Category Archives: Lung Health

High-Fat Meal Increases Airway Inflammation, Contributes To Asthma

Bronchodilator2Individuals with asthma who ate a high-fat meal showed increased airway inflammation several hours later. The high-fat meal also inhibited their response to asthma medication, in this case Ventolin (albuterol):

A High-Fat Challenge Increases Airway Inflammation And Impairs Bronchodilator Recovery In Asthma, Journal of Allergy and Clinical Immunology, May 2011

“CONCLUSION: A high-fat meal augments neutrophilic airway inflammation, with the effect dependent on the type of fat* consumed. A high-fat meal also suppresses bronchodilator recovery in asthma. Modifying dietary fat intake may be useful in asthma.”

* Saturated fat was particularly disruptive. From the press release:1

“Subjects who had consumed the high-fat meal had a marked increase in airway neutrophils and TLR4 mRNA gene expression. TLR4 is a cell surface receptor that is activated by nutritional fatty acids: TLR4 ‘senses’ the presence of saturated fatty acids, and prompts the cell to respond to the fatty acids as if they were an invading pathogen, releasing inflammatory mediators.”

Lead author, Dr. Lisa Wood:

“This is the first study to show that a high fat meal increases airway inflammation, so this is a very important finding.”

This is a systemic effect of consuming lots of meat, dairy, and other high-fat, especially high-saturated-fat foods. Systemic because the fat gets digested, absorbed, and enters the bloodstream. There is also a local effect. Eating lots of fat and oil (including vegetable oils, e.g. olive oil) will relax the LES, the Lower Esophageal Sphincter, a ring of muscle at the bottom the the esophagus where it meets the stomach. Fat also delays stomach emptying. Both of these will increase risk of reflux, or GERD. And GERD contributes to asthma.

1 High-Fat Meals a No-No For Asthma Patients, Press release for the study which was presented at the 2010 American Thoracic Society annual meeting.

COPD – How To Breathe Better, How To Keep Your Weight Up

COPDCausesI just saw a study on COPD and walking that really popped out at me.

Chronic Obstructive Pulmonary disease, or COPD, is really common, probably the most common lung disease, or set of lung diseases, in this country. There are two main forms, which often occur together:

Chronic bronchitis, which involves a long-term cough with mucus
Emphysema, which involves destruction of the lungs over time

Here’s the prevalence, from CDC:

COPDPrevalence

Look at that concentration just west of the east coast.  CDC says, “The states with the highest COPD prevalence are clustered along the Ohio and lower Mississippi Rivers.” Exposure to cigarette smoke and other air pollutants are the main cause. Symptoms show up sooner and are worse in people with poor general health.

Like other chronic diseases (heart disease, cancer, diabetes) you usually have it for years before a doctor tells you so. One thing that sends a person to a doctor? Unexplained weight loss. COPD patients use more calories for breathing. A healthy person might use about 100 calories/day to expand and contract the lungs. A person with COPD uses between 430 and 720 calories/day for the same purpose, even if they are unaware of it.

Cold air is especially difficult for people with COPD because one job of the lungs is to raise the temperature of inhaled air to 98.2°F or body temperature. Calories.

There’s no cure. But exercise, especially walking, helps. That’s why this study drew my attention:

Influence Of Changes In Physical Activity On Frequency Of Hospitalization In Chronic Obstructive Pulmonary Disease, Respirology, April 2014

“Conclusions: Patients with COPD with a low level of physical activity (PA) or who reduced their PA over time were more likely to experience a significant increase in the rate of hospitalization for eCOPD. Changes to a higher level of PA or maintaining a moderate or high level of PA over time, with a low intensity activity such as walking for at least 3–6 km/day, could reduce the rate of hospitalizations for eCOPD.”

It found that people who regularly walked about 2 miles a day, and gave it up, experienced a 2.5-fold increase in their risk for hospitalization after about 3 years. That’s a big increase over a relatively short time. You can imagine they were feeling pretty lousy in the months prior to their hospitalization.

Crystal Phend, senior writer at MedPageToday, in her article Backing Off Exercise Worsens COPD, wrote:

Those who moved from the highest level of activity* to any lower category also doubled their subsequent risk (OR 2.13, P=0.017).

The associations were independent of age, lung function, and prior hospitalizations for exacerbations.

“This suggests that small changes in physical activity habits could significantly improve an important outcome as hospitalization during exacerbation of COPD in those patients,” the researchers concluded.

However, maintaining a lower level of physical activity also roughly doubled risk compared with sticking to a higher level of physical exercise.

The mechanism could be decreasing systemic inflammation, improving lung efficiency, or strengthening lung muscles, but reverse causation and unmeasured confounding were possible as well, they acknowledged.

* Low physical activity was considered less than 1.9 miles (3 km) per day or less, moderate was 1.9 to 3.7 miles (3 to 6 km) daily, and high was anything above that.

So, not only giving it up, but just reducing how much you walk can worsen symptoms.  Walking seems like an effective, non-pharmacological, and inexpensive way to improve lung function.  As long as you keep with it.

How to Keep Your Weight Up? WebMD offered these suggestions:

  • Mix a teaspoon of butter, margarine or olive oil into hot foods such as vegetables, soups and potatoes; it adds 45 calories
  • Eat mayonnaise instead of salad dressing; mayonnaise has 100 calories which is about twice that of salad dressing
  • Use peanut butter liberally; it has lots of protein and about 90 calories per tablespoon
  • Use honey generously for sweetening and as a snack
  • Drink milkshakes made with high-fat ice cream; try adding protein powder or egg substitutes for added calories and proteins
  • Keep high-calorie, healthy snacks around and easy to grab; examples: olives, walnuts, raw almonds and dried fruits
  • Add flaxseed oil or olive oil to cottage cheese with fruit
  • String cheese is easy and bite-size with 80 calories per stick

I like the dried fruit and nut idea. These are probably great weight loss tips in reverse.