Asthma, GERD connected, say scientists slow on the uptake
This is from the latest LEF magazine newsletter:
The incidence of asthma cases has surged in recent years, although researchers aren’t sure exactly why. According to some studies, up to 5 percent of the US population is affected by asthma, with half of these cases developing before age 10 (Kasper DL et al 2005). Asthma attacks can be triggered by allergies and environmental irritants. Scientists have also discovered links between asthma and other diseases and conditions, including gastroesophageal reflux disease (GERD) and obesity (Flaherman V et al 2006).
Scientists are also beginning to better understand the interaction between allergies, asthma, and oxidative stress. Oxidative stress occurs when highly reactive molecules, known as free radicals, interact with molecules within the body, especially DNA and mitochondrial membranes. Experimental evidence suggests that some pollutants, such as vehicle exhaust, may produce oxidative stress in the bronchial tubes (Gilmour MI et al 2006). Studies suggest that dietary supplementation with precursors of glutathione (an internal antioxidant), such as cysteine and alpha-lipoic acid, can enhance the pulmonary defenses, thus countering oxidative stress (Bridgeman MM et al 1991).
Interestingly, asthma and GERD seem to be strongly associated. GERD is a chronic condition in which partially digested stomach contents, including acid, flow backward into the esophagus. Heartburn and other symptoms usually result. Although the relationship between asthma and GERD is unclear, there is evidence for two related mechanisms. The irritation by acid of nerve receptors in the esophagus may produce a reflex irritability in the vagus nerve, producing increased sensitivity to cough-inducing stimuli in the lungs. Alternatively (or in addition), microscopic food particles and acid may be aspirated into the lungs from the refluxed material, triggering the initial round of inflammation that sets off the attack (Jiang SP et al 2005). Both mechanisms involve an initial inflammatory stimulus from the irritating stomach contents. LEF, Asthma
The “rising air pollution” theory of asthma has been discounted numerous times and in numerous different ways, but it is still trotted out on a regular basis by people who can’t imagine what else could possibly be different between industrial countries and rural peasant communities. People have a tendency to assume simple connections: because asthma affects the lungs, it must be “something in the air” that causes it! The hygeine hypothesis is more plausible and actually has some evidence to support it, but is still very tenuous. I’ll give folks a clue here: the difference between industrial countries and rural peasant communities is E-numbers. As well as being backed up by clinical trials on asthmatics, it’s backed up by epidemiological evidence: Italy. Italians are very wary of using food additives and regard additive-free, fresh food as a mark of good quality. Asthma rates in Italy are much lower than the rest of Europe. This is in spite of the average Italian’s diet being heavily laden with strong flavours like tomato, and large quantities of refined carbohydrate (pasta).
I’ve read articles where scientists ponder on the asthma/GERD connection before, and they make me want to bang my head on the desk. The same goes for when I read articles on the asthma/eczema/arthritis connection, or the asthma/ADHD connection, the fibromyalgia/ADD connection, or any combination thereof, or indeed any article that describes all of these conditions as being associated with or caused by “stress”. Whatever “stress” is defined as, it isn’t a cause of chronic disease, but a symptom!
Here, LEF have an only vaguely plausible mechanical explanation for the connection. I have a friend in his thirties who has suffered from GERD for many years and has treated it with H2 blockers. Recently he tried seeing a nutritionist, a complete fraudster who waved a crystal around. She told him he was “allergic” to gluten and dairy, and he embarked on a gluten and dairy free diet. Three months later we asked how he was doing, and he had developed asthma. His doctor told him to get rid of his pet dog, which he had owned for over a year. I suspect the truth is he had started eating sausages for breakfast, and had begun eating more vegetables and chocolate in place of bread and dairy.
Asthma and GERD are both food chemical related. They emerge from an interaction of factors: genetic vulnerabilities, combined with multiple chemical interactions and provocations. Salicylates (in fruits, vegetables and tea) are particularly good at irritating the stomach lining and the airways. Lectins (in grains) attack the protective glycoprotein surface of the stomach lining allowing pathogens in, salicylates further degrade it by opening tight junctions and promoting internal bleeding. Histamine produces inflammation and irritation of both airways and stomach. Sulphites trigger asthma attacks in 70% of asthmatics, 30% react to other additives including MSG, and 20% react to salicylates. Add to this common environmental allergic triggers like pollen and animal dander, and you have a recipe for disaster.