Dear Readers,
Here are answers to some of the questions we've received recently. We hope they are helpful to you. We read all comments, and we are very interested in hearing your thoughts, learning about your experiences, and understanding what questions you have.
Blog Q: In the book The Paleo Diet Dr. Cordain do not allow yams and sweet potatoes. In the blog they are recommend to those who are underweight (11-November-09). I am a patient with Multiple Sclerosis and am underweight. May I eat these vegetables?
A: In The Paleo Diet Dr. Cordain recommends avoiding high starch foods because they are usually high-glycemic load foods. Those foods cause hyperinsulinemia, which is at the root of many western diseases such as acne, myopia, polycystic ovary syndrome, male vertex balding, early menarche, certain epithelial cells carcinomas, obesity, type 2 diabetes, hypertension, etc.
In your case, high glycemic load foods like yams shouldn’t be a problem, but use them in moderation--especially after exercising, as the muscle will more efficiently absorb glucose. However, potatoes are not allowed for MS patients, as they are sources of harmful substances--namely saponins (Chaconine and Solanine). Saponins can increase intestinal permeability which is one of the factors involved in almost all autoimmune diseases.
Blog Q: I want to start on the Paleo Diet, but I live in a medium sized town and have not been able to find a source for pastured meat. I wonder if New Zealand lamb--which always seems to be available at my supermarket--is okay? Is it pastured? Also, is farmed Atlantic salmon acceptable, no one carries wild.
A: We have not studied the efficacy of New Zealand Lamb relative to the Paleo Diet, but a quick online search seems to indicate that you could consume this as part of the Paleo Diet.
Regarding farmed Atlantic Salmon: it is not the best choice. Maybe you can find another kind of cold water fish, such as sardine, anchovy, mackerel or tuna, which has not been farmed. We suggest you inquire at your local fish market.
Blog Q: I've never used coconut oil, and I'm hesitating because I can't stand the taste of coconut. Is the coconut taste very strong in coconut oil?
A: Yes, coconut oil’s flavor is quite strong.
Links to papers pertaining to Maelán's blog comment reply of 9 December 2009:
LDL Cholesterol: “Bad” Cholesterol, or Bad Science?
Dietary Intake of Long-Chain Polyunsaturated Fatty Acids during the Paleolithic
The Nutritional Characteristics of a Contemporary Diet Based Upon Paleolithic Food Groups
Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets
Origins and evolution of the Western diet: health implications for the 21st century
Hyperinsulinemic diseases of civilization: more than just Syndrome X
Here is the fundamental misunderstanding again. Starchy foods are not the root cause of hyperglycemia. Hyperglycemia is caused by the liver malfunctioning. Many healthy primitive cultures ate high starch, high glycemic diets without issue. It only becomes an issue with liver dysfunction. What else are symptoms of liver dysfunction? Diabetes, heart disease, metabolic syndrome, obesity. Hyperglycemia does not cause these other problems, instead, hyperglycemia is simply another symptom of the same underlying problem.
ReplyDeleteSo instead of vilifying starches, I think you should concentrate on the things that cause liver dysfunction, specific major examples include excess fructose and omega 6 polyunsaturated fats.
I appreciate Dr Cordain's work, he has done so much to research and advance optimum nutrition. On this issue, however, I feel that he is not keeping up with the research, and is basically repeating a politically correct idea.
I was very disappointed with your book. Although I practice a paleo/primal style diet based in Low Carb, I found you to be another diet author with a strong fear of FAT. Never do you say meat wihout the modifier Lean as if you are tring to prevent any Atkins backlash. Since Taubes' landmark book GCBC- it has been shown that animal fat and saturated fat is not the problem but carbs and sugars. I enjoy the idea of Paleo (and they consumed a lot of fat) but was disappointed in your book. Sorry I'm trying to be honest and respectful.
ReplyDeleteMy point was the fear of FAT. Om6 and all sugars are a problem far greater than fat. Many primitive cultures- name me some other than the every carb pushers favorite Kitavans? The problem is NOT FAT as Dr Cordain's book repeatly states. And throughout the book he stress the need to eat wild game meats like Buffalo, which is only leaner do to the fact that it isn't grain fed like our cattle, He brings in up in a chapter towards the end, but it should have been stated throughout the book.
ReplyDeleteCoconut oil doesn't have to have a strong taste. Spectrum Organics sells an organic extra virgin coconut oil that has very little smell or taste. It is available in my local supermarket.
ReplyDeleteDr. Cordain,
ReplyDeleteWondering your thoughts on Casein as a substitue for whey protein? Is Casein as insulinogenic as whey?
I realize its a dairy-derived protein and probably not Paleo. Looking for your feedback quickly. Thank you!
Kyle Schneider
Posted on behalf of Maelan:
ReplyDeleteCasein comprises 80% of milk proteins and is responsible for increased IGF-1 serum levels. IGF-1 has several deleterious health effects, such as promoting certain cancers and hormonal disruptions. So we do not recommend substituting casein for whey.
We hope this helps.
Posted on behalf of Maelán:
ReplyDeleteDear Sir (Ed),
Yes, we agree with you in that starchy food is not the only culprit in hyperglicemia or hyperinsulinemia. There's some scant evidence showing that maybe bioactive compounds found (lectins) in grain and legume carbohydrates
wreak havoc leptin and insulin metabolism thereby leading to insulin resistance, hyperglicemia and leptin resistance. Some hunter gatherer populations eat up to 69% of their calories from carbohydrates (even starchy carbohydrates) yet they do not develop hyperglicemia, this is the case with
the habitants from Kitava-Papua New Guinea.
Furthermore, metabolic programming plays a key role in susceptibility to insulin resistance. Low birth weight infants are more prone to develop type 2 diabetes in their adulthood.
On the other hand, hypothalamic control of the vagus nerve is also a key player regarding the control of glucose efflux from the liver.
In summary, not only starchy food contributes to development of hyperglycemia, as you have said.
Maelán
Posted on behalf of Maelán:
ReplyDeleteDear Sir (PJNOIR),
Dr. Cordain has written several scientific papers where he has shown that hunter-gatherers ate even more total fats (range 28-47%) than western populations (34%). Because animals are currently fed with grains and vegetable oils they may contribute to a disrupted omega-6/omega-3 ratio which is associated to increased risk of cardiovascular disease, especially when increased large LDL levels are found in the blood. It is oxidized LDL--and not LDL per se--which is actually associated to CVD. Furthermore, trans fatty acids found in processed meats contribute to increases in oxLDL levels and thereby increase the risk of CVD.
The bottom line is that Dr. Cordain does not support restricting fat intake if they are the correct fats. We can not deny the deleterious effect of high LDL (produced by some saturated fats, such as Palmitic Acid) in a toxic environment: smoking, alcohol, increased omega-6/omega-3 ratio, poor glucose tolerance, hyperinsulinemia, low micronutrient intake, elevated homocysteine, etc. where LDL could be oxidized. Moreover, we are aware of the fact that some saturated fats decrease LDL cholesterol, e.g. Stearic Acid (18:0). So, it is pretty much the kind of fats rather than the amount of fats that contribute to CVD. What seems more and more clear in the scientific community is that cereal-based carbohydrates are the real culprits in CVD.
Here's an explanation to a similar question regarding the mechanism by which oxLDL causes atherosclerosis:
Saturated fatty acids intake and the risk of developing cardiovascular disease (CVD) is a topic with a lot of controversy. In the last years a wide body of research has suggested that increased consumption of certain
saturated fatty acids (Lauric acid, myristic acid and palmitic acid) down-regulate LDL receptor and thereby increase LDL plasma levels, and this has been associated with increased risk of CVD. On the other hand, stearic acid (a 18 carbon saturated fatty acid) has been shown to decrease LDL plasma levels. However, this view is too simplistic, as they are several other factors contributing to CVD, such as smoking, exercise, trans-fatty acids, increased omega-6/omega-3 ratio, free-radicals, nutrient deficiency, homocysteine, alcohol intake and low-grade chronic inflammation among others. Moreover, some studies have suggested that there’s not enough scientific data to support the view that increased total or LDL cholesterol is an independent risk factor for CVD, but rather oxidized LDL. Plaque production is mediated by oxidized LDL but not LDL. Oxidized LDL can produce shedding of the inner layer of the artery, namely glycocalix. Then oxidized LDL infiltrates in the intima of the artery. Oxidized LDL is eaten by macrophagues, a process known as phagocytosis, and therefore macrophagues are transformed into foam cells which produce the fibrous cap. Once the fibrous cap has been produced we need to break it down in order to produce an ischemic event. Lectins and low-grade chronic inflammation are involved in the activation of matrix metalloproteinases, which breaks down the fibrous cap.
In summary, high total cholesterol or LDL levels do not increase CVD risk, but rather oxidized LDL. To produce oxidized LDL we need the factors mentioned above. Hence, consumption of saturated fatty acids is not an issue if we control several other factors such as those mentioned before.
Dr. Cordain wrote a chapter in his book where he shows that saturated fat consumption in ancient hunter-gatherer populations were usually above the recommended 10% of energy from saturated fats, but non-atherogenic.
The bottom line is that we do not recommend cutting down saturated fatty acid intake, but rather decreasing high-glycemic load foods, vegetable oils, refined sugars, grains, legumes and dairy.
See the addendum to this post above for links to papers backing up these explanations.
We hope this helps
Maelán
Re Blog Q's Question: A small or medium-sized town would not HAVE a fish market. Our medium-large sized town does not have a fish market or a real butcher -- we are lucky to have a Vitamin Cottage. He may have to go directly to the ranch and buy meat from an old-fashioned family farm if he can find one. Maybe he can take up hunting. Also, the farmer's market can be a good place to find clean food.
ReplyDeleteVanessa P