Category Archives: Food - Page 2

The Healthfulness of Eggs

Posted by on November 12, 2013 95 comments

Our book has 199 reviews at Amazon.com, and almost 80% of them are 5-star reviews, for which we thank you. But once in a while we get a 1-star review, usually from a vegan. Recently we got a 1-star review from someone named “Victor” which actually cited two papers:

This book recommends eating red meat, white rice, and eggs? Ridiculous. These aren’t healthy foods. They aren’t good for your body.

Red meat and eggs both promote colon cancer. White rice has a terribly high glycemic load and glycemic index, which can increase the risk of getting diabetes.

Evidence:

“Egg consumption and mortality from colon and rectal cancers: an ecological study.”

“Red Meat-Derived Heterocyclic Amines Increase Risk of Colon Cancer: A Population-Based Case-Control Study”

Look up other research studies that support these two. They all go hand in hand.

You can deny the evidence however much you want, but the truth is that red meat, white rice, eggs (as well as dairy products) will NOT promote your health.

Odd: I expect a critic who objects to red meat, eggs, and dairy to be a vegan, but Victor objects to rice too. One wonders what foods Victor doesn’t object to, and whether he manages to eat at all. (UPDATE: Victor is a vegan.)

His objection to red meat is irrelevant to PHD, since heterocyclic amines form at temperatures above 400˚F which do not occur in the gentle cooking methods we advocate. Indeed, our book explicitly warns against cooking methods that generate HCAs on page 234. It’s pretty easy to avoid these cooking methods, because they char meat. Indeed, the study Victor cites is based on a food survey called CHARRED. [1]

The “red meat” category in epidemiological studies includes not only beef and lamb, but pork and processed meats. Industrial foods like processed meats have their own problems which we warn about in our book, and undercooked pork can carry dangerous infections which we also warn about in the book and on this blog.

But none of those caveats touch gently cooked beef or lamb. All the evidence indicates that these are thoroughly healthful foods.

Victor objects to rice because of its high glycemic index, an issue which we’ve addressed in the book and on this blog in the safe starches debate and my post on how to avoid hyperglycemic toxicity.

Which brings us to Victor’s bête noire, eggs. I was curious, so I looked up the study Victor cited linking eggs to colon cancer. [2]

An Association at the Country Level Between Egg Consumption and Colon Cancer

This turns out to be quite a simple paper; the research in it could have been done in a day or two. They gathered some data from two online sources: the Food and Agriculture Organization of the United Nations, which has food consumption data for countries, and the World Health Organization, which has health statistics by country. Then they made some scatter plots in Excel, and found an association between eggs and colon cancer. Here it is:

eggs 1

For some reason they included only 34 countries; the FAO and the WHO gather data from nearly every country on earth. They stated, “The selection of the countries was based primarily on the availability of relatively reliable data on mortality from colon and rectal cancers and consumption of eggs, other food groups or nutrients, and cigarettes.” (The “other food groups and cigarettes” – fat, meat, vegetable, fruit, alcohol, and cigarette consumption – were used as adjustment variables in a regression analysis.)

Now, country-level ecological studies have a poor reputation in nutritional epidemiology. One reason is that there are many confounding variables. Foremost among them is income. Health outcomes are strongly dependent on income, with high-income countries eating more animal foods and living longer. But do people live longer because of what they eat, or because they are richer?

Then, when we look at a disease like colon cancer, what we find is that the healthier and longer-lived the country, the more colon cancer cases it has. Cancer is a disease of the elderly, and in societies where people die young, there are few cancer deaths. On the other hand, if some magical food were invented that cured cardiovascular disease, then in countries where that food was eaten cancer would be the leading cause of death. In such a case, we would find consumption of that food to be positively associated with colon cancer rates, even though the food made everyone healthier.

So before one takes an ecological association like the one noted in this paper seriously, it is good to step back and look at the big picture.

As it happens, I have FAO and WHO data in an Excel spreadsheet, so it didn’t take long to make a few charts.

Eggs and Mortality or Life Expectancy

I used 2003-4 data which gave me data from 164 countries for both egg consumption and health outcomes.

Here is the relation between egg consumption and adult mortality. (“Adult mortality” means the probability of dying between ages 15 and 64 per 1000 people.)

eggs 2

There is a clear correlation: more eggs, lower mortality.

Here is the association between egg consumption and life expectancy:

eggs 3

Again, there is a clear correlation: the more eggs a country consumes, the longer its people live. Note that the country with the highest egg consumption, Japan which obtains fully 2.71% of energy from eggs, has the longest life expectancy.

What about the association between eggs and cancer? Here it is, with cancer mortality standardized by age:

eggs 4

Eyeballing it, there seems to be no correlation at all. I’ve had Excel calculate a linear fit here, and it turns out cancer mortality actually seems to decline very slightly as egg consumption increases.

If eggs are associated with lower mortality and longer lifespans, but have no effect on cancer, then you’d expect them to be associated with lower rates of cardiovascular disease mortality. So they are:

eggs 5

Countries with low egg consumption have CVD mortality about double that of countries with high egg consumption.

I was curious if reducing the sample from the full set of 163 countries to the 34 used in the paper would alter the data. It does. Here is cancer mortality plotted against egg consumption for the 34 countries included in the paper Victor cited:

eggs 6

In this subset of countries the correlation of egg consumption with cancer mortality is reversed and becomes positive. It looks like the paper chose its countries well, if its goal was to show a negative effect from egg consumption.

Eggs Are a Health Food

One lesson this exercise teaches is that if you look at population-level data for associations, restrict your sample of countries to a subset of the available data, and restrict the health outcome you analyze to a small fraction of the causes of death, you can make any food, including eggs, look bad.

But if one looks at total mortality or life expectancy, eggs seem to be quite a healthful food. Higher egg consumption correlates with lower mortality and longer lifespan. The country in the world with the highest egg consumption, Japan, has the longest lifespans.

Is it plausible that eggs extend lifespan by reducing cardiovascular disease mortality? Yes! Eggs are along with liver the best food source of choline, and choline is a critical nutrient for vascular and metabolic health. Chapter 35 of our book discusses this nutrient.

Is it plausible that eggs promote colon cancer? Not really. There has not to my knowledge been proposed any plausible mechanism by which eggs promote cancer generally or colon cancer specifically.

Since eggs are strongly correlated with lower cardiovascular mortality and plausible causal mechanisms are known, while eggs are correlated with zero change or perhaps a slight reduction in cancer mortality and there is no known mechanism tying them to cancer risk, we should regard eggs as a health food.

To assure adequate choline intake, PHD recommends eating 3 egg yolks per day. They are one of our “supplemental foods” that should be eaten routinely.

Conclusion

Victor seems to have fallen for a rookie mistake: taking associations too seriously.

Positive associations with diseases exist for every food. Consider what would happen if you took a variable totally unconnected to health – say, the mean number of stars above a certain brightness in a country’s night sky – and looked for associations with national health outcomes. Simply by chance, some diseases would show a positive association and some would show a negative correlation. If you only publish the positive associations, you can scare naïve readers into thinking that starlight causes assorted diseases.

And if you repeat the exercise for foods, you could scare naïve readers into avoiding every single food in existence, as Victor has eschewed beef, lamb, eggs, and rice.

Pubmed is a large database, with over 22 million articles. Not all of these articles represent careful work that seeks to establish a robust truth. Many articles are published “for practice,” even if they have nothing useful to say. Graduate students have to learn how to run regression analyses, write papers, and get them published; even senior academics may be rewarded for publishing weak or pointless papers. We shouldn’t let them scare us into a needlessly restricted diet.

References

[1] Helmus DS et al. Red Meat-Derived Heterocyclic Amines Increase Risk of Colon Cancer: A Population-Based Case-Control Study. Nutr Cancer. 2013 Oct 29. [Epub ahead of print] http://pmid.us/24168237.

[2] Zhang J et al. Egg consumption and mortality from colon and rectal cancers: an ecological study. Nutr Cancer. 2003;46(2):158-65. http://pmid.us/14690791.

Coconut Fish Pie

Posted by on April 14, 2013 36 comments

Louise Yang and Jeremy Hendon blog at Ancestral Chef, and I had the pleasure of talking with them at PaleoFX. They share a lot in common with Shou-Ching and I; you can read about Louise’s eclectic background here. Like us, they combine busy professional lives with a love of food, and try to create simple and easy to prepare but delicious meals drawing upon all the world’s cuisines. Louise has also defended the honor of the potato, which endears her to us. Louise has kindly agreed to share one of her favorite recipes. Here’s Louise!

achef cfp 1

Growing up in England, I was destined to love pies. 

For those of you who haven’t visited England or Australia, when I say “pies,” I don’t mean the typical American dessert pie (although I have to admit a fondness for gooey apple pies); I mean the savory pies filled with delicious meats and with sauces oozing out from their starchy coverings.

From steak and kidney pies, to cottage pies, to shepherd’s pies – there’s pretty much a pie for every food you can imagine!

Well, I didn’t want being Paleo/PHD to distract me from my obvious pie-eating destiny, and so the coconut fish pie was born.

Note: The full ingredients list and instructions are at the end.

Preparing Coconut Fish Pie

Start by boiling 3 or 4 sweet potatoes (or potatoes) until they’re tender (check by pushing a fork into them).  You can speed up the process by peeling and chopping the sweet potatoes (or potatoes) and then boiling them. 

achef cfp 2

Blend the peeled sweet potatoes (or potatoes) in your food processor with 2 tablespoons coconut oil and 1/4 cup coconut milk until it turns into a nice mash.  Put the mash aside while you make the rest of the pie.

Boil 3 eggs, and preheat the oven to 350F (175C).

Chop up 1 cup of carrots.

achef cfp 2b

Chop up ½ cup of green beans.

achef cfp 2c

And chop up 1 leek (approx. 1 cup).

achef cfp 2d

Pour the rest of the 1 can (13.5oz or 400ml) of coconut milk (i.e., what you didn’t use for the mash) into a saucepan and heat on medium heat.  Add in the chopped vegetables.

achef cfp 3

While the vegetables are cooking, cut approx. 1.5 lbs of white fish (I used tilapia) into 1-inch cubes/chunks (you can also substitute some prawns or scallops for the fish).

achef cfp 4

Place the fish into the saucepan as well.

achef cfp 5

Grate 2 teaspoons of fresh ginger into the pot (tip: store ginger in the freezer and grate some into your dishes when needed).  Add salt and pepper to taste.

achef cfp 5b

Cook for 5 more minutes on medium heat and then pour into an 8 by 8 pyrex oven dish or else into several small ramekins or miniature casserole dishes (4-8 depending on how large the ramekins are).

achef cfp 6

achef cfp 6b

Peel the hard boiled eggs, and cut them into small pieces and place them into the dish as well.

achef cfp 6c

Gently spread the sweet potato (or potato) mash over the top of the fish mixture so that the entire mixture is covered (it doesn’t need to be a thick layer).  If the fish mixture has too much liquid, then spoon some of the liquid out.

achef cfp 7

As an optional topping to make the pie just a bit prettier, mix 4 tablespoons of coconut flakes with 2 tablespoons of melted butter (omit this if you’re dairy-free).

achef cfp 8

Gently sprinkle the coconut flakes mixture over the top of the mash.

achef cfp 9

Bake in the oven for 20 minutes (you’ll see the sauce boiling and the coconut flakes will get a bit toasted).  Leave to cool for a few minutes and serve!

achef cfp 9b

Fish Pie Recipe

Makes 4-6 servings  Preparation Time: 40 minutes  Cooking Time: 20 minutes

Ingredients:

Topping:

  • 3-4 medium sized sweet potatoes (or potatoes)
  • 2 tablespoons coconut oil
  • 1/4 cup coconut milk (leave the rest of can of coconut milk for the fish mixture).
  • 1/4 cup coconut flakes and 2 tablespoons melted butter (optional topping)

Fish Mixture:

  • 1.5 lb white fish (or prawns or scallops), cut into small 1-inch chunks
  • Rest of 1 can (13.5 oz or 400ml) coconut milk
  • 1 cup carrots, chopped
  • ½ cup green beans, chopped
  • 1 leek (1 cup), chopped
  • 2 teaspoons fresh ginger, grated
  • Salt and pepper to taste
  • 3 hard boiled eggs, chopped

Instructions:

  1. Boil the sweet potatoes (or potatoes) until they are soft (you can peel and chop them up if you want them to cook faster).  Food process with 2 tablespoons of coconut oil and ¼ cup of coconut milk.
  2. Hard boil 3 eggs.
  3. Pre-heat oven to 350F.
  4. Heat the rest of the can of coconut milk in a saucepan on medium heat.  When it starts boiling, add the chopped carrots, leek, and green beans.
  5. Cut up the fish into 1-inch cubes/chunks and add to the saucepan.
  6. Grate some fresh ginger into the saucepan and season with salt and pepper to taste.  Cook for 5 more minutes.
  7. Spoon the fish mixture into an 8 by 8 inch pyrex oven dish or into individual ramekins (4-8 depending on ramekin size).
  8. Peel and chop up the hard boiled eggs and drop them into the fish mixture.
  9. Spread the mash over the top of the fish mixture.
  10. For the optional topping, melt 2 tablespoons of butter and mix in 1/4 cup of coconut flakes.  Sprinkle the coconut flakes mixture over the top of the sweet potato mash.
  11. Place in oven for approx. 20-25 minutes.  Make sure after 20 minutes that the coconut flakes are not turning too brown.

 

Leg of Lamb with Cinnamon-Thyme-Fennel Rub

Posted by on April 7, 2013 17 comments

This was our Easter dinner. As you’ll see, the idea was stolen from Gordon Ramsay with few changes; it came out great.

Preparation

Begin with a 4-5 pound (2 kg) boneless leg of lamb. Drive a narrow but sharp knife into the lamb, twirling it to carve out cylindrical holes. Make 3 or 4 holes and into each place a cinnamon stick and a sprig of thyme. (This is illustrated in Ramsay’s video below.)

Here’s a picture of the cinnamon sticks and thyme sprigs that we used, plus some vegetables, seasoning, and honey that we’ll use later:

Next, mix some dry seasonings for a rub. We used:

  • 1 tsp fennel seed
  • 1 tsp smoked paprika
  • ½ tsp cayenne pepper
  • ½ tsp cinnamon
  • ½ tsp allspice
  • ½ tsp turmeric
  • ½ tsp cloves

Coat the lamb in the rub. Don’t worry if you don’t have all of these seasonings; use whatever assortment you like. We do recommend including the smoked paprika and allspice.

By the way, over the past few years we bought a number of disposable pepper grinders that contained whole peppercorns, and gathered a collection of empty grinders. Recently we began buying spices as whole seeds and storing them in the grinders, grinding the spices fresh as we need them. Freshly ground spices do taste better than pre-ground spices!

The next step is to prepare some vegetables – we used carrot, celery, and onion – and to sear the surface of the lamb on the stove so that the meat will retain moisture in the oven.

In previous recipe (“Roast Beef, Beets, and Potatoes,” April 8, 2012), we skipped the stovetop step. In that recipe, to seal the surface we pre-heated the oven to 400 F and after 10 minutes cooking reduced the heat to 300 F.

In Gordon Ramsay’s rendering (see video below), he sautées the vegetables with olive oil and honey before searing the lamb. The honey caramelizes, adding flavor.

We decided to take an intermediate approach that is more in line with our preference for gentle cooking. We briefly cooked the vegetables in olive oil at low heat on the stove, and added honey so as to coat the vegetables evenly.

Here were the vegetables on the stove, in the pyrex pan we used also in the oven:

After a few minutes we pushed the vegetables to the side of the pan and seared the lamb at medium heat, 1 minutes per side. After searing the seasoned lamb is ready for the oven, placed fatty side up:

We cooked at 300ºF (150ºC) for one hour. It came out like this:

Sliced, it looks like this:

We had space in the oven so we baked some potatoes and beets along with the lamb. They were placed in a cake pan that hasn’t been used for its original purpose in many years:

We’ve found it’s least messy to cook the beets first and peel them after cooking.

The final step was making a sauce to drizzle over the meat. This was composed of a simple mixture of:

  • Juice and zest from one lemon
  • 3 tbsp olive oil
  • 1 tsp mustard

Served on the plate, it looked like this:

Conclusion

Gordon Ramsay’s video offers a good view of the process:

It’s an easy dish to prepare, but quite delicious!

Shou-Ching’s Mom’s Kimchi

Posted by on March 21, 2013 93 comments

We previously offered a recipe for Homemade Kimchi (June 26, 2011). It is an excellent recipe, but Shou-Ching wanted to continue experimenting until she reproduced the flavor and texture of her mother’s kimchi that she loved as a child growing up in Korea.

She thinks she’s got it.

Health Benefits of Kimchi

But before we share the recipe, a few reasons to make kimchi. Kimchi has been reported to:

  • Reduce body weight and blood pressure in the overweight and obese. [1]
  • Inhibit autoimmune diseases such as atopic dermatitis [2]
  • Inhibit development of allergy. [3]
  • Have anticancer effects. [4]
  • Inhibit development of atherosclerosis. [5]
  • Have antimicrobial effects on some of the most common gut pathogens, including Listeria, Staphylococcus, Salmonella, Vibrio, and Enterobacter. [6]

Against those benefits, kimchi consumption has been associated with higher rates of stomach cancer [7], perhaps due to its high content of salt [8] or N-nitroso compounds [9].

Homemade kimchi is far superior to store-bought kimchi. To accelerate fermentation, commercial kimchis usually contain sugar, but this means they will go bad soon after exposure to oxygen. Homemade kimchi, without added sugar, can retain its freshness up to several weeks after it is first exposed to air. The mix of bacteria in homemade kimchi may be far more healthful.

Preparing the Kimchi

This version starts with one large head of Chinese or Napa cabbage and the following vegetables:

  • A daikon radish
  • An equal volume of carrots
  • Green onion
  • Garlic
  • Ginger

Set aside the cabbage for a bit. Shred the radish and carrots in a grater; mince the green onion, garlic, and ginger in a food processor. Add 3 tbsp chili powder:

Mix the vegetables thoroughly and add salt and fish sauce (optional, but we use 1 tbsp of a light fish sauce) to taste:

Cover these vegetables in plastic wrap, to start the fermentation off in the right direction, for a few hours while preparing the cabbage.

Cut the head of cabbage lengthwise in half, and then each half in quarters, all lengthwise:

Then chop along the other direction until the whole cabbage is reduced to bite size pieces.

Transfer the chopped cabbage to a bowl a handful at a time – a handful of cabbage, a teaspoon of salt; a handful of cabbage, a teaspoon of salt; continue transferring cabbage and salt until all the cabbage is in the bowl:

Put a weight on top of the cabbage to compress it and release water:

Wait two hours. Over this time the cabbage will shrink as it loses water:

After two hours, rinse the cabbage in fresh water and put it in a strainer. Take the cabbage in your hands and squeeze water out; then transfer the dehydrated cabbage to the other bowl with the mixed vegetables. Continue until all the cabbage has been transferred.

Mix the cabbage and the other vegetables thoroughly:

Taste the mixture to see if it needs more salt. Transfer everything to a container that can make an airtight seal for the fermentation process.

It is important to create an anaerobic environment, similar to that in the gut. This pyrex bowl with a plastic lid makes an airtight seal:

In case pressure should build up and break the seal, we enclosed the container in a plastic bag:

Leave the sealed container at room temperature in a dark place for four to seven days before opening. It should have a mildly sour (acidic) taste; that signifies the presence of lactic acid from lactic acid generating bacteria.

Serve:

Conclusion

Depending on how much water was squeezed out of the cabbage, the kimchi may be more or less watery. There’s nothing wrong with a watery ferment, but when more water is present, more salt may be needed to achieve an appropriately acidic ferment.

As time goes on, the kimchi will become increasingly sour. When the taste starts to become unpleasant, Koreans cook the kimchi into a soup, killing the bacteria. Some of the benefits of kimchi are retained if the kimchi is cooked. [3]

Although with live cultures anything is possible and a few people may experience digestive disturbances from eating kimchi, many more find that kimchi improves their digestive function. It is an excellent probiotic.

References

[1] Kim EK et al. Fermented kimchi reduces body weight and improves metabolic parameters in overweight and obese patients. Nutr Res. 2011 Jun;31(6):436-43. http://pmid.us/21745625.

[2] Won TJ et al. Therapeutic potential of Lactobacillus plantarum CJLP133 for house-dust mite-induced dermatitis in NC/Nga mice. Cell Immunol. 2012 May-Jun;277(1-2):49-57. http://pmid.us/22726349. Won TJ et al. Oral administration of Lactobacillus strains from Kimchi inhibits atopic dermatitis in NC/Nga mice. J Appl Microbiol. 2011 May;110(5):1195-202. http://pmid.us/21338447.

[3] Hong HJ et al. Differential suppression of heat-killed lactobacilli isolated from kimchi, a Korean traditional food, on airway hyper-responsiveness in mice. J Clin Immunol. 2010 May;30(3):449-58. http://pmid.us/20204477.

[4] Park KY et al. Kimchi and an active component, beta-sitosterol, reduce oncogenic H-Ras(v12)-induced DNA synthesis. J Med Food. 2003 Fall;6(3):151-6. http://pmid.us/14585179.

[5] Kim HJ et al. 3-(4′-hydroxyl-3′,5′-dimethoxyphenyl)propionic acid, an active principle of kimchi, inhibits development of atherosclerosis in rabbits. J Agric Food Chem. 2007 Dec 12;55(25):10486-92. http://pmid.us/18004805.

[6] Kim YS et al. Growth inhibitory effects of kimchi (Korean traditional fermented vegetable product) against Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus. J Food Prot. 2008 Feb;71(2):325-32. http://pmid.us/18326182. Sheo HJ, Seo YS. The antibacterial action of Chinese cabbage kimchi juice on Staphylococcus aureus, Salmonella enteritidis, Vibrio parahaemolyticus and Enterobacter cloacae. J Korean Soc Food Sci Nutr 2003, 32:1351-1356.  Hat tip Rafael Borneo, http://dietasaludperfecta.blogspot.com.ar/2013/03/kimchi-un-superalimento.html.

[7] Zhang YW et al. Effects of dietary factors and the NAT2 acetylator status on gastric cancer in Koreans. Int J Cancer. 2009 Jul 1;125(1):139-45. http://pmid.us/19350634. Nan HM et al. Kimchi and soybean pastes are risk factors of gastric cancer. World J Gastroenterol. 2005 Jun 7;11(21):3175-81. http://pmid.us/15929164.

[8] Lee SA et al. Effect of diet and Helicobacter pylori infection to the risk of early gastric cancer. J Epidemiol. 2003 May;13(3):162-8. http://pmid.us/12749604.

[9] Seel DJ et al. N-nitroso compounds in two nitrosated food products in southwest Korea. Food Chem Toxicol. 1994 Dec;32(12):1117-23. http://pmid.us/7813983.