Dear Readers,
Dr. Cordain was recently asked by a reporter from the journal Nature to comment on an article entitled "Mozambican Grass Seed Consumption During the Middle Stone Age" by Julio Mercader in the journal Science, citing evidence that humans consumed grain much earlier than was previously thought. In addition, one of our readers asked Dr. Cordain to comment on an article in Scientific American entitled "Humans feasting on grains for at least 100,000 years," by Katherine Harmon.
Dear Dr. Cordain,
I am a huge fan of your books and have been eating a paleo diet for years. I've had your graph of the land/water meat/fish, and fruit, nut, seed % breakdown taped to my fridge for years, although I'm so familiar with it that i no longer need to look at it for reference.
The Paleo Diet is predicated upon the fact that humans did not have grain cultivation and consumption until 5,000-8,000 years ago, which coincides with the advent of 'modern' civilization diseases. Up until now, this hypothesis have not been challenged as the archival evidence of grain agriculture matches it.
However, the current issue of Scientific American has an article stating archaeological evidence that humans were eating lots of grains 100,000 years ago.
http://www.scientificamerican.com/blog/post.cfm?id=humans-feasting-on-grains-for-at-le-2009-12-17
I am most curious about your opinion about this and how it effects the paleo dietary theory.
Thanks!
Dr. Cordain's response:
This is an interesting paper ( Mercader J. Mozambican grass seed consumption during the middle stone age. Science 2009;326:1680-83) as it may push probable (but clearly not definite) cereal grain consumption by hominins back to at least 105,000 years ago. Prior to this evidence, the earliest exploitation of wild cereal grains was reported by Piperno and colleagues at Ohalo II in Israel and dating to ~23,500 years ago (Nature 2004;430:670-73). As opposed to the Ohalo II data in which a large saddle stone was discovered with obvious repetitive grinding marks and embedded starch granules attributed to a variety of grains and seeds that were concurrently present with the artifact , the data from Ngalue is less convincing for the use of cereal grains as seasonal food. No associated intact grass seeds have been discovered in the cave at Ngalue, nor were anvil stones with repetitive grinding marks found. Hence, at best, the data suggests sporadic use (and not necessarily consumption) of grains at this early date. Clearly, large scale processing of sorghum for consumption for extended periods seems unlikely.
Further, It should be pointed out that consumption of wild grass seeds of any kind requires extensive technology and processing to yield a digestible and edible food that likely did not exist 105,000 years ago. Harvesting of wild grass seeds without some kind of technology (e.g. sickles and scythes [not present at this time]) is tedious and difficult at best. Additionally, containers of some sort (baskets [not present at this time], pottery [not present] or animal skin containers are needed to collect the tiny grains. Many grain species require flailing to separate the seed from the chaff and then further winnowing ([baskets not present]), or animal skins] to separate the seeds from the chaff. Intact grains are not digestible by humans unless they are first ground into a flour (which breaks down the cell walls), and then cooked (typically in water – e.g. boiling [technology not present]) or parched in a fire which gelatinizes the starch granules, and thereby makes them available for digestion and absorption. Because each and every one of these processing steps requires additional energy on the part of the gatherer, most contemporary hunter gatherers did not exploit grains except as starvation foods because they yielded such little energy relative to the energy obtained (optimal foraging theory).
If indeed the grinder/core axes with telltale starch granules were used to make flour from sorghum seeds, then the flour still had to be cooked to gelatinize the starch granules to make it digestible. In Neolithic peoples, grass seed flour most typically is mixed with water to make a paste (dough) that is then cooked into flat breads. It is highly unlikely that the technology or the behavioral sophistication existed 105,000 years ago to make flat breads. Whole grains can be parched intact in fires, but this process is less effective than making flour into a paste and cooking it to gelatinize the starch granules. Hence, it is difficult to reconcile the chain of events proposed by the authors (appearance of sorghum starch granules on cobbles or grinders = pounding or grinding of sorghum grains = consumption of sorghum). I wouldn’t hang my hat on this evidence indicating grains were necessarily consumed by hominins at this early date. To my mind, the Ohalo II data still represents the best earliest evidence for grain consumption by hominins.
Cordially,
Loren Cordain, Ph.D., Professor
Showing posts with label grains. Show all posts
Showing posts with label grains. Show all posts
Saturday, December 26, 2009
Tuesday, November 10, 2009
Paleo Diet Q & A - 11.10.09
Dear Readers,
Here are more Q & A from the Paleo Diet community. We're very encouraged by your responses to our posts so far, and our team is reviewing your questions left as comments here on the blog.
Thank you for your continued interest in The Paleo Diet.
Q: I am wondering your collective thoughts on grains that have been sprouted? Are these still a big no as well? My understanding has been that sprouted grains differ greatly than non-sprouted?
A: Yes, sprouted grains and beans are a much healthier option. When we 'sprout grains' we are allowing the seed to germinate and a shoot will emerge from the seed. This is the part that is cut off and eaten. Therefore, the seed itself is not actually consumed (as is the case with whole grains and wheat flours where the seed proteins and starches are milled and eaten). Since lectins are packaged along with the seed to protect against predation, once the seed sprouts, the lectin concentration diminishes within a couple days. In a week's time the sprouts should have no residual lectins.
Gliadin and glutenin are the dominate proteins located in the endosperm of the seed. The starchy endosperm is located alongside the embryo (germ) within the seed, and provides nutrients the embryo needs as it is sprouting and growing. Therefore, there should be no gliadin or glutenin proteins in the sprout, but rather primarily non-digestible cellulous (dietary fiber). One can consume sprouted grains and beans without fear of anti-nutrients. However, keep in mind that these are still nutritionally poor in terms of micronutrients. Leafy greens and other vegetables contribute high fiber AND a higher concentration of nutrients-grains are still 'nutritional lightweights'.
I would like to amend my earlier statement: We can consume GRAIN sprouts without fear of anti-nutrients. However, legume sprouts still appear to contain considerable concentrations of saponins--the secondary compounds responsible for increasing gut permeability. Alfalfa sprouts (which are actually in the pea family) have an especially high concentration.
Q: I am just starting on the Paleo Diet and have read the book The Paleo Diet. However, I do not find advice on combining foods. Can fruits, nuts, vegetables and meat be all eaten at the same meal, or should they be eaten at different times so that appropriate and efficient digestive processes can take place?
A: Usually Paleo Recipes would combine carbohydrates and proteins, such as a salad with turkey breast, however, we would recommend not mixing fruits with main meals as they sometimes produce bloating or indigestion because the sugars in fruits are not well digested when combined with either fats or protein. My advice is to listen to your body and see what happens when you eat fruit with protein or fats. If you don't experience bloating or indigestion, go ahead and eat fresh fruits for dessert.
Q: Is there a definitive test for leaky gut?
I am 64 years old and retired. I have lived in the central mountains of Colorado for the past seven years, and generally, in good health. I use a treadmill for walking in the winter with an occasional downhill ski day or snow shoe day. In the summer I hike and spend most of day outside around the house. I was glad to see your latest "Update" talks about people in their later years.
I have been on the Paleo Diet since 2004, each year getting closer to 100%. I stopped dairy except for once a month when a pint of B&J ice cream calls to me from the freezer. The grains were the last to go. A rye bread chicken sandwich for lunch was replaced with steamed fresh broccoli and chicken. Potato chips were finally replaced with pecans and almonds, but the table salt on all meals is still in my diet. I eat fresh fruit throughout the day. Supper was composed of tomatoes, celery, onions, potatoes, mushrooms, carrots, raisins, green peppers, spices and ground bison or chicken. I say was because I read a few weeks ago in The Paleo Diet Update about Leaky Gut, and realized the nightshade family of vegetables may not be good for me if I have a leaky gut.
I took a blood test about 17 years ago named the "ELISA/ACT". This tested the lymphocytes for their reaction to 235 purified foods, preservatives, and chemicals most commonly found in the American diet back in 1992. My results indicated a strong reaction to 11 items and an intermediate reaction to 13 items. I have avoided eating most these items since the test. My blood tests from the 9HealthFair for the last 5 years have been good. I had a colonoscopy 4 years ago which was good.
My questions are:
- I know there is a definitive blood test for Celiac disease, but is there a definitive test for a leaky gut? If the blood test I took 17 years ago indicated food molecules in my blood, then will I always have a Leaky Gut to these foods? i.e. If I stop these foods for 2 months or more will my gut stop leaking?
- If my blood tests results from the 9HealthFair were all in the normal range, then doesn't that indicate a Leaky Gut may not be present?
If you remove nutrients known to increase gut permeability, then the L:M test results will probably improve. However, if you've been following The Paleo Diet, then the L:M test should be OK.
Yes, if you eat The Paleo Diet, then the antibodies against those foods you tested for some time ago should decrease.
Q: Hi -- my husband was recently introduced to The Paleo Diet through his gym. He has lost over 40 pounds in just over 2 months and continues to lose weight even though he would have liked to level out a while ago. He is 6'1" and weighs 170 pounds and looks a little skeletal. What can he eat to help him level out and even gain a little weight back? Is there a web site that gives an example meal plan with desired calorie intake, or some tips you can give us to help prepare foods that will give him a little more fat?
I am unsure what to try besides having him eat avocados and lots of nuts, and drizzling olive and canola oils over his vegetables. All the websites we have gone through talk about the added benefit of weight loss achieved by this diet, but none that we have found so far tell you what to do to stop the weight loss once you have reached your desired weight. Thank you for your time!
A: If your husband is active he should emphasize a high glycemic load food post-workout, such as a recovery drink with glucose, bananas, grapes and Branched Chain Amino Acids (BCAA) with a dosage of 6-7 grams. This post-workout period lasts approximately 30 minutes, and is the best time to replenish your muscles with energy. Otherwise, his body will start to burn fat (and lose weight) in order to recover energy levels. He can also add a protein shake an hour and a half later, such as egg protein powder. The goal should be 1.2 grams/kg body weight.
Please keep us posted.
Please submit your comments and questions for the Paleo Diet team.
Paleo Diet Food Pyramid
Dear Readers,
Recently we received a question from a member of the Paleo Diet community asking whether there was a Paleo Diet food pyramid. Dr. Cordain published what he dubbed Humanity's Evolutionary Food Pyramid (aka The Paleo Diet Food Pyramid) in the inaugural edition of The Paleo Diet Update (Volume 1, Issue 1), originally published in February, 2005. The USDA food pyramid is also included in this post for reference.
The key recommendations Dr. Cordain suggested in his article from Volume 1, Issue 1 are:
- Avoid the several ounces of grains per day the USDA Dietary Guidelines recommend.
- Don’t buy into the diary industry’s well-financed and politically connected campaign to convince you that you need to drink milk.
- Increase your intake of omega 3 fatty acids.
- Eat more protein and less high glycemic load carbohydrates than are recommended by the USDA Dietary Guidelines.
Monday, November 9, 2009
Paleo Diet Q & A - 11.9.09
Dear Readers,We hope you're finding our Q&A posts from the Paleo Diet community to be useful and informative. We've received several new questions and comments on previous Q&A posts, and encourage you submit yours.
We receive a great amount of feedback, and we are not able to always answer personally. We do read all questions, and are very interested in hearing your thoughts and learning about your experiences with the Paleo Diet.
Q: Dr. Cordain, I was interested in your Sept. 25th issue because of long standing problems (since the early 1980's) with Chronic Fatigue Syndrome and also various bowel problems. I have been doing quite well for the last seven or so years (thought I am 70 now) thanks to the Paleo Diet, but am not fully recovered. With regard to your list of foods to avoid, I do avoid, completely, all those foods except pepper with capsaisin. Over the course of a week, I consume 2 teaspoons of cayenne pepper. I do this specifically to help with widespread inflammation as capsaisin in known for healing inflammation. I am alarmed now that something I am eating is actually working against my recovery and healing, but I can't understand why a product that reduces the inflammation connected with CFS and bowel disease would be contributing to those diseases. Perhaps you made this obvious in your report, and I simply didn't understand it. But if you could make it more clear to me, in layman's language, I would be very grateful.
Thank you.
A: Yes, capsaicin has anti-inflammatory properties. However, in case of irritable bowel syndrome, capsaicin is able to increase intestinal permeability and this condition can increase the activity of the immune system lining the gut, which means low grade chronic inflammation, despite capsaicin's anti-inflammatory properties. In other words, increased intestinal permeability (and hence inflammation) exceeds the anti-inflammatory capacity of capsaicin. If you didn't have irritable bowel syndrome capsaicin would be an anti-inflammatory nutrient. As you may know, increased intestinal permeability allows increased passage of gut bacteria and nutrient antigens into circulation, and this is associated to CFS (see reference list of the last newsletter).
On the other hand, in the case of intestinal irritability, we recommend the use of several supplements such as Probiotics (6-9 billions/day), Prebiotics (2-4 grams/day, L-glutamine (0,2grs/kg/day), Zinc (25mg/day), vitamin D3 (test your blood levels and be sure to be in the 50-70ng/ml range) and omega-3 fatty acids (4 grams a day at the beginning).
We hope this helps.
Q: I am a personal coach working with some clients on health issues. At a table discussion last week a colleague mentioned that amaranth and quinoa are exceptions in the general GRAIN category and therefore acceptable in the Paleo Diet. I think not, but would like your opinion.
A: You are correct. Quinoa and amaranth are grain-like crops with potential harmful substances namely saponins. Saponins have been demonstrated to increase intestinal permeability which is one of the factors contributing to many autoimmune diseases, as well as irritable bowel syndrome. So, we recommend to avoid quinoa and amaranth, specially if you suffer from an autoimmune disease.
Q: I am not a fan of the taste of shellfish or seafood. Can I still obtain the same benefits of this diet if I only eat the meat and not any of the suggested fish or seafood?
A: There are a lot of crucial substances for optimal health in fish and seafood such as omega-3 fatty acids, zinc, selenium, vitamin E, etc. So, if you can't eat it we suggest you to take some supplements, such as:
- Omega-3 fatty acids: EPA+DHA 3-4 grams a day
- Zinc 25mg a day
- Multivitamin/multimineral supplement
Thursday, November 5, 2009
Paleo Diet Q & A - 11.5.09
Dear Readers,
More Q & A from the Paleo Diet community:
Q: I believe in the Paleo Diet and want to introduce it into my lifestyle but I have a chronic renal condition (IgA nephropathy) which is still mild. Can I still follow this diet but eating moderate protein instead of high? Or do you have any other suggestions to how I can go about it? The doctors never advised me to restrict my protein intake but I have read many articles that says that restricting protein intake benefits renal disease sufferers.
A: Circumstantial data from the Inuit people, before westernization, suggests that they ate high protein diets for a lifetime, and likely had normal kidney function. The available human data suggests that the kidney responds to a higher protein diet by increasing the glomerular filtration rate (GFR). This response is not pathological, but rather a healthful response as the effective GFR remains constant as kidney mass increases. The analogy is like a muscle that responds to lifting more weight - it hypertrophies (gets larger) to adapt to the increased load.
Yes, people with pre-existing kidney disease will worsen on a higher protein diet. My recommendation for these people would be to reduce the glycemic load of their diet (e.g. get rid of most processed food) first and carefully monitor kidney function until it begins to improve. Ironically, it is likely a high glycemic load diet that worsens kidney function in the first place.
Q: I am not yet on the Paleo diet, though I would really like to be. I do not doubt the validity of the science or the biology that leads to the Paleolithic diet being so successful. However, living in the Western world means that just about everything has dairy and grains in it, along with unhealthy refined carbohydrates and trans fatty acids, therefore the most logical and reliable way to get a healthy Paleo diet is to buy the basic organic ingredients and make meals from them oneself.
Unfortunately, I don't know what the correct proportions of the food groups for a well-balanced Paleo diet are; i.e. how much fruit and vegetables compared with lean meat compared with nuts and seeds compared with fish, etc?
I also wanted to ask about the sorts of foods that should be eaten instead of grains and dairy. Although I am aware that calcium uptake is based on many factors besides just calcium intake, what is the source of calcium in the diet? Fish bones and the like? For grains, what should we eat instead for those meals: I know it has been said that vegetables of some kind (or fruit) should be eaten with every meal, but what does that make breakfast and lunch besides a pile of vegetables?
What else do we eat with them?
With this increase in fruit and veg consumption (about how many portions per day do you recommend?), how do we prevent ourselves getting massive diarrhoea? I personally had one point in my life where I was eating over 30 portions of fruit and five portions of veg per day. Is this too much, perhaps even to the point of being unhealthy?
Furthermore, with this increase in meat and seafood consumption, even with the reduction in grain and dairy production, will not an increased percentage of Paleo dieters hasten the trends of soil erosion and landscape damage due to the increase quantity of land required for farming to feed people?
Finally, with increased individual meat consumption, would not the risk of things like gout increase? Would it not at least potentially be risking the same health problems and complications of the Atkin's Diet?
Thank you for your help.
A: Regarding the optimal proportion of fruits, vegetables, lean meats and seafood there's not a consensus. Some studies made by Dr. Cordain et al. have shown plant to animal ratio ranges from 35:65 to 65:35 percent. This depends on latitude, season, climate, culture, etc. However, all ancestral diets shared key characteristics. Food sources were limited to unprocessed plants for ages, and unprocessed land and marine animals hunted from the proximate environment. We believe that the most common pattern was 30-35% protein (40% is the toxic ceiling), 30% fats and 40% carbohidrates. This means that lunch and dinner are based on lean meats or seafood and vegetables. Breakfast could be an opportunity to eat fruits, nuts, eggs or even vegetables and protein (turkey breast), see our newsletter v5_#39. Fruits and nuts are good options for snacks.
Grains and dairy are nutritionally poor when compared to fruits, vegetables, seafood and lean meats. So, grains and dairy have no natural substitute. Milk and grains are usually eaten with breakfast, and I've provided some ideas for breakfast. In our published research section on our website you can download Dr. Cordain's scientific paper regarding grains titled: Cereal grains: humanity's double edged sword.
Broccoli, cauliflower, kale and all green leaves are good calcium sources without the problematic issues that dairy has: they increase metabolic acidity which leads to bone calcium loss.
Yes, too much fruit consumption is not the healthiest choice. High fructose intake is related to many metabolic diseases, especially obesity. Diarrhea is usually associated to fructose intolerance.
So, one doesn't have to precisely count caloric intake from protein, fats and carbohydrates as long as you combine seafood and lean meats with vegetables in meals and use fruits and nuts as breakfast and snack options.
Regarding gout: gout is considered part of a metabolic syndrome and insulin resistance is at the root of gout illness. Along these lines, gout is rare among pre-agricultural populations (Hunter-gatherers). Serum uric acid levels depends on the amount entering the bloodstream and the amount leaving the bloodstream. The amount of uric acid entering the bloodstream depends on the amount of it produced by the liver (1/3 from diet and 2/3 from body turn-over of cells). The amount of uric acid leaving the bloodstream depends on the kidneys' excretion capacity. The metabolic syndrome and insulin resistance induce kidney underexcretion of uric acid. On the other hand, when the kidney is faced with high protein purine-containing foods, serum uric acid levels decrease because the kidney increases uric acid excretion (this is an evolutionary trade-off).
So, the real problem is increased liver production of uric acid and kidney uric acid underexcretion. High glycemic load foods (as found in the typical Western diet and not in The Paleo Diet), and subsequent hyperinsulinemia halts the kidney capacity to excrete uric acid. Regarding liver production of uric acid: fructose--and particularly High Fructose Corn Syrup (HFCS)--decreases inorganic phosphate in the liver, and this increases the production of uric acid from purines.
The Paleo Diet helps to fight gout as it is based on low-glycemic load foods, high protein, and no HCFS foods.
We hope this helps.
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