Self Diagnosing Food Allergies

Continuing discussion on food allergies, there is concern amongst dietitians in Australia that people are self-diagnosing themselves as having food allergies and intolerances. While avoiding a food items is not the issues, there is a problem:

The number of adults being diagnosed with food allergies has remained constant, but the number of people incorrectly self-diagnosing food allergies and intolerances has skyrocketed,’ Ms Graham said.

She said a problem with self-diagnosis was the risk of missing an underlying health problem.

[link]

Not mentioned in the article is that fact that if wheat or dairy are being excluded from the diet, the diet could missing essential nutrients and sufficient energy, especially for children.

The bottom line, as always, is if you think you may have an allergy visit your doctor and get tested.

Another Cold

Bleuh!

I have another cold and I’m all achy. It was three weeks since my last one - I have had a lot of colds this winter and I thought I was going to get away with it. Until I had little sleep on Saturday night and the weather went cold on us.

Sniffle, snuffle.

Some good ideas for posts lined up. I just have to get my head unblocked and be able to think.

I am eating lots of soup and planning nice warm stews to eat for the next few days

Food Allergies

Professor Richard E. Goodman, from Nebraska-Lincoln visited the local Institute of Food Technologists’ (IFT) section and gave a very interesting talk about food allergies. He is an active member of FARRP (Food Allergy Resource and Research Group), which is a resource for the food industry to test for and research known and potential allergens.

In this post, I tried to summarize the bits I remember but as I did not take notes, I found this information on the web. Thus, if anything is wrong, it is my fault, not Dr Goodman’s.

Food allergy is an adverse clinical reaction to food due to any type of abnormal immune response to food protein.

There are two mechanisms by which a food allergy can trigger the immune system. The first is IgE-mediated:

from actagainstallergy posted with vodpod
IgE-mediated food allergies are mostly immediate reactions, occurring within in minutes to hours of ingestions. The IgE response is the cause of anaphylactic shock, which is the cause of death after eating peanuts and bee stings. In this case, the allergic response is so extreme that it causes the air passages to swell; blood pressure drops leading to the inability to breathe and eventually, if not treated, it is fatal.

The second mechanism, which is mentioned by Dr Goodman and on the Act Against Allergy website, is Non-IgE mediated and involves the interaction of T-cells with the allergen and the part of the body where it is located:

Non-IgE mediated food allergies are usually delayed, taking 24 -48 h for a reaction.

Key symptoms of food allergies include hives, hoarse voice and asthma. In a severe reaction, there may be low blood pressure and blocked airways. Other symptoms that may occur include abdominal pain, angioedema (swelling, especially of the eyelids, face, lips, and tongue), diarrhea, difficulty swallowing, light-headedness or fainting, nasal congestion, nausea, and oral allergy syndrome (OAS). Symptoms of OAS are:

• Itchy lips, tongue, and throat
• Swollen lips (sometimes)

This last interested me. I have already discussed the problems I have when drink alcoholic beverages, especially beer, but I also have OAS in response to fennel and ginger*.

Common food allergens seem to vary depending on where you live. In the US, since January 2006

…the Food and Drug Administration (FDA) is requiring food labels to clearly state if food products contain any ingredients that contain protein derived from the eight major allergenic foods. As a result of the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA), manufacturers are required to identify in plain English the presence of ingredients that contain protein derived from milk**, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, or soybeans in the list of ingredients or to say “contains” followed by name of the source of the food allergen after or adjacent to the list of ingredients.

source

[highlights mine]

Peanuts, treenuts and shellfish are the most common foods to trigger anaphylactic shock.
In Europe, the EU directive since November 2005 states that:

The 13 main food allergens must be listed: gluten-containing cereals, shellfish, fish, egg, peanut, soy, milk, tree nuts, celery, mustard, sesame seed, lupine and mollusks. Products derived from these allergens must be named without exception if used as an ingredient. In addition, sulfite must be listed if more than 10mg/kg is used.

Source

Currently, the only way to prevent an allergic response to a food item is avoidance. Ephedrine can be used, via an EpiPen to stop an anaphylaxis response, but will not prevent the reaction occurring again.

—

More food allergy links:

MedicineNet

FamilyDoc: Just the Facts

emedicine - excerpt

There is also a consumer advocacy and support group: The Food Allergy and Anaphylaxis Network (FAAN).

Footnotes

*I have another response to ginger in that it irritates my urethra (the passage from the bladder out) and so when I eat or drink anything gingery (ginger beer anyone), I have to remember to drink lots of water to reduce this irritation. I used to get, I thought, a lot of cystitis or infections in my urethra. Finally, I noticed that “infections” were linked to the day after when I went out for a curry, which was fairly frequent as a graduate student. Sigh. I probably should be grateful that curryhouses are not so common here in the US.

**Fortunately all the websites I found differentiate between food intolerance and food allergy. A food intolerance is when you cannot digest something properly, such as lactose. This means that the ingredient remains intact until the colonic microflora get hold of it. Then the gut bugs have a party. Seriously. A serious party.

A is for Antihistamine

I take one of these every night. When I forget, I have a runny itchy nose all day. I did not have allergies until I moved to America, but all the new pollen must have triggered something.

Honey and Botulism: Problem for Infants

See Revere at Effect Measure: Honey and Botulism

Eating Broccoli Protects Your Heart

A recent study published online by the Journal of Agriculture and Food Chemistry reports on the role of broccoli as a cardioprotector. Broccoli contains high concentrations of selenium (65 nanograms/g broccoli) and glucosinolates, especially isothicyanate sulforaphane (23.6 micrograms/g broccoli). Both selenium and sulforaphane are shown to protect the heart and the cardiovascular system. Sulforaphane induces the redox regulator protein, thioredoxin, which has a cardioprotective role by reducing oxidative stress.

A clinical study reported that eating fresh broccoli sprouts for a week lowered serum low density lipoprotein levels (LDL is the so-called “bad” cholesterol) and a prospective study in Iowa showed a strong association between broccoli consumption and a lowering of the risk of coronary heart disease.

In the study reported in JAFC, rats were either feed, on top of regular rat chow, a broccoli slurry or water for a month before slaughter. At which time the hearts were isolated, stabilized and then subjected to 30 minutes of total ischemia followed by reperfusion*. Heart function was assessed 10, 30, 60, 90 and 120 mins after ischemia finished.

Hearts from rats fed on broccoli slurry showed faster recovery in left ventricular function and aortic flow. Heart rate was not affected by treatment. In addition, hearts from broccoli-fed rats had a smaller myocardial infarct size and the number of cardiomyocytes which under went cell death (apotosis) was reduced.

Hearts from broccoli-fed rats showed a similar response to ischemia as hearts in which thioredoxin had been upregulated. Broccoli possibly limits heart damage by inducing the production of thioredoxin and related proteins. These proteins play important roles in maintaining the inner cell redox potential. Selenium is required as part of the enzymes glutathione peroxidase and thioredoxin reductase, and sulforaphane up-regulates thioredoxin reductase stimulating thioredoxin production and reducing oxidative damage in the cell.

Reference:

Mukherjee, S.; Gangopadhyay, H.; Das, D. K. Broccoli: A Unique Vegetable That Protects Mammalian Hearts through the Redox Cycling of the Thioredoxin Superfamily. J. Agric. Food Chem. 2007. (online)

Notes:

From what I scan-read in Wikipedia, ischemia occurs by preventing blood flow to the heart and reperfusion is when blood is allowed back. Reperfusion can cause injury because the sudden influx of oxygen and blood can cause oxidative damage and inflammation.

Health - reason for no posts

The last couple of weeks have been very busy for me as I started substitute teaching and to cap that I caught a cold. I blame the middle schoolers myself.

Regular posting will resume sometime, somewhere.

Cat Unleashed

I took this picture at Philadelphia Folk Festival last Sunday when the band Les Yeux Noirs were warming up because music frees me up and relaxes me at the same time. The theme for the next Scientiae Carnival is Unleashed, so describing the effect music has on me seemed appropriate. But what has this to do with science or me as a scientist?

I am one of those people who has to move to music to the extent it is painful to sit and listen to good music especially bands like Les Yeux Noirs, Davey Spillane, and, naturally, the Mammals. How do people go to folk concerts and sit and listen? Some people seem to barely tap their feet. Dancing is exhilarating and emphasizes the effect of music - a synergistic effect or a positive feedback loop. The more I dance, the better the effect of music. Listening to music also helps me get over illness. Once as a preteen, I was at school feeling ill - the singing lesson was the best thing about that day. I also find that certain music is good when I have period pain or a headache and it can help with anger management - there is nothing like a good loud “London’s Calling” by the Clash to let out frustration. The effect of music is not just hearing it performed but also caused by performing. Whatever mood I am in, after singing practice or choir rehearsal I am relaxed and content.

Music also releases thoughts. Quite often after a good concert, either listening or performed, I think more clearly and have more exciting ideas. Though, if I need to concentrate I cannot have any distractions so music gets turned off.

I am sure that a neuroscientist would have an explanation for this effect of music on the mind - perhaps it causes the release of endorphins or serotonin?

scientiae-carnival

Botulism

After the latest food recall, which has been recently extended, I wondered what exactly is botulism. All I could remember from food microbiology was that it was an food borne illness caused by the botulinum toxin which is produced by the bacteria Clostridium botulinum.

Book Review: Books on Osteoporosis

Following up from my post on bones and bone loss, I was looking for an appropriate book for my parents so that they could better understand what was going on. I did not really find one as they are in England and the books I considered were for an American audience.

In my local library, I found:

1. Mayo Clinic on Osteoporosis
2. Gillian Sanson: The Myth of Osteoporosis
3. Jan Madden: Yoga Builds Bones

The last book was probably the least helpful for my parents as they would be unable to do any of the recommended exercises in the book. In fact, unless you are an experienced yogi or are working with a yoga teacher, the exercises in this book would be challenging.

Sanson’s book was all right. She does a good job explaining the science of osteoporosis so that it is understandable for a layperson. Unfortunately, she then launches into quackery solutions, like this on diet:

…it is important to eat foods that are alkaline. Increasing your intake of alkaline-producing foods - leafy greens, sea vegetables, nonstarchy vegetables, nuts and seeds - will create a bone-nutrient rich, pH balancing diet that reduces calcium excretion and bone loss.

She then illogically goes on to say:

An investigation of the diets of elderly men and women in Framingham, MA, found that people who ate more fruits and vegetables rich in potassium and magnesium had less bone mass loss in the hip and forearm than those elderly people who ate less of these foods. A follow-up study also found that high fruit and vegetable intake appears to be protective in men, and a high candy consumption is associated with low bone mass in both men and women

These statements are contradictory as fruits, especially, are probably some of the more acid foods. Also it does not really matter about the pH of the food you consume as the stomach produces gastric juice which has a very low pH, probably around pH 1.0. Thus, unless you have a pre-existing medical condition or you are taking medicines which mean that your gastric juice pH is high, it unlikely that the pH of the food you eat has any effect at all on your body’s pH.

The final book by the Mayo Clinic was excellent. Each chapter had been peer-reviewed and it showed. The science was solid and understandable. It explains the latest medicine. It gives simple exercise that Mum might be able to carry out. The book has a chapter on how to recover from a fracture. If my parents lived in the US, this is the book I would purchase for them. I might still get it for them - they can just ignore the US bias.