This is a simplified summary of the last two posts. Polyunsaturated fats in the diet are mostly omega-6 or omega-3. These get converted into a diverse and influential class of signaling molecules in the body called eicosanoids. On their way to becoming eicosanoids, they get elongated. These elongated versions can be measured in tissue, and the higher the proportion of elongated omega-6 in the total pool, the higher the risk of a heart attack. Eicosanoids are either omega-6 or omega-3-derived. Omega-6 eicosanoids, in general, are very potent...
Minggu, 31 Mei 2009
Rabu, 27 Mei 2009
Eicosanoids and Ischemic Heart Disease, Part II

Here's where it gets more complicated and more interesting. The ratio of omega-6 to omega-3 matters, but so does the total amount of each. This is a graph from a 1992 paper by Dr. Lands: Allow me to explain. These lines are based on values predicted by a formula developed by Dr. Lands that determines the proportion of omega-6 in tissue HUFA (highly unsaturated fatty acids; includes 20- to 22-carbon omega-6 and omega-3 fats), based on dietary intake...
Minggu, 24 Mei 2009
Eicosanoids and Ischemic Heart Disease

Dr. William Lands, one of the pioneers of the eicosanoid field, compiled this graph. It may be the single most important clue we have about the relationship between diet and ischemic heart disease (heart attacks).To explain it fully, we have to take a few steps back. Dietary polyunsaturated fatty acids (PUFA) are primarily omega-6 and omega-3. This is a chemical designation that refers to the position of a double bond along the fatty acid's carbon...
Jumat, 22 Mei 2009
Eicosanoids, Fatty Liver and Insulin Resistance
I have to take a brief intermission from the heart disease series to write about a very important paper I just read in the journal Obesity, "COX-2-mediated Inflammation in Fat is Crucial for Obesity-linked Insulin Resistance and Fatty Liver". It's actually related to cardiovascular disease, although indirectly.First, some background. Polyunsaturated fatty acids (PUFA) come mostly from omega-6 and omega-3 sources. Omega-6 and omega-3 are precursors to eicosanoids, a large and poorly understood class of signaling molecules that play a role in...
Selasa, 19 Mei 2009
The Coronary Heart Disease Epidemic: Possible Culprits Part II

In the last post, I reviewed some of the factors that I believe could have contributed to the epidemic of heart attacks that began in the 1920s and 1930s in the U.S. and U.K., and continues today. I ended on smoking, which appears to be a major player. But even smoking is clearly trumped by another factor or combination of factors, judging by the unusually low incidence of heart attacks in France, Japan and on Kitava.One of the major changes in...
Sabtu, 16 Mei 2009
The Coronary Heart Disease Epidemic: Possible Culprits Part I

In the last post, I reviewed two studies that suggested heart attacks were rare in the U.K. until the 1920s -1930s. In this post, I'll be discussing some of the diet and lifestyle factors that preceded and associated with the coronary heart disease epidemic in the U.K and U.S. I've cherry picked factors that I believe could have played a causal role. Many things changed during that time period, and I don't want to give the impression that I have...
Selasa, 12 Mei 2009
The Coronary Heart Disease Epidemic

Few people alive today are old enough to remember the beginning of the coronary heart disease (CHD) epidemic in the 1920s and 1930s, when physicians in the U.S. and U.K. began sounding alarm bells that an uncommon disease was rapidly becoming the leading cause of death. By the 1950s, their predictions had come true. A decade later, a new generation of physicians replaced their predecessors and began to doubt that heart attacks had ever been rare....
Kamis, 07 Mei 2009
Dihydro-Vitamin K1
Step right up ladies and gents; I have a new miracle vitamin for you. Totally unknown to our ignorant pre-industrial ancestors, it's called dihydro-vitamin K1. It's formed during the oil hydrogenation process, so the richest sources are hydrogenated fats like margarine, shortening and commercial deep fry oil. Some of its benefits may include:Inhibiting vitamin K2 metabolismReducing bone mineral densityCausing organ damage and inhibiting platelet formation in animal modelsDramatically increasing the death rate of spontaneously hypertensive ratsDihydro-vitamin...
Senin, 04 Mei 2009
Pastured Eggs
Eggs are an exceptionally nutritious food. It's not surprising, considering they contain everything necessary to build a chick! But all eggs are not created equal. Anyone who has seen the tall, orange yolk, viscous white, and tough shell of a true pastured egg knows they're profoundly different. So has anyone who's tasted one. This has been vigorously denied by the American Egg Board and the Egg Nutrition Council, primarily representing conventional egg farmers, which assert that eggs from giant smelly barns are nutritionally equal to their...
Vitamin A, Vitamin D and Osteoporosis Reprise
Chris Masterjohn just pointed out a new study that examined the relationship of vitamin A to osteoporosis in the context of vitamin D intake. The study is part of the massive Women's Health Initiative, which involved over 75,000 women. The conclusion:No association between vitamin A or retinol intake and the risk of hip or total fractures was observed in postmenopausal women. Only a modest increase in total fracture risk with high vitamin A and retinol intakes was observed in the low vitamin D-intake group.In other words, only women with a low...
Sabtu, 02 Mei 2009
Iodine
I recently saw a post on Dr. Davis's Heart Scan Blog that reminded me I intended to write about iodine. Iodine is an essential trace mineral. It's required for the formation of activated thyroid hormones T3 and T4. The amount of thyroid hormones in circulation, and the body's sensitivity to them, strongly influences metabolic rate. Iodine deficiency can lead to weight gain and low energy. In more severe cases, it can produce goiter, an enlargement of the thyroid gland.Iodine deficiency is also the most common cause of preventable mental retardation...
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