Here are a few recent studies on the science of fat loss.
1) Artificial sweeteners increase appetite.
Purdue University researchers discovered that rats given snacks with artificial sweeteners had impaired ability to compensate for the calories in the snack. At mealtimes, they ate more and gained three times more weight than rats fed normally sweetened snacks. It is not clear if this study translate into human behavior as well or if the rats' response was species specific.
[Int J Obesity, 28: 993-935, 2004]
2) What is the best exercise intensity for fat loss?
Researchers at UC Berkeley have found that the body prefers to burn fat for energy while at rest and at low exercise intensities. At above 65 percent of maximum effort, the body quickly shifts to primarily carbohydrate use for fuel. The rate of fat cell breakdown for energy decreases rapidly with higher exercise intensities. So to lose fat, one should exercise at low to moderate intensity, right? Wrong!
While it is true that low-intensity exercise burns more fat during exercise, you actually burn more fat during a 24-hour period following high-intensity exercise than after low-intensity exercise. High-intensity exercise burns more calories during the exercise bout and increases metabolic rate following exercise, thus burning more fat while at rest during the post-exercise period.
To maximize fat loss, exercise at as high an intensity as you can.
[Nutrition, 20: 716-727, 2004]
3. Lack of sleep increases obesity risk.
In a study that has been widely reported in the mainstream media, researchers at the U.S. National Institute of Mental Health found that lack of sleep increases the risk of obesity. The study followed nearly 500 people over 13 years. The people who gained the most weight were those who lost the most sleep as they aged.
One possible mechanism for this outcome is the reduction in leptin levels that occurs with reduced sleep. Leptin is one of the body's chemicals that controls body fat stores. Lower leptin levels results in increased appetite and slower metabolism.
[Sleep, 27: 661-666, 2004]
4. A calorie is not a calorie.
Nutrition researchers from the University of Wisconsin, Madison, have shown that proteins yield less available calories (after digestion) than either fats or carbohydrates. Burning protein in a bomb calorimeter (to measure the energy contained in foods) provides 5.65 calories, while only 4.0 calories are available after absorption. Values for fats are 9.4 and 8.9 calories, and carbohydrates are 4.1 and 4.0 calories. You lose nearly 30 percent of the energy from protein in digestion but only 2 percent from carbohydrates.
When trying to lose weight, increase your protein intake and reduce your carbohydrates. You will feel more full after eating, burn more calories to digest the meal, and alter your blood chemistry to favor fat burning.
[Am J Clin Nutr, 79: 899S-906S, 2004]
Tuesday, March 29, 2005
Thursday, March 24, 2005
Fish Oil May Help Prevent Alzheimer's Disease
A new study appearing in the March 23 online issue of the Journal of Neuroscience suggests that diets high in omega-3 fats -- which are found in cold water fish such as mackerel, sardines, and salmon -- may help prevent Alzheimer's disease.
From the Health Central article:
Cole's team studied older mice genetically engineered to develop Alzheimer's disease. They fed one group food fortified with docosahexenoic acid (DHA), the omega-3 fatty acid found in several types of cold water fish. They fed the other group a diet low in DHA.
Diets low in DHA have been linked to impaired mental functioning, and DHA levels are lower in the blood and brains of Alzheimer's disease patients, Cole said.
After three to five months, which translates to several years in humans, the group of mice fed the DHA-rich diet had 70 percent less buildup of amyloid protein in the brain. This sticky protein is what makes up the plaques in the brain that are the hallmark of Alzheimer's.
"The protein is markedly reduced even when we start the diet late in life," Cole said.
The American Heart Association recommends two servings of cold water fish a week. However, there are so many benefits to omega-3 fats -- increased insulin sensitivity, increased joint function in those with arthritis, better heart health, increased memory and learning functions, and the list goes on -- that they should be a daily part of everyone's diet. I suggest as much as six grams a day of fish oil taken as capsules or eaten as fish.
[Click the header to read the rest of the Health Central article.]
From the Health Central article:
Cole's team studied older mice genetically engineered to develop Alzheimer's disease. They fed one group food fortified with docosahexenoic acid (DHA), the omega-3 fatty acid found in several types of cold water fish. They fed the other group a diet low in DHA.
Diets low in DHA have been linked to impaired mental functioning, and DHA levels are lower in the blood and brains of Alzheimer's disease patients, Cole said.
After three to five months, which translates to several years in humans, the group of mice fed the DHA-rich diet had 70 percent less buildup of amyloid protein in the brain. This sticky protein is what makes up the plaques in the brain that are the hallmark of Alzheimer's.
"The protein is markedly reduced even when we start the diet late in life," Cole said.
The American Heart Association recommends two servings of cold water fish a week. However, there are so many benefits to omega-3 fats -- increased insulin sensitivity, increased joint function in those with arthritis, better heart health, increased memory and learning functions, and the list goes on -- that they should be a daily part of everyone's diet. I suggest as much as six grams a day of fish oil taken as capsules or eaten as fish.
[Click the header to read the rest of the Health Central article.]
Thursday, March 17, 2005
The Wonders of Garlic
[Note: This is adapted from an article I published in the November 2003 issue of Equilibrium.]
A handful of studies on garlic recently grabbed my attention. I had never done much research on garlic and had read only a few review articles on garlic as an aid to reducing cholesterol and fighting off colds, none of which were conclusive in their recommendations. I thought of garlic as little more than an old folk remedy -- not worthy of further research. Sometimes, the common folk are way ahead of the scientists.
A recent study caused me to reconsider my stance and do more thorough research. The name of the study was what captivated me: "Garlic Supplementation Increases Testicular Testosterone and Decreases Plasma Corticosterone in Rats Fed a High Protein Diet" (Yuriko Oi, et al). This study was first published in 2001, so it's old news in the scientific world. But due to the nature of academic publishing -- a for-profit venture that excludes non-academics lacking the money to buy costly subscriptions or pay on an article-by-article basis -- these studies often never reach those of us who can benefit from them.
The study, which used rats as subjects, showed that high-dose treatment with garlic combined with a high-protein diet led to a statistically significant increase in testosterone and a significant decrease in corticosterone. What this means for those of us who weight train and consume larger quantities of protein is that garlic supplementation offers a natural way to get benefits (though not nearly as profound) once thought only available from steroids. Low testosterone levels are implicated in everything from prostate cancer to depression, from low libido to heart disease, and from muscle wasting to poor skin tone, so a natural way to increase T levels could provide serious health benefits.
Garlic may now join tribulus and longjack as herbal approaches to increasing testosterone in males. Increased testosterone leads to better protein synthesis, which leads to larger and stronger muscular development. The decrease in corticosterone, thought to be one of the primary mechanisms of anabolic steroids, also contributes to an increase in protein synthesis. If the study can be replicated, garlic may be the first truly natural substance that can produce the "steroid-like effects" supplement companies are always promising. But the benefits of garlic are far more varied than its use as a body composition supplement or hormone stimulant.
A study from late 2002 showed that garlic, specifically Kyolic garlic (aged garlic extract), could counter the liver damage associated with acetaminophen (Tylenol) poisoning. Acetaminophen poisoning kills 500 Americans each year and leaves thousands more with impaired liver function. Kyolic garlic, through its ability to stimulate the production of glutathione (a powerful antioxidant), may limit the damage and possibly act as an antidote, much the way alpha lipoic acid works in cases of mushroom poisoning that damage the liver. According to the study, an effective prophylactic dose to provide protection against acetaminophen poisoning was 3000 milligrams a day of Kyolic garlic.
[We could lobby to have a dangerous drug like Tylenol removed from store shelves so that we'd never need garlic to treat Tylenol poisoning, but we'd be fighting one of the biggest pharmaceutical companies in the world. With large pharmaceutical companies owning many very powerful politicians, it would be a losing fight. Besides, the government is currently busy going after non-lethal, beneficial supplements like ephedra and prohormones, so they don't have time to remove truly dangerous drugs like Tylenol from store shelves.]
Another recent study suggests garlic may reduce the risk of prostate cancer. One small clove of garlic a day, or the supplemental equivalent, lowers the risk of prostate cancer by more than half. That is serious protection against one of the most prominent forms of cancer in men. I'd speculate that this result stems from the aforementioned ability of garlic to produce increased testosterone levels, a newly discovered treatment for prostate cancer. The study suggests the same benefits can be gained by eating onions, and even better results (73 percent risk reduction) can be obtained by eating scallions. Eating garlic and onions on a regular basis may not do much for your social life, but it could prevent this dangerous form of cancer.
Yet another recent study implicates Kyolic garlic in the prevention of neuron death in the brain. Dying neurons are thought to be a contributing factor to neuro-degenerative diseases such as Alzheimer's disease. In much the same way as alpha lipoic acid stops neuron death through its antioxidant activity, garlic seems to do the same thing, although through different mechanisms. Garlic may soon be regarded as a powerful antioxidant, in the same class as ALA, blueberries, and vitamin E.
The same fine people who brought us the study showing garlic raises testosterone, and therefore protein synthesis, published a study a couple of years earlier showing garlic increases the breakdown of fat as an energy source. The study showed increases in noradrenaline and adrenaline as a result of garlic supplementation. Both of these substances trigger the body to break down fat stores for energy. Essentially, high-dose garlic might be able to replace ephedra as a natural thermogenic (heat-producing) agent, but without the associated rise in blood pressure and pulse. The results of this study inspired the one discussed above because the researchers believed the thermogenic response was due to increases in hormone levels, not to simple stimulation of the sympathetic nervous system. This speculation is based on the known ability of anabolic steroids, like testosterone, to decrease body fat stores while also increasing protein synthesis and nitrogen retention, all of which contribute to bigger muscles and lower body fat levels.
Finally, it is worth noting all the other benefits of garlic that have been more widely publicized. Garlic may be a powerful tool in fighting insulin resistance, high cholesterol, and some forms of cancers (possibly those that are estrogenic in origin, such as prostate cancer, some forms of breast cancer, and the less serious skin cancer, basal cell carcinoma). In fact, a recent study shows that basal cell carcinomas suffer apoptosis (cellular suicide) as a result of exposure to a specific garlic constituent (ajoene).
One of the best-known uses for Kyolic garlic, or at least one of the most studied, is as an immune system booster. Subjects who received 1800 mg a day of Kyolic garlic showed a 155.5 percent increase in immune-system killer-cell activity. Studies with Kyolic garlic in AIDS patients showed an ability to raise killer-cell activity from seriously low to normal. There is also evidence suggesting that garlic can kill the bacteria (Heliobacter pylori) that has been linked to stomach ulcers.
Based on available evidence, a daily intake of 1000 to 5000 milligrams of Kyolic garlic, or any standardized garlic extract, might support immune health, normalized blood sugar levels, reductions in cholesterol, increases in testosterone, reductions in corticosterone, and possible reductions in the risk for some forms of cancer. Look for individual constituents to be isolated and marketed for specific uses in the future. You could also eat one to three cloves of garlic a day to get all the herb's benefits, but be prepared to be healthy all by yourself.
(Thank you to Life Extension Magazine for publicizing many of these studies for the first time.)
A handful of studies on garlic recently grabbed my attention. I had never done much research on garlic and had read only a few review articles on garlic as an aid to reducing cholesterol and fighting off colds, none of which were conclusive in their recommendations. I thought of garlic as little more than an old folk remedy -- not worthy of further research. Sometimes, the common folk are way ahead of the scientists.
A recent study caused me to reconsider my stance and do more thorough research. The name of the study was what captivated me: "Garlic Supplementation Increases Testicular Testosterone and Decreases Plasma Corticosterone in Rats Fed a High Protein Diet" (Yuriko Oi, et al). This study was first published in 2001, so it's old news in the scientific world. But due to the nature of academic publishing -- a for-profit venture that excludes non-academics lacking the money to buy costly subscriptions or pay on an article-by-article basis -- these studies often never reach those of us who can benefit from them.
The study, which used rats as subjects, showed that high-dose treatment with garlic combined with a high-protein diet led to a statistically significant increase in testosterone and a significant decrease in corticosterone. What this means for those of us who weight train and consume larger quantities of protein is that garlic supplementation offers a natural way to get benefits (though not nearly as profound) once thought only available from steroids. Low testosterone levels are implicated in everything from prostate cancer to depression, from low libido to heart disease, and from muscle wasting to poor skin tone, so a natural way to increase T levels could provide serious health benefits.
Garlic may now join tribulus and longjack as herbal approaches to increasing testosterone in males. Increased testosterone leads to better protein synthesis, which leads to larger and stronger muscular development. The decrease in corticosterone, thought to be one of the primary mechanisms of anabolic steroids, also contributes to an increase in protein synthesis. If the study can be replicated, garlic may be the first truly natural substance that can produce the "steroid-like effects" supplement companies are always promising. But the benefits of garlic are far more varied than its use as a body composition supplement or hormone stimulant.
A study from late 2002 showed that garlic, specifically Kyolic garlic (aged garlic extract), could counter the liver damage associated with acetaminophen (Tylenol) poisoning. Acetaminophen poisoning kills 500 Americans each year and leaves thousands more with impaired liver function. Kyolic garlic, through its ability to stimulate the production of glutathione (a powerful antioxidant), may limit the damage and possibly act as an antidote, much the way alpha lipoic acid works in cases of mushroom poisoning that damage the liver. According to the study, an effective prophylactic dose to provide protection against acetaminophen poisoning was 3000 milligrams a day of Kyolic garlic.
[We could lobby to have a dangerous drug like Tylenol removed from store shelves so that we'd never need garlic to treat Tylenol poisoning, but we'd be fighting one of the biggest pharmaceutical companies in the world. With large pharmaceutical companies owning many very powerful politicians, it would be a losing fight. Besides, the government is currently busy going after non-lethal, beneficial supplements like ephedra and prohormones, so they don't have time to remove truly dangerous drugs like Tylenol from store shelves.]
Another recent study suggests garlic may reduce the risk of prostate cancer. One small clove of garlic a day, or the supplemental equivalent, lowers the risk of prostate cancer by more than half. That is serious protection against one of the most prominent forms of cancer in men. I'd speculate that this result stems from the aforementioned ability of garlic to produce increased testosterone levels, a newly discovered treatment for prostate cancer. The study suggests the same benefits can be gained by eating onions, and even better results (73 percent risk reduction) can be obtained by eating scallions. Eating garlic and onions on a regular basis may not do much for your social life, but it could prevent this dangerous form of cancer.
Yet another recent study implicates Kyolic garlic in the prevention of neuron death in the brain. Dying neurons are thought to be a contributing factor to neuro-degenerative diseases such as Alzheimer's disease. In much the same way as alpha lipoic acid stops neuron death through its antioxidant activity, garlic seems to do the same thing, although through different mechanisms. Garlic may soon be regarded as a powerful antioxidant, in the same class as ALA, blueberries, and vitamin E.
The same fine people who brought us the study showing garlic raises testosterone, and therefore protein synthesis, published a study a couple of years earlier showing garlic increases the breakdown of fat as an energy source. The study showed increases in noradrenaline and adrenaline as a result of garlic supplementation. Both of these substances trigger the body to break down fat stores for energy. Essentially, high-dose garlic might be able to replace ephedra as a natural thermogenic (heat-producing) agent, but without the associated rise in blood pressure and pulse. The results of this study inspired the one discussed above because the researchers believed the thermogenic response was due to increases in hormone levels, not to simple stimulation of the sympathetic nervous system. This speculation is based on the known ability of anabolic steroids, like testosterone, to decrease body fat stores while also increasing protein synthesis and nitrogen retention, all of which contribute to bigger muscles and lower body fat levels.
Finally, it is worth noting all the other benefits of garlic that have been more widely publicized. Garlic may be a powerful tool in fighting insulin resistance, high cholesterol, and some forms of cancers (possibly those that are estrogenic in origin, such as prostate cancer, some forms of breast cancer, and the less serious skin cancer, basal cell carcinoma). In fact, a recent study shows that basal cell carcinomas suffer apoptosis (cellular suicide) as a result of exposure to a specific garlic constituent (ajoene).
One of the best-known uses for Kyolic garlic, or at least one of the most studied, is as an immune system booster. Subjects who received 1800 mg a day of Kyolic garlic showed a 155.5 percent increase in immune-system killer-cell activity. Studies with Kyolic garlic in AIDS patients showed an ability to raise killer-cell activity from seriously low to normal. There is also evidence suggesting that garlic can kill the bacteria (Heliobacter pylori) that has been linked to stomach ulcers.
Based on available evidence, a daily intake of 1000 to 5000 milligrams of Kyolic garlic, or any standardized garlic extract, might support immune health, normalized blood sugar levels, reductions in cholesterol, increases in testosterone, reductions in corticosterone, and possible reductions in the risk for some forms of cancer. Look for individual constituents to be isolated and marketed for specific uses in the future. You could also eat one to three cloves of garlic a day to get all the herb's benefits, but be prepared to be healthy all by yourself.
(Thank you to Life Extension Magazine for publicizing many of these studies for the first time.)
Monday, March 14, 2005
Higher Education Slows Mental Declines Associated with Aging
A new report in Neuropsychology (published by the APA) suggests that the more years of education one has, the less one's memory will decline with age. [Full text of the study is available from the APA Public Affairs Office and at apa.org/journals/releases/neu192181.pdf or click the header to read an article summarizing the study.]
In a study comparing younger adults (aged 18-30 with 11-20 years of education) against older adults (65 and up with 8-21 years of education) in a memory function test, it was found that younger adult brains used the temporal lobes, while older adult brains relied more on the frontal lobes to perform the task.
This is significant in that the frontal lobes are associated with higher brain functions. The authors of the study speculate that older adults are forced to use the frontal cortex as a result of decreased access to the temporal lobes, but they did not offer a control group of less educated older adults for comparison.
I would suggest that older adults use the frontal cortex more than younger adults as a direct result of being older and not simply as a result of education. The frontal cortex is the last area of the brain to mature in adults and is thought to reach maturity in the early to mid 20's. Younger adults may not have full access to the frontal cortex. The study doesn't provide control groups, so this is just speculation.
The take-home message here is that keeping the brain active throughout life is the best way to prevent or delay mental decline from aging. Many studies have shown this to be true. Part of an integral approach to optimal health is ongoing education in whatever areas drive your interest. A sound body needs a sound mind, as well as a sound heart and a vibrant soul.
In a study comparing younger adults (aged 18-30 with 11-20 years of education) against older adults (65 and up with 8-21 years of education) in a memory function test, it was found that younger adult brains used the temporal lobes, while older adult brains relied more on the frontal lobes to perform the task.
This is significant in that the frontal lobes are associated with higher brain functions. The authors of the study speculate that older adults are forced to use the frontal cortex as a result of decreased access to the temporal lobes, but they did not offer a control group of less educated older adults for comparison.
I would suggest that older adults use the frontal cortex more than younger adults as a direct result of being older and not simply as a result of education. The frontal cortex is the last area of the brain to mature in adults and is thought to reach maturity in the early to mid 20's. Younger adults may not have full access to the frontal cortex. The study doesn't provide control groups, so this is just speculation.
The take-home message here is that keeping the brain active throughout life is the best way to prevent or delay mental decline from aging. Many studies have shown this to be true. Part of an integral approach to optimal health is ongoing education in whatever areas drive your interest. A sound body needs a sound mind, as well as a sound heart and a vibrant soul.
Sunday, March 13, 2005
Recent Studies on the Subject of Training
1) Weight Training Suppresses Myostatin: Med Sci Sports Exerc, 36: 787-793, 2004)
Myostatin is the protein in the body that limits muscle growth. Cattle that are bred without the myostatin gene grow enormous amounts of lean muscle with very little body fat, even in the absence of exercise. Weight training in humans seems to suppress expression of the myostatin gene, which allows the body to build muscle in response to the training. Several new supplements claim to even further suppress myostatin, but none have yet been tested in a labratory setting. The real future is in creating a virus that can deactivate myostatin -- a development that is no more than five years away from being reality.
2) Weight Training Is Crucial for Weight/Fat Control: Med Sci Sports Exerc, 36: 973-982, 2004)
It's only in the last few years that weight training has gained status in efforts to lose body fat. Previously, it was assumed that aerobic exercise and a low-calorie diet was enough. Some studies have shown that weight training with aerobics is the best combination for reducing abdominal fat (J Physiol Anthropol, 22: 129-135, 2003). The study did not show why this approach worked, however. A new study by Danish researchers demonstrates that fast-twitch muscle fibers (strength and power fibers) are used in weight training, while slow-twitch fibers (endurance fibers) are used in aerobics. The study showed that fast-twitch fibers burned more calories after training when slow-twitch fibers were depleted of glycogen during aerobic exercise.
Although some people prefer to do their aerobics before weight training, I recommend weight training first, which will also use up glycogen stores, followed by aerobic training. In this scenario, fat will be the primary energy source for the aerobic session.
3) Volume and Intensity Should Vary for Maximum Muscle Growth: Med Sci Sports Exerc, 36: 965-972, 2004)
Many trainees use the same set and rep schemes day in and day out, year after year, and wonder why they aren't making any progress. The body has two basic muscle fiber types (this isn't really true, but it gets very complex very quickly if all fiber types are addressed): type-I fibers are slow-twitch and are endurance fibers; type-II fibers are fast-twitch and are strength and power fibers. Type-I fibers grow with high reps (12 and above) and type-II fibers grow with lower reps (1-6). Consequently, most trainees use the standard 3 sets of 8-12 reps for each exercise in an attempt to get the best of both worlds.
The problem is that type-I fibers don't really grow very big or very fast. Type-II fibers can grow larger and, if trained correctly, can grow much faster. When type-II fibers are fatigued, type-I fibers pick up some of the slack.
Vary your training, either within a given workout (3-6 heavy sets for low reps followed by a high rep set) or within a training week (a heavy day and a light day for each muscle group). Making your muscles grow is not as simple as just lifting some weights and eating some extra protein -- there is a science to muscle growth, and understanding the science (or hiring a trainer who does) will give you much better results in the gym.
Myostatin is the protein in the body that limits muscle growth. Cattle that are bred without the myostatin gene grow enormous amounts of lean muscle with very little body fat, even in the absence of exercise. Weight training in humans seems to suppress expression of the myostatin gene, which allows the body to build muscle in response to the training. Several new supplements claim to even further suppress myostatin, but none have yet been tested in a labratory setting. The real future is in creating a virus that can deactivate myostatin -- a development that is no more than five years away from being reality.
2) Weight Training Is Crucial for Weight/Fat Control: Med Sci Sports Exerc, 36: 973-982, 2004)
It's only in the last few years that weight training has gained status in efforts to lose body fat. Previously, it was assumed that aerobic exercise and a low-calorie diet was enough. Some studies have shown that weight training with aerobics is the best combination for reducing abdominal fat (J Physiol Anthropol, 22: 129-135, 2003). The study did not show why this approach worked, however. A new study by Danish researchers demonstrates that fast-twitch muscle fibers (strength and power fibers) are used in weight training, while slow-twitch fibers (endurance fibers) are used in aerobics. The study showed that fast-twitch fibers burned more calories after training when slow-twitch fibers were depleted of glycogen during aerobic exercise.
Although some people prefer to do their aerobics before weight training, I recommend weight training first, which will also use up glycogen stores, followed by aerobic training. In this scenario, fat will be the primary energy source for the aerobic session.
3) Volume and Intensity Should Vary for Maximum Muscle Growth: Med Sci Sports Exerc, 36: 965-972, 2004)
Many trainees use the same set and rep schemes day in and day out, year after year, and wonder why they aren't making any progress. The body has two basic muscle fiber types (this isn't really true, but it gets very complex very quickly if all fiber types are addressed): type-I fibers are slow-twitch and are endurance fibers; type-II fibers are fast-twitch and are strength and power fibers. Type-I fibers grow with high reps (12 and above) and type-II fibers grow with lower reps (1-6). Consequently, most trainees use the standard 3 sets of 8-12 reps for each exercise in an attempt to get the best of both worlds.
The problem is that type-I fibers don't really grow very big or very fast. Type-II fibers can grow larger and, if trained correctly, can grow much faster. When type-II fibers are fatigued, type-I fibers pick up some of the slack.
Vary your training, either within a given workout (3-6 heavy sets for low reps followed by a high rep set) or within a training week (a heavy day and a light day for each muscle group). Making your muscles grow is not as simple as just lifting some weights and eating some extra protein -- there is a science to muscle growth, and understanding the science (or hiring a trainer who does) will give you much better results in the gym.
Sunday, March 6, 2005
Some Plastic Water Bottles Are Unsafe
A recent editor's note in Sweat Magazine, an Arizona sports and fitness resource, cites evidence that some types of water bottles are not safe and may pose serious health risks.
Type 7 plastics, which are made from polycarbonates, seem to pose the greatest health risks. These plastics leach bisphenol-A into foods and liquids stored in containers made from this substance. BPA acts like an estrogen in the body -- which is common for many chemicals leached from plastics -- and if present during certain times can cause a defect in cell division known as aneuploidy. In this condition, chromosomes do not divide evenly when the cell splits, which results in cells containing fewer chromosomes than healthy cells. According to the research, these abnormal cells can lead to cancer, miscarriage, and birth defects.
Another type of plastic that is very common in water bottles (of three major brands I looked at, all three used this form of plastic) is known as #1 PETE. This form of plastic should not be reused due to the risk of DEHA and acetaldehyde leaching from the plastic -- both of which are carcinogens.
The safest forms of plastics, according to environmental advocates, are polypropylene (#5 PP), high density polyethylene (#2 HDPE), and low density polyethylene (#4 LDPE). Look for these numbers inside the "recycle" triangle on the bottoms of plastic bottles.
If you absolutely must reuse commercial water bottles, make every effort to keep them refrigerated as much as possible and avoid leaving them in direct sunlight. Never refill them with carbonated beverages or hot liquids. Wash them with soap and water regularly and rinse them with diluted bleach water once a week.
However, your best bet is to buy some good quality, safe plastic water bottles and fill them with filtered water from a home filtering system. For those times when you need to buy bottled water, avoid the temptation to reuse it and recycle the empty bottle.
Type 7 plastics, which are made from polycarbonates, seem to pose the greatest health risks. These plastics leach bisphenol-A into foods and liquids stored in containers made from this substance. BPA acts like an estrogen in the body -- which is common for many chemicals leached from plastics -- and if present during certain times can cause a defect in cell division known as aneuploidy. In this condition, chromosomes do not divide evenly when the cell splits, which results in cells containing fewer chromosomes than healthy cells. According to the research, these abnormal cells can lead to cancer, miscarriage, and birth defects.
Another type of plastic that is very common in water bottles (of three major brands I looked at, all three used this form of plastic) is known as #1 PETE. This form of plastic should not be reused due to the risk of DEHA and acetaldehyde leaching from the plastic -- both of which are carcinogens.
The safest forms of plastics, according to environmental advocates, are polypropylene (#5 PP), high density polyethylene (#2 HDPE), and low density polyethylene (#4 LDPE). Look for these numbers inside the "recycle" triangle on the bottoms of plastic bottles.
If you absolutely must reuse commercial water bottles, make every effort to keep them refrigerated as much as possible and avoid leaving them in direct sunlight. Never refill them with carbonated beverages or hot liquids. Wash them with soap and water regularly and rinse them with diluted bleach water once a week.
However, your best bet is to buy some good quality, safe plastic water bottles and fill them with filtered water from a home filtering system. For those times when you need to buy bottled water, avoid the temptation to reuse it and recycle the empty bottle.
Wednesday, March 2, 2005
56 Percent of NFL Players Obese?
A pseudo-study [click the header to read the story at ESPN.com] conducted by University of North Carolina endocrinologist Joyce Harp and student Lindsay Hecht used player statistics on the NFL Web site to calculate BMIs for 2,168 NFL players, most of the active players in the 2003-04 season. The results showed that 56 percent of the players had a BMI of 30 or more, which would make them obese according to the standard assessment of BMI scores.
However, BMI does not take into account the body composition of the person being measured -- only the ratio of height to weight. For example, a 6' 2" player who weighs 235 pounds has a BMI of slightly over 30. Yet he might only have 10 percent body fat, which would make him very healthy. The BMI might be an adequate tool for the general population, but it isn't a reliable measure of health for athletes or anyone who trains with weights.
There are undoubtedly some players in the NFL who are overweight, especially linemen. They are a small group of players on any team. Look at the "skill" players -- quarterbacks, running backs, receivers, defensive backs, linebackers, and even tight ends -- and you're not likely to find a player with more than 12 percent body fat.
This study is not an indictment of the NFL and its players. It is, however, an indictment of how useless the BMI scale is for athletes who carry a large amount of muscle.
On a personal note, I am 6' tall and weigh in at about 210. My body fat is around 10-12 percent right now, but my BMI is 28.5, which makes me overweight (25-29) and nearly obese (30 or higher). If insurance companies were to use BMI numbers to determine health risks on policies, my rates would be unfairly high considering my overall health and body composition.
However, BMI does not take into account the body composition of the person being measured -- only the ratio of height to weight. For example, a 6' 2" player who weighs 235 pounds has a BMI of slightly over 30. Yet he might only have 10 percent body fat, which would make him very healthy. The BMI might be an adequate tool for the general population, but it isn't a reliable measure of health for athletes or anyone who trains with weights.
There are undoubtedly some players in the NFL who are overweight, especially linemen. They are a small group of players on any team. Look at the "skill" players -- quarterbacks, running backs, receivers, defensive backs, linebackers, and even tight ends -- and you're not likely to find a player with more than 12 percent body fat.
This study is not an indictment of the NFL and its players. It is, however, an indictment of how useless the BMI scale is for athletes who carry a large amount of muscle.
On a personal note, I am 6' tall and weigh in at about 210. My body fat is around 10-12 percent right now, but my BMI is 28.5, which makes me overweight (25-29) and nearly obese (30 or higher). If insurance companies were to use BMI numbers to determine health risks on policies, my rates would be unfairly high considering my overall health and body composition.
Tuesday, March 1, 2005
Use Vinegar to Improve Insulin Levels
Can't decide which salad dressing to get when you're out for lunch? Go for the vinaigrette. An increasing body of research is supporting the use of vinegar to control blood sugar and reduce the risk of developing diabetes.
From the ScienceDaily article: "The vinegar study, which was published in Diabetes Care, involved 10 people with type 2 diabetes, 11 people with prediabetes who are at high risk for diabetes and eight healthy people. Before eating a breakfast of orange juice and a bagel with butter, which contained 87 grams of carbohydrates, the participants were assigned to consume 2 tablespoons of apple cider vinegar in a glass of water sweetened with saccharine, or a placebo. A week later, the placebo and vinegar groups switched, and then ate the same breakfast.
The researchers, led by Carol Johnston, PhD, RD, a professor of nutrition at Arizona State University, measured the participants' blood sugar before and after the breakfast. They found that vinegar consumption slowed the rise of blood sugar after the high-carbohydrate meal. In all three groups, the vinegar led to improvements in blood sugar levels after the meal, though it had the biggest impact on people with prediabetes, cutting their blood sugar levels after the meal by 34 percent. In people with diabetes, blood sugar levels dropped by about 20 percent with the vinegar."
Researchers believe that vinegar reduces the rise in blood sugar that occurs after a meal by interfering with the absorption of the high-carbohydrate foods. "The acetic acid in vinegar may inhibit enzymes that digest starch," Dr. Johnston explains. "So the carbohydrate molecules aren't available for absorption and are eliminated as fecal matter."
However, many strength athletes use vinegar when trying to gain weight in an effort to reduce the accretion of body fat that often accompanies "bulking cycles" in training. Anecdotal evidence suggests that vinegar makes the body more sensitive to insulin, which reduces the amount of insulin needed after a meal to process the calories. This lowers blood sugar levels, as found in the study (the lower percentage of improvement in the diabetics likely results from their already compromised insulin function), but it also minimizes the amount of calories stored as fat and increases the storage of glucose in muscle tissue.
Choose vinegar that contains 5 percent acetic acid. Different types of vinegar, including balsamic, red wine, apple cider, and white vinegar, may have this concentration. One to two tablespoons before a meal should be adequate to obtain the desired increase in insulin sensitivity.
From the ScienceDaily article: "The vinegar study, which was published in Diabetes Care, involved 10 people with type 2 diabetes, 11 people with prediabetes who are at high risk for diabetes and eight healthy people. Before eating a breakfast of orange juice and a bagel with butter, which contained 87 grams of carbohydrates, the participants were assigned to consume 2 tablespoons of apple cider vinegar in a glass of water sweetened with saccharine, or a placebo. A week later, the placebo and vinegar groups switched, and then ate the same breakfast.
The researchers, led by Carol Johnston, PhD, RD, a professor of nutrition at Arizona State University, measured the participants' blood sugar before and after the breakfast. They found that vinegar consumption slowed the rise of blood sugar after the high-carbohydrate meal. In all three groups, the vinegar led to improvements in blood sugar levels after the meal, though it had the biggest impact on people with prediabetes, cutting their blood sugar levels after the meal by 34 percent. In people with diabetes, blood sugar levels dropped by about 20 percent with the vinegar."
Researchers believe that vinegar reduces the rise in blood sugar that occurs after a meal by interfering with the absorption of the high-carbohydrate foods. "The acetic acid in vinegar may inhibit enzymes that digest starch," Dr. Johnston explains. "So the carbohydrate molecules aren't available for absorption and are eliminated as fecal matter."
However, many strength athletes use vinegar when trying to gain weight in an effort to reduce the accretion of body fat that often accompanies "bulking cycles" in training. Anecdotal evidence suggests that vinegar makes the body more sensitive to insulin, which reduces the amount of insulin needed after a meal to process the calories. This lowers blood sugar levels, as found in the study (the lower percentage of improvement in the diabetics likely results from their already compromised insulin function), but it also minimizes the amount of calories stored as fat and increases the storage of glucose in muscle tissue.
Choose vinegar that contains 5 percent acetic acid. Different types of vinegar, including balsamic, red wine, apple cider, and white vinegar, may have this concentration. One to two tablespoons before a meal should be adequate to obtain the desired increase in insulin sensitivity.
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