Who is at risk and why?

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 persons 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 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.

What are common allergic conditions and their symptoms and signs?

The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Although the various allergic diseases may appear different, they all result from an exaggerated immune response to foreign substances in sensitive people. The following brief descriptions will serve as an overview of common allergic disorders.

Placebo effect may be at play in acupuncture studies: analysis

Reuters Health – Acupuncture can bring some relief to people with knee arthritis, but the benefits may be at least partly from a placebo effect, a new research review suggests.

In an analysis of 9 clinical trials from the past 15 years, researchers found that acupuncture generally seemed to improve knee arthritis sufferers’ pain and stiffness in the short term. The patients had osteoarthritis, a degenerative joint disease associated with age, as opposed to arthritis associated with an autoimmune disorder.

However, a closer look showed that the benefits were limited to trials that compared acupuncture with doing nothing or with “usual care,” such as anti-inflammatory medication.

In trials that compared acupuncture with “sham” acupuncture, on the other hand, there was no clear evidence that the real therapy was more effective.

Sham acupuncture is accomplished by using non-penetrating needles, or inserting needles only into the superficial layer of skin, at random sites rather than the specific points used in real acupuncture. In studies that evaluated electro-acupuncture, the sham version involved phony electrodes and “mock” electrical stimulation of acupuncture points.

The point is to keep study participants from knowing whether they were receiving the real or the placebo treatment. This helps separate the specific effects of a therapy from any placebo effects — where people feel better simply because they believe they’ve been treated.

The new findings suggest that the benefits of acupuncture for knee arthritis are at least partly due to patients’ expectations, the study authors report in the Annals of Internal Medicine.

However, that doesn’t mean acupuncture is not worthwhile, according to the researchers, led by Eric Manheimer of the University of Maryland School of Medicine in Baltimore.

Research does suggest that acupuncture has a “genuine biological effect,” and there was evidence in some studies that the real therapy resulted in somewhat better short-term effects than sham acupuncture, the researchers note.

For their study, Manheimer and his colleagues combined the results of nine clinical trials conducted in Europe, the U.S. and Thailand. The trials included a total of more than 3,500 subjects.

Each trial included a patient group that received acupuncture for knee arthritis, as well as a “control” group. In some studies, control patients were placed on a waiting list for acupuncture, while in others they received some standard therapy that acupuncture patients did not. Control patients in other studies received sham acupuncture.

In general, the Manheimer’s team found, only studies that pitted acupuncture against doing nothing, or against standard care, showed clear benefits. The results of the sham-controlled trials were too mixed to show any benefits, according to the researchers.

The investigators do not, however, dismiss the potential benefits of acupuncture for knee arthritis. Indeed, they note, a possible explanation for the mixed results is that sham acupuncture had some actual biological effects.

Given the overall safety of acupuncture, the researchers conclude, patients can still consider it as one option in a “multidisciplinary approach” to treating knee arthritis.

Vitamin D helps brain to work well at later age

Vitamin D may have a key role in helping the brain to keep working well in later life, suggests research published ahead of print in the Journal of Neurology Neurosurgery and Psychiatry.

Previous research indicates that inadequate vitamin D intake may be linked to poorer mental agility in the ageing brain, but the results have been inconsistent.
The researchers base their current findings on just over 3000 European men between the ages of 40 and 79, who were all part of the international European Male Ageing Study, drawn from eight different cities across Europe.

Their mental agility was assessed using a range of tests, designed to measure memory and speed of information processing as well as mood and physical activity levels, both of which affect mental agility.

Blood samples were then taken to measure circulating levels of vitamin D, which is obtained through dietary sources and by exposure to sunlight.

High circulating vitamin D levels were associated with high scores on the memory and information processing tests, but after adjusting for mood and physical activity, the association remained for only one of the two information processing tests.

Low vitamin D levels were associated with poor scores, with levels of 35 nmol/litre or under marking the threshold of poorer performance.

Experimental data point to the biological plausibility for an association between low circulating levels of vitamin D and poorer mental agility, but exactly how the two might be connected is not clear, say the authors.

Possible suggestions include vitamin D’s role in increasing certain hormonal activity or the protection of neurones and chemical signalling pathways.

The findings show that the magnitude of the association between vitamin D level and mental agility was comparatively small, say the authors.

But if it were possible to stave off the effects of ageing on the brain with vitamin D supplements, then the implications for population health could be quite significant, they contend, because many people, particularly in older age, arevitamin D deficient.