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Showing posts from December, 2009

Female Athlete Triad

When I was in high school, one of my best friends was a long-distance runner and a dancer. After only a few months of training, I knew something was wrong. She changed her diet to one of protein and almost no other calories. She was obsessed with exercise leading to a loss of many of her friends. Later on she lost a lot of weight and, to me, instead of becoming healthier she appeared to look pretty unhealthy. What I didn't know then was that my friend may have suffered from the "female athlete triad". It is a three-part syndrome that affects the health and performance of female athletes and includes osteoporosis, disordered eating and menstrual disorders. Each of these are inter-related and inter-play. Together they can cause serious illness or death. Writing in a review in British Medical Journal, Dr. Karen Birch explains that the syndrome can be caused by pressures psychological and physiological associated with a sports requirements to perform optimally, which can l

Growth hormone: The fountain of youth

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Growth hormone, also known as human growth hormone, seems to be implicated in a number of metabolic conditions associated with aging, and, more generally, poor health. In adults, growth hormone deficiency is associated with: decreased calcium retention and osteoporosis, loss of muscle mass, increased fat deposition, decreased protein synthesis, and immunodeficiency. In children, growth hormone deficiency is associated with stunted growth. Levels of growth hormones decline with age, and their decrease is believed to contribute to the aging process. Abdominal obesity is associated with low levels of growth hormone, and is also associated with the onset of the metabolic syndrome , a precursor of diabetes and cardiovascular disease. While there are many treatments in the market that include exogenous administration of growth hormones (e.g., through injection), there are several natural ways in which growth hormone levels can be increased. These natural ways can often lead to more effective

Half-hearted Atkins diet and cardiovascular disease

I would like to comment on a recent  article comparing the Atkins, Ornish and South Beach diets (Miller et al., 2009; full reference at the end of this posting), which has been causing quite a lot of commotion among bloggers recently. Especially low carb. bloggers. An excellent post by Michael Eades clarifies a number of issues with the study, including what one could argue is the study's main flaw. Apparently the study compared a half-hearted Atkins diet, with probably equally half-hearted Ornish and  South   Beach  diets. I refer to the study's Atkins diet as half-hearted because it seems to rely on a daily consumption of between 120 and 180 grams of carbohydrates. This is unlikely to lead to ketosis, the cornerstone of the Atkins diet, where the body uses ketone bodies (made from dietary as well as body fat) as a source of energy. As I see it, the main findings of the study were that the participants in the half-hearted Atkins diet, after a period of 4 weeks on the diet,

Family influence on meals

My thoughts after reading "A Review of Family Meal Influence on Adolescents' Dietary Intake" by Sarah Woodruff and Rhona Hanning: It's pretty easy to imagine why having dinner with one's family would instill positive nutritional habits. Even the word family exudes in its meaning what goes further to credit an environment of caring and, above all, nurturing. When mother and father are at the table, they are naturally given to see to it that their children are eating well. At the same time, they must also set the right example. Thus, it's clear why the authors of the article found that the studies reviewed found that those adolescents who ate with their families had a higher intake dairy, fruits and vegetables. I would further suggest that family influence comes with wisdom as to healthy eating pattens. For example, when grandma or grandpa or mom or dad make a meal, they themselves are passing on food traidtions that may have well sustained generations with bet

Total cholesterol and cardiovascular disease: A U-curve relationship

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The hypothesis that blood cholesterol levels are positively correlated with heart disease (the lipid hypothesis) dates back to Rudolph Virchow in the mid-1800s. One famous study that supported this hypothesis was Ancel Keys's Seven Countries Study, conducted between the 1950s and 1970s. This study eventually served as the foundation on which much of the advice that we receive today from doctors is based, even though several other studies have been published since that provide little support for the lipid hypothesis. The graph below (source: canibaisereis.com , with many thanks to O Primitivo) shows the results of one study, involving many more countries than Key's Seven Countries Study, that actually suggests a NEGATIVE linear correlation between total cholesterol and cardiovascular disease. Now, most relationships in nature are nonlinear, with quite a few following a pattern that looks like a U-curve (plain or inverted); sometimes called a J-curve pattern. The graph below (sou

What's an ALT test?

Alanine aminotransferase (ALT) is an enzyme that is concentrated in the hepatocytes. When the liver is injured or affected by disease, the enzyme is released into the bloodstream. When jaundice occurs, for example, elevated ALT levels can distinguish a liver injury or disease instead of red blood cell hemolysis. The test is performed on a patient by collecting 7-10 mL of blood in a red-top tube, then sending it to a lab for analysis. If a patient does have liver dysfunction, then the clinician should note that bleeding times may be longer. Significantly elevated ALT levels may indicate hepatits, hepatitis necrosis or hepatits ischemia. Moderately increased levels may indicate cirrhosis, cholestatis, a hepatic tumor, a hepatotoxic drug, obstructive jaundice, severe burns or trauma to striated muscle. Drugs that may elevate ALT levels include acetaminophens, clofibrate, codeine, salicylates, tetracyclines among many others. ALT levels may also increase to a lesser extent due to myositis

When You Have an Abnormal Lipid Profile

An abnormal lipid profile is a consistent indicator of atherosclerosis and cardiovascular disease (CHD). Blood lipids include total cholesterol, LDL-C, HDL-C and triglycerides. Because each of these factors are ultimately affected by diet, it serves to reason to recommend dietary strategies to help lower total cholesterol and LDL-C, increase HDL-C and reduce triglyceride levels. ATP III uses the term therapeutic lifestyle changes (TLC) for recommendations that can help to improve abnormal lipid profiles and reduce risk of CHD. TLC makes recommendations for saturated fat (less than 7% of total calories), polyunsaturated fat (up to 10% of total calories), monounsaturated fat (up to 20% of total calories), total fat (25-35% of total calories, fiber (20-30g/d), protein (approx. 15% of total calories), and cholesterol (less than 200 mg/d). The total calories recommendation, in addition, is based on a balance of energy intake and expenditure to maintain a healthy weight (1). Because it is of

When should prevention of atherosclerosis start?

I have three children, one boy, 13 and two girls, 10 and 11. As far as I’m concerned prevention of atherosclerosis should begin as early as possible. That means yesterday. However, I understand that there exists some uncertainty of exactly what age to begin prevention. It has to do partly with juvenile fatty streaks. What may appear unimaginable is that the occurrence of juvenile fatty streaks somehow may have an importance in child development. Most North American children develop fatty streaks in their aortas by age 3 and in coronary arteries along with macrophage foam cells by age 10 (1); by the time children are reaching puberty, they may already have developed fatty streak lesions. Fatty streaks are nothing new. As offered by McGill et al, our hominin forebears likely developed them as do current non-human Old and New World primates even when living in natural habitats. Studies of other mammals reveal that many of them also develop fatty streaks. From an evolutionary perspective,

Refined carbs, sugar, and cholesterol: My own experience

A few years ago I went to the doctor for a routine appointment, and I was told that my LDL cholesterol was elevated. I was in my early 40s. My lipid profile was the following - LDL: 156, HDL: 38, triglycerides: 188. The LDL was calculated. I was weighing about 210 lbs, which was too high for my height (5 ft 8 in). My blood pressure was low, as it has always been - systolic: 109, diastolic: 68. My doctor gave me the standard advice in these cases: exercise, lose weight, and, most importantly, reduce your intake of saturated fat . I was also told that I would probably have to take statins, as my high LDL likely had something to do with my genetic makeup. Again, this is quite standard, and we see it all over the place, particularly in commercials for statins. I told my doctor that I would do some research on the topic, which I am going to save for other posts. Let me get to the point, by telling you what my lipid profile is today - LDL: 123, HDL: 66 , triglycerides: 46 . Again, the LDL va

When to use a C-peptide test

Normally, measuring insulin directly is more accurate with diabetics. But C-peptide levels more accurately reflect islet cell function in situations of insulinomas as well as cases of diabetics taking exogenous insulin (for treatment or secretly). C-peptide, short for "connecting peptide" is the protein connecting beta/alpha chains of proinsulin. The chains are separated when proinsulin becomes insulin and C-peptide. C-peptide ends up in equal amounts to insulin in the portal vein, lasts longer than insulin so can be found more readily in peripheral circulation, and correlates with insulin levels. Summarized from Pagana, K.D., Pagana, T.J. Mostby's Manual of Diagnostic and Laboratory Tests, 3rd ed. Mosby Elsvier, 2006, p. 197.

Why get a glycosylated hemoglobin test?

Measuring blood glucose periodically is critical for staying off the blood sugar rollercoaster. But how can a clinician be sure a patient hasn't gotten on board the rollercoaster? This is when glyosylated hemoglobin comes into the picture. What happens is that when a person is diabetic and doesn't adequately control blood glucose, her or his blood glucose becomes elevated. The hyperglycemia that results begins to affect certain proteins in the blood as well as hemoglobin. Blood glucose bonds to the hemoglobin and it becomes "glycosylated". The glycosylation mainly happens to hemoglobin A (HbA, the major form of hemoglobin, and it's pretty much irreversible. After a few weeks, the amount of glycosylated hemoglobin will decline, but only if blood sugar is controlled. If it's not controlled, then a physician can order a glycosylated HbAIC test, or AIC test. A person without diabetes should have about 4-8% HbAIC and the American Diabetes recommends diabetics to st

Baby Steven

John and Susan are both prone to being overweight. They are concerned that their infant son, Steven will also have weight problems. They are referred to you when Steven is 5 months old. Steven's growth data are as follows Age Weight Length Birth 8lb 20inches 1 week 8lb 1oz 20 inches 1 month ll lb. 21.5 inches 2 month 12lb 8oz 23 inches 3 month 14lb 8oz 23.5 inches 4 month 16lb 25.5 inches 5 month 18lb 26.5 inches Steven breast feeds six times daily for about 20-25 minutes at each feeding. He is not presently receiving any other sources of nourishment. Answer the following questions for John and Susan: Their pediatrician told them that Steven's weight is above average. Is he gaining too much weight? When charted, Steven’s birth weight and weight gain for the next two months is at about the 50th percentile (1 p. 566). His weight gain afterward appears to be higher than average and he is at the 90th percentile by 5 months (1 p. 566). Steven’s birth length for four months is at abo