How Related Are Weight And Health?
August 14, 2008
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The conventional wisdom is that if you are normal sized you are healthy and if you are overweight you are unhealthy. However, a recent analysis has suggested that it is not that simple and that weight and health may not be related in a straightforward way.
More data from NHANES (National Health and Nutrition Examination Survey) suggests that some “normal weight” people are unhealthy and that some people considered overweight do not have signs of cardiac disease or other diseases that have been conventionally associated with obesity.
Of course being thin has never necessarily meant healthy. For instance, my mother who suffers form Crohn’s disease is thin due to her disease. However, in this analysis of the NHANES surveys, of those with normal weight there were a significant proportion who had what the authors called “metabolic markers of obesity”.
What were considered to be metabolic markers of obesity? They included high blood pressure, elevated triglycerides, high fasting blood glucose, high levels of C reactive protein (hsCRP) and low levels of HDL (the good) cholesterol.
The proportion of normal weight people with these markers increased with age, from 10.3% for ages 20 to 24 years , 16.9% between 35 and 49 years, 41.7% between 50 and 64 years, 54.7% between 65 and 79 years, and 56.2% 80 years and older.
Conversely, for those considered overweight and would be expected to have the metabolic markers, there were many who were in the optimal range. Healthy levels of the markers decreased with age, but represented a substantial proportion of the survey participants. The ranges were 47.7% between 20 and 34 years, 31.1% between 35 and 49 years, 20.4% between 50 and 64 years, 14.3% between 65 and 79 years, and 22.1% 80 years and older.
This sort of goes against what we are told. It will be interesting to see how the discussion of the data develops. The data does suggest that you need to go and get tested for cholesterol, glucose, triglycerides etc, whatever your size. Find out what your numbers are, then go from there.
Technorati Tags: weight, metabolic, obesity, NHANES
Popularity: 11% [?]
Low Fat vs. Low Carb vs. Mediterranean Diet
July 19, 2008
A new study compared low fat, low carb and Mediterranean diets. The findings were that those on the low carb and Mediterranean diets, lost more weight and had more improved cholesterol and triglyceride levels, than those on the low fat diet.
The study was conducted at a remote nuclear facility in Israel, so there was control over the diets of the participants. There were many more men than women in the study, so the findings for women may be less general. The low fat and Mediterranean were calorie restricted, the low carb diet was not calorie restricted.
All dieters lost weight, but those on the low fat diet lost the least. Men lost most on the low carb diet, whereas women lost most on the Mediterranean diet.
HDL cholesterol (the good cholesterol) increased most on the low carb diet, closely followed by the Mediterranean diet and the worst was the low fat diet. LDL cholesterol (the bad cholesterol) decreased the most on the Mediterranean diet, the low carb diet was intermediate and there was only a small decrease on the low fat diet. Triglycerides dropped most with the low carb diet, the Mediterranean diet had a slightly small drop and the low fat diet had a much smaller drop.
These results suggest that low carb and Mediterranean diets may be more effective than a low fat diet both for weight loss and improving cholesterol and triglyceride levels.
Since the low carb and Mediterranean diets are almost equally effective, then choosing the diet that suits your tastes and lifestyle, is going to be what is most successful.
The study is published in the New England Journal of Medicine 359:229-241, 2008.
photo credit: sethschoen
[tags]low fat, low carb, Mediterranean, diet, weight, cholesterol, triglycerides[/tag]
Popularity: 33% [?]
Artichoke Leaf: The Next Wonder Food!
July 8, 2008
Expect to hear quite a bit about artichoke leaf and artichoke leaf extract, which is often abbreviated to ALE. I predict that supplements containing artichoke leaf will soon be popping up everywhere. A search of PubMed using artichoke brings up a number of studies on a wide range of potential benefits. The most recent is lowering cholesterol.
The globe artichoke (Cynara cardunculus) is a perennial thistle and is closely related to the cardoon. Other types of thistles have been suggested to have a range of health benefits. These include milk thistle for treatment of liver diseases and burdock, which is said to be a blood purifier.
Artichoke leaf extracts are widely available in Europe. They have been sold primarily as a treatment for indigestion, some urinary problems (hyperuricemia) and gout. Recently they have been shown to have positive effects on symptoms of irritable bowel syndrome.
Globe artichokes, of course, have antioxidants. I suspect that there is not a single plant that does not have some form of antioxidant. In particular artichokes have been suggested to protect the liver from oxidative stress. Artichoke leaf extract has also been shown to limit damage form oxidative stress in high intensity physical activity.
The most recent study looked at the effects of the leaf extract on moderately increased cholesterol levels. Those that consumed 1280 mg of artichoke leaf extract for 12 weeks saw a decrease in total cholesterol. I wonder how many artichokes I would have to eat to get the equivalent amount. Probably all the butter and mayo would counteract the good effect.
photo credit: Dylan Parker
[tags]artichoke leaf, artichoke leaf extract, ALE, globe artichoke, cholesterol, antioxidant[tags]
Popularity: 26% [?]
Worms: The Answer To Immune Problems?
July 3, 2008
There have been several articles recently about how worms may be good for you, not the kind in the soil but those that are parasites in the human body. The idea is that worms (helminths) may help calm the immune system.
What makes the perfect parasite? For those that want to survive in the body, it is stopping the body responding and attacking you, or trying to get rid of you. A happy parasite wants a happy host.
Further some organisms end up in a symbiotic relationship. Symbiosis is often defined as a relationship where there is benefit to both participants.
So what do immune-dreived health problems have to do with worms?
In order to stay in the digestive tract many worms suppress parts of the immune system. This way the body does not try to attack the worms. So when infected with worms the body will turn down some (but not all) immune responses. This is not a new idea, it has been known for quite a while.
What is new is the suggestion the body got used to having the worms and was in balance with them. So that in modern times with improvements in sanitation and medication, when we lost our worms our immune systems got out of whack and in some people got revved up. In other words perhaps it was of a symbiotic relationship, beneficial to all.
Why has this new idea been proposed?
One thing that everybody agrees on is that in recent times there has been a huge increase in immune diseases ranging from hay fever to inflammatory bowel disease. These are all diseases where the immune system becomes more active.
So, of course, this leads to the question, why has there been this very sudden increase in a wide range of immune diseases?
There are all kinds of theories. One is the hygiene hypothesis. The idea is that being no longer exposed to certain bacteria, fungi, worms etc., that our immune systems are not trained properly, and may in many people get out of control.
One of the first demonstrations of role of worms was the experimental infection of 29 patients with active Crohn’s disease (an inflammatory bowel disease) with pig whipworm. An amazing 23 patients showed improvement, with 21 of these going into remission. Gut 54:87-90, 2005 (PubMed). Later studies have shown good results with ulcerative colitis, another inflammatory bowel disease.
Are we going to be getting worm egg prescriptions in the future? Unlikely. There is now a push to find the range of mechanisms that the worms use to suppress the human responses. It is very likely that drugs based on this knowledge will be tested for use on many diseases that have an inflammatory component. These will include hay fever, asthma, eczema, multiple sclerosis and the inflammatory bowel diseases. It will also include diseases that you might not realize involve immune responses such as diabetes and atherosclerosis (blocking of arteries).
photo credit: moneydick The image is of Caenorhabditis elegans a harmless roundworm that lives in the soil.
Technorati Tags: worms, helminths, parasite, allergy, inflammatory disease, Crohn’s
Popularity: 38% [?]
LDL Cholesterol Lowering Drugs: The Statins
June 20, 2008
Continuing from yesterday’s theme, I thought I would write a short explanation of the statin family of drugs, that are used for treating bad levels of cholesterol. Statins are the most prescribed drugs in the US. In fact, Atorvastatin (Lipitor), much of the time, has been the most prescribed drug for the last couple of years. (It was toppled by Viagra for a while, but came back.)
It is important to remember that your body has to have cholesterol. The major uses are; as part of the membranes of cells, and in the formation of a number of hormones.
No matter how much cholesterol you eat, your body (mainly the liver) will always make some cholesterol.
LDL (low density lipid) cholesterol contains cholesterol that is made by, or reprocessed by the liver. It is transported by the blood throughout the body, and cells that need some cholesterol will take what they need from the blood. So you need to have LDL cholesterol circulating in your blood. It is just that when there is too much that there may be problems.
Currently, the standard for treating high LDL cholesterol levels are the statins. The statins include lovastatin (Mevacor), simvastatin (Zocor), pravastatin (Pravachol), fluvastatin (Lescol), atorvastatin (Lipitor) and rosuvastatin (Crestor). The first name of each pair is the name of the drug, the second name in brackets is the commercial name for that drug. Yesterdays post about red yeast rice involves lovastatin.
These drugs are all inhibitors of the enzyme HMG CoA reductase. This enzyme is a major enzyme in the process of making of cholesterol by cells. When the enzyme is inhibited, cells in the body make less cholesterol. Then, when the cells get short of cholesterol they start to take up cholesterol from the blood to meet their requirements, then the level of LDL cholesterol in the blood drops.
(Statins are thought to have a number of other good effects too, independent of their cholesterol lowering ability. These are wide ranging and the subject of much research and controversy.)
To summarize, statins decrease the amount of cholesterol that the body can make, so then to meet requirements cells take up LDL cholesterol from the blood, which cause the level of LDL cholesterol in the blood to decrease.
photo credit: tellumo The sign is in Sausalito.
Technorati Tags: cholesterol, LDL cholesterol, drug, statin, lovastatin, atorvastatin, Lipitor
Popularity: 33% [?]
Red Yeast Rice For Cholesterol Lowering?
June 18, 2008
There has been quite a bit of news lately about red yeast rice and its use for lowering cholesterol. The short answer is yes red yeast rice can lower cholesterol. However, there are some important considerations when deciding whether to use this supplement for cholesterol lowering.
What is red yeast rice?
This is rice that has been mixed with red yeast (Monascus pupureus) and allowed to ferment. The resulting fermentation products include a group of substances that have cholesterol lowering ability. One of these substances is the compound known as monacolin K, also known as lovastatin (Mevacor). Lovastatin was the first of the prescription statins available for lowering cholesterol. The commercial synthesized statins also include Zocor, Lipitor, Pravachol, Lescol and Crestor.
What are the potential problems with taking red yeast rice?
Some brands do not control (or measure) the amount of the active ingredient. Different batches may have almost none, or huge doses of monacolin K. Almost none is obviously not going to be any help with lowering cholesterol. Too much can result in muscle damage, also known as myopathy. (PubMed)
If the red yeast rice fermentation is not properly controlled there can be harmful products made too. When a number of red yeast rice preparation were tested some of them contained citrinin, which is a toxin that will damage your kidneys. (PubMed above)
Red yeast rice can have interactions with other medications. Some which will increase the risk of muscle damage or other side effects. This list of medications that potentially may result in side effects includes all drug interactions and cautions listed for lovastatin. As with the commercial cholesterol lowering statins Mevacor, Zocor and Lipitor, no grapefruit or grapefruit-containing products should be consumed. Grapefruit, also, increases the risk of muscle damage. If you are taking any other medications fully investigate whether combined with red yeast rice there may be side effects.
The FDA has banned some brands of red yeast rice products. However, it is likely in the future that products with strict manufacturing guidelines and extensive analysis will eventually be available.
As always caveat emptor (buyer beware).
Technorati Tags: red yeast rice, lovastatin, citrinin, cholesterol lowering
Popularity: 36% [?]
ApoB, LDL Cholesterol And Cardiovascular Disease Risk
March 29, 2008
A statement by the American College of Cardiology and the American Diabetes Association, which will be published in the April issue of Diabetes Care, suggests that ApoB levels should be measured in addition to LDL cholesterol (the “bad” cholesterol) to assess cardiovascular risk in some patients with borderline or slightly elevated LDL cholesterol. ApoB is a protein that found on the surface of with LDL cholesterol particles.
It has long been known that there is a subpopulation of people who even though they have borderlinel or slightly elevated LDL cholesterol are at a high risk for heart attack, stroke etc. Elevated LDL cholesterol definitely puts people at a higher risk for cardiovascular disease, but what about those with borderline or moderate elevations who develop heart and vascular disease?
Generally LDL cholesterol is not actually measured when standard blood lipid panels are done. It is calculated by a formula using measurements of total cholesterol, HDL cholesterol (the “good” cholesterol) and triglyceride. So the calculation just estimates how much cholesterol is in the LDL fraction in blood.
Cholesterol is not free in the blood; it is contained in particles. There are LDL particles, HDL particles etc. LDL particles in the blood are not all the same size or density. They have a size range, with the smallest being the most dense, and the biggest being the least dense. An analogy is comparing lead shot with a Styrofoam packing peanut. The lead shot is smaller but heavy; the Styrofoam is bigger and less dense.
The standard calculation of the amount of LDL cholesterol does not give an indication of the numbers of LDL particles. If there are lots of small dense particles, then the LDL cholesterol measurement might not be very high even though there are lots of LDL particles.
The smallest densest particles are thought to be most atherogenic (most atherosclerosis causing) and most likely to cause cardiovascular disease, while the biggest and “fluffiest” are the least atherogenic.
So, considering LDL cholesterol measurement. If there are lots of predominantly small dense particles in the blood, the calculated LDL cholesterol may not be really high since the small particles do not have very much cholesterol. However, the risk of cardiovascular disease may be significant, since there are actually lots of small dense LDL particles.
Since each LDL particle has one ApoB (apolipoprotein B100) on its surface, then the amount of ApoB can be used to estimate the number of LDL particles. So particularly if LDL cholesterol is borderline or slightly elevated then the amount of ApoB can give an estimate of the number of particles and from this the percentage of atherogenic small dense particles can be calculated.
The measurement of ApoB will therefore be particularly beneficial for predicting which patients with borderline or slightly elevated cholesterol are at risk of cardiovascular disease. Those who have relatively high ApoB would then be candidates for more aggressive cholesterol lowering treatments and could be monitored for early detection of the development of cardiovascular disease.
Technorati Tags: LDL cholesterol, ApoB, cardiovascular disease, atherosclerosis
Popularity: 78% [?]
Stanols and Sterols in Cholesterol Lowering Foods
March 28, 2008
We have heard a lot recently about cholesterol lowering foods, in particularly stanols and sterols. What are these phytosterols and how do they help with reducing cholesterol levels?
This is a topic about which I know quite a bit. Once a year I teach medical students about treatments for hyperlipidemias (high lipid or fats). Blood lipids are cholesterol and triglycerides. High cholesterol is associated with cardiovascular disease and contributes to atherosclerosis. I could say a lot more but the point of this post is cholesterol lowering foods, so perhaps another day I will give more information about cholesterol.
One group of foods that have cholesterol lowering potential is those that contain stanols and sterols. These are also known as phytosterols and are found in plants. The stanols and sterols have a structure similar to cholesterol.
Phytosterols block uptake of some of the cholesterol in the intestine, when foods that contain cholesterol are eaten. (Major dietary sources of cholesterol are meats, dairy and shrimp. Plants do not contain cholesterol.) Any cholesterol that is blocked form uptake by the phytosterols just passes on through the gut and out, with all the other stuff that is not absorbed. In this way less cholesterol is taken up by the body, and this may help lower blood cholesterol levels.
Which foods contain stanols and sterols? All plants contain phytosterols, however in many plants the levels are very low. Avocados are one of the foods with the highest level of sterol. They contain about 100 milligrams of beta sitosterol per 4 oz serving. Other foods that contain both sterols and stanols are vegetable oils including soy and corn oils and nuts. Grains contain smaller amounts.
Recently stanol esters have been added to a number of foods to help with cholesterol reduction. The original foods marketed that contained stanol esters were margarines (or often called spreads). The first margarine was Benecol which was first sold in Scandinavia, in Finland. The stanol esters in Benecol are from processing of pine trees. In the US the other spread that was early into the market was Take Control from Unilever, which is manufactured from soybeans. Stanol esters are now found in a number of products such as other spreads, yogurt and energy bars and will soon be incorporated into a wider range of foods including pasta.
Many of the foods containing significant levels phytosterols are quite high in calories so they should be eaten in moderation as part of a balanced diet.
Technorati Tags: cholesterol, phytosterol, stanol, sterol, avocado, margarine, stanol ester, spread
Popularity: 89% [?]
New Cholesterol Research could lead to New Type of Treatment
February 6, 2008
The levels of both bad and good cholesterol in the blood are strongly related to risk of cardiovascular disease. A new finding suggests that there is a protein in the blood that has an effect on how much LDL (the bad cholesterol) is circulating in the blood. Further which versions of this protein a person has, can affect their LDL levels.
In the body, cells have proteins located on their surface called LDL receptors. These receptors have a high binding capacity for LDL particles. After LDL has bound to the receptor, the receptor with the LDL attached is then taken up into the inside of the cell. This is how LDL is removed from the blood.
The new protein, called PCSK9, binds to the LDL receptor and blocks the binding of LDL particles. The blocking of the LDL receptor means that less LDL is taken out of the blood and so the level of LDL in the blood is higher. The researchers have found that about 3% of people have a mutant form of the protein. Those that have the mutant form have lower LDL levels since the receptor is not so blocked. Additionally those with the mutant form have a lower risk for cardiovascular disease.
Two people have been identified that do not have the protein at-all. These two people are healthy and no evidence of heart disease. Their LDL cholesterol is an amazing 20 (mg/dl).
This research suggests that if a drug could be found that inactivates PSCK9, then LDL receptors would not be blocked. This would lead to higher amounts of LDL being removed form the blood, so LDL levels would be significantly lowered. This would be a blockbuster drug and potentially revolutionize the treatment of cholesterol and cardiovascular disease.
The research was published online in Proceedings of the National Academy of Sciences, as an open access article.
Technorati Tags: cardiovascular disease, cholesterol, LDL, LDL receptor, PSCK9
Popularity: 52% [?]
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