Development and Maintenance of Lung Tissue
The mucous membranes of the lungs, where gas exchange of carbon dioxide and oxygen
occurs, are comprised of unique epithelial (lining) tissue. In addition, large numbers
of white blood cells are in close proximity to the lung membranes to protect the body
from inhaled microbes that may attempt to invade and overwhelm the entire living system.
Moreover, mast cells, containing histamine granules, are situated throughout this tissue
to open tiny pores in capillaries, allowing white blood cells to leave the blood stream
and move to sites of infection.
Certain nutrients are indispensable for optimal development and maintenance of lung
mucus membrane tissue.
- Carotenes (some of which are precursors to vitamin A) are essential to the growth and maintenance of healthy epithelial tissue throughout the body. Natural sources include the wide array of green leafy vegetables and their concentrates, as well as yellow, orange, and red vegetables (e.g., carrots, sweet potatoes, etc.) and fruits, (e.g., apricots, peaches, etc.).
- Preformed Vitamin A, as found in cod liver oil, is also quite valuable. (Keep daily vitamin A intake below 10,000 IU in any woman who is or may become pregnant.)
- Zinc, found in such food sources as pumpkin seeds and flaxseed, is a companion nutrient that works in cooperation with carotenes and vitamin A to support the integrity of epithelial tissue. Zinc also inhibits the multiplication of microbes, including viruses.
- Vitamin C, obtainable in many fresh fruits and vegetables, is critical to the functioning of immune cells defending our health along the membranes, as well as the neutralizing of the many free radicals generated during inflammatory processes and gas exchange in the lungs.
- Flavonoids (as in greens, dark berries, grape seed, etc.) and other antioxidants (as in olive leaf) support the antioxidant activities of vitamin C, reinforce connective tissue integrity in the membranes, and help to stabilize the membranes of mast cells (thereby modulating histamine release).
Lungs Under Siege
Chronic inflammation is the most common disease process in just about every tissue in
the body. The human lung mucous membranes have a combined exposed surface area between 270 and
900 square feet. The lungs lack the protective structures found in the skin. Therefore,
inflammation is common in the lung. (That’s why it is absolutely insane to make matters worse
by smoking.) But unlike other tissues, the generation of fibrous tissue in response to
inflammation does not occur as commonly. Maintenance of optimal lung function despite aging
requires optimal essential fatty acid balance to produce local hormones that modulate
Continuous, ongoing inflammatory processes can take place in the lungs. Moreover, disease
states (e.g., asthma, chronic bronchitis) entail continuous inflammation even without external
stimulation or irritation. These inflammatory processes take their toll over time. Even
otherwise healthy persons who have never smoked gradually lose lung functional capacity with
age because their lungs are being continually challenged by infectious microbes and air
particles that trigger inflammatory responses.
Effects of Omega-3 Fatty Acids on Lung Tissue
It is well established that dietary omega-3s affect the composition of cell membranes of
lung tissue, the production of local hormones (prostaglandins and leukotrienes) that modulate
inflammatory processes, and the movement and activities of white blood cells on mucus
membranes. These effects constitute clear evidence that omega-3s affect potential modulators
of lung disease. As with studies involving other organ systems, it is critical that
sufficient amounts of omega-3 sources be used, while decreasing interfering omega-6 sources,
and the period of omega-3 intervention be long enough (at least 3 to 6 months) for the full
benefit of omega-3s to manifest.
Because dietary intake of essential fatty acids may be able to modulate local hormone
activity in the lung, as it does in other tissues, non-inflammatory fatty acids, found in
such omega-3 sources as flaxseed oil and fish oil, may protect against lung disease and slow
the usual decline in lung function with age.
Asthma is a chronic inflammatory disorder of the tissues of the respiratory airways.
Inflammation of the bronchial mucous membranes increases mucus production. To make matters
worse, airway membranes are hyper-responsive to stimuli. There is also a tendency for the
smooth muscle tissue in the bronchial tubes to constrict, narrowing the airways even further.
The combination of excess mucus secretion and bronchial spasm cause the classic symptoms of
asthma -- wheezing, coughing, and shortness of breath. Many factors contribute to asthmatic
tendency -- genetic predisposition, allergens in the environment, environmental toxins,
infectious agents, emotional stress, and nutritional factors. Yet, the common manifestation
at the tissue level is airway inflammation that involves immune system imbalance -- excessive
influence of tissue mast cells and white blood cells (basophils) that release histamine, a
compound critical to the inflammatory process.
Researchers are coming to the conclusion that the recent dramatic increase in asthma
prevalence in industrialized nations and the advent of asthma in susceptible persons who
migrate to Western countries indicate the role of environmental factors, such as diet, in the
onset of this disorder.
Flavonoids, as found in onions, apples, berries, and grape seed, can help stabilize mast
cell membranes in a fashion that reduces lung tissue hyper-sensitivity, and histamine release.
Omega-3 fatty acids also have an important role to play due to their ability to reduce
undesirable inflammatory tendency. Clinical trials have demonstrated the ability of omega-3s
to reduce bronchial inflammation in asthmatics, even when they are deliberately challenged
with known airborne allergens. A large study of thousands of people living in northern
European nations found that weekly fish consumption in adulthood protects against asthma
symptoms. Those who never ate fish in childhood were at an increased risk for asthma. Both
of these results indicate a possible threshold effect of fish, fish oil, and cod liver oil
on asthma. Fish oil supplementation has also proven beneficial in childhood asthma.
The dosage levels found to be effective in asthma are sufficient fish oil to provide
17-26 mg EPA and 7-11 mg DHA per kilogram (2.2 pounds) of body weight in a child. In adults,
the dosage for chronic inflammatory states is sufficient fish oil to provide 3,000 mg
combined EPA/DHA daily. Of course, all of this needs to be managed by a qualified health
care professional. Do not expect rapid results. It takes time, perhaps three to six months
at the appropriate dosage to begin to see the benefits of changing fatty acids and
antioxidants on the membranes of cells lining the lung mucous membranes.
Chronic Obstructive Pulmonary Disease (COPD)
Chronic obstructive pulmonary disease is a combination of two concurrent disorders –
emphysema (destruction of the alveoli, gas exchange units in the lung mucous membranes) and
chronic bronchitis (inflammation of the mucus membrane of the bronchial tubes). The major
cause of this debilitating illness is smoking. The damage done to respiratory tissue by
smoking initiates and sustains a chronic inflammatory process that leads in the long term to
such destruction of lung function that people with COPD require continuous oxygen support
just to be able to function.
Remarkably, research is revealing the benefit that omega-3 fatty acids can bring to bear
even under the severe stress of smoking on vulnerable lung tissue. Because the omega-3 fatty
acids are used to make local tissue hormones that reduce inflammation tendency, they can be
of benefit in reducing chronic inflammation even if a person is a chain smoker.
For example, a study of the eating habits of nearly 9,000 smokers found that the intake
of EPA and DHA, the omega-3s found in ocean fish and fish oil, was inversely related to risk
for COPD. That is, the higher the EPA/DHA intake, the lower the COPD risk; and the lower the
EPA/DHA intake, the higher the COPD risk. The results caused the investigators to conclude
that a high intake of omega-3 fatty acids may protect cigarette smokers from COPD.
During another study, blood levels of EPA and DHA were tested in 2,300 smokers. In this
study it was found that higher blood levels of DHA, but not EPA, indicated lower risk for
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