A new study by University of Melbourne researchers found that secondhand smoke may contribute to generational asthma. They discovered that children were more likely to develop asthma if their father had exposure to cigarette smoke during childhood. Moreover, the findings revealed that children’s asthma risk increased if their father lived in a smoker’s house and began smoking.

The researchers said the findings reveal how smoking can cause declining health in multiple generations, not just the smoker themselves. The study, led by University of Melbourne researchers Mr. Jiacheng Liu and Dr. Dinh Bui, appeared in the European Respiratory Journal. 

The team gathered data from the Tasmanian Longitudinal Health Study (TAHS), led by the University of Melbourne Professor Shyamali Dharmage. Founded in 1968, TAHS remains one of the world’s most extensive, longest-running respiratory studies.

For the smoking study, researchers analyzed data from 1,689 children who grew up in Tasmania, along with their fathers and paternal grandparents. Next, they wanted to determine the relationship between instances of childhood asthma and whether their fathers lived in a smoking household.

They compared data on whether the children had asthma before turning seven and whether the fathers lived with smokers before they turned fifteen. Also, the researchers included data on whether the fathers currently or formerly smoked cigarettes. Surprisingly, they found a strong association between childhood asthma and secondhand smoke exposure.

Study Finds Secondhand Smoke May Cause Generational Asthma

asthma researchers

Mr. Liu said: “We found that the risk of non-allergic asthma in children increases by 59 percent if their fathers were exposed to secondhand smoke in childhood, compared to children whose fathers were not exposed.

“The risk was even higher, at 72 per cent, if the fathers were exposed to secondhand smoke and went on to smoke themselves.”

Dr. Bui said the research reveals how smoking doesn’t just impact the smoker’s health. It affects their children and grandchildren as well since it causes DNA damage. However, men abstaining from smoking will have a better chance of having healthy children.

“For men who were exposed to secondhand smoke as children, our study suggests that they can still lower the risk they pass on to their own children, if they avoid smoking,” Dr. Bui said.

Researchers still don’t know precisely how the damage from smoking gets passed down through generations. However, Professor Dharmage believes epigenetic changes may lead to a higher risk of asthma.

“This is where factors in our environment, such as tobacco smoke, interact with our genes to modify their expression. These changes can be inherited but may be partially reversible for each generation,” Dharmage said.

“It’s possible that tobacco smoke is creating epigenetic changes in the cells that will go on to produce sperm when boys grow up. These changes can then be passed on to their children.”

Next, researchers will examine whether the higher asthma risk lingers into adulthood. Also, they want to understand if fathers who lived with smokers as children pass an increased risk of allergies or lung diseases to their offspring.

Other Causes of Asthma

According to the American Lung Association, genetics and exposure to environmental toxins strongly contribute to asthma development. Some of the most significant risk factors for asthma include:

  • Family history. A parent with asthma makes you three to six times more likely to develop it.
  • Many indoor and outdoor allergens can trigger asthma symptoms. The most common allergic conditions linked to asthma include pollen, mold, dust mites, cockroaches, pet dander, and rodents. People with allergic conditions like eczema and hay fever also have a higher risk of developing asthma.
  • Viral respiratory infections. Infants and children with respiratory illnesses that cause wheezing have a higher risk of chronic asthma.
  • Environmental irritants. Exposure to industrial chemicals and vapors in the workplace, such as paint or harmful gases, can trigger asthma symptoms. Wood fires, charcoal grills, and dust particles in the air may also cause breathing problems.
  • Air Pollution. Regular exposure to air pollution, such as smog and ozone, can trigger asthma symptoms or cause it to develop. People living in urban areas have the highest risk for asthma. Sadly, researchers have observed a disturbing increase in pediatric asthma due to traffic pollution. Their study found that nitrogen dioxide, a pollutant in vehicle exhaust and industrial sites, contributed to nearly two million pediatric asthma causes in 2019. Studies have also discovered a link between air pollution and reduced lung function in adults.
  • Overweight or obese children and adults also have a greater asthma risk. Scientists believe that chronic inflammation in the body due to excess weight may lower lung capacity. Research shows that obese patients experience more severe symptoms and have more difficulty managing the condition than patients with a healthy weight.
  • Certain weather conditions can exacerbate or bring about an asthma episode. Dry wind, cold air, or sudden changes in the weather usually have the strongest link to asthma. For instance, thunderstorms can trigger breathing issues because rain releases pollen particles, and wind spreads them around. People with asthma who inhale pollen may find it harder to breathe.

Tips on Managing Asthma Symptoms

  • Take medications as prescribed. You might need long-term asthma control medications and a quick-relief inhaler to manage symptoms. If allergens worsen your asthma, take biologics (medicines for people with severe asthma) or allergy shots.
  • Get regular exercise. Physical activity can strengthen the heart and lungs, which will help reduce asthma symptoms. Also, maintain a healthy weight to ensure your airways don’t become obstructed.
  • Avoid or limit exposure to your triggers. Use your air conditioner to lower humidity and reduce indoor pollen levels. Consider using a dehumidifier to prevent mold from forming, and clean your home regularly. Also, stay indoors on days with poor air quality or wear a face mask while outside to avoid inhaling environmental irritants.

smoking cessation

Final Thoughts on Study Linking Secondhand Smoke to Generational Asthma

University of Melbourne researchers discovered that secondhand smoke could lead to generational asthma. They found that children’s risk increased by 59% if their father grew up with parents who smoked. Children had a 72% risk of developing breathing issues if their fathers were exposed to secondhand smoke and also became smokers. The research shows that abstaining from smoking lowers the chance of passing health problems to future generations.