Secondhand smoke is being investigated for promoting a large number of other health problems as well. The current case-control study examines the potential link between secondhand smoke and chronic rhinosinusitis among adults.

Secondhand smoke exposure is linked to chronic rhinosinusitis, according to the results of a matched case-control study reported in the April issue of Archives of Otolaryngology–Head & Neck Surgery.

“Most studies of the associations between SHS [secondhand smoke] exposure and respiratory disease in adults have investigated odor and irritation, respiratory symptoms, lung function, asthma, chronic obstructive pulmonary disease, and lung cancer,” write C. Martin Tammemagi, DVM, MSc, PhD, from Brock University in St. Catharines, Ontario, Canada, and colleagues. “Few studies have focused on chronic rhinosinusitis (CRS), although evidence suggests that such a relationship may exist.”

The goal of this study was to evaluate the association of secondhand smoke with chronic rhinosinusitis using conditional logistic regression odds ratios (ORs). At the Henry Ford Health System in Detroit, Michigan, 306 nonsmoking patients diagnosed with an incident case of chronic rhinosinusitis were matched by age, sex, and race/ethnicity to 306 nonsmoking control subjects. The primary endpoints were exposure to secondhand smoke for the 5 years before diagnosis of chronic rhinosinusitis in case patients and before study entry in control subjects, in the home, work place, public places, and private social functions outside the home.

Among case patients and control subjects, respectively, 41 (13.4%) and 28 (9.1%) had secondhand smoke exposure at home; 57 (18.6%) and 21 (6.9%) at work; 276 (90.2%) and 258 (84.3%) in public places; and 157 (51.3%) and 85 (27.8%) at private social functions. This yielded ORs of 1.69 (95% confidence interval [CI], 0.92 – 3.10) for secondhand smoke exposure at home; 2.81 (95% CI, 1.42 – 5.57) for exposure at work; 1.48 (95% CI, 0.88 – 2.49) for exposure in public places; and 2.60 (95% CI, 1.74 – 3.89) for exposure at private functions, after adjustment for potential confounders including socioeconomic status and exposures to air pollution, chemicals, or respiratory irritants.

There was a strong, independent dose-response relationship between chronic rhinosinusitis and the number of venues where secondhand smoke exposure occurred (OR per 1 of 4 levels, 2.03; 95% CI, 1.55 – 2.66). Secondhand smoke appeared to account for approximately 40.0% of chronic rhinosinusitis.

“Exposure to SHS is common and significantly independently associated with CRS,” the study authors write. “These findings have important clinical and public health implications.”

Limitations of this study include retrospective design, possible recall bias, inability to determine whether the associations between secondhand smoke and chronic rhinosinusitis differed by causal subtype, and lack of biologic measurements of secondhand smoke exposure.

“On the basis of our findings, physicians should recommend that patients who are susceptible to CRS or who have CRS avoid exposure to SHS,” the study authors conclude. “The dose-response relationship between SHS and CRS indicates that even modest levels of exposure carry some risk.”

Source:

www.medscape.com, May 2010 Newsletter

From all over the world have come the most exciting findings ever reported about vitamin A. More than a dozen studies have linked diets rich in vitamin A to a surprising amount of protection against some forms of cancer.

In Chicago, scientists found only two cases of lung cancer among 500 men, including some smokers, who eat many fruits and vegetables rich in vitamin A. That was only one-seventh as many lung cancer cases as were found in 500 men who ate few of these foods.

And in Norway, the findings were no different. Men who ate many vegetables rich in vitamin A had only one-third as much lung cancer as those eating little of these foods.

In Japan, the story was the same. Researches found 30 percent fewer cases of lung cancer among people who ate vegetables rich in vitamin A every day. The daily vegetable eaters also had lower rates of stomach cancer.

Cancer scientists have been so fascinated by these findings that the ability of vitamin A to protect us from cancer has become one of their top interests. Many are already convinced that we should be eating more foods rich in vitamin A. The Committee on Diet, Nutrition, and Cancer of the National academy of sciences has urged us to do so.

Studies have linked a diet rich in vitamin A to protection from cancer in eight different organs. The evidence is strongest for cancer of the lung, stomach, or esophagus.

But there is more good news. Research also ties vitamin A to protection from cancers of the mouth, colon, rectum, prostate, and bladder. There is less evidence here than for lung, stomach, and esophageal cancer. But there is enough to merit our attention.

Three Types of Vitamin A

“Vitamin A” is very general term. It refers to several substances that can take care of the body’s need for this nutrient.

For many of the body’s functions that need vitamin A, any form will do. But in cancer prevention, the picture looks different. As things stand right now, it seems that only some kinds of vitamin A in food.

• Retinol is the vitamin A in animal foods.
• Carotene, (or beta-carotene) is the main kind of vitamin A in fruits and vegetables.
• Carotenoids are other forms of vitamin A found in fruits and vegetables. They are a very minor source of vitamin A.

Of these different kids of vitamin A, carotene is linked most strongly to protection from cancer.

….carotene is linked most strongly to protection from cancer.

Vitamin A Supplements Are Different

Of course, we can also get vitamin A from pills. The form used in vitamin compounds is not carotene or retinol. It usually is a synthetic form of vitamin A called vitamin A palmitate. Little research has been done on the ability of this kind of vitamin A to protect against cancer.

For this reason, it is not good idea to rely on vitamin A pills to reduce your risk of cancer. Scientists simply don’t know if this type of vitamin A has any value in preventing cancer.

You may also be aware that the kind of vitamin A usually contained in vitamin capsules or tablets can be toxic if taken in very high doses.

Newspapers and magazines have published some articles about special forms of vitamin A that show remarkable anti-cancer potential in laboratory animals. Scientists have used these forms of vitamin A, called retinoids, to block cancers of the lung, bladder, and breast in test animals.

Retinoids may be on the drugstore shelves someday. But right now they are not for sale. Their use is strictly experimental.

The Recommendation and How to Meet It

The Committee on Diet, Nutrition, and Cancer recommends daily consumption of fruits and vegetables. The committee advises us to emphasize those fruits and vegetables that are rich in carotene, the most important kind of vitamin A in plant foods.

To help in selecting foods, the Committee prepared the following chart which classifies foods as low, medium, or high in carotene.

Carotene in Fruits and Vegetables

Note: Chart adapted from a 1989 compilation by the Committee on Diet, Nutrition,

and Cancer, National Academy of Science, U.S.A.

Before I continue to write this subject, I suggest you to find another point of view concerning the power of vitamin A in  fighting cancer, a useful  article for you posted in Blog of Health.

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