Here is today's edition of the Paleo Diet Q & A. Thank you to everyone who has posted comments and questions.
Q: I enjoy your newsletters and eat an occasional Paleo Diet (I get lazy and eat like the norm and then get back to the Paleo way). Anyway it is my husband I am concerned with. Approx. 2 months ago he suffered from the H1N1 flu which moved into his lungs to bronchitis, then stress from work created heart palpation, shortness of breathe, dizziness, weight loss...the list goes on. I know the Paleo diet helps with a lot of aliments...what about stress
A: We believe that The Paleo Diet can prevent, or even reverse, many chronic degenerative diseases, included psychiatric diseases. We recently published a newsletter covering this topic, which you can purchase in our website (The Paleo Diet Update v5, #39 - Leaky Gut, Irritable Bowel Syndrome (IBS), and Psychiatric Disease).
Currently there aren't clinical trials showing the effects of The Paleo Diet on mood disorders, however a recent wide body of research shows that some pathways may link The Paleo Diet to mood improvement. A Belgian scientist has demonstrated the effects of a "leaky gut diet" (free of dairy and gluten) on mood and chronic fatigue syndrome. But this is not strictly a Paleo Diet, so we believe The Paleo Diet could even improve more, as briefly explained below.
Recent research has demonstrated that the mechanisms underlying depression and anxiety are:
a) Impaired neurotransmitter metabolism
b) Impaired neuroendocrine function
c) Impaired neural plasticity
Chronic low-grade inflammation is a the root of all of these pathophysiologic pathways. The Paleo Diet fights against inflammation because emphasizes a proper omega6/omega3 ratio and avoids immunostimulants substances such as lectins and saponins (found in cereal grains and legumes).
Hyperinsulinemia is also related to disrupted brain glucose metabolism and The Paleo Diet helps with hyperinsulinemia.
Furthermore, a critical point in low-grade inflammation is leaky gut syndrome or increased intestinal permeability. Increased gut permeability may allow increased passage of bacterial and/or dietary antigens into circulation inducing an immune activation and inflammation. The Paleo Diet is free of the foods that induce leaky gut syndrome and therefore low grade inflammation may decrease.
The case of your husband could be explained because a viral infection activates the immune system and high amounts of cytokines (immune cells messengers) are produced. Cytokines are at the root of the above mentioned pathways leading to depression and anxiety. A well known model of cytokine induced anxiety/depression is treatment with Interferon Alpha in Hepatitis C patients which often leads to depression or anxiety.
Q: I recently began my new life as a paleo eater – but I don’t seem to find information on coconut. Is it okay to eat the fresh and ground nut meat – and what about coconut oil?
A: Yes, I understand your confusion. The state of nutrition is very confusing, primarily because there is not an overriding paradigm that helps people put nutritional questions into context. We believe of course that the evolutionary paradigm can guide you to the correct answers, though ultimately the science speaks for itself.
On this page from our web site, you can see the fatty acid profile of various nuts: http://www.thepaleodiet.com/nutritional_tools/nuts_table.html
The most important factor to consider when eating fat is the composition. Our ancestors evolved eating a range of macronutrients that certainly varied by region and diet, but the fatty acid profile of the foods they ate were much different than that which the average Westerner eats today. Here is a good guideline for the composition of the fat you eat:
- Monounsaturated fats –50% of total fat energy
- Polyunsaturated fats – 25% of total fat energy
- Omega 3 fatty acids – 7% of total fat energy (preferably long-chain omega-3s such as EPA and DHA)
- Omega 6 fatty acids – 18% of total fat energy
- Saturated fat – 25% of total fat energy
- Stearic acid – 12.5% of total fat energy
- Lauric, myristic, and palmitic acid – 12.5% of total fat energy
So for instance, the American Heart Association (AHA) recommends that one not exceed 10% of total energy (not total fat energy). Thus, in 2,000 calorie diet, 200 calories are permitted by the AHA from saturated fat. In the Paleo Diet, only 12.5 % of all fats are pro-atherogenic, so even if 50% of total energy (1000 kcal) comes from fat, only 12.5% (125 kcal) is atherogenic -- well below AHA recommendations.
Certain saturated fatty acids downregulate the LDL receptor, leading to higher circulating levels of LDL (“bad”) cholesterol. These are primarily lauric acid (12:0), myristic acid (14:0), and palmitic acid (16:0), which should generally be limited to no more than 10% of total calories. Stearic acid, though it is a saturated fat, does not raise plasma cholesterol levels.
Grass-fed meat or wild game tends to have a healthful fatty acid profile, whereas most factory-farmed meat is raised on corn, and has a very different fatty acid profile which can lead to elevated cholesterol concentrations.
Coconut oil is about 90% saturated fat. Of that, 44.6% is lauric acid, 16.8% is myristic, and 8.2% is palmitic. So excess amounts will likely promote atherosclerosis, though this does not necessarily mean a heart attack will result. There has been research Jamaica and other areas where coconuts are a large part of the diet, where there is severe atheroma caused presumably by the coconut oil, yet the atheroma does not seem to cause coronary thrombosis.
Coconut oil also has medium chain triglycerides (MCTs), which can help promote gut integrity, and in general we would recommend anyone with digestive issues or autoimmune disease consider adding MCTs to their diet. Coconut oil would also be more stable for use in cooking, and would last longer before going rancid.
So, I hope that helps. The fat intake of our hunter-gatherer ancesters would have included marrow from long bones, and also long-chain omega-3 fats from brains. While we may not be able to (or want to) eat that way today, the closer we can emulate the dietary composition of our Paleolithic ancestors, the more we will be eating according to how our genome has evolved.