Kamis, 21 Januari 2010

Daftar Isi Postingan Akses Informasi Terkini


Rabu, 20 Januari 2010

Krauss's New Article on Saturated Fat Intervention Trials

Dr. Ronald Krauss's group just published another article in the American Journal of Clinical Nutrition, this time on the intervention trials examining the effectiveness of reducing saturated fat and/or replacing it with other nutrients, particularly carbohydrate or polyunsaturated seed oils. I don't agree with everything in this article. For example, they cite the Finnish Mental Hospital trial. They openly acknowledge some contradictory data, although they left out the Sydney diet-heart study and the Rose et al. corn oil study, both of which showed greatly increased mortality from replacing animal fats with polyunsaturated seed oils. Nevertheless, they get it right in the end:
Particularly given the differential effects of dietary saturated fats and carbohydrates on concentrations of larger and smaller LDL particles, respectively, dietary efforts to improve the increasing burden of CVD risk associated with atherogenic dyslipidemia should primarily emphasize the limitation of refined carbohydrate intakes and a reduction in excess adiposity.
This is really cool. Krauss is channeling Weston Price. If this keeps up, I may have no reason to blog anymore!

Sabtu, 16 Januari 2010

The Body Fat Setpoint, Part II: Mechanisms of Fat Gain

The Timeline of Fat Gain

Modern humans are unusual mammals in that fat mass varies greatly between individuals. Some animals carry a large amount of fat for a specific purpose, such as hibernation or migration. But all individuals of the same sex and social position will carry approximately the same amount of fat at any given time of year. Likewise, in hunter-gatherer societies worldwide, there isn't much variation in body weight-- nearly everyone is lean. Not necessarily lean like Usain Bolt, but not overweight.

Although overweight and obesity occurred forty years ago in the U.S. and U.K., they were much less common than today, particularly in children. Here are data from the U.S. Centers for Disease Control NHANES surveys (from this post):

Together, this shows that a) leanness is the most natural condition for the human body, and b) something about our changing environment, not our genes, has caused our body fat to grow.

Fat Mass is Regulated by a Feedback Circuit Between Fat Tissue and the Brain

In the last post, I described how the body regulates fat mass, attempting to keep it within a narrow window or "setpoint". Body fat produces a hormone called leptin, which signals to the brain and other organs to decrease appetite, increase the metabolic rate and increase physical activity. More fat means more leptin, which then causes the extra fat to be burned. The little glitch is that some people become resistant to leptin, so that their brain doesn't hear the fat tissue screaming that it's already full. Leptin resistance nearly always accompanies obesity, because it's a precondition of significant fat gain. If a person weren't leptin resistant, he wouldn't have the ability to gain more than a few pounds of fat without heroic overeating (which is very very unpleasant when your brain is telling you to stop). Animal models of leptin resistance develop something that resembles human metabolic syndrome (abdominal obesity, blood lipid abnormalities, insulin resistance, high blood pressure).

The Role of the Hypothalamus


The hypothalamus is on the underside of the brain connected to the pituitary gland. It's the main site of leptin action in the brain, and it controls the majority of leptin's effects on appetite, energy expenditure and insulin sensitivity. Most of the known gene variations that are associated with overweight in humans influence the function of the hypothalamus in some way (1). Not surprisingly, leptin resistance in the hypothalamus has been proposed as a cause of obesity. It's been shown in rats and mice that hypothalamic leptin resistance occurs in diet-induced obesity, and it's almost certainly the case in humans as well. What's causing leptin resistance in the hypothalamus?

There are three leading explanations at this point that are not mutually exclusive. One is cellular stress in the endoplasmic reticulum, a structure inside the cell that's used for protein synthesis and folding. I've read the most recent paper on this in detail, and I found it unconvincing (2). I'm open to the idea, but it needs more rigorous support.

A second explanation is inflammation in the hypothalamus. Inflammation inhibits leptin and insulin signaling in a variety of cell types. At least two studies have shown that diet-induced obesity in rodents leads to inflammation in the hypothalamus (3, 4)*. If leptin is getting to the hypothalamus, but the hypothalamus is insensitive to it, it will require more leptin to get the same signal, and fat mass will creep up until it reaches a higher setpoint.

The other possibility is that leptin simply isn't reaching the hypothalamus. The brain is a unique organ. It's enclosed by the blood-brain barrier (BBB), which greatly restricts what can enter and leave it. Both insulin and leptin are actively transported across the BBB. It's been known for a decade that obesity in rodents is associated with a lower rate of leptin transport across the BBB (5, 6).

What causes a decrease in leptin transport across the BBB? Triglycerides are a major factor. These are circulating fats going from the liver and the digestive tract to other tissues. They're one of the blood lipid measurements the doctor makes when he draws your blood. Several studies in rodents have shown that high triglycerides cause a reduction in leptin transport across the BBB, and reducing triglycerides allows greater leptin transport and fat loss (7, 8). In support of this theory, the triglyceride-reducing drug gemfibrozil also causes weight loss in humans (9)**. Guess what else reduces triglycerides and causes weight loss? Low-carbohydrate diets, and avoiding sugar and refined carbohydrates in particular.

In the next post, I'll get more specific about what factors could be causing hypothalamic inflammation and/or reduced leptin transport across the BBB. I'll also discuss some ideas on how to reduce leptin resistance sustainably through diet and exercise.


* This is accomplished by feeding them sad little pellets that look like greasy chalk. They're made up mostly of lard, soybean oil, casein, maltodextrin or cornstarch, sugar, vitamins and minerals (this is a link to the the most commonly used diet for inducing obesity in rodents). Food doesn't get any more refined than this stuff, and adding just about anything to it, from fiber to fruit extracts, makes it less damaging.

** Fibrates are PPAR agonists, so the weight loss could also be due to something besides the reduction in triglycerides.

Kamis, 14 Januari 2010

New Saturated Fat Review Article by Dr. Ronald Krauss

I never thought I'd see the day when one of the most prominent lipid researchers in the world did an honest review of the observational studies evaluating the link between saturated fat and cardiovascular disease. Dr. Ronald Krauss's group has published a review article titled "Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease". As anyone with two eyes and access to the medical literature would conclude (including myself), they found no association whatsoever between saturated fat intake and heart disease or stroke:
A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD.
Bravo, Dr. Krauss. That was a brave move.

Thanks to Peter for pointing out this article.

Minggu, 10 Januari 2010

Paleo is Going Mainstream

There was an article on the modern "Paleolithic" lifestyle in the New York Times today. I thought it was a pretty fair treatment of the subject, although it did paint it as more macho and carnivorous than it needs to be. It features three attractive NY cave people. It appeared in the styles section here. Paleo is going mainstream. We can expect media health authorities to start getting defensive about it any minute now.

Sabtu, 09 Januari 2010

How to Prevent Coronary Heart Disease and Heart Attack

Coronary heart disease and heart attack like heart infarction can in great extend be prevented by lifestyle measures.

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THE DIRECT CAUSES OF HEART DISEASE

The direct causes of coronary heart disease and heart attack are factors like these:

- Narrowing of blood vessels in the heart and the rest of the body by arteriosclerosis.
- High blood cholesterol level.
- High blood pressure.
- Over-weight.
- Diabetes.
- High level of the amino acid homocystein in the blood.
- High content of low density lipoprotein (LDL) and low content of high density lipoprotein (HDL) in the blood. Lipoprotein is a combination of protein and fatty substances bound together.
- Inflammation in the circulatory system.
- High age.
- Inherited tendencies for high cholesterol levels and heart disease.
- Men have somewhat greater chance of getting heart disease than women.

These factors are interrelated in complicated ways, and are causing or amplifying each other. For example, arteriosclerosis will cause higher blood pressure, and high blood pressure will cause even more arteriosclerosis. Many of these factors are ultimately caused or aggravated by these lifestyle factors:

-A too high consume of fat, cholesterol and sugar.
-Consuming the wrong fat types.
-Lack of fibre, vitamins, minerals and other diet deficiencies.
-Stress at work and in the daily life.
-Smoking.
-Lack of exercise.

Lifestyle adjustments will therefore be the main methods of preventing heart failure.


GENERAL DIET ADVICES

A diet with the aim of preventing heart disease is generally the same as a diet to prevent cancer and other diseases. Here are the general diet advices

- Avoid or reduce the amount of food that are industrially processed, artificially made or heavily fried.

- Eat fish at least every second day. Also eat seafood and fouls.

- Do not eat very much red meat.

- Eat 5 fruits or vegetables each day. Each piece should be of the size of an apple or carrot. They should be raw or carefully boiled so that the nutrients are not washed out.

- Eat full corn bread, full corn cereals, peas, beans and potatoes.

- Eat just a moderate amount of fat.

- Consume cholesterol rich foods like egg, spawn or liver in just moderate amounts.

- Ideally most fat you eat, should be of the type mono-unsaturated. You also need some poly-unsaturated fat of the types omega-3, and omega 6, but not too much of omega-6. The consumption of saturated fat should be moderate.

- In order to achieve right fat balance, much of the fat supply should come from a blending of sources like olive, olive oil, canola oil, nuts, nut oil, sunflower, sunflower oil, linseed oil (flax oil), fish and fish oil.

- Use only a moderate amount of soy oil and corn oil in the diet. Only using such oil types will give you too much poly-unsaturated fat of the omega-6-type.

- Use just a very moderate amount of fat sources like butter, coconut oil and palm oil. A high consumption of these fat sources gives you too much saturated fat.

- Avoid altogether fat that has been chemically altered, giving so-called trans-fat. This type of fat is often found in margarine, cookies, snacks, fast food and other pre-made food.

- Consume just a very moderate amount of sugar, refined flour or refined cereals.

- Consume just a moderate amount of tranquilizers and stimulants like alcohol and caffeine.

- Use just a moderate amount of salt in the food. However, in warm weather and by hard physical work, you will need more salt.


DIET SUPPLEMENTS THAT HELP PREVENT HEART DISEASE

Evidence suggests that it will be helpful to take some supplements of natural substances to prevent heart disease and help to ameliorate already manifest heart problems. These supplements are:

- Omega-3-fatty acids derived from fish and other marine sources, especially the fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) and alfa-linolaeic acid. 1 gram a day of each of these substances may be taken as a supplement. Higher amounts should only be taken under medical supervision, since higher amount of these substances may cause bleeding tendencies, and may suppress the immune system.

- Supplement of vitamin C has been thought to help prevent heart disease, but newer findings cast doubt upon this.

- Vitamin B6 (Pyridoxine), folic acid / folate, vitamin b12 and riboflavin seem to prevent the building up of the substance homocystein in the blood and thereby help prevent heart disease, according to results from research projects.


GET RID OF OVER-WEIGHT

The lifestyle measures listed in this article will also help you loose weight. If these measures are not enough, you should consider engaging in a more specific weight reduction program. You should choose a program that has a moderate fat content philosophy. Some weight reduction programs have a higher fat and low carbohydrate consume philosophy, and those are probably not the best ones to reduce the chance of getting heart disease.


EXERCISE

You should do some exercise of at least half an hour at least every second day. Condition training as vigorous walking, jogging, cycling or swimming is best for reducing the heart attack probability. Muscular building exercises are also of value, especially exercises building leg muscles


STOP SMOKING

If you smoke, stopping or reducing this habit radically will decrease the chance of getting heart problems.


CONTROL DIABETES

If you suffer from diabetes type 1, a good control of the disease by insulin medication and by diet adjustments will help to prevent heart disease.

Many people over the age of 50, and an increasing number of young people suffer from diabetes type 2 because of bad lifestyle. This disease does not necessarily give dramatic symptoms, but the disease increases the chance of getting serious heart problems, and many have the disease without knowing it. This disease can be prevented by the same lifestyle measures depicted above. If you already have got the disease, a more rigorous control of carbohydrate intake is necessary. And sometimes also medication must be used. People over the age of 50 and younger people that do not feel well should find out if they suffer from this condition.


TAKING ASPIRIN

Low doses of acetyl salicylic acid or aspirin prevent heart disease by persons bearing a high risk for heart disease. However, this medication increases the risk of bleeding and should not be used without constant medical supervision. For persons with a low risk of heart disease, the dangers of aspirin will be greater than the benefits.



About The Author:
Knut Holt is an internet consultant and marketer focusing on health items.----TO FIND natural help against common diseases, for example: Heart problems, over-weight, acne, hypothyroidism, fatigue, depression, anxiety, hemorrhoids, joint pain, allergies, rheumatism, respiratory diseases, and more PLEASE VISIT:--- http://www.abicana.com/shop2.htm

Jumat, 01 Januari 2010

How To Recognize The Symptoms Of Migraine Headaches

You have started to have severe headaches. These headaches last for a few hours and are recurring a couple of times a month. You suspect that it may be migraine headaches but how do you know for sure? This article will give you the signs and symptoms of a migraine. A word or caution. It is not smart to diagnose yourself. If you are having frequent headaches and aren't sure of the cause, see your doctor right away. He may want to do some tests to rule more serious problems
A migraine is a headache that is so severe it can be disabling and it will sometimes be accompanied by an aura. An aura is a warning sign that a migraine is coming. Auras usually appear anywhere from 15 to 30 minutes before a migraine starts. A migraine can last for two hours or it can last for as long as 72 hours if not treated.

Approximately 11 out of 100 people will get migraines, and women get them more than men. Hormonal changes have been thought to be a huge factor in the development of migraines. Other triggers can be certain foods, environmental changes and stress.

The symptoms of migraine headaches are:

Pain. This can range from moderate to severe. Some people will feel pain on either side of the head, while other people may feel it bilaterally. The pain may be described as throbbing or pulsating.

A true migraine will become worse with physical activity. This is why it interrupts your daily activities. Just walking across the room can cause excruciating pain.

The pain can cause nausea and occasionally vomiting. If the vomiting becomes severe you may need to get your doctor to prescribe an anti-emetic, such as Reglan or Compazine.

Hypersensitivity to sounds or lights is another common symptom of migraines. Most people want to lie down in a dark, quiet room until the pain subsides.

Some people that have migraines will experience auras prior to a headache. These auras may continue for the duration of the migraine. An aura can consist of:

- Bright flashes of light
- Bright zigzagging lines that interrupt your vision field.
- Diffuse blind spots in your field of vision.
- A tingling feeling in a leg or an arm.

Migraines themselves pose no real threat to you. But go to the emergency room immediately if you experience a sudden headache that seems to explode inside your head. If you have a headache with fever, mental confusion or a stiff neck. A headache that continues to get worse after coughing or straining or any other sudden movement. These may all be symptoms of a more serious problem and should not be ignored.

Migraines can be manageable with the right treatment. Talk to your doctor about your best options. There is no reason for you to suffer from the symptoms of a migraine headache.

For more help on the prevention, treatment and remedies for migraines please see the Complete Guide To Migraine Headaches.

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