More Smoke, More Stroke

According to a 2021 report by The Lancet, stroke was the third leading cause of death worldwide, after ischemic heart disease and COVID-19, based on the Global Burden of Disease (GBD) classification. The data further shows that stroke accounts for an estimated 12 million cases and over 7 million deaths globally each year. 

Africa is home to some of the highest rates of stroke worldwide, with alarming incidence, prevalence, and fatality rates. Recent figures detailed in the infographic below underscore the importance of pragmatic and concerted public health interventions.

Considerable scientific evidence has found that cigarette smoking is a causal risk factor for all forms of stroke. This is due to the inflammation wreaked on blood vessels, leading to the formation of clots, buildup of plaque in the arteries, or general weakening of the blood vessels.

The two main types of stroke include ischemic and hemorrhagic. Ischemic strokes are the most prevalent and refer to when a blood clot has blocked blood vessels in the brain. Given that smoking causes the blood vessels to narrow–triggering plaque and clots–this increases the risk of an ischemic stroke. Hemorrhagic strokes–or bleeding strokes–occur when a blood vessel (specifically, an artery) in the brain ruptures, causing blood loss and damage to the brain. The nicotine and carbon monoxide found in cigarette smoke weaken the arteries, which makes them more susceptible to bursting or breaking, leading to a hemorrhagic stroke. 

To put it into perspective, up to one-quarter of all strokes are directly attributable to smoking. Smokers are twice as likely to suffer from a stroke event, and twice as likely to die from them. This risk increases with frequency–smoking 25 or more cigarettes daily (e.g. exceeding one pack of cigarettes) leaves users five times more likely to suffer from a stroke event, and about five times more likely to die from one.

Given these alarming statistics, raising awareness is crucial. In honor of this year’s World Stroke Day, observed annually on October 29th, this piece aims to raise awareness of the substantial burden of non-communicable diseases–particularly stroke incidents–using the case study of Nigeria, one of the main tobacco production hubs on the continent, in addition to Kenya.

Awareness of links between cigarette smoking and strokes still needs to improve in many parts of the world, including Africa. Supporting better tobacco control policy design and implementation in Africa, the Tobacco Control Data Initiative (TCDI) seeks to improve access to country-specific tobacco control data for governments, civil society, and academia. The six country-specific TCDI websites provide stakeholders with data to inform the design and implementation of effective tobacco control policies through comprehensive primary and secondary research.  

The Link Between Secondhand Smoke and Stroke

Unfortunately, no level of exposure to secondhand smoke is risk-free. Scientific evidence has shown that secondhand smoke is a causal risk factor for strokes. Breathing secondhand smoke increases the risk of stroke by 20 to 30 percent. There is even another layer of exposure–known as thirdhand–which refers to the lingering residue from tobacco smoke that can be detected on surfaces, furniture, floors, curtains, and walls for several months. These enclosed spaces absorb the tobacco smoke toxins and gradually

release them back into the air. Infants and young children are thought to be the most susceptible to this type of exposure, likely due to development behaviors (e.g. having a breathing zone closer to the ground) that lead them to reportedly ingest double the amount of dust particles compared to adults. 

In this piece, we’ll discuss the stroke-related implications of tobacco usage with an emphasis on the health and economic burden in Nigeria. The following sections feature data presented in a 2019 modeling study conducted by the Centre for the Study of Economies in Africa, Development Gateway’s sustainability partner on TCDI, in addition to a recently published research manuscript on Mortality from Tobacco Use in Kenya, carried out as part of TCDI’s activities in Kenya. Data from this research may also be found on the TCDI Kenya dashboard.

Health and Economic Costs of Smoking Tobacco in Nigeria

Nigeria reports the highest absolute number of active smokers on the continent. Smoking is responsible for approximately 29,000 deaths per year. Tobacco-attributable stroke events represented 13 percent of cases, after Chronic Obstructive Pulmonary Disease (63 percent). 

In 2019, the total economic burden of tobacco in Nigeria was estimated at 634 billion Naira, or approximately USD 2.07 billion. This includes direct and indirect medical treatment costs (i.e., productivity losses and informal caregiving). CSEA’s 2019 modeling study in Nigeria studied four hospitals over three Nigerian regions, namely Oyo (Southwest), Enugu (Southeast), and Abuja (North). Direct medical costs for stroke were micro-costed at 1.2 million Naira, or approximately USD 730. Indirect costs were micro-costed at 363 thousand Naira, or USD 220.

The TCDI Kenya team published a research manuscript quantifying the mortality burden attributable to smoking tobacco in Kenya, from 2012 to 2021. Over the 9-period studied, 60,228 deaths were attributed to tobacco-related diseases. Approximately 9,948 (16.5%) of these observed deaths were attributed to smoking, with cardiovascular diseases–including stroke–accounting for an estimated 885 deaths (8.9% of the total).

Strengthening Tobacco Control Through Tax Reform

The following bullet points highlight two effective tobacco control policy interventions described in CSEA’s 2018 study titled “The Economics of Tobacco Control in Nigeria: Modeling the Fiscal and Health Effects of a Tobacco Excise Tax Change in Nigeria.” The study recommended that such interventions should comprise of the following:

• Changing the tax system from ad valorem to specific excise taxes. 

Ad valorem taxes are based on the value of the products (e.g., a percentage on the factory or retail price), while specific taxes are levied based on quantity (e.g., tax per carton/per cigarette/per gram loose-leaf). A specific excise tax system is recommended because it leads to higher retail prices–offering a more predictable revenue stream–and is easier to administer than ad valorem taxes. Additionally, specific excise taxes treat all tobacco products equally, meaning that tobacco products pay the same amount of tax, regardless of brand or product type. So, in short, a simpler tax system is favorable.

• Continuously increasing the excise tax burden on tobacco products.

Excise taxes are comprised of specific and ad valorem and refer to a legislated tax on specific goods.

Ultimately, increasing the tax burden on tobacco products would save lives. If the price of cigarette packs were to increase by 50 percent through taxes, in a decade, 30,000 smoking-attributable deaths would be prevented, and 21,000 strokes would be avoided. Savings from direct and indirect costs equate to 597 billion Naira, and additional earned tax revenue amounts to 369 billion Naira. 

A prime avenue for promoting public health and fostering sustainable development is embedding comprehensive tobacco taxes in a country’s tobacco control strategy. This tax-based approach is especially advantageous in light of the significant–and sometimes prohibitive–costs of funding tobacco control interventions. It represents a win-win measure, as countries can benefit from the additional earned tax revenue while focusing on competing national priorities. This strategy should also feature recommended policy measures detailed in the FCTC, such as graphic health warnings, bans on tobacco advertising, promotion and sponsorship, and smoke-free areas. 

World Stroke Day is key in promoting awareness of stroke prevention, early recognition of symptoms, and the critical role of lifestyle choices in reducing risk. This global day brings attention to the preventable nature of strokes and encourages worldwide efforts to support healthier lifestyles, including smoking cessation, to reduce stroke incidents.