Breathe easy: good nutrition can help keep your lungs healthy
Emily Bergeron
Most of us find ourselves short of breath at one time or another. But for folks living with chronic lung disease, labored breathing is more serious than an occasional gasp for air. Chronic lung disease is the fourth leading cause of death in the U.S., claiming more than 120,000 lives each year.
The U.S. Centers for Disease Control and Prevention estimate that nearly 13 million people are living with chronic obstructive pulmonary disease (COPD), while over 17 million suffer from asthma, two common chronic lung conditions.
COPD–a collective term for chronic bronchitis and emphysema–leads to an irreversible obstruction of airflow in the lungs. In chronic bronchitis, lung tissue becomes inflamed and scarred, while in emphysema the lung’s air sacs are permanently weakened. In asthma, environmental triggers like cold air or allergens cause airways to become inflamed and narrowed, although not permanently.
The lung damage from all three conditions results in similar symptoms: shortness of breath, chest tightness, coughing and excessive mucus production. The good news is that COPD and asthma are largely preventable.
“Not smoking is the number one best prevention,” advises Neil Schachter, M.D., associate director of the pulmonary division at Mount Sinai School of Medicine in New York City. Reducing exposure to environmental pollutants is also key. Still, nutrition has garnered much attention recently, as researchers are discovering links between diet and lung health. EN examines the latest evidence.
Antioxidants to the Rescue? Oxygen-rich lung tissue provides a prime target upon which dangerous free radicals can wreak havoc. An imbalance between oxidant stress and antioxidant resources can lead to cell death and eventually a loss of lung function.
Just such an imbalance was found in a recent study from the University of Delhi in India. Numerous indicators of oxidative stress were identified in the blood of 38 people with asthma, but not in 23 healthy controls. Researchers theorize that dietary antioxidants, such as those found in fruits and vegetables, may play an important role in combating this oxidative stress.
Vitamin C is thought to be the most abundant antioxidant on the lung surface and, indeed, numerous studies have found that C protects lung function. Vitamin E has also been investigated as a potential protector of lungs because of its role in scavenging free radicals on lipid-laden cell membranes. A study led by Holger J. Schunemann, M.D., of the State University of New York (SUNY) at Buffalo, found that in more than 1,600 men and women dietary intake of vitamins C and E was linked to improved lung function.
Promising Phytonutrients. The SUNY study also found that the carotenoids lutein and zeaxanthin benefit lung function. Most other studies have focused on, and found a connection between, the carotenoid beta-carotene and lung health.
A major public health study from The Netherlands suggests that flavonoids may also play a protective role. Dutch researchers found that foods rich in a class of flavonoids called catechins benefited both lung function and COPD symptoms. Curiously, however, tea, a main source of catechins, was not beneficial.
“It may be that the benefit from flavonoids is not due to catechins, but to some other factor that goes hand in hand,” explains a study co-author, Henriette Smit, Ph.D., of the National Institute of Public Health and the Environment in the Netherlands.
Identifying specific antioxidants that are responsible for health effects has been a challenge for researchers, says Norman Edelman, M.D., of the University Medical Center at SUNY Stony Brook and a spokesperson for the American Lung Association. For this reason, nutritionists advise getting your antioxidants from a variety of whole foods like fruits, vegetables and whole grains, with a daily multivitamin for added insurance.
Role for Sodium and Magnesium?
Researchers believe the minerals sodium and magnesium may influence the tiny smooth muscle cells in airways. Too much sodium might constrict airways, while magnesium may help to relax them. Study results, however, have not been conclusive.
Prudent advice to help promote lung health includes limiting your intake of salt and highly processed foods, while also getting plenty of magnesium by eating fruits, vegetables and nuts. Super sources of magnesium include almonds, artichokes, avocados, bran, cashews, lentils and spinach.
Fishy Findings. Eskimo populations have suffered little from lung disease, and researchers think the abundance of omega-3 fatty acids from the oily fish in their diet might be the reason why. A diet high in omega-3 fats may help calm inflamed airways by limiting the production of substances called eicosanoids, which trigger inflammation. Mount Sinai’s Schachter advises eating two servings of fish a week to provide protection against COPD and asthma. Fish oil supplements, he says, don’t seem to have the same effect.
Drink to Your Health? The Netherlands public health study also suggests that alcohol may help promote lung health. The Dutch researchers report that men and women who drink one to three glasses of alcohol a day have better lung function and fewer COPD symptoms than either nondrinkers or heavy drinkers. Those who also ate fruits, vegetables and whole grains fared even better. The researchers suggest a direct effect of alcohol itself.
Other researchers also credit wine’s resident antioxidant, resveratrol, for a beneficial effect on lungs.
“We have known for some time that resveratrol has antioxidant activity and recent studies suggest that it may also have anti-inflammatory effects,” explains Peter Barnes, M.D., professor of thoracic medicine at Imperial College in London. Still, EN does not encourage using alcohol as a preventive for lung disease; stick to nutrition measures with less potential risk.
More Reason to Keep Weight Down.
Research from the University of Arizona found that women who are overweight are nearly three-and-a-half times more likely to develop asthma than thinner women. This supports findings from Harvard’s Nurses’ Health Study.
The mounting evidence for a link between weight and asthma in women has researchers theorizing that sex hormones might somehow be involved. The obesity-asthma link may also be partly due to excess weight constricting the chest wall and narrow airways. In addition, experts think heavier people may have poor diets, especially low intakes of antioxidant vitamins.
Alternative Therapies. Caffeine and the herb ma huang, also known as ephedra, are promoted as alternative treatments to aid breathing. Chemically, both substances are related to methylxanthine, a medication used to treat asthma. However, the use of caffeine and ephedra for chronic lung diseases has not been well studied for safety, and experts advise against their use.
The Bottom Line. Lung health is taken for granted….until it’s compromised. Start protecting it now and you’ll breathe easy later. A lifestyle for healthy lungs is the same as for keeping your heart healthy and combating cancer: Eat plenty of fruits, vegetables and whole grains, eat fish, go easy on sodium, exercise and maintain a healthy weight.
RELATED ARTICLE: EN’s advice for breathing easy.
Don’t smoke (80% to 90% of COPD is caused by smoking). Avoid environmental pollutants. Get plenty of antioxidants by eating five to nine fruits and vegetables a day. Opt for whole grains like whole-wheat bread, whole-wheat pasta and brown rice to boost your intake of phytonutrients. Eat fish rich in omega-3 fatty acids–salmon, mackerel, albacore tuna or sardines–a few times a week. Limit sodium by choosing whole foods over processed foods and using spices and herbs to season instead of salt. Maintain a healthy weight by watching portion sizes and keeping active.
–E.B.
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