatherers probably ate low-carb diets. However, ketosis would have been associated with times of stress:

  • Ketosis occurs during fasting, and involuntary fasting is a threat to health that forces eating of marginal foods from which infection risks are high.
  • Ketosis can also be induced by a lack of carb-containing plant foods; this would naturally lead to a shortage of animal foods, and famine, soon after. Famine depresses immunity and increases risk of infection.
  • Drought was probably a common cause of both lack of carb-rich foods and famine. Drought would tend to force reliance on marginal, polluted or infected water sources.

In the modern world, we control our food intake and can generate ketosis safely without ever reaching a famine state that significantly depresses immunity. There are safe ways to activate GPR109A via intermittent ketogenic dieting with minimal risk of ill effects.

I believe the chief risks from ketogenic dieting are:

1.      Promotion of protozoal and fungal infections. While ketogenic dieting is helpful against bacterial and viral infections, fungi and protozoa are eukaryotes who can metabolize ketones in their mitochondria. In fact, because ketones are water-soluble small molecules and diffuse into pathogen mitochondria, while glucose and fatty acids are chaperoned through the human body by transport molecules, ketones are a uniquely available energy substrate for parasitic fungi and protozoa. Moreover, glucose is a major resource for the immune defense against these pathogens, and induction of ketosis by carb restriction can diminish immunity against protozoa and fungi. Since protozoal infections such as Toxoplasma gondii and fungal infections such as Candida are now common, each afflicting perhaps 30% of the population or more, this is a major concern.

2.      Ketosis induced through severe carb and protein restriction may trigger the dangers of zero-carb dieting. I’ve done a series on this (it started here).

The solution is to achieve ketosis intermittently, through tactics like daily intermittent fasting, and to induce it positively through the consumption of short-chain fats such as are found in coconut oil or MCTs, or through leucine supplementation. A healthy diet, ketogenic or not, should meet our recommendations of at least 200 carb calories from starches and at least 600 calories from carbs plus protein.

Physical Activity

Exercise is another method for raising HDL that seems entirely healthful.

In the evolutionary environment, continuous exertion probably signaled danger: either a difficult hunt or, more likely, some form of warfare with other humans. In either case, injury and a need for wound repair was a likely prospect. Breaching of the skin barrier by wounds mean infections. Since HDL plays a role in wound repair and infection resistance, it would make sense to upregulate HDL production during exertion.

In one 12-week trial, HDL was raised by 24.8% on a moderate-intensity walking program and by 20.9% on a high-intensity walking program. [3]

In the evolutionary milieu, sitting for 16 hours a day would have indicated a lack of danger and little need for HDL. It turns out that daily sitting time strong predicts low HDL – and it only takes a day for HDL levels to adjust. In rats, 16 hours of daily inactivity caused a 20-25% drop in HDL levels by the end of the first day [4]:

The same phenomenon occurs in humans: 20 days of bed rest leads to a 20% reduction in HDL [5].

Resistance training also helps, but perhaps not as much as reduced sitting time. Obese sedentary women raised HDL by 15% following a 9-week, 3 times per week resistance training protocol. [6]

Overall, the most effective way to raise is HDL through activity is simply to reduce the daily time spent sitting and increase the time spent standing or walking.

Sitting is also a major risk factor for obesity, diabetes, and cardiovascular disease. [7] So it looks like high activity levels are strongly health-improving.

Until recently I was sitting or sleeping about 23 hours a day, which can’t be healthful. To repair that I recently built a standing desk. Now I stand, kneel (on a padded bench), or half-kneel half-stand throughout my working hours. I strongly recommend a standing desk as an effective way to increase HDL.

High-Fat Diets and Dairy Fat Consumption

When long-chain fats are eaten, they are transported from the intestine by particles called chylomicrons. Researchers injected radiolabeled chylomicrons into rats to determine the fate of the components. They found that chylomicrons frequently turn into HDL:

Catabolism of chylomicrons is associated with a rapid transfer of phospholipid, apoA-I, and possibly apoA-IV into HDL. Chylomicron phospholipid appears to give rise to vesicles which are probably incorporated into preexisting HDL. Chylomicron surface components may be an important source of plasma HDL. [8] (Hat tip CarbSane.)

Which long-chain fats are best? A case can be made for dairy fats.

There is a clear association between eating dairy fats and having high HDL. Blood levels of trans-palmitoleic acid, an omega-7 trans-fat obtainable only by eating milk products from ruminants, is strongly associated in prospective cohort studies with higher HDL. [9b] Feeding experiments in guinea pigs confirm that butter oil increases HDL. [9]

Seth Roberts cut his coronary artery calcification score by 24% by eating a half-stick of butter per day; perhaps butter’s HDL-raising property deserves the credit. High dairy fat consumption is associated with improved health in prospective cohort studies, for instance much lower rates of diabetes and lower CRP levels. [9b]

The reason dairy fats work is uncertain. The mechanism could be via chylomicron breakdown, and other fats might work nearly as well. People who eat the most dairy fats probably eat high-fat diets that are low in omega-6 fats, and omega-6 fats reduce HDL; so the dairy fats could just be a marker for high-fat low-omega-6 diets. However, it’s possible that the ruminant trans-fat CLA is especially beneficial. It might not hurt to copy Seth, and eat a lot of butter.

Alcohol

Interestingly, drinking alcohol may be a healthful way to raise HDL. We’ve previously discussed epidemiological evidence for health benefits from drinking and the matter of how to drink safely (Is It Smart to Drink?, Sep 9, 2010), but didn’t discuss alcohol’s effect on HDL.

Well, it’s significant. Alcohol increases HDL-C level, with higher doses of ethanol leading to higher HDL levels and lower rates of coronary artery disease. This works as long as there is no liver damage. Once liver damage begins, alcohol lowers HDL. [10]

This is good news because alcohol alone does not damage the liver – only the combination of alcohol with polyunsaturated fats – either omega-6 or omega-3 will do. As long as alcohol is consumed only with saturated fats, it is likely to be beneficial to health.

Here’s some numbers relating alcohol dose to HDL increase:

  • One beer per day raised HDL by 4.4% without affecting other lipid parameters. [11]
  • A half-bottle of wine per day (containing 39 g ethanol) raised HDL by 17% without affecting other lipid parameters. [12]

It is possible that red wine is particularly beneficial for HDL due to certain plant compounds that accompany the alcohol. [13]

In an analysis of the MRFIT trial, alcohol’s HDL-raising effect was found to be responsible for half of its benefits for mortality from coronary heart disease. [14] It appears that alcohol’s other health benefits, from its glucose-lowering effect to its stress-relieving effect, are less important for health than its HDL-raising effect.

Niacin

Niacin supplementation is the most common doctor-prescribed way to raise HDL. Dr. William Davis of Track Your Plaque fame is an ardent advocate of niacin, as are many other cardiologists.

Niacin increases HDL the same way ketones do, by activating the ketone receptor GPR109A. Gram doses of niacin are roughly equally effective with tablespoon doses of coconut oil in raising HDL. For instance, four grams of niacin per day for 6 weeks raised HDL levels by 50%. [15]

However, there are two key differences:

1.      Niacin is toxic whereas ketones are not.

2.      Ketones diffuse throughout the body whereas niacin binds certain cells, notably fat cells, preferentially and this concentrates its toxicity.

The localization of niacin to fatty tissues is clear in this radiogram taken 5 minutes after injection of radioactive-labeled niacin to a mouse [16]:

Major sites of niacin binding are the skin, the liver, and the fat surrounding the kidney. This is why these are sites of niacin toxicity: the toxins from niacin conversion are localized here.

Skin flushing is the most obvious sign of niacin toxicity, but organs can also be damaged. As one review states, “Unfortunately, when used as a pharmaceutical, niacin has more than its share of drug toxicities, including hepatotoxicity, gastric toxicity, glucotoxicity, and, most commonly, skin toxicity.” [17]

Niacin toxicity results from the manner in which it is converted to the active forms of vitamin B3, NAD and NADP. Niacinamide, an alternative form of vitamin B3, is converted to NAD and NADP without toxicity, but does not stimulate the GPR109A receptor and does not raise HDL levels.

Time-release niacin is especially prone to poisoning the liver. [18] The liver’s main niacin disposal pathway can only metabolize a small amount of niacin at a time. Time-release niacin causes more niacin to pass through this high-toxicity liver pathway.

Another issue with niacin is that NAD is the rate-limiting vitamin for bacterial metabolism. Excess vitamin B3 intake, therefore, promotes bacterial infections.

In general, I consider niacin to be an alternative to coconut oil-driven ketosis rather than a complement to it. Both niacin and ketones act on the same receptor, and the HDL increases from coconut oil alone are so large (commonly to 120 mg/dl or higher) that adding niacin on top would be gilding the lily.

Since benefits from niacin against atherosclerosis probably come either from HDL increases or from other effects of activating GPR109A [19], it is likely that coconut oil delivers all or nearly all the benefits of niacin.

In most cases, due to its lack of toxicity, coconut oil should be preferred. The exception would be people who have significant protozoal or fungal infections but not bacterial infections. Since ketones feed the former while niacin feeds the latter, such people may benefit from niacin instead of coconut oil.

Some other HDL-raising factors

In general, good nutritional status supports high HDL levels. In some populations, multivitamin and multimineral supplements have been shown to raise HDL. [20]

Micronutrients that are beneficial may include vitamin C, taurine, and glycine. Bile acids are made from cholesterol using vitamin C and are then conjugated with taurine and glycine. Bile duct blockage tends to lower HDL and providing bile-supporting nutrients like vitamin C [21] and taurine [22, 23] can under some circumstances raise HDL. Glycine is richly present in gelatin (cooked collagen), and taurine in uncooked or rare meats.

Plant fiber and polyphenols have been reported to raise HDL. For instance, a polyphenol-rich carob fiber was found to raise HDL by 7% while lowering LDL [24], and psyllium has been reported to raise HDL [25]. It is unclear to me whether this is a beneficial pathway or not. On the one hand, butyrate and other volatile fatty acids from gut flora may stimulate the ketone receptor. On the other hand, many of these polyphenols are directly toxic, and fiber increases gut bacterial populations and endotoxin flux into the body. HDL may be upregulated because it has more toxins to clear.

Higher potassium excretion is associated with higher HDL, suggesting that high intake of potassium-rich foods like potatoes, bananas, and vegetables might raise HDL. [26] Since potassium-rich foods are also usually fiber-rich, this association may be mediated by short-chain fats from fermentation of fiber by gut bacteria. But potassium is a nutrient low-carb dieters can easily become deficient in, so it may be worth tending to.

Some Things to Avoid

Dietary components that promote lipid peroxidation, including fructose, omega-6 fats, and trans-fats, lower HDL levels. Smoking also lowers HDL. [27]

A Japanese study found that “Concerning dietary habits, total cholesterol was lower by a mean of 13 mg/dl (0.34 mmol/L), triglycerides lower by 40 mg/dl (0.45 mmol/L), and HDL-cholesterol higher by 5 mg/dl (0.13 mmol/L) in the group who ate 7 or more Japanese-style meals in the 9 meals during 3 days than in the group who ate 3 or less Japanese-style meals in the 9 meals.” [27]

Japanese-style meals are low-toxicity and essentially Perfect Health Diet compliant. The alternative is probably western style food high in wheat, vegetable oils, and sugar.

Conclusion

HDL can be raised in destructive ways – such as ingestion of toxins or pathogens – but there are healthy ways to raise HDL.

I believe the following four ways are healthiest, and are sufficient to optimize HDL levels:

  • Eat a nourishing diet rich in saturated and monounsaturated fat, especially dairy fat, but low in omega-6 fats, fructose, and other toxins. In short: eat the Perfect Health Diet.
  • Be physically active. Be on your feet as much as possible; favor a standing desk over sitting. Do resistance exercise or other intense exercise occasionally.
  • Engage in intermittent fasting, and consume a lot of coconut oil, coconut milk, or MCTs to stimulate the ketone receptor.
  • Drink alcoholic beverages – but only when consuming meals low in polyunsaturated fats. Drink up when you eat beef, but be cautious when the entrée is salmon.

Niacin, the most effective pharmaceutical for raising HDL, has some toxicity and is probably inferior to coconut oil and intermittent fasting except in people with protozoal or fungal infections.

Our best wishes for high HDL!

Related posts:

References

[1] Navab M et al. HDL and cardiovascular disease: atherogenic and atheroprotective mechanisms. Nat Rev Cardiol. 2011 Apr;8(4):222-32. http://pmid.us/21304474.

[2] Ahmed K et al. GPR109A, GPR109B and GPR81, a family of hydroxy-carboxylic acid receptors. Trends Pharmacol Sci. 2009 Nov;30(11):557-62. http://pmid.us/19837462.

[3] Spate-Douglas T, Keyser RE. Exercise intensity: its effect on the high-density lipoprotein profile. Arch Phys Med Rehabil. 1999 Jun;80(6):691-5. http://pmid.us/10378497.

[4] Bey L, Hamilton MT. Suppression of skeletal muscle lipoprotein lipase activity during physical inactivity: a molecular reason to maintain daily low-intensity activity. J Physiol. 2003 Sep 1;551(Pt 2):673-82. http://pmid.us/12815182.

[5] Yanagibori R et al. The effects of 20 days bed rest on serum lipids and lipoprotein concentrations in healthy young subjects. J Gravit Physiol. 1997 Jan;4(1):S82-90. http://pmid.us/11541183.

[6] Costa RR et al. Effects of resistance training on the lipid profile in obese women. J Sports Med Phys Fitness. 2011 Mar;51(1):169-77. http://pmid.us/21297577.

[7] Hamilton MT et al. Role of low energy expenditure and sitting in obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease. Diabetes. 2007 Nov;56(11):2655-67. http://pmid.us/17827399.

[8] Tall AR et al. Metabolic fate of chylomicron phospholipids and apoproteins in the rat. J Clin Invest. 1979 Oct;64(4):977-89. http://pmid.us/225354.

[9] Rice BH et al. Ruminant-produced trans-fatty acids raise plasma total and small HDL particle concentrations in male Hartley guinea pigs. J Nutr. 2010 Dec;140(12):2173-9. http://pmid.us/20980644.

[9b] Mozaffarian D et al. Trans-palmitoleic acid, metabolic risk factors, and new-onset diabetes in U.S. adults: a cohort study. Ann Intern Med. 2010 Dec 21;153(12):790-9. http://pmid.us/21173413.

[10] Lakshman R et al. Is alcohol beneficial or harmful for cardioprotection? Genes Nutr. [Epub ahead of print] http://pmid.us/20012900.

[11] Thornton J et al. Moderate alcohol intake reduces bile cholesterol saturation and raises HDL cholesterol. Lancet. 1983 Oct 8;2(8354):819-22. http://pmid.us/6137650.

[12] McConnell MV et al. Effects of a single, daily alcoholic beverage on lipid and hemostatic markers of cardiovascular risk. Am J Cardiol. 1997 Nov 1;80(9):1226-8. http://pmid.us/9359559.

[13] Brien SE et al. Effect of alcohol consumption on biological markers associated with risk of coronary heart disease: systematic review and meta-analysis of interventional studies. BMJ. 2011 Feb 22;342:d636. http://pmid.us/21343206.

[14] Suh I et al. Alcohol use and mortality from coronary heart disease: the role of high-density lipoprotein cholesterol. The Multiple Risk Factor Intervention Trial Research Group. Ann Intern Med. 1992 Jun 1;116(11):881-7. http://pmid.us/1580443.

[15] Carlson LA, Hamsten A, Asplund A. Pronounced lowering of serum levels of lipoprotein Lp(a) in hyperlipidaemic subjects treated with nicotinic acid. J Intern Med 1989; 226: 271–6.

[16] Carlson LA. Nicotinic acid: the broad-spectrum lipid drug. A 50th anniversary review. J Intern Med. 2005 Aug;258(2):94-114. http://pmid.us/16018787.

[17] Dunbar RL, Gelfand JM. Seeing red: flushing out instigators of niacin-associated skin toxicity. J Clin Invest. 2010 Aug 2;120(8):2651-5. http://pmid.us/20664168.

[18] Bassan M. A case for immediate-release niacin. Heart Lung. 2011 Mar 15. [Epub ahead of print] http://pmid.us/21414665.

[19] Lukasova M et al. Nicotinic acid inhibits progression of atherosclerosis in mice through its receptor GPR109A expressed by immune cells. J Clin Invest. 2011 Mar 1;121(3):1163-73. http://pmid.us/21317532.

[20] Li Y et al. Effects of multivitamin and mineral supplementation on adiposity, energy expenditure and lipid profiles in obese Chinese women. Int J Obes (Lond). 2010 Jun;34(6):1070-7. http://pmid.us/20142823.

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What’s the Trouble With Sweet Potatoes?

We’re continuing with a series on people who have reported something going wrong when they tested some variation of the Perfect Health Diet. (The first post summarized experiences, good and bad; the second looked at difficulties suddenly adding carbohydrates to a very low-carb diet.)

The next issue was reported by Chris Masterjohn; he had trouble with sweet potatoes:

Although sweet potatoes are considered a safe starch on the Perfect Health Diet, they are not very safe for me. When I discovered how yummy sweet potato fries are, I started eating several sweet potatoes per day. Within a few days, I was limping and my neck was stiff. By the end of the week, my limp was extreme. I looked online to see if I was eating anything high in oxalates, and sure enough, sweet potatoes are loaded with them. My symptoms dramatically improved after one day off sweet potatoes and were gone the second day.

Chris’s commenter Lisa also had trouble with sweet potatoes:

I’ve been very achy since I started eating sweet potatoes daily. Why would some of us be maladapted to oxalates?… I’m wondering if after a long stint of LC/paleo eating I’ve become intolerant to oxalates or to starch in general.

Clearly sweet potatoes are not safe for everyone. What might be causing the trouble?

Fructose and Fiber as Possible Confounders

One factor to consider is that there are different varieties of sweet potato. We eat an Asian sweet potato variety which is not nearly as sweet as conventional American sweet potatoes; it has a yellow flesh and a chestnut flavor. It is botanically a yam, not a sweet potato. It looks like this (via “my super sweet twenty-six”):

Like so many modern foods, the standard American sweet potato has been bred for sweetness. Here is data from http://nutritiondata.com comparing 100 g of potatoes, yams, sweet potatoes, and grapes for sugar, starch, and fiber content:

Food Sugar (g) Starch (g) Fiber (g)
Potato 1.2 17.3 2.2
Yam 0.5 23.1 3.9
Sweet potato 6.5 7.5 3.3
Grapes 15.5 0.0 0.9

All have similar calories. Yams are largely sugar-free, but sweet potatoes are intermediate between grapes and potatoes in both sugar and starch content. They are sort of half fruit, half starch.

Thus, it is conceivable that sweet potatoes could trigger an issue like fructose malabsorption; or that fructose or fiber might feed certain gut infections that would not be similarly fed by potatoes.

Oxalate

Chris believed his problem was due to oxalate. Sweet potatoes do contain oxalate, although they are not the only plant foods which do.

In fact, by far the largest source of oxalate in the American diet is spinach. Spinach by itself accounts for over 40% of all oxalate consumed by Americans; potatoes for about 10%. [1] Wheat bran has high levels of oxalate.

Why are oxalates troublesome?  Some people have sensitivities to oxalate. Rarely, genetic defects in the enzymes that degrade oxalate cause a disease called primary hyperoxaluria; this disease afflicts 1 to 3 people in a million.  Other conditions can elevate calcium or oxalate in the urine and increase the risk of calcium oxalate kidney stones. This is especially likely in people who are deficient in magnesium or who don’t eat citrate. [2]

Another pathway by which oxalate might cause trouble is via fungal infections. Candida and other fungi form calcium oxalate crystals in tissue [3,4]; fungi appear to be responsible for the yellow-brown calcium oxalate biofilms which form on stone monuments. [5]

But the literature suggests that oxalate sensitivities are rare. If oxalate sensitivity is present, then it should manifest itself when eating spinach, wheat bran, and other oxalate rich foods. Since Chris has praised spinach and wheat recently, I wonder if it is really the oxalate that caused his trouble.

Phytoalexins

Another possibility is a class of toxins called phytoalexins.

Ordinarily, sweet potatoes are largely toxin free. But when attacked by fungus or molds, sweet potatoes generate a variety of food toxins. As two papers describe them:

Sweet potatoes contain phytoalexins that can cause lung edema and are hepatotoxic to mice. At least one of these, 4-ipomeanol, can cause extensive lung clara cell necrosis and can increase the severity of pneumonia in mice. Some phytoalexins in sweet potatoes are hepatotoxic and nephrotoxic to mice. [6]

Ipomeanine (IPN), 4-ipomeanol (4-IPO), 1-ipomeanol (1-IPO), and 1,4-ipomeadiol (DIOL) are toxic 3-substituted furans found in mold-damaged sweet potatoes. IPN and 4-IPO are the most toxic, but all produce pulmonary toxicity in cattle and rodents, and 4-IPO induces hepatotoxicity in humans. [7]

Cattle will die if fed mold-damaged sweetpotatoes:

Unfortunate bovine fatalities occurring after ingestion of mold-damaged sweetpotatoes preclude the use of the culled tubers in livestock feed. In cattle, mold-damaged sweetpotatoes induce an acute respiratory distress syndrome resulting in asphyxiation. [8]

Toxins may be present even if mold damage is not visible:

Fermentation of 6 weeks duration was observed to inadequately eliminate the lung, liver, and kidney toxicity caused by mold-damaged sweetpotatoes. In fact, fermentation exacerbated the hepatotoxicity of mold-damaged sweetpotatoes. This is also the first demonstration that sweetpotato regions lacking visible mold damage can induce lung and kidney injury … [8]

Allergies

Sweet potatoes are generally considered to be one of the least allergenic of foods. However, infants sometimes do have sensitivities to sweet potato. This may reflect an immature gut flora in the infants; perhaps specific bacterial species — possibly including the oxalate-digesting Oxalobacter [9] — make sweet potatoes tolerable? If so, it raises the possibility that adults with incomplete gut flora might also have sweet potato sensitivities.

There is also the possibility of allergies to mold toxins in infected sweet potatoes.

Food Sensitivities as a Diagnostic Tool

Food sensitivities can sometimes be helpful in diagnosing certain health conditions:

  • Leaky gut. People with a leaky gut will have many food sensitivities; people with a healthy gut will have few.
  • Small bowel infections. People with infections of the small intestine will usually have a negative reaction to fructose.
  • Colonic infections. People with infections of the colon may react badly to fiber, and obtain relief on low-fiber diets.

There is a chance that oxalate may benefit fungal infections, so I suppose an oxalate sensitivity could be diagnostic for that, although in my experience fungal infections are usually slow-reacting to food and the response is rarely obvious.

Conclusion

In our book [p 121] we note that all plants make pesticidal toxins. Thus, no plant food can be guaranteed to be safe.

Normally, levels of pesticidal toxins are low in sweet potatoes. But it’s always desirable to inspect sweet potatoes for visible damage, and to discard any that are discolored or show other evidence of toxin production.

I confess to being puzzled as to how sweet potatoes caused Chris’s symptoms. If he tolerates spinach and wheat bran, it seems unlikely that the oxalate in sweet potatoes would be responsible. He might wish to test various foods and try to narrow down the source of his sensitivity.

For our part, we may cease listing sweet potatoes among our “safe starches” and specify yams instead, since a “safe starch” should probably be low in fructose.

References

[1] Taylor EN, Curhan GC. Oxalate intake and the risk for nephrolithiasis. J Am Soc Nephrol. 2007 Jul;18(7):2198-204. http://pmid.us/17538185.

[2] McConnell N et al. Risk factors for developing renal stones in inflammatory bowel disease. BJU Int. 2002 Jun;89(9):835-41. http://pmid.us/12010224.

[3] Takeuchi H et al. Detection by light microscopy of Candida in thin sections of bladder stone. Urology. 1989 Dec;34(6):385-7. http://pmid.us/2688263.

[4] Muntz FH. Oxalate-producing pulmonary aspergillosis in an alpaca. Vet Pathol. 1999 Nov;36(6):631-2. http://pmid.us/10568451.

[5] Pinna D. Fungal physiology and the formation of calcium oxalate films on stone monuments. Aerobiologia. 1993 9(2-3):157-167. http://www.springerlink.com/content/n72l71352t1r0r04/.

[6] Beier RC. Natural pesticides and bioactive components in foods. Rev Environ Contam Toxicol. 1990;113:47-137. http://pmid.us/2404325.

[7] Chen LJ et al. Metabolism of furans in vitro: ipomeanine and 4-ipomeanol. Chem Res Toxicol. 2006 Oct;19(10):1320-9. http://pmid.us/17040101.

[8] Thibodeau MS et al. Effect of fermentation on Sweetpotato (Ipomoea batatas) toxicity in mice. J Agric Food Chem. 2004 Jan 28;52(2):380-4. http://pmid.us/14733525. B76FN5FG89GM

[9] Hatch M et al. Enteric oxalate elimination is induced and oxalate is normalized in a mouse model of Primary Hyperoxaluria following intestinal colonization with Oxalobacter. Am J Physiol Gastrointest Liver Physiol. 2010 Dec 16. [Epub ahead of print]. http://pmid.us/21163900.