Friday, September 7, 2007

Mast Cells: The Good, Bad and Ugly

Stanford researchers have found that mast cells, known for triggering the itch and inflammation in allergy attacks, can also calm down the flare-ups. These findings were published in the September online version of Nature Immunology.

The new findings reveal that, in mice, mast cells help decrease skin damage over time from sun exposure or from poison oak by releasing the immune-suppressing molecule, interleukin-10 (IL-10), the same brilliant anti-inflammatory tissue repair interleukin released by our bodies after prolonged exercise stimulates the release of the tissue breakdown proinflammatory interleukins, IL-6.

The findings contradict mast cells' reputation for being the trigger-happy gunslinger in an allergic reaction. Located just beneath the skin and in the loose connective tissue throughout the body, mast cells lie in wait for intruders. Packed with granules containing inflammation-inciting molecules such as histamine, they sometimes react to non-threatening trespassers, such as pollens or plant oils. Mast cell response to pollen can cause excessive tearing and eyeball itching that drives thousands of folks crazy every spring.

The ugly side: over zealous mast cell confrontations can cause allergic reaction and, in extreme cases, the life-threatening overreaction of anaphylaxis seen in bee-sting or peanut allergies.

"The fact that one sees the mast cell playing a role in resolving inflammation is surprising," said Juan Rivera, PhD, chief of the Molecular Inflammation section of the National Institute of Arthritis and Musculoskeletal and Skin Diseases. "All of the research thus far has focused on how quickly mast cells unleash inflammation rather than how they might mitigate it. I find it very intriguing finding that the mast cell plays this dual role."

The obvious question for our readers: does the human mast cell eventually release IL-10 to stop the ocular reaction to spring pollens if there is no pharmaceutical interference in the process?

Thursday, September 6, 2007

Vitamin D Deficiency

Dr. Larry Norton, of Memorial Sloan Kettering Cancer Institute, spoke out this morning on the CBS Early Show about the pandemic deficiency of Vitamin D and its consequences. He pointed out that most people away from equatorial areas are deficient because of more clothing, work indoors, less daylight time especially in the winter months, and the use of sun screen in excess.Vitamin D deficiency has received attention recently because of its link to cancers of the breast and colon.

Dr. Norton pointed out that despite the fortification of some foods with vitamin D, there was still a deficiency. He recommended supplementation with multivitamins high in Vitamin D3. He pointed out that recommended amounts generally were too low and recommended at least 2000 International Units daily (the current RDA is only 400 IUs. ). Toxicity, he pointed out, only occurs when intake exceeded twice that amount. He went on to say that he recommended vitamin supplements as the best way of assuring that adults received the necessary amounts for needed effect.

Vitamin D plays an important role in the maintenance of organ systems, and a deficiency may be manifested in forms such as rickets in childhood, and several types of cancer in adults. It regulates the calcium and phosphorus levels in the blood by promoting their absorption from food in the intestines and by promoting re-absorption of calcium in the kidneys. It promotes bone formation and mineralization and is essential in the development of an intact and strong skeleton. It affects the immune system by promoting immuno-suppression, phagocytosis, and anti-tumor activity.

So much emphasis has been placed on the harmful effects of sunlight and the need for sun-block that the public has become brainwashed.

Fortified foods represent the major dietary sources of vitamin D, as very few foods naturally contain significant amounts of vitamin D. In some countries, foods such as milk, yogurt, margarine, oil spreads, breakfast cereals, pastries and bread are fortified with vitamin to minimize the risk of vitamin D deficiency. In the United States and Canada, for example, fortified milk typically provides 100 IU per glass, or one quarter of the estimated adequate intake for adults over the age of 50. This amount has been shown to be inadequate.

The bottom line: Your multivitamin should contain more Vitamin D3 to compensate for the lack of its production in the skin due to inadequate exposure.

Tuesday, September 4, 2007

Homocysteine and B Vitamins

The Western Norway B-Vitamin Intervention Trial (WENBIT) results presented at the European Society of Cardiology Congress 2007 today, showed NO benefit for either supplemental folate with vitamin B12, or vitamin B6 in patients with established heart disease.

Could these CVD / homocysteine /folate /B12 /B6 studies possibly be collecting the wrong data on the wrong group?

It may be that faulty methionine metabolism hyperhomocysteinemia , which is most always caused by deficiencies of folate, B12 and B6, triggers gene-based (mRNA) inflammatory signals in the cells of the vascular walls representing a major pathogenetic pathway of atherosclerosis. This could be happening years before heart disease is established.
This concept is not dissimilar to metabolic syndrome (insulin resistance) being an issue years before type 2 diabetes is diagnosed.

Treatment with folate, B12 and B6 after disease is established may be too late, just as treatment with folate after the 28th day of fetal gestation is too late to prevent neural tube defects, although it's still important for the folate deficient pregnant Mom at risk for megaloblastic anemia.

A number of epidemiological studies have clearly shown that higher blood homocysteine levels are associated with higher risks of coronary, cerebral, and peripheral vascular disease and are inversely related to blood levels of folate and of vitamin B12 and vitamin B6.

Observational studies cannot exclude the possibility that elevated homocysteine levels may be associated with some other factor, rather than being causally related to vascular disease.

Large-scale randomized trials on healthy people are now in order to determine if supplemental folate, B12 and B6 could PREVENT hyperhomocysteinemia before it triggers the endothelium inflammatory process associated with most all heart and vascular disease.