The Issue: There have been a number of recent news reports suggesting some kind of link between obesity and asthma. Experts know that asthma patients are more likely than healthy individuals to be overweight. The question, though, is whether obesity led to asthma (or asthma-like symptoms), or whether asthma led to excess weight gain. Some medications used to treat asthma can cause weight gain.
People who have asthma are often less active because of their breathing problems. But, at the same time, inflammation is a common internal trait that occurs both in obesity and asthma. So, experts wonder if the inflammatory process could be linked somehow. A review of previously published studies from the National Jewish Medical and Research Center has led experts to conclude that obesity is a significant risk factor for asthma.
Study Structure: The study was conducted by E. Rand Sutherland, M.D., and David Beuther, M.D., both assistant professors of medicine at National Jewish. The physicians analyzed the results of seven large studies that followed people who did not have asthma originally, but who developed it later. More than 330,000 patients were involved in the seven studies reviewed.
The Findings: Dr. Sutherland and Dr. Beuther found through the course of their analysis that people who are overweight were one-and-a-half times more likely to develop asthma as people whose weight is within a healthy range. Overweight is defined as those with a body mass index, or BMI for short, of greater than or equal to 25. Obese people are those who have a BMI of 30 or more. Obese people are almost twice as likely (1.92 times more likely) to develop asthma as those who are not overweight. In short, being overweight means you have 50 percent greater chance of getting asthma.
How BMI Works: BMI, or body mass index, is a comparison of your weight to your height, in order to determine if your weight is in a healthy range. For example, in the National Jewish review, people who had the following ratios would have fallen into a BMI range of 25 or more (defined as overweight):
- 5'4"/145 pounds
- 5'10"/209 pounds
- 6'0"/221 pounds
People who had the following ratios would have fallen into a BMI range of 30 or more (defined as obese):
- 5'4'/174 pounds
- 5'10"/174 pounds
- 6'0"/184 pounds
Significance: Past studies have shown that new asthma cases are developing in the U.S. at a rate of about one-half of one percent each year. That might not seem like all that much, but consider that two-thirds of the 220 million adults in the U.S. are overweight. That translates to about 250,000 new asthma cases per year.
What You Can Do: Reaching or maintaining a healthy weight is one way of lowering your odds for getting asthma. Even if you already have asthma and are overweight, losing weight will benefit your health in many ways, including helping to reduce your asthma symptoms. Healthy eating habits are one of the best methods for achieving a health weight range. Even small changes may yield major health benefits.
How to Eat Healthy: Eating healthy is a matter of making lasting changes in the way you eat, what you eat, and how much you eat. We have an entire site here at About.com dedicated to healthy eating and nutrition, but here are some quick tips to help you get started with healthy eating habits:
- Eat more fruits and vegetables each day, five to seven servings
- Switch to whole-grain products
- Don't overdo it with the portions
- Drink plenty of water each day
- Limit the amounts of caffeine-containing liquids and alcoholic beverages
- Eat more fresh foods and less prepared, fried, processed and canned foods
- Limit high-fat and high-sugar foods
At our Calorie Count channel here at About.com Health, you can find all kinds of tools and information that will help you lose weight, if you need to. There are recipes (Diet Coke Cake, anyone?) and you can even analyze the calorie count for any food you eat. Check it out here for free.
Sources: National Jewish. Excess weight estimated to cause
more than 250,000 new asthma cases each year in U.S. Available at:
http://www.nationaljewish.org/news/y2007/obesity-asthma.aspx Accessed February 12, 2007.
National Heart, Lung, and Blood Institute. Aim for a healthy weight. Available at: http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/recommen.htm. Accessed February 12, 2007.
