Wean Today, Wheeze Tomorrow?
By Phyllis Ring
Breastfeeding has been credited with a long list of health benefits in recent years. Proven to reduce the incidence of urinary, respiratory and middle-ear infections, infant diarrhea, gastrointestinal diseases and diabetes, it has even been associated with higher IQ scores.
Findings released at a 1999 conference of the American Lung Association and American Thoracic Society are further cause for appreciation – or maybe a sigh of relief. This study of more than 2000 Australian children revealed that those exclusively breastfed for at least the first four months of life had substantially lower risk of developing asthma by age 6. Conducted by Wendy Oddy of the TVW Telethon Institute for Child Health in West Perth, Western Australia, the study found that introduction of milk other than breast milk before the age of 4 months added significantly to the risk factor for asthma.
Makes Medical Sense
“I’m not at all surprised,” says Dr. Gail S. Hertz, pediatrician and International Board Certified Lactation Consultant in York, Pa. “Human milk is species-specific and contains what is required for the optimal health and well-being of the child.”
Dr. Jack Newman, pediatrician and co-author of The Ultimate Breastfeeding Book of Answers The Ultimate Breastfeeding Book of Answers (Prima Publishing, August 2000), calls the Australian study, very well done. “There is undoubtedly an allergic factor in asthma,” he says. “There is good evidence that breastfeeding decreases the child’s allergic responses, especially if the breastfeeding is exclusive. The addition of foreign proteins [such as cow's milk or soy] at a young age can result in allergic manifestations. In theory, one drink of formula could do it.”
Even where asthma and allergies are present in a child, breastfeeding can reduce their impact, especially after the minimum period of four to six months that the two studies specify.
Desiree Clark of Rye, N.H., saw the advantages after her son, Harrison, now 1 year old, was diagnosed with asthma at 6 months. His history of eczema and projectile vomiting had made her wary of introducing solids, and she experimented with her own diet to try and alleviate his symptoms.
“At 6 months, he had a cold that went into his lungs,” she says. “I took him to the doctor because I had heard a rattling sound in his chest.” The doctors called it ‘reactive airways,’ which is the new term for asthma. She continued breastfeeding as his source of nutrition. “The vomiting has gone away entirely, and the eczema is slowly getting better,” she says. “Though Harrison has had colds since the asthma diagnosis, one that lasted almost six weeks, he has shown no further symptoms of asthma.”
Reasons to Reduce the Risks
Asthma, a chronic respiratory condition, causes inflammation and swelling of tissues in the airways, frequent constriction of the bronchial passages and excess secretion of mucus by airway walls – all of which restrict the volume of air flow to the lungs.
The leading cause of hospitalization in children, according to the Centers for Disease Control and Prevention (CDC), which estimates that five million U.S children are affected, asthma is a public health problem growing at epidemic rates. It increased in children under age 4 by 160 percent between 1980 and 1994 and is considered the leading chronic childhood illness.
Difficult to diagnose in young children who can’t always communicate their symptoms, it can lead to permanent respiratory damage if left untreated. Indicators are wheezing, shortness of breath, chest-tightening, a chronic cough with no obvious cause, excessively runny nose and a greater susceptibility to respiratory infections.
Asthma often runs in families and susceptibility can be influenced by early-life exposure to allergens, known as triggers, which include certain proteins (egg, peanut, dairy), dust mites, pollen, cigarette smoke and other substances. Theories suggest that other influences include crowded urban environments and an overall decrease in breastfeeding, with resulting loss of preventive antibodies for babies.
Go the Distance for Exclusive Benefits
Breastfeeding as a protective factor for asthma has been the subject of controversy for many years. “The reason that researchers may get varying results in their studies is due to how they define and categorize breastfeeding,” Dr. Hertz says. “Is receiving ANY breast milk breastfeeding? To some researchers it is. There is more evidence that exclusive breastfeeding – that is, receiving breast milk and no other substances like formula – is a different situation than partially breastfeeding.”
Oddy’s study echoes the World Health Organization’s recommendation that, if possible, mothers exclusively breastfeed for at least the first four to six months of a baby’s life. Her study found that, compared with children who were exclusively breastfed for the first four months, children not breastfed exclusively were 27 percent more likely to have doctor-diagnosed asthma by age 6; 41 percent more likely to have wheezed in the last 12 months; and 74 percent more likely to have sleep disturbance due to wheezing within the last 12 months.
“Again, in Wendy Oddy’s study, the duration of exclusive breastfeeding was the key to the difference,” says Dr. Hertz. She explains that this is probably due in part to the absence in breast milk of foreign proteins that act as asthma triggers and the protection it affords from non-beneficial bacteria that develops in the gut of babies not exclusively breastfed.
Why Breast is Best
According to Dr. Newman, the duration of exclusive breastfeeding probably enhances breast milk’s unique ability to help various infant body systems mature. “There are factors which mature the gut more rapidly, factors which stimulate the baby’s immune system to mature more rapidly,” he says. “Both could affect the body’s response to whatever brings on asthma. There are also several factors in the milk which reduce inflammation, the basis we now think of the asthmatic episode.”
What is it about breastmilk that seems to contribute to future lung health and asthma prevention? “Let’s turn this question around,” Dr. Hertz says. “What is it about formula exposure that makes it more likely that children will be affected by respiratory illnesses and asthma? From the illness-prevention aspect, it has to do with immunoglubulins like secretory IgA, infection-fighting cells and antibacterial factors that a baby doesn’t get in formula, but that the breastfed baby gets from its mother’s breast milk. From the asthma aspect, there is a connection between certain respiratory illnesses like RSV (respiratory syncytial virus) and wheezing later in life. The question of sensitization to foreign proteins probably plays a part as well.”
Oddy describes how small droplets of milk that naturally enter the baby’s airways and lungs during feeding can actually deliver antibodies and other protective factors to the child’s respiratory tract that protect against respiratory infection. She also notes that the breakdown of breast milk’s fatty acids in an infant’s stomach helps reduce the risk of infection in the lungs, and her study found that exclusively breastfed babies have significantly larger thymus glands during infancy. This primary central gland of the immune system is likely to have significant effects on immune system development that would extend well into childhood and beyond.
“I am glad about the publication of the study,” Dr. Newman says. “We seem to need evidence that breastfeeding is better. What we really need is evidence to show that formula feeding is as good as the normal, physiologic – that is, breastfeeding. There is no such evidence.”
