Monthly Archives: March 2012

Red Meat and White Rice, Oh My!

This started as a note for an Around the Web, but has grown … so it will stand on its own.

The Red Meat Study

The Paleosphere has been abuzz about the red meat study from the Harvard School of Public Health. I don’t have much to say about it because the claimed effect is small and, at first glance, not enough data was presented to critique their analysis. There are plenty of confounding issues: (1) We know pork has problems that beef and lamb do not (see The Trouble With Pork, Part 3: Pathogens and earlier posts in that series), but all three meats were lumped together in a “red meat” category. (2) As Chris Masterjohn has pointed out, the data consisted of food frequency questionnaires given to health professionals, and most respondents understated their red meat consumption. Those who reported high meat consumption were “rebels” who smoked, drank, and did not exercise. (3) The analysis included multivariate adjustment for many factors, which can have large effects on assessed risk. Study authors can easily bias the results substantially in whatever direction they prefer. I’ve discussed that problem in The Case of the Killer Vitamins.

So it’s hard to judge the merits of the red meat study. However, another study from HSPH researchers came out at the same time that was outright misleading.

The White Rice and Diabetes Study

This study re-analyzed four studies from four countries – China, Japan, Australia, and the United States – to see how the incidence of diabetes diagnosis related to white rice consumption within each country.

Here was the main data:

The key thing to notice is that the y-axis of this plot is NOT incidence of type 2 diabetes. It is relative risk within each country for type 2 diabetes.

I looked up diabetes incidence and rice consumption in these four countries. Here is the scatter plot:

Here is the complete FAO database of 86 countries, with a linear fit to the data:

UPDATE: O Primitivo has data for 162 countries and a better chart. Here it is – click to enlarge:

If anything, diabetes incidence goes down as rice consumption increases. Countries with the highest white rice consumption, such as Thailand, the Philippines, Indonesia, and Bangladesh, have very low rates of diabetes. The outlier with 20% diabetes prevalence is the United Arab Emirates.

A plausible story is this:

  1. Something entirely unrelated to white rice causes metabolic syndrome. Possibly, the something which causes metabolic syndrome is dietary and is displaced from the diet by rice consumption, thus countries with higher rice consumption have lower incidence of metabolic syndrome.
  2. Fact: Diabetes is diagnosed as a fasting glucose that exceeds a fixed threshold of 126 mg/dl, and in those with metabolic syndrome (but not those without) higher carb consumption leads to higher fasting blood glucose.
  3. Therefore, the fraction of those with metabolic syndrome diagnosed as diabetic will increase as their carb consumption increases.
  4. In China and Japan, but not in the US and Australia, white rice consumption is a marker of carb consumption. So the fraction of those with metabolic syndrome diagnosed as diabetic will increase with white rice consumption in China and Japan, but will be uncorrelated with white rice consumption in the US and Australia.

Thus, diabetes incidence may be lower in China and Japan (due to lower incidence of metabolic syndrome on Asian diets), but higher among Chinese and Japanese eating the most rice (due to higher rates of diagnosis on the blood sugar criterion). This explains all of the data and is biologically sound.

What did the HSPH researchers conclude?

Higher consumption of white rice is associated with a significantly increased risk of type 2 diabetes, especially in Asian (Chinese and Japanese) populations.

No: Internationally, higher consumption of white rice is associated with a significantly reduced risk of type 2 diabetes, and the Chinese and Japanese experience is consistent with that. Carb consumption is associated with a higher rate of diabetes diagnosis within populations at otherwise similar risk for diabetes. White rice consumption is correlated to carb consumption especially strongly in Asian (Chinese and Japanese) populations.

Food Reward and “Eat Less, Move More” in Diabetes

Of course, the study authors knew that diabetes incidence is lower in countries that eat more white rice. How do they reconcile this with their claim that white rice increases diabetes risk?

The recent transition in nutrition characterised by dramatically decreased physical activity levels and much improved security and variety of food has led to increased prevalence of obesity and insulin resistance in Asian countries. Although rice has been a staple food in Asian populations for thousands of years, this transition may render Asian populations more susceptible to the adverse effects of high intakes of white rice …

In other words, rice-eating countries have higher physical activity and more boring food – just look at the notoriously tasteless cuisines of Thailand, China, and Japan – and their inability to eat high quantities of food has hitherto protected Thais, Chinese, Japanese, Filipinos, and Indonesians from diabetes.

However, once those rice eaters become office workers and learn how to spice their rice with more varied flavors, the deadly nature of rice may be revealed.

Stephan Guyenet writes that “Food Reward [is] Approaching a Scientific Consensus.” It certainly seems so; it is emerging as a catch-all explanation for everything, a perspective that can be trotted out in a few concluding sentences to reconcile a hypothesis (white rice causes diabetes) with data that contradict it.

Conclusion

To me, the HSPH white rice study doesn’t look like science. It looks like gaming of the grant process – generating surprising and disturbing results that seem to warrant further study, even if the researchers themselves know the results are most likely false.

Consensus or no – and consensus in science isn’t necessarily a sign of truth (hat tip: FrankG) – the food reward perspective seems to me an incomplete explanation for what is going on. It puts a lot of weight on a transition from highly palatable (Thai, Japanese, Chinese) food to “hyperpalatable” (American, junk) food as an explanation for obesity and diabetes. It seems to me that the lack of nutrients and abundance of toxins in the junk food may be just as important as its “hyperpalatability.” It’s the inability of the junk food to satisfy that is the problem, not its palatability.

I’m glad that the food reward perspective may start being tested against Asian experiences. That may shed a lot of light on these issues.

Food Fortification: A Risky Experiment?

We’ve learned enough in the last two years to revisit the supplementation advice from our book, and toward that end I am starting a series on micronutrients.

I’ve recently been looking at some papers studying the effects of food fortification with micronutrients. These changes provide a sort of “natural experiment” which may provide insight into the benefits and risks of supplementation.

Fortification of Food

Grain products are the most important category of fortified foods. Industrially produced baked goods must generally use enriched flour, and Wikipedia (“Enriched Flour”) tells us what they’re enriched with:

According to the FDA, a pound of enriched flour must have the following quantities of nutrients to qualify: 2.9 milligrams of thiamin, 1.8 milligrams of riboflavin, 24 milligrams of niacin, 0.7 milligrams of folic acid, and 20 milligrams of iron.

This is an ironic choice of nutrients. While thiamin and riboflavin are harmless, niacin, folic acid, and iron are three micronutrients we recommend NOT supplementing in the book. Another nutrient we recommend NOT supplementing, vitamin A, is also a fortified nutrient, although not in flour.

Sales Cartoon #6021 by Andertoons

Perhaps not even for that!

A history of nutrient fortification over time can be found at this USDA site. Enrichment has a long history, but the amount of fortification has increased substantially since the 1960s. Enrichment mixtures were added to rice, cornmeal/grits, and margarine beginning in 1969, and to ready-to-eat cereals, flour, and semolina beginning in 1973. Inclusion of high levels of folic acid in all enriched foods became mandatory in 1998.

You may have noticed that when putting raw rice in water, a white powder comes off the rice. This is the enrichment mixture which contains folic acid. According to the American Rice Company (hat tip: Matthew Dalby),

The enrichment mixture is applied to rice as a coating. Therefore, it is recommended that rice not be rinsed before or after cooking and not be cooked in excessive amounts of water and then drained. The enrichment … would be lost.

This is useful information: We can remove the enrichment coating by rinsing rice before cooking. That may turn out to be a good idea!

The Contribution of Fortification to Nutrient Intake

Using USDA data for the four nutrients most likely to be harmful in excess, I made up a chart of the contribution of fortified nutrients to total nutrient intake among Americans. It looks like this:

You can see sharp rises in fortified niacin and folic acid in 1973, in iron in 1983, and again in folic acid in 1998. By 1998, folic acid in fortified foods constituted 44% of all dietary folate, and enrichment mixtures provided one-third of all iron and niacin. Fortified vitamin A provided about 10% of all dietary vitamin A from 1964 through 2000.

Folic Acid

Here is a chart of per capita daily intake of fortified folic acid plus natural food folate in the United States since 1950:

Folate intake from foods has always been around 300 mcg per day, and jumped sharply when folic acid intake became mandatory in 1998. The USDA estimates that intake of folate, including folic acid, jumped from 372 mcg per person per day in 1997 to 678 mcg in 1998, and has remained above 665 mcg ever since (source).

For those who eat a lot of wheat products, intake may be even higher. A pound of enriched white flour has 770 mcg folic acid along with its 1660 calories. If Americans were getting 372 mcg folate from food prior to folic acid fortification, then someone eating a pound of enriched wheat products per day would be getting about 1,142 mcg folate from all food sources.

It’s not uncommon to eat substantial amounts of enriched wheat. The typical American eats 474 g (1800 calories) carbohydrate per day. Most of that is from enriched grains. Those eating industrially produced breads, cookies, crackers, and breakfast cereals may have a very high folic acid intake.

Add in a multivitamin – most multivitamins have 400 mcg and prenatal vitamins have 800 mcg – and a sizable fraction of the population has a folate intake of 1,500 to 1,900 mcg per day, 1200 to 1600 of it as synthetic folic acid. This is well above the tolerable upper limit (UL) for folic acid of 1000 mcg (Wikipedia, “Folate”).

Averaged over all Americans, folic acid from fortified foods comprises 44% of all food-sourced folate, but for Americans taking a multivitamin folic acid becomes 65% of all folate and, for those taking a prenatal vitamin, 75%.

There are several potential health problems that could arise from excessive intake of folic acid, and I’ll explore a few in this series.

Iron and Niacin

Iron intake has risen by about 50% due to fortification:

Niacin intake has also risen about 50%:

These two nutrients have similar concerns:

  • An excess of each promotes infections. Niacin (in the NAD+ form) is the rate-limiting factor in bacterial metabolism. Iron is a critical mineral for oxygen handling and is needed by most infectious pathogens; in fact the immune response tries to lock up iron in ferritin during infections.
  • Both niacin and iron are involved in oxygen handling during metabolism and an excess of each can aggravate oxidative stress.

Vitamin A

Although fortification never increased vitamin A intake by more than 10%, it may serve as a marker for consumption of artificial sources of vitamin A from supplements. Moreover, total food intake of vitamin A was apparently affected by fortification; food intake of vitamin A rises in the 1960s when fortification was growing, and falls after 2000 when intake of fortified vitamin A decreased:

In the book we noted studies showing that people whose intake of vitamin A was above 10,000 IU/day tended to have higher mortality. This was most commonly observed in people taking multivitamins.

There was a period of enthusiasm for vitamin A supplementation between the 1960s and 2000. Multivitamins had more vitamin A in that period. After studies showed negative results, the vitamin A content of multivitamins was reduced.

It is possible that the source of problems may not be vitamin A per se, but degradation products of vitamin A. I’ve previously blogged about how vitamin A plus DHA (a fatty acid in fish oil) plus oxidative stress can produce highly toxic degradation products (see DHA and Angiogenesis: The Bottom Line, May 4, 2011; Omega-3s, Angiogenesis and Cancer: Part II, Apr 29, 2011; Omega-3 Fats, Angiogenesis, and Cancer: Part I, Apr 26, 2011).

Naturally occurring vitamin A in foods is located in lipid fractions and protected from oxidation by accompanying antioxidants (eg vitamin E) and oxidation-resistant lipids. Vitamin A from fortification is not so carefully protected. The Food and Agriculture Organization of the United Nations comments:

Foods which have been successfully fortified with vitamin A include margarine, fats and oils, milk, sugar, cereals, and instant noodles with spice mix. Moisture contents in excess of about 7-8% in a food are known to adversely affect the stability of vitamin A. Beyond the critical moisture content there is a rapid increase in water activity which permits various deteriorative reactions to occur. Repeated heating, as may be experienced with vegetable oils used for frying, is known to significantly degrade vitamin A. The hygroscopic nature of salt has prevented its use as a vehicle for vitamin A fortification in countries of high humidity. In trying overcome this problem, a new vitamin A fortificant, encapsulated to provide an additional moisture barrier, was evaluated with limited success. The cost of using highly protected fortificants can be prohibitive in many cases.

There aren’t many foods that don’t contain 7% water, or acquire it after fortification, so degradation is a real concern.

Vitamin A in multivitamins may also be exposed to degradation. The possibility of vitamin A degradation, especially in combination with DHA from fish oil and oxidative stress, is why I’m skeptical of the health merits of fermented cod liver oil.

Conclusion

I think exploring the effects of fortification will be an interesting topic.

We will consider whether fortification may play a role in various diseases that have become more common since 1970 or 1998, such as obesity, diabetes, and autism.

And we will consider what the health effects of food fortification may tell us about how to optimize micronutrient supplementation.

 

PaleoFX

PaleoFX was a terrific meeting. It’s not easy to stage such a large event. Kudos to Michelle and Keith Norris, Kevin Cottrell, and the 100 volunteers who worked so hard to make it a success. Jack Kruse in his keynote speech talked of “paying it forward,” and the volunteers and organizers certainly did that.

Jack is a better speaker than writer, and I enjoyed the talk. He recounted a story of a woman he met as a surgical resident. She had an inoperable cancer; Jack closed the incision in the operating room, and she lived for another six months. She willed her wine collection to Jack, and each day before she died she took a single bottle from each case to the beach and wrote a letter to Jack explaining its provenance and what it meant to her. The package of letters came along with the wine after her death, and in a note she mentioned the story of the Old Man and the Starfish, and told Jack, “You are my starfish.” She advised him to withdraw from the rat race and enjoy life, as she had in her final six months. Jack didn’t pay much heed to that advice until 2006. Then, after reflection and perhaps some cold thermogenesis, he realized that he ought to “pay it forward” by working “transformational change.” At this point he pulled out what he said was a stick of dynamite and a lighter:

He said that the dynamite could work transformational change on the University of Texas, and it was our obligation to go out in the world and work transformational change by converting others to Paleo.

Luckily the fire marshal was not present, or PaleoFX might have come to a premature end.

The next day began with a talk by CJ Hunt, producer of the documentary “In Search of the Perfect Human Diet.” CJ has a great personal story: he had a heart attack at age 24, but now in his 50s looks like a young and athletic man. Here is the trailer:

CJ can’t market the movie widely until after film festivals, so if you’re interested, the place to buy is through his web site.

Robb Wolf was next, and talked about how he made Norcal into such a successful gym. Robb is an outstanding businessman and his advice for gym operators was excellent.

Cooking demos were next. Check out Nom Nom Paleo for some great pictures of food and people.

Next was a panel I served on, “Ancestral Wellness Through the Decades.” I was impressed with Skyler Tanner, who came well prepared. Melissa Hartwig, Emily Talley, Dr Shilpi Mehta, and Jack Kruse all had good things to say and we covered a lot of ground.

More panels and talks by Mark Sisson and Ron Rosedale followed. The “Whole Foods vs Supplements” panel with Chris Kresser, Amy Kubal, Diana Rodgers, Liz Wolf, Diane Sanfilippo, Dr Dan Kalish, and Joe Johnson was excellent.

After the day was over we had an author book signing and then the audio-visual team recorded interviews with presenters.

The audio-visual team was really, really good: I understand it was the team that produces Anthony Johnson’s The 21 Convention. One of the A/V guys stayed up all night Thursday night putting together a video from the first day’s action, and it was played first thing Friday and was really professionally done. Quite impressive. A DVD of the conference will go on sale in about 60 days, and I’m sure it will be outstanding.

We finally got back to our hotel at 11 pm, our only food having been some chipotle chicken for lunch. Chris Kresser, Dan Pardi, and I went to a Pappadeaux restaurant for some baked potatoes.

Friday, after the video, began with an open Q&A panel: “Ask the Paleo Experts.” The biggest fireworks came with a “safe starches” question, directly specifically to Jack Kruse and myself. Jack has been arguing that one shouldn’t eat any carbs in the winter – here is Jack on the subject of eating a banana in winter:

Only humans who fail to listen to evolutions rule book of engagement die. You can eat a banana in the winter and feel fine but Mother Nature says it’s impossible………therefore we ought not to do it. I will follow her lead over a diet book guru or the opinions of a bunch of people who let their thoughts subjugate their genes. Feelings and thoughts do not trump neural biochemistry …

Jack turned to me and said something like “I’d like Paul to explain why, if Neuropeptide Y is downregulated in cold weather, it can be safe to eat starches.” My answer was that we are warm-blooded mammals and maintain a constant body temperature so that our basic biochemistry, including the ability to digest and utilize glucose, works no matter what the outside temperature. Ron Rosedale, Nora Gedgaudas, and Emily Deans added to the discussion. Here’s a photo of half the panel, from Bryan Lambeth:

From the left are Emily Deans, David Pendergrass, Keith Norris, Lane Sebring, and myself. Offcamera were Jack Kruse, Ron Rosedale, Nora Gedgaudas, Dean Dwyer, and Dallas Hartwig.

After the panel came my talk. It was my “fitness” talk and covered “Some Overlooked Factors in Fitness.” One of the topics I covered was body composition. After the talk I had a long chat with Jimmy Moore about how eating some carbs can improve body composition and facilitate weight loss. He said it was starting to make sense to him. Today he tweeted:

Wouldn’t it be funny if I actually started eating rice again? Stay tuned. @pauljaminet #safestarches

Who knows, maybe we’ll revive the PHD weight loss experiment Jimmy and I talked about last fall. Stay tuned!

While all these talks and panels were going on upstairs, there was a continuous string of Strength and Movement sessions on the first floor. I didn’t have enough time for those, but I did make time for a 15-minute mashing session from Kate Catlow of the Mindful Body Center. Great!

I spent most of Friday chatting to people. The great value of conferences like this is the opportunity to meet others in the Paleo community and to look for ways we can cooperate to achieve good things. I even got a head start on this: Nora Gedgaudas sat next to me in our flight into Austin. In her review of the conference, Emily Deans mentioned a few things under discussion:

I drove with Paul Jaminet in the car and we talked about his upcoming plans, Shou-Ching’s research, and his work with Aaron Blaisdell to help with publishing an Ancestral Health academic journal, all very exciting stuff.

Nothing is settled yet but there will probably be a few initiatives to report in coming months.

I think PaleoFX planted a few seeds that may grow into bigger things. Many thanks to the organizers and volunteers who made it all possible! I hope that a good time was had by all.

Around the Web; PaleoFX Edition

I’ll be speaking and sitting on two panels at the Paleo(fx) conference this week, Wednesday-Friday in Austin, Texas. The meeting has a great lineup of speakers and I’m looking forward to meeting a lot of interesting people there. If you’re there, be sure to introduce yourself!

[1] Music to Read By: Glen Campbell has Alzheimer’s, and is doing a farewell tour. His final concert will be June 30 in Bayfield, Wisconsin. Here is “Wichita Lineman”:

And “Rhinestone Cowboy”:

[2] Interesting posts this week:

My favorite post of the week: Emily Deans reports on the Pathogen Host Defense theory of depression. Depression is part of the immune response to infection: it is how the immune system gets us to rest and avoid other people so as to keep the infection from spreading. The supporting evidence: every genetic allele known to increase the incidence of depression, also increases immunity to infectious disease. Moral of the story: if you’re depressed, find and treat your infections.

Bix discusses the role of histamine in depression. Antihistamines relieve depression. Of course, they may also inhibit the immune system from fighting an infection.

Kamal Patel has a new website on pain management, paindatabase.com; he opens with an excellent discussion of nightshades. Peter Frost notes that redheads are more sensitive to pain.

Dr. Steve Parker reviews the classic study in which diabetic Australian aborigines were returned to their ancestral lifestyle.

Angelique Corthals presents an offbeat theory of multiple sclerosis. Another offbeat theory: Via Melissa McEwen, a paper argues that Crohn’s may result from bacteria which survive in refrigerators.

Chris Kresser discusses folic acid dangers, a topic I’ve recently done some thinking about.

Allan Balliet has a podcast interview with Dr Thomas Cowan, author of The Fourfold Path to Healing: Working with the Laws of Nutrition, Therapeutics, Movement and Meditation in the Art of Medicine.

Tony Federico was able to fix his cholesterol by adding carbs. CarbSane finds she sleeps better on 100g per day starches (PHD proportions) than she did on VLC. Cameron also had trouble on VLC.

Serum IL-6 levels predict mortality and disability. IL-6 is part of the immune response to many infections.

An 87-year-old billionaire aims to live to 125. He eats a lot of fruit and vegetable smoothies.

Parvovirus B19 is present in the thyroid glands of 90% of Hashimoto’s patients.

Stephan Guyenet got some nice exposure at Boing Boing, talking about how the cafeteria diet seduces rats. Matt Metzgar’s personal experiments are supportive of Stephan’s view.

Sean at PragueStepChild has a terrific post pointing out the flawed logic underlying a new “food reward in a pill” drug.

Seth Roberts warns that supplement quality can vary widely.

Apparently Dr Steve Phinney thinks the best fat is a mix of butter, olive oil, and canola oil. I think it’s possible to do better.

The Daily Mail reports that passing weak electric currents through the brain can lift patients out of depression for up to six weeks.

Via Dave Asprey, an “M2A” (mouth to anus) capsule enables photography of the intestine. He’s got video. Dave also has a rapid fat loss protocol: a diet of coffee, butter, and supplements. I prefer our Food for a Fast.

Warning: Dr Clark says that coffee is bad for people with gluten sensitivity, due to cross-reactive antibodies.

Dr Mercola defends free speech, and objects to an FDA assertion that walnuts are drugs. Yahoo reports that the United States Department of Agriculture (USDA) is buying 7 million pounds of “pink slime” beef for the school lunch program.

I didn’t know this: “In healthy individuals, blood sugar rises to ~135 mg/dL after 15 minutes of vigorous exercise…. In Type 1 diabetics, the same intensity and duration of exercise produced blood sugars that exceeded 150 mg/dL in spite of continuous insulin infusion.” (from Sam Knox)

Via PaleoHacks, how a pig gets divided up into meats.

Matthew Green satirizes Paleo.

Finally, Apple came out with a new product last week, and Yoni Freedhoff has the marketing video:

[3] Cute animal:

Via Yves Smith.

[4] Meet Ray Audette: The author of NeanderThin: Eat Like a Caveman to Achieve a Lean, Strong, Healthy Body and one of the pioneers of Paleo:

[5] Not the weekly video: Dr. Mark Cucuzzella offers “The Principles of Natural Running”:

[6] Shou-Ching’s Photo Art:

[7] Weekly Video: Ever wondered what auroras look like from space?

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