Grandchildren could develop asthma from their grandmother’s smoking

There are umpteen reasons to quit smoking for good, and it seems that on a daily basis there is yet another story to hit the headlines that highlights more evidence of the massive damage that tobacco does to a person’s health and wellbeing.

However, the researchers behind a study published in the March edition of Review of Obstetrics & Gynecology has pushed the boundaries a little further in this respect with claims regarding smoking and genetic inheritance.

Two Los Angeles Biomedical Research Institute (LA BioMed), John S. Torday, Ph.D, and Virender K. Rehan, M.D, believe that having a grandmother who smoked can greatly increase your chance of developing the lung respiratory condition asthma – even if your mother was a non-smoker.

They state that the chemicals and environmental factors which impact our body in the present day could have after-effects for family members in future generations due to the nicotine leaving a ‘mark’ on the genome (our complete set of DNA), making future generations more likely to develop conditions such as asthma or COPD.

Referencing studies conducted by Dr. Rehan, the researchers explained in their editorial that pregnant rats administered nicotine went on to breed asthmatic pups, who then also produced asthmatic pups – even though there was no exposure to nicotine in the third generation.

In addition, the researchers also cited the Children’s Health Study from Southern California, which demonstrated that grandmaternal smoking when pregnant can greatly increase the asthma risk for grandchildren, regardless of whether the mother had been a smoker.

The researchers concluded that asthma seen in the second generation was ‘epigenetic modification’ (an environmental factor resulting in a genetic alteration). It was determined that both the lung cells and sex cells were being impacted by nicotine in ways that caused the lungs that developed from those cells to then develop abnormally – resulting in asthma.

This latest study is not the first one to connect smoking asthma, however could be deemed one of the more controversial. Previous studies have long established a link between a mother smoking at her children having a higher risk of developing asthma. Dr. Erika von Mutius published a study in The Journal of Allergy and Clinical Immunology over ten years ago where he said: “exposure to tobacco smoke in utero significantly increases asthma risk.”

Dr. Torday commented: “These studies break new ground in validating and further explaining the mechanisms involved in the transmission of epigenetic human diseases. The transmission of the asthma to the second generation and its prevention by a specifically-targeted molecular intervention are the first unequivocal demonstrations of multi-generational transmission of an epigenetically-mediated effect on the offspring.”

Dr. Rehan further added: “Asthma is the most common chronic disease of childhood, resulting in a significant impact on the lives of children and driving up medical costs for all. While many factors contribute to asthma, smoking during pregnancy is a well-established one and one that can be avoided. Eliminating smoking during pregnancy would significantly reduce the prevalence of childhood asthma for this generation and for future generations.”

Child asthma problems alleviated since the smoking ban

A study has found that the total number of children requiring hospital treatment because of their asthma has declined since the introduction of the July 2007 smoking ban – prohibiting lighting up in all enclosed public spaces such as restaurants, nightclubs, bars, shopping centres, etc.

The Imperial College London’s analysis on NHS figures has been published in the journal Pediatrics. They looked at admission rates dating all the way back to April 2002 and  they explain there has been an incredible 8.9% reduction in hospital admissions following the first 12 months after the ban came into play.

Intriguingly, researchers identified that preceding the 2007 ban there was a 2.2% rise each year in the number of children admitted to hospital due to severe asthma symptoms that include coughing, wheezing, shortness of breath and tightness in the chest. Taking into account the predicted 2.2% rise annually, researchers say that in those first 12 months, the ban had therefore helped to decrease admissions by 12% with this decline continuing in subsequent years and a 3.4% fall per year for the next two years. This clearly demonstrates the positive impact the legislation is having on health in addition to emphasising how damaging cigarette smoke actually is.

Lead researcher Dr Christopher Millett says that the drop works out at an estimated 6,802 fewer hospital admissions in the first three years of the smoking legislation coming into effect.

Dr Millett spoke on the huge health benefits since the introduction of the ban, commenting: “There is already evidence that eliminating smoking from public places has resulted in substantial population health benefits in England, and this study shows that those benefits extend to reducing hospital admissions for childhood asthma. Previous studies have also suggested that the smoke-free law changed people’s attitudes about exposing others to second-hand smoke and led more people to abstain from smoking voluntarily at home and in cars. We think that exposing children to less second-hand smoke in these settings probably played an important role in reducing asthma attacks. The findings are good news for England, and they should encourage countries where public smoking is permitted to consider introducing similar legislation.”

Medical Specialists Pharmacy finds Dr Millett’s comments particularly interesting as he touches on many topics that we have previously addressed such as the underestimated subject of second-hand (passive) smoking. Not just displeasing because of the foul odour, second-hand smoking can be a killer and those who do smoke need to be clued-up about this serious matter and consider the harm they are inflicting on those around them – in addition to themselves. Parents who are smoking inside their cars  is another factor not considered often enough and the impact this has to their children’s health – especially if a child is asthmatic as this is one factor that can cause their symptoms to flare-up.

Emily Humphreys, head of policy and public affairs at Asthma UK, was happy with the findings of the study and she said: “It’s great to see growing evidence of the positive impact of smoke-free legislation. This is something we campaigned for, so it is particularly encouraging that there has been a fall in children’s hospital admissions for asthma since its introduction.”

Asthma is a long-term respiratory condition where the air passages within the lungs become unexpectedly inflamed, narrowed and swollen. This leads to a prevention of airflow into and out of the lungs. Asthma attacks happen usually following a response to an allergen, cold air, exercise, or emotional stress.

There are a predicted 5.4 million people in the UK currently receive treatment for asthma – 1 in every 11 children and 1 in every 12 adults. This equates to 8.8% of the total population (62 million estimated in 2010). In addition, it affects a staggering 300 million people worldwide.

Although there is no cure, asthma can be controlled through the use of preventer and reliever inhalers and Medical Specialists provide many varieties of each and more information about these and how to obtain them can be found on the Asthma and Allergies area of the website.