An article published in the British Journal of Nutrition summarizes the roles of select vitamins and trace elements in immune function. Adequate intakes of micronutrients are required for the immune system to function efficiently. Micronutrient deficiency suppresses immunity by affecting antibody responses, leading to imbalances in the immune system. This situation increases susceptibility to infections, which increases disease and death risk. In addition, infections aggravate micronutrient deficiencies by reducing nutrient intake, increasing losses, and interfering with utilization by altering metabolic pathways. Inadequate intakes of micronutrients are common in people with eating disorders, smokers (active and passive), individuals with chronic alcohol abuse, certain diseases, during pregnancy and lactation, and in the elderly.
Micronutrients contribute to the body's natural defenses on three levels by supporting physical barriers (skin/mucosa), cellular immunity, and antibody production. Vitamins A, C, E, and the mineral zinc assist in enhancing the skin barrier function. Vitamins A, B6, B12, C, D, E, and folic acid, and the minerals iron, zinc, copper and selenium work synergistically to support the protective activities of the immune cells. Finally, all these micronutrients, with the exception of vitamin C and iron, are essential for the production of antibodies.
Overall, inadequate intake and status of these vitamins and minerals may lead to a suppressed immune system, which increases the risk of infections and aggravates malnutrition. Therefore, supplementation with a multivitamin that includes these micronutrients can support the body's natural defense system by enhancing all three levels of immunity.
Source: Br J Nutr. 2007 Oct;98 Suppl 1:S29-35.
Wednesday, April 29, 2009
Wednesday, April 1, 2009
Why Cholesterol-Free Foods Can Be Dangerous
By Dr. W. Gifford Jones
March 27, 2005
Today the word "cholesterol" has become as familiar to Americans as motherhood and apple pie. But unlike these two it's unloved and meant to be avoided. So if you're a marketing whiz kid, would you try to increase sales with a red label stating your product is "cholesterol free"? Unfortunately, life is never so simple and there are several marketing conundrums for both promoters and unsuspecting consumers. And do cholesterol-lowering drugs (CLDs) exchange one devil for another?
Dr. Khhursheed Jeejeebhoy, professor of medicine at the University of Toronto, reported in The Medical Post that consumers don't realize that many cholesterol-free foods contain large amounts of sugar and trans-fatty acids .
This is not a healthy combination. Too much sugar and excess calories of any kind are linked to obesity, diabetes and heart disease. And trans-fatty acids have been associated with cardiovascular problems.
But not only advertising companies have befuddled the public about nutrition. What researchers claim to be gospel one day is not the whole truth the next. It's no wonder that many people are confused about cholesterol, fats and other dietary proposals.
The first misconception occurred when blood cholesterol level became the be-all-and-end-all as the cause of heart disease. Some researchers questioned that.
They discovered that almost 50 per cent of patients with coronary artery disease had normal blood cholesterol levels. In fact, Dr. Jeejeebhoy points out that some East Asians with severe coronary disease were found to have either normal or low levels of blood cholesterol.
Another study showed that men in Scotland and Sweden had the same blood cholesterol levels, but Scottish males had three times the number of heart attacks as the Swedes. Obviously something else was happening. Were the Scots drinking too much of their own scotch? Or not eating enough vegetables and fruits which are harder to get in Scotland?
Later researchers concluded that saturated fats were the bad guys on the street increasing blood cholesterol. This is when consumers began to use margarine with polyunsaturated fats and started cooking food in corn oil rather than butter.
Recently scientists discovered that there are also good and bad polyunsaturated fatty acids. The bad ones, Omega-6 fatty acids present in cookies and packaged foods, promote inflammation and blood clots. Omega-3 fatty acids found in fish decrease the risk of inflammation and heart attack.
Today another factor has been found to play an increasing role in heart disease. It's called insulin resistance. Type 1 diabetes is a genetic problem in which too little insulin is produced by the pancreas. Type 2 diabetes occurs when there are sufficient amounts of insulin but the cells refuse to accept it. It's like having a tank full of gas, but the engine won't use it because of obesity.
Today obesity causes 90 percent of diabetes. And 50 per cent of diabetics are destined to die from heart disease. What a sad commentary on our way of life!
I don't have a crystal ball to predict the outcome of all these studies. At the moment millions of people are taking cholesterol-lowering drugs (CLDs). A recent report published in The New England Journal of Medicine shows what happens when larger doses of Lipitor, the most popular of the CLDs, are prescribed.
As suspected it decreased the risk of dying from cardiovascular diseases. But they increased the risk of dying from other diseases and failed to show an overall reduction in deaths. In effect, patients were exchanging one way of dying for another. This is not an enticing trade.
I wish I could be convinced that the billions spent on cholesterol-lowering drugs is a good bargain. But I've always been concerned that it's questionable to push for lower and lower levels of cholesterol, a vital substance for many bodily functions. Particularly, when we know that CLDs have been associated with liver inflammation, muscle degeneration and death.
I believe history will show that more lives would be saved if people paid more attention to the numbers on the weight scale, and stayed away from packaged foods loaded with calories, sugar and the wrong fats.
Source: http://www.canadafreepress.com/medical/cardio-vascular032705.htm
Omega-3 fatty acids key to cell health
By Judy Fortin
CNN
ATLANTA, Georgia (CNN) -- The name sounds like something out of a science fiction novel, but omega-3 fatty acids are a necessary part of our diet. "Every cell in the body requires omega-3 to function normally," says Dr. Andrew Stoll, author of "The Omega-3 Connection." "They are a class of fats, good fats that are actually as essential as vitamins to our health."
Researchers discovered that omega-3 protects the heart about 30 years ago. Doctors now know that the compound controls inflammation and protects cells by forming part of the cell membrane. "We know that omega-3 can protect the heart, the lungs, the kidneys, really every organ system that we know of, including the brain," says Stoll.
The problem is that most Americans don't get enough of the compound in their diet. Part of the reason, Stoll says, is they don't eat enough fish.
Fatty fish such as salmon, mackerel, herring and sardines are the best sources of omega-3 for the diet. For most patients, Stoll recommends one or two servings of the cooked fish a week. Unlike other fish, which store the compound in their liver, the four recommended varieties store the compound in their muscles, which are eaten by humans.
While certain fish are loaded with omega-3 and protein, they also contain some mercury, dioxins and PCBs. "It's a difficult situation to balance out," explains Stoll. "You need to eat some fish to be healthy, but if you eat too much fish, you're putting yourself at risk. ... So most Americans just can't eat enough fish to get omega-3 in their diet."
Stoll cautions pregnant women, those who are nursing and young children from eating any fish. He says toxins can be harmful to developing babies and youngsters.
Stoll suggests taking a daily fish oil supplement instead or finding another source. Vegetarians, for instance, can get the compound from specially enriched omega-3 eggs.
Flaxseed is another source of a different type of omega-3. Stoll says it's a good way to increase your fiber, but flax doesn't offer the same benefits of the compound found in fatty fish. He also warns that the bodies of two-thirds of the population cannot convert the omega-3 found in flaxseed.
According to Stoll, "Taking more than three tablespoons a day of raw flaxseed or ground flaxseed can inhibit the uptake of iodine in the thyroid, which can produce a goiter or enlargement of the thyroid gland."
While Stoll doesn't call omega-3 a dietary miracle, he does say, "We need it for optimal health. ... If you have very little omega-3 in your diet, you will be prone to inflammatory disorders."
Judy Fortin is a correspondent with CNN Medical News
CNN
ATLANTA, Georgia (CNN) -- The name sounds like something out of a science fiction novel, but omega-3 fatty acids are a necessary part of our diet. "Every cell in the body requires omega-3 to function normally," says Dr. Andrew Stoll, author of "The Omega-3 Connection." "They are a class of fats, good fats that are actually as essential as vitamins to our health."
Researchers discovered that omega-3 protects the heart about 30 years ago. Doctors now know that the compound controls inflammation and protects cells by forming part of the cell membrane. "We know that omega-3 can protect the heart, the lungs, the kidneys, really every organ system that we know of, including the brain," says Stoll.
The problem is that most Americans don't get enough of the compound in their diet. Part of the reason, Stoll says, is they don't eat enough fish.
Fatty fish such as salmon, mackerel, herring and sardines are the best sources of omega-3 for the diet. For most patients, Stoll recommends one or two servings of the cooked fish a week. Unlike other fish, which store the compound in their liver, the four recommended varieties store the compound in their muscles, which are eaten by humans.
While certain fish are loaded with omega-3 and protein, they also contain some mercury, dioxins and PCBs. "It's a difficult situation to balance out," explains Stoll. "You need to eat some fish to be healthy, but if you eat too much fish, you're putting yourself at risk. ... So most Americans just can't eat enough fish to get omega-3 in their diet."
Stoll cautions pregnant women, those who are nursing and young children from eating any fish. He says toxins can be harmful to developing babies and youngsters.
Stoll suggests taking a daily fish oil supplement instead or finding another source. Vegetarians, for instance, can get the compound from specially enriched omega-3 eggs.
Flaxseed is another source of a different type of omega-3. Stoll says it's a good way to increase your fiber, but flax doesn't offer the same benefits of the compound found in fatty fish. He also warns that the bodies of two-thirds of the population cannot convert the omega-3 found in flaxseed.
According to Stoll, "Taking more than three tablespoons a day of raw flaxseed or ground flaxseed can inhibit the uptake of iodine in the thyroid, which can produce a goiter or enlargement of the thyroid gland."
While Stoll doesn't call omega-3 a dietary miracle, he does say, "We need it for optimal health. ... If you have very little omega-3 in your diet, you will be prone to inflammatory disorders."
Judy Fortin is a correspondent with CNN Medical News
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