Over 1 billion people in the world smoke tobacco, and of these around 5 million die each year. Cigarette smoke contains over 4,000 chemicals, including nicotine, carbon monoxide and hydrogen cyanide.
Is there any harm in having only two smokes per day?
Smoking as few as 2 cigarettes per day doubles the number of cells in your blood stream that have damaged nuclei. A cells nucleus is where it's DNA is found. The type of cells damaged in this way are called endothelial cells and they are the ones that help make up the lining your blood vessels, such as arteries and capillaries. These endothelial cells can also be found flowing within your blood stream. In scientific terms, it can be said that smoking 2 cigarettes per day doubles the number of nuclear-damaged endothelial cells in your circulating blood stream.
This increase in damaged cells probably causes a decrease in how well your wounds can heal, as the wounds need to develop new blood vessels in order to heal.
Is there any harm in having only one smoke per day?
One research study examined the smoking of one cigarette by a dozen healthy young intermittent smokers. The researchers looked at microparticles that are found in the blood stream. These are less than one thousandth of a millimetre in size (i.e 0.1 to 1.0 µm in diameter).These particles can contain various substances, (also known as cytokines, growth factors and proteases) which are directly related to physiological conditions such as inflammation and thrombosis (blood clotting).
The study found that smoking just one cigarette caused a rise of microparticles, which help induce inflammation. This increase in microparticles probably causes a decrease in how well your wounds can heal, as the wounds will be more inflamed than is desirable.
Types of Collagen
Smoking also slows down healing by how it influences a certain type of molecule, called collagen. There are over 16 types of collagen, but 80 - 90% of collage belongs to Types I, II & III.
Type I collage is found in your skin, tendons, ligaments, and bone,
Type II collage is located in your cartilage, and the fluid in your eyeballs (called vitreous humor)
Type III collagen is also in our skin, as well as muscles and blood vessels.
So how does smoking affect collagen and MMP & TIMP?
Smoking is known by many people as a cause of premature facial wrinkling and interfering with wound healing, but the many ways it does this are still being studied.
One study compared the amount of collagen production (synthesis) in the skin of smokers and non-smokers.
The researchers looked at 47 current smokers and 51 individuals who had never smoked from northern Finland. They did this by studying the people after giving them blisters!
It was discovered that the rate of production of Type I and III collagens were lower by 18% and 22% in smokers compared with non-smokers.
If you smoke, even only 1 or 2 cigarettes per day, and experience a strain or a sprain to your ligaments, tendons and muscles, or even have a fractured bone, then you will heal slower because the extra collagen your injured parts need will be produced less quickly, and also you will have more inflammation and less healthy blood vessels. Unfortunately the detrimental effects of smoking can not be reversed by physiotherapy treatment, but they can be reversed to some extent when smoking ceases.
Principal Physiotherapist, IceFire Physiotherapy, Brendale (in the northern suburbs of Brisbane, beside Albany Creek, Eatons Hill, Warner and Strathpine)