Tuesday, December 20, 2011

Is It a Food Allergy or Intolerance?

From WebMD:

What Is a Food Allergy?

A food allergy is an immune system response. It occurs when the body mistakes an ingredient in food -- usually a protein -- as harmful and creates a defense system (antibodies) to fight it. Food allergy symptoms develop when the antibodies are battling the "invading" food. The most common food allergies are peanuts, tree nuts (such as walnuts, pecans and almonds), fish, and shellfish, milk, eggs, soy products, and wheat.


What Is Food Intolerance?

Food intolerance is a digestive system response rather than an immune system response. It occurs when something in a food irritates a person's digestive system or when a person is unable to properly digest or breakdown, the food. Intolerance to lactose, which is found in milk and other dairy products, is the most common food intolerance.


What Are the Symptoms of a Food Allergy?

Symptoms of a food allergy can range from mild to severe, and the amount of food necessary to trigger a reaction varies from person to person. Symptoms of a food allergy may include:

  • Rash or hives
  • Nausea
  • Stomach pain
  • Diarrhea
  • Itchy skin
  • Shortness of breath
  • Chest pain
  • Swelling of the airways to the lungs
  • Anaphylaxis
What Are the Symptoms of Food Intolerance?

Symptoms of food intolerance include:
  • Nausea
  • Stomach pain
  • Gas, cramps, or bloating
  • Vomiting
  • Heartburn
  • Diarrhea
  • Headaches
  • Irritability or nervousness

How Common Are Food Allergies and Intolerances?

Food allergies affect about 4% of teens and adults and 5% of children. Food intolerances are much more common. In fact, nearly everyone at one time has had an unpleasant reaction to something they ate. Some people have specific food intolerances. Lactose intolerance, the most common food intolerance, affects about 10% of Americans.

What Causes Food Allergies and Intolerances?

Food allergies arise from sensitivity to chemical compounds (proteins) in food. They develop after you are exposed to a food protein that your body thinks is harmful. The first time you eat the food containing the protein, your immune system responds by creating specific disease-fighting antibodies (called immunoglobulin E or IgE). When you eat the food again, it triggers the release of IgE antibodies and other chemicals, including histamine, in an effort to expel the protein "invader" from your body. Histamine is a powerful chemical that can affect the respiratory system, gastrointestinal tract, skin, or cardiovascular system.


As a result of this response, food allergy symptoms occur. The allergy symptoms you have depend on where in the body the histamine is released. If it is released in the ears, nose, and throat, you may have an itchy nose and mouth, or trouble breathing or swallowing. If histamine is released in the skin, you may develop hives or a rash. If histamine is released in the gastrointestinal tract, you likely will develop stomach pains, cramps, or diarrhea. Many people experience a combination of symptoms as the food is eaten and digested.
Food allergies often run in families, suggesting that the condition can be inherited.


There are many factors that may contribute to food intolerance. In some cases, as with lactose intolerance, the person lacks the chemicals, called enzymes, necessary to properly digest certain proteins found in food. Also common are intolerances to some chemical ingredients added to food to provide color, enhance taste, and protect against the growth of bacteria. These ingredients include various dyes and monosodium glutamate (MSG), a flavor enhancer.


Substances called sulfites are also a source of intolerance for some people. They may occur naturally, as in red wines or may be added to prevent the growth of mold.


Salicylates are a group of plant chemicals found naturally in many fruits, vegetables, nuts, coffee, juices, beer, and wine. Aspirin also is a compound of the salicylate family. Foods containing salicylates may trigger allergy symptoms in people who are sensitive to aspirin. Of course, any food consumed in excessive quantities can cause digestive symptoms.


How Can You Tell the Difference Between a Food Allergy and Intolerance?

Food allergies can be triggered by even a small amount of the food and occur every time the food is consumed. People with food allergies are generally advised to avoid the offending foods completely. On the other hand, food intolerances often are dose related.


People with food intolerance may not have symptoms unless they eat a large portion of the food or eat the food frequently. For example, a person with lactose intolerance may be able to drink milk in coffee or a single glass of milk, but becomes sick if he or she drinks several glasses of milk.


Food allergies and intolerances also are different from food poisoning, which generally results from spoiled or tainted food and affects more than one person eating the food. Your health care provider can help determine if you have an food allergy or intolerance, and establish a plan to help control your symptoms.


How Are Food Intolerances Diagnosed?

Most food intolerances are found through trial and error to determine which food or foods cause symptoms. You may be asked to keep a food diary to record what you eat and when you get symptoms, and then look for common factors.
Another way to identify problem foods is to go on an elimination diet. This involves completely eliminating any suspect foods from your diet until you are symptom-free. You then begin to reintroduce the foods, one at a time. This can help you pinpoint which foods cause symptoms. Seek the advice of your health care provider or a registered dietitian before beginning an elimination diet to be sure your diet provides adequate nutrition.


How Are Food Intolerances Treated?


Treatment for a food intolerance is based on avoiding or reducing your intake of problem foods and treating symptoms when they arise.

Can Food Intolerances Be Prevented?

Taking a few simple steps can help you prevent the symptoms associated with food intolerance.


Learn which foods in which amounts cause you to have symptoms and limit your intake to amounts you can handle.

When you dine out, ask your server about how your meal will be prepared. Some meals may contain foods you cannot tolerate and that may not be evident from the description on the menu.

Learn to read food labels and check the ingredients for problem foods. Don't forget to check condiments and seasonings. They may contain MSG or another additive that can lead to symptoms.

Fibromyalgia Symptoms

Reviewed By Laura J. Martin, MD
What Are the Symptoms of Fibromyalgia?

Symptoms of fibromyalgia include:
  • Chronic muscle pain, muscle spasms or tightness, weakness in the limbs, and leg cramp
  • Moderate or severe fatigue and decreased energy
  • Insomnia or waking up feeling just as tired as when you went to sleep
  • Stiffness upon waking or after staying in one position for too long
  • Difficulty remembering, concentrating, and performing simple mental tasks (“fibro fog”)
  • Abdominal pain, bloating, nausea, and constipation alternating with diarrhea (irritable bowel syndrome)
  • Tension or migraine headaches
  • Jaw and facial tenderness
  • Sensitivity to one or more of the following: odors, noise, bright lights, medications, certain foods, and cold
  • Feeling anxious or depressed
  • Numbness or tingling in the face, arms, hands, legs, or feet
  • Increase in urinary urgency or frequency (irritable bladder)
  • Reduced tolerance for exercise and muscle pain after exercise
  • A feeling of swelling (without actual swelling) in the hands and feet
  • Painful menstrual periods
  • Dizziness

Fibromyalgia symptoms may intensify depending on the time of day -- morning, late afternoon, and evening tend to be the worst times, while 11 a.m. to 3 p.m. tends to be the best time. Symptoms may also get worse with fatigue, tension, inactivity, changes in the weather, cold or drafty conditions, overexertion, hormonal fluctuations (such as just before your period or during menopause), stress, depression, or other emotional factors.


If the condition is not diagnosed and treated early, symptoms can go on indefinitely, or they may disappear for months and then recur.

Who Gets Allergies?

Allergies can develop at any age, possibly even in the womb. They commonly occur in children but may give rise to symptoms for the first time in adulthood. Asthma may persist in adults while nasal allergies tend to decline in old age.


Why, you may ask, are some people "sensitive" to certain allergens while most are not? Why do allergic people produce more IgE than those who are non-allergic? The major distinguishing factor appears to be heredity. For some time, it has been known that allergic conditions tend to cluster in families. Your own risk of developing allergies is related to your parents' allergy history. If neither parent is allergic, the chance that you will have allergies is about 15%. If one parent is allergic, your risk increases to 30% and if both are allergic, your risk is greater than 60%.


Although you may inherit the tendency to develop allergies, you may never actually have allergy symptoms. You also do not necessarily inherit the same allergies or the same diseases as your parents. It is unclear what determines which substances will trigger a reaction in an allergic person. Additionally, which diseases might develop or how severe the symptoms might be is unknown.


Another major piece of the allergy puzzle is the environment. It is clear that you must have a genetic tendency and be exposed to an allergen in order to develop an allergy. Additionally, the more intense and repetitive the exposure to an allergen and the earlier in life it occurs, the more likely it is that an allergy will develop.


There are other important influences that may conspire to cause allergic conditions. Some of these include smoking, pollution, infection, and hormones.

Could Losing Weight Ease Your Arthritis Pain?

By Gina Shaw

For 12 years, Robin Lutchansky spent most of her time in a wheelchair. The pain from her severe osteoarthritis, first diagnosed in her early 30s, made it difficult to walk more than short distances.

Then, a little over three years ago, Lutchansky found her way to a pain management clinic that taught her how to exercise -- first, teaching her how to walk again. Over the next three years, Lutchansky, now 51, gradually lost nearly 100 pounds with calorie reduction and exercise.


“I did it slowly. I started out just lifting 2-pound weights, and I walked in the pool every day,” she says.


Today, Lutchansky is out of the wheelchair and back at work as a public relations representative for a high-tech firm, and says that her daily pain levels have gone from an 8 or a 9 to a 1. “It’s amazing. It’s a new life. I had no idea it was possible.”

What Weight Does to Your Joints

If you are at all overweight, one of the best ways to reduce osteoarthritis pain is by taking off excess pounds. Being overweight increases the load that you put on your joints -- your knees, your hips, your ankle -- with every step you take.


“When we walk, when we go up and down stairs, or get into or out of a chair or car, we can put three to five times our body weight, and sometimes more, on the joints,” says Geoffrey Westrich, attending orthopedic surgeon and Director of Joint Replacement Research at the Hospital for Special Surgery in New York. “So if you’re 50 pounds overweight, you’re putting around 250 pounds of increased stress across your knees and hips."


Over time, that extra weight makes you much more prone to developing arthritis and can cause arthritis to progress much more rapidly, leading to much more pain once it has developed.


Fortunately, the same principle works in reverse. “For every pound people lose, they lose 3 pounds of stress across their knee and 6 pounds of stress on their hip, on average,” says Westrich.


Small Steps, Big Changes

You don’t have to lose 100 pounds, like Lutchansky, to see a difference in your pain levels. C. Thomas Vangsness, Jr., MD, professor of orthopaedic surgery and chief of sports medicine at the Keck School of Medicine at the University of Southern California, says most of his arthritis patients who lose weight notice that their pain is diminishing after losing about 20 pounds.


Jane Angelich, a 58-year-old California businesswoman, has lost 33 pounds on Weight Watchers.

“What a difference!” she says. “It starts when I get out of bed in the morning. No more limping around and groaning for the first few minutes. Instead of finding excuses to sit on my couch instead of walking around, I now walk the equivalent of a 5k without any issues and can even function the next day!”

Losing weight cannot repair the damage that’s already been done to your joints by arthritis, but in addition to decreasing your pain, it can also help to slow down the further progression of the disease. One study found that knee osteoarthritis in obese men would decrease by 21.5% if they lost enough weight to be categorized as merely overweight; for women, arthritis would decrease by 31%.


“The damage is already done, and arthritis is a progressive process,” says Westrich. “But weight loss can be tremendously helpful in alleviating pain, allowing greater function, and prolonging the period of time before someone needs joint replacement surgery.”



And if you haven’t developed arthritis but you’re worried about it, losing excess weight can significantly lower your risk. If you’re significantly overweight, every 11 pounds you lose cuts your risk of developing arthritis by more than 50%.


Making It Happen

The best way to lose weight, any doctor will tell you, is to eat less, eat healthy foods, and exercise more. But while someone with arthritis can start to change their eating habits in pretty much the same way that someone without the disease can, having arthritis makes exercise a little more complicated.
High-impact exercise, like running, jogging, and aerobics, can put too much stress on the joints, so doctors recommend against these activities. “They can hasten the arthritis process and cause injury,” says Westrich.

Instead, Vangsness recommends that his patients pursue one of three types of exercise that are particularly well suited for people with arthritis:
  • Swimming
  • Cycling (especially on a recumbent stationary bike, which is easier on knees and hips than a standard bike)
  • Elliptical trainers
“These all get your heart rate up without putting any stress on the knee,” he says. “The buoyancy of water helps to alleviate pain during water exercise. And working out using a stationary bike or an elliptical trainer can help strengthen key muscles like the quadriceps. If your quadriceps are strong, that can cushion the ‘heel strike’ moment when you step forward while walking, and decrease pain as well.”


He adds that some of his extremely obese patients have gotten their weight loss started through gastric bypass or gastric banding surgery. “They start peeling off the pounds, and this tremendous loss of weight really knocks down their pain,” he says. “It’s like a whole new knee. And after losing that weight, they can exercise where they couldn’t before, strengthen their muscles, and further reduce pain.”

Vitamin D FAQ: Vitamin D Sources, Deficiency and Intake

The Truth About Vitamin D


By Daniel J. DeNoon
The hottest topic in medicine isn't the newest drug or the latest surgical device. It's vitamin D.

What brought the simmering debate to a boil was a 2007 study showing that people taking normal vitamin D supplements were 7% less likely to die than those who didn't take the daily supplements.

A year later, a major study found that when women with low vitamin D levels get breast cancer, they have a much higher chance of dying from their cancer than women with normal vitamin D levels.
That was surprising news. But just as surprising are assertions that many men, women, and children have insufficient blood levels of this important vitamin.

How many? Data suggest many of us don't get the vitamin D we need. For example, one study of childbearing women in the Northern U.S. found insufficient vitamin D levels in 54% of black women and in 42% of white women.

These findings led the American Academy of Pediatrics to double the recommended amount of vitamin D a child should take -- and have led many doctors to advise their adult patients to increase their vitamin D intake.

Not so fast, says an expert panel convened by the prestigious Institute of Medicine. In its long-awaited November 2010 report, the IOM committee expressed dismay at the idea that many people are vitamin D deficient.

"Of great concern recently have been reports of widespread vitamin D deficiency in the North American population," the committee wrote. "The concern is not well founded. In fact, the cut-point values used to define deficiency, or as some have suggested, 'insufficiency,' have not been established systematically using data from studies of good quality."

The IOM committee put its emphasis on what science has proved, not on what studies may suggest. Using this conservative approach, the committee found no proof that vitamin D has health effects beyond building strong bones.

"While the current interest in vitamin D as a nutrient with broad and expanded benefits is understandable, it is not supported by the available evidence," the IOM committee concluded.

  
Why do I need vitamin D?

Your body must have vitamin D to absorb calcium and promote bone growth. Too little vitamin D results in soft bones in children (rickets) and fragile, misshapen bones in adults (osteomalacia). You also need vitamin D for other important body functions.

Vitamin D deficiency has now been linked to breast cancer, colon cancer, prostate cancer, heart disease, depression, weight gain, and other maladies. These studies show that people with higher levels of vitamin D have a lower risk of disease, although they do not definitively prove that lack of vitamin D causes disease -- or that vitamin D supplements would lower risk.
The Vitamin D Council -- a scientist-led group promoting vitamin D deficiency awareness -- suggests vitamin D treatment might be found helpful in treating or preventing autism, autoimmune disease, cancer, chronic pain, depression, diabetes, heart disease, high bloodpressure, flu, neuromuscular diseases, and osteoporosis. However, there have been no definitive clinical trials.

That's why the Institute of Medicine expert committee's November 2010 review found no conclusive evidence that vitamin D, by itself, offers wide-ranging health benefits.

"Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake," the IOM committee concluded.

The only proven benefit of vitamin D is its role in helping calcium build strong bones. But that's far from the whole story. Vitamin D helps regulate the immune system and the neuromuscular system. Vitamin D also plays major roles in the life cycle of human cells.
Vitamin D is so important that your body makes it by itself -- but only after skin exposure to sufficient sunlight. This is a problem for people in northern climates. In the U.S., only people who live south of a line drawn from Los Angeles to Columbia, S.C., get enough sunlight for vitamin D production throughout the year.

Dark skin absorbs less sunlight, so people with dark skin do not get as much vitamin D from sun exposure as do light-skinned people. This is a particular problem for African-Americans in the northern U.S.


How can I get enough vitamin D?

Thirty minutes of sun exposure to the face, legs, or back -- without sunscreen -- at least twice a week should give you plenty of vitamin D.

But this much direct sun exposure might also expose you to potentially dangerous levels of cancer-causing UV radiation. And unless you live in the South or Southwest, you probably won't get enough sunlight during the winter months for your body to make enough vitamin D. The American Academy of Dermatology recommends against getting vitamin D from unprotected exposure to sunlight.
It's probably a better idea to get vitamin D from foods or from supplements.

Will a vitamin D test tell me if I need more vitamin D?

That depends on whom you ask. As part of your regular blood test, your doctor can order a test for 25-hydroxyvitamin D (25-OHD).

The problem is not with the test. The problem is how to interpret the results. An expert committee convened by the Institute of Medicine in November 2010 concluded that "the cut-point values used to define deficiency, or as some have suggested, 'insufficiency,' have not been established systematically using data from studies of good quality."

Even so, most experts agree that anyone with a 25-OHD level of less than 15 ng/mL or 37.5 nmol/L (depending on the units reported by a lab) needs more vitamin D. A 2002 study found that 42% of African-American women of childbearing age had vitamin D levels below 15 ng/mL.
The IOM committee says that people are at risk of vitamin D deficiency at 25-OHD levels below 30 nmol/L (12 ng/mL), and that some people -- but not everyone -- may be at risk of vitamin D deficiency at 25-OHD levels from 30 nmol/L up to 50 nmol/L (12-20 ng/mL).
The Vitamin D Council considers the ideal 25-OHD level to be between 40 ng/mL and 70 ng/mL. But the IOM says there is no evidence of increased benefit at levels above 30 ng/mL, and that "there may be reason for concern" at levels above 50 ng/mL.
"There is a critical public health and clinical practice need for consensus cut-points for serum 25-OHD," the IOM committee states

Which foods contain vitamin D?

Surprisingly few foods contain vitamin D -- unless it's added to the food. That's because your body is built to get vitamin D through your skin (from sunlight) rather than through your mouth (by food). But once your body has enough, it doesn't matter whether you got it through your skin or through your stomach.

There are three vitamin D super foods:

  • Salmon (especially wild-caught)
  • Mackerel (especially wild-caught; eat up to 12 ounces a week of a variety of fish and shellfish that are low in mercury)
  • Mushrooms exposed to ultraviolet light to increase vitamin D

Other food sources of vitamin D include:
  • Cod liver oil (warning: cod liver oil is rich in vitamin A; too much may be bad for you)
  • Tuna canned in water
  • Sardines canned in oil
  • Milk or yogurt -- regardless of whether it's whole, nonfat, or reduced fat -- fortified with vitamin D
  • Beef or calf liver
  • Egg yolks
  • Cheese

Nearly all milk in the U.S. is fortified with vitamin D. So are many brands of orange juice, yogurt, margarine, and ready-to-eat breakfast cereals.


How much vitamin D do I need?

In November 2010, the Institute of Medicine's expert committee set a new "dietary reference intake" for vitamin D.
Assuming that a person gets virtually no vitamin D from sunshine -- and that this person gets adequate amounts of calcium -- the IOM committee recommends getting the following amounts of vitamin D from diet or supplements (Note that the IOM's upper limit is not a recommended intake, but what the IOM considers the highest safe level):
Infants age 0 to 6 months: adequate intake, 400 IU/day; maximum safe upper level of intake, 1,000 IU/day

Infants age 6 to 12 months: adequate intake, 400 IU/day; maximum safe upper level of intake, 1,500 IU/day

Age 1-3 years: adequate intake, 600 IU/day; maximum safe upper level of intake, 2,500 IU/day

Age 4-8 years: adequate intake, 600 IU/day; maximum safe upper level of intake, 3,000 IU/day

Age 9-70: adequate intake, 600 IU/day; maximum safe upper level of intake, 4,000 IU/day

Age 71+ years: adequate intake, 800 IU/day; maximum safe upper level of intake, 4,000 IU/day

That's not enough, says Boston University vitamin D expert Michael Holick, MD, PhD, professor of medicine, physiology, and biophysics, Boston University Medical Center. Holick recommends a dose of 1,000 IU a day of vitamin D for both infants and adults -- unless they're getting plenty of safe sun exposure.
  
In 2008, the American Academy of Pediatrics recommended that breastfed infants receive 400 IU of vitamin D every day until they are weaned. This doubled the AAP's previous recommendation.
The AAP also recommends 400 IU/day of vitamin D for children and teens who drink less than a quart of vitamin D-fortified milk per day.
The Vitamin D Council recommends that healthy adults take 2,000 IU of vitamin D daily -- more if they get little or no sun exposure.
There's evidence that people with a lot of body fat need more vitamin D than lean people.

But it's clear that the IOM's conservative recommendations will stir debate in the scientific and medical communities. Here's a rule of thumb: If you're considering taking more vitamin D than the IOM committee recommends, first check with your doctor or pediatrician.

Can I get too much vitamin D?

Too much of any good thing is a bad thing. Too much vitamin D can cause an abnormally high blood calcium level, which could result in nausea, constipation, confusion, abnormal heart rhythm, and even kidney stones

It's nearly impossible to get too much vitamin D from sunlight or from foods (unless you take way too much cod liver oil). Nearly all vitamin D overdoses come from supplements.
The Institute of Medicine's Food and Nutrition Board's old 1997 recommendations suggested that 2,000 IU per day of vitamin D is safe for adults and that 1,000 IU per day is safe for infants up to 12 months of age. Many observers expected a drastic increase in the IOM's 2010 update.

That didn't exactly happen. The IOM committee did increase its "upper level intake" -- that is, the boundary at which it feared vitamin D would become unsafe. That dose is 4,000 IU/day for adults, 3,000 IU/day for kids ages 4-8, 2,500 IU/day for kids ages 1-3, 1,500 IU/day for infants ages 6-12 months, and 1,000 IU/day for infants ages 0-6 months.
But some recent studies suggest that healthy adults can tolerate more than 10,000 IU of vitamin D per day. John Jacob Cannell, MD, executive director of The Vitamin D Council, notes that the skin makes 10,000 IU of vitamin D after 30 minutes of full-body sun exposure. He suggests that 10,000 IU of vitamin D is not toxic.

According to the National Institutes of Health, 25-OHD levels that are consistently over 200 ng/mL are "potentially toxic."
The IOM committee found no conclusive evidence that increased vitamin D levels confer increased health benefits, "challenging the concept that 'more is better.'"

What kind of vitamin D is best?

The recommended form of vitamin D is vitamin D3 or cholecalciferol. This is the natural form of vitamin D that your body makes from sunlight. Supplements are made from the fat of lambs' wool.

However, a clinical study reported in 2008 suggested that vitamin D2 works as well as vitamin D3.

Many supplements contain vitamin D as vitamin D2 or calciferol. It's derived from irradiated fungus. Because this is not the form of vitamin D naturally made by your body, WebMD nutritionist Kathleen M. Zelman, MPH, RD, recommends using the D3 form for those taking vitamin D supplements.
Because of its potency, different forms of vitamin D are used in prescription medications. If you have a prescription for one of these medications, do not switch to another form of vitamin D without checking with your doctor.
Does vitamin D interact with other medications?

Yes. Steroid medications such as prednisone can interfere with vitamin D metabolism. If you take steroid drugs regularly, discuss vitamin D with your doctor.

The weight loss drug orlistat -- brand names include Xenical and Alli -- may cut absorption of vitamin D. So does the cholesterol-lowering drug cholestyramine (sold as Questran, LoCholest, and Prevalite). People taking these drugs should discuss vitamin intake with their doctors.

The seizure drugs Phenobarbital and Dilantin (phenytoin), affect vitamin D metabolism and affect calcium absorption. So do anti-tuberculosis drugs.

On the other hand, cholesterol-lowering statin drugs and thiazide diuretics increase vitamin D levels.