CO2 Buildup
A report from the American Public Health Association and researchers at Harvard puts a lot of the blame for the high rate of asthma on global warming, smog and the atmosphere's growing burden of carbon dioxide. These are linked to industries and car exhaust that release pollution.

In this increasing burden of toxins released into the atmosphere, the rate of asthma among toddlers has grown to be particularly worrisome. Their rate of asthma has climbed more than twice the national average: by 160% between 1980 and 1994. According to these researchers (Inside the Greenhouse: The Impacts of CO2 (Carbon Dioxide) and Climate Change on Public Health in the Inner City), global warming-which involves large increases in atmospheric carbon dioxide released by internal combustion engines and and industrial processes-has fomented the asthma epidemic in several ways:

• Extra heat in the atmosphere has stimulated rapid plant growth that results in more fungus, pollen and spores; this causes allergies that often lead to asthma. Weeds like ragweed, which release allergenic particles, have greatly increased during the past few years.
• Extreme weather has caused more floods and damp houses, leading to more indoor air pollution from molds.
• Diesel pollutants are now combining with pollen and mold to irritate lungs, causing troublesome allergic reactions.

Bus Fume Hazards
The report notes that in neighborhoods like Harlem, in New York City, 25% of all children suffer asthma. Rates are particularly high in children who live in apartments that are located along bus routes.

A finding that surprised the scientists is the fact that carbon dioxide released by city traffic and the burning of coal and natural gas persists over urban areas, causing a dome of CO2 pollution.

Research on air quality in New York City, Phoenix and Baltimore shows that these lingering CO2 domes contain from 400 parts per million (ppm) of carbon dioxide to 600 ppm. Those levels are significantly above the global average of 379 ppm. Over the course of the earth's history, going back more than 400,000 years before the Industrial Age, research shows the atmosphere has averaged only 180 to 280 ppm.

Nighttime Distress
Breathing difficulties that increase at night can point to asthma, according to Robert Fink, MD: "Asthma can be a nocturnal disease, at its worst between 10 pm and 4 am, when cortisol [a hormone that regulates many bodily functions] levels are lowest" (Pediatric Asthma: Diagnosis and Treatment Goals, Medscape).

Dr. Fink says that if problems with breathing are bad enough to interfere with sleep, a health practitioner should be consulted to analyze the difficulty.

Diet and Asthma
Although nobody can guarantee protection against asthma, research suggests that eating plenty of fruits and vegetables can significantly reduce your risk. For instance, a study in Australia found that people who ate the most apples and pears reduced their chances of suffering from this breath-robbing disorder.

In research involving about 1,600 people, aged 20 to 44, they found that those who consumed the largest quantity of these fruits enjoyed the lowest rate of asthma (AJCN 2003; 78:414).

This is the latest study to confirm the fact that apples and other fruits help to keep lungs healthy. " There is extensive evidence from studies over the last 10 to 15 years that a diet rich in fruits and vegetables is beneficial to lung health," observes Carol Trenga, PhD, a research scientist at the University of Washington in Seattle. "The most compelling evidence is linked to fruits high in vitamin C, which are associated with improved lung function in the general population of adults and children."

Produce for Smokers
Quitting smoking represents one of the best ways to reduce lung disease. But even if you smoke, research on smokers has found that those who ate a moderate amount of fruits and vegetables have fewer lung problems (American Thoracic Society 97th International Conference 5/2001).

And you don't have to change your diet very much to make a difference: In that research, merely eating one and half pieces of fruit a day or eating about a tablespoon of vegetables daily significantly dropped smokers' chances of serious lung disease.

Fruits and Veggies to the Rescue
In a study at the University of Nottingham, United Kingdom, scientists looking at the diets of more than 2,500 people found that eating five or more apples or three tomatoes a week increased lung function. Eating apples and tomatoes also reduced the risk of wheezing.

" The likelihood is that any effect is due to the concerted action of all the nutrients in apples and tomatoes, especially the antioxidants that are particularly rich in the peel of apples and contribute to the coloring of tomatoes," says researcher Sarah Lewis, PhD.

" Antioxidants may work by protecting the airways against the insult of tobacco smoke and other atmospheric pollutants," she adds.
Dr. Trenga recommends that everyone eat at least five servings of fruits and vegetables a day. She also notes, "[I]t is reasonable to suggest modest supplementation with for example, vitamin C (250-500 mg twice/day) and vitamin E (up to 400 IU per day), in at-risk populations as a complementary therapy after considering the specific needs of the individual...These levels are very safe and have other health benefits (such as vitamin E and heart disease) in addition to potentially improving lung health."

Herbal Relief
Since asthma is linked to allergies, herbs that help to quell respiratory allergies can possibly lower your risk of asthma. A blend of standardized herbal extracts that contains Phyllanthus emblica (Indian gooseberry or amla), Terminalia chebula (Harda or Haritaki), Terminalia bellerica (bedda nut tree), Albizia lebbeck (Indian walnut), Zingiber officinale (ginger root), Piper longum (Indian long pepper), and Piper nigrum (black pepper) has been found to improve breathing and reduce the effect of allergies (FASEB J 2004; Vol II:A912, Abs. 600.8). Other studies have shown that these herbs can relieve nasal congestion, ease sneezing and clear bothersome mucus (J Am Coll Nutr 22(5): Abs 46, 2003).

Antibiotic Avoidance
Avoiding antibiotics may also lower the risk of asthma. " Over the past four decades there has been an explosive increase in allergy and asthma in westernized countries, says Mairi Noverr, PhD, a researcher who has looked at the lin between antibiotic use with asthma and allergies. " We propose that the link between antibiotic use and dysregulated pulmonary immunity is through antibiotic-induced long term alterations in the bacterial and fungal GI microflora."

In other words, Dr. Noverr's research shows that beneficial bacteria in people's intestines, which take part in strengthening immunity and regulating the immune response to pollen, may have been harmed by the overprescription of antibiotics by physicians. Dr. Noverr and his fellow researchers gave lab animals antibiotics before exposing them to candida albicans (a yeast infection). They then exposed the animals to mold spores. The result: a greater sensitivity to inhaling the spores and breathing problems similar to what people experience during hay fever season (104th General Meeting American Society of Microbiology).

" The studies presented here are the first direct demonstration that antibiotic therapy can promote the development of an allergic airway response," says Dr. Noverr. On a global scale, the outlook for asthma is worrisome. As other countries continue their industrial growth, the burden on the earth's atmosphere will grow. Meanwhile, few serious measures are being taken to reduce global warming, and the national diet frequently neglects lung-friendly vegetables and fruits. But within that uncertain scenario, you can boost your chances of healthy lungs: Eat more apples. Stay away from smoky buses. Hope for clear skies.