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Study after study finds negative health effects from air pollution, such as heart disease (here, here, and here). Now two more studies found that living in areas with high air pollution is linked to a higher stroke risk. One study (done in Japan) found an increase of ischemic stroke on the same day as exposure to high levels of air pollution, while the other (done in London, UK) found a higher risk of death after stroke (especially ischemic strokes) in patients who live in areas of high air pollution. This was especially pronounced with exposure to smaller or fine particulate matter (PM2.5)- which is found in high quantities in vehicle exhaust fumes.

It is thought that the fine particles in the air (PM2.5) contribute to the development of potentially fatal diseases various ways - by causing chronic inflammation, and also because they slip past the body's defenses and can be absorbed deep into the lungs and bloodstream. They are not sneezed or coughed out the way larger natural particles, like airborne soil and sand, are removed from the body's airways. What can be done? Other studies have found that when air pollution is reduced, than the risk of death is reduced. So yes, pollution controls on vehicles such as trucks and buses are good. And just think how much air pollution will be reduced when electric vehicles replace current gas powered cars and trucks. From Medscape:

Air Pollution Linked to Higher Stroke Mortality

More evidence showing that living in areas with high levels of air pollution is linked to a higher stroke risk has come from two new studies. Both studies are published online in the journal Stroke. The first, from the United Kingdom, shows a higher risk for death after a stroke in patients who live in areas of high air pollution, and the other, a Japanese study, suggests a higher risk for a new stroke the same day as exposure to high levels of air pollution.

"We have shown a significantly increased risk of death after stroke in patients who had long-term exposure to high levels air pollution before their stroke occurred," senior author of the UK study, Charles Wolfe, MD.... "This was particularly pronounced for high exposure to smaller particulate matter — particles below 2.5 μm in diameter (PM2.5) — which are found in high quantities in exhaust fumes." For the study, Professor Wolfe and colleagues analyzed data from the South London Stroke Register, a population-based register covering an urban, multiethnic population.....Results showed an increased risk for death up to 5 years after stroke in patients living in areas of high air pollution.

"While this study adds to the evidence linking air pollution to cardiovascular disease, it cannot prove causality as it has an observational design," Professor Wolfe commented...."So it is difficult to say for certain that it is the air pollution that is responsible but there are many studies now that have shown similar associations," he said. He noted that the smaller particles (PM2.5) were associated with a worse effect on mortality and this correlated with biological studies that have shown a greater inflammatory effect of small particulate matter vs larger particulate matter on the vessel wall. "Our study suggests that people who have previously had an ischemic stroke, but not a hemorrhagic stroke, may be more vulnerable and at a higher risk of death to chronic, long-term exposure of PM," they conclude.

The Japanese study, by lead author Ryu Matsuo, MD, PhD, Department of Health Care Administration and Management Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, and colleagues, looked at acute exposure to air pollution and shows a small increase in the risk of having a stroke within a day of high exposure to pollution. For the study, the researchers analyzed data on 6885 ischemic stroke patients from a multicenter hospital-based stroke registry in Japan who were previously independent and hospitalized within 24 hours of stroke onset.

Professor Wolfe said his group have conducted a similar study looking at exposure of air pollution in the year before stroke, which showed a 23% increase in stroke risk in those exposed to higher levels of PM2.5. 

Uh oh - once again a drug taken for a common problem (heartburn) is linked to an unexpected negative health effect (higher risk of strokes). Millions of Americans take proton pump inhibitors  (PPIs) to treat acid reflux and heartburn. They are among the most prescribed drugs in the United States, are frequently taken for long periods of time, and are available over the counter. But according to preliminary research presented at a 2016 American Heart Association conference, these medications may also increase the risk of ischemic stroke. Ischemic strokes, which are the most common type of stroke, occur when a blood clot cuts off blood flow to the brain.

Earlier research has linked proton pump inhibitors to increased risk of dementia in older patients, disruption of gut microbes, increased risk of C. difficile infections, and kidney disease. Stomach acid seems to play a role in the normal balance of microbes in the digestive system. When someone takes PPIs it lowers their amount of stomach acid, and so disrupts the gut microbial community (and these changes last for at least a month after discontinuing the drug).

The research was conducted in Denmark among a quarter-million patients who suffered from stomach pain and indigestion, and were taking one of four PPIs: Prilosec, Protonix, Prevacid or Nexium. Overall, they found that ischemic stroke risk increased by 21% among patients who were taking a PPI. The researchers found either no increased risk or minimal increased risk of stroke when taking low doses of PPIs. But at the highest doses of PPIs, they found that stroke risk increased from 30% (Prevaacid) to a high of 94% (Protonix). Another group of medications used to treat heartburn - called H2 blockers - were not linked to increased stroke risk.

Hey, what this research suggests is that not everything should be treated with pills. Medical professionals agree: the safest and best way to reduce heartburn is by making some lifestyle changes. Eat smaller meals (and not right before bedtime), lose weight if needed, don't eat very fatty meals, drink less alcohol, and don't smoke. From EurekAlert:

Popular heartburn medication may increase ischemic stroke risk

A popular group of antacids known as proton pump inhibitors, or PPIs, used to reduce stomach acid and treat heartburn may increase the risk of ischemic stroke, according to preliminary research presented at the American Heart Association's Scientific Sessions 2016.

"PPIs have been associated with unhealthy vascular function, including heart attacks, kidney disease and dementia," said Thomas Sehested, M.D., study lead author and a researcher at the Danish Heart Foundation in Copenhagen, Denmark. "We wanted to see if PPIs also posed a risk for ischemic stroke, especially given their increasing use in the general population." Ischemic stroke, the most common type of stroke, is caused by clots blocking blood flow to or in the brain.

Researchers analyzed the records of 244,679 Danish patients, average age 57, who had an endoscopy -- a procedure used to identify the causes of stomach pain and indigestion. During nearly six years of follow up, 9,489 patients had an ischemic stroke for the first time in their lives. Researchers determined if the stroke occurred while patients were using 1 of 4 PPIs: omeprazole (Prilosec), pantoprazole (Protonix), lansoprazole (Prevacid) and esomeprazole (Nexium).

For ischemic stroke, researchers found:Overall stroke risk increased by 21 percent when patients were taking a PPI. At the lowest doses of the PPIs, there was slight or no increased stroke risk. At the highest dose for these 4 PPI's, stroke risk increased from 30 percent for lansoprazole (Prevacid) to 94 percent for pantoprazole (Protonix). There was no increased risk of stroke associated with another group of acid-reducing medications known as H2 blockers, which include famotidine (Pepcid) and ranitidine (Zantac).

Authors believe that their findings, along with previous studies, should encourage more cautious use of PPIs. Sehested noted that most PPIs in the United States are now available over the counter. Doctors prescribing PPIs, should carefully consider whether their use is warranted and for how long: "We know that from prior studies that a lot of individuals are using PPIs for a much longer time than indicated, which is especially true for elderly patients."

Get active, really active, to reduce your risk for 5 diseases: breast cancer, colon cancer, heart disease, and ischemic stroke. Instead of the 150 minutes of brisk walking or 75 minutes per week of running (which is equal to the 600 metabolic equivalent (MET) minutes now recommended by the World Health Organization), this study found that much more exercise is needed for best health results.

This study (which was a review and analysis of 174 studies) found that there is a dose-response effect, with the most reduction in the risk of the 5 conditions by getting 3000 to 4000 MET minutes per week. This sounds like a lot, but the researchers  point out that this can be achieved by incorporating exercise into your daily routines. The researchers write: "A person can achieve 3000 MET minutes/week by incorporating different types of physical activity into the daily routine—for example, climbing stairs 10 minutes, vacuuming 15 minutes, gardening 20 minutes, running 20 minutes, and walking or cycling for transportation 25 minutes on a daily basis would together achieve about 3000 MET minutes a week."

So start thinking creatively about how to increase exercise or activity into your daily life, especially moderate or vigorous intensity activity. For example, park your car far from the store door, or better yet, bicycle or walk to the store from home. From Medscape:

Get Moving: High Physical-Activity Level Reduces Risk of 5 Diseases

High levels of physical activity can reduce the risk for five major diseases, including type 2 diabetes, new research shows. Findings from the systematic review and meta-analysis were published online ....The data, from a total 174 studies comprising 149,184,285 total person-years of follow-up, suggest that the more total regular daily physical activity one engages in — including recreation, transportation, occupational activity, and/or daily chores — the lower the risks for breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke.

However, significant reductions in those conditions were seen only with total activity levels considerably higher than the minimum 600 metabolic equivalent (MET) minutes per week recommended by the World Health Organization for health benefits. That 600 METs equates to about 150 minutes/week of brisk walking or 75 minutes/week of running. (A MET is defined as the ratio of the metabolic rate during that activity to the metabolic rate when resting.) Risks of the five conditions dropped significantly with an increase in MET minutes per week from 600 to 3000 to 4000, with less additive benefit seen above that level.

For reference, the authors say, "a person can achieve 3000 MET minutes/week by incorporating different types of physical activity into the daily routine — for example, climbing stairs 10 minutes, vacuuming 15 minutes, gardening 20 minutes, running 20 minutes, and walking or cycling for transportation 25 minutes on a daily basis would together achieve about 3000 MET minutes a week." "This amount might seem a bit large, but this is about total activity across all domains of life.…For people who currently don't exercise, clinicians could encourage them to incorporate physical activity into their daily routines, [such as] turning household chores into exercise. 

Another recent meta-analysis of trials involving more than one million individuals indicated that an hour of moderate-intensity activity, such as brisk walking or cycling, offsets the health risks of 8 hours of sitting. The message that physical inactivity is a killer — leading to 5.3 million premature deaths annually worldwide, which is as many as caused by smoking and twice as many as associated with obesity, has been emerging over the past few years, with warnings that "sitting is the new smoking."

This new research is the first meta-analysis to quantify the dose-response association between total physical activity across all domains and the risk of five chronic diseases. The 174 prospective cohort studies included 35 for breast cancer, 19 for colon cancer, 55 for diabetes, 43 for ischemic heart disease, and 26 for ischemic stroke. (Some included more than one end point.)....Higher levels of total physical activity were associated with lower risks of all five outcomes.

With the development of diabetes, for example, compared with no physical activity, those with 600 MET minutes per week (the minimum recommended level of activity) had a 2% lower risk. That risk reduction jumped by an additional 19% with an increase from 600 to 3600 METs/week. Gains were smaller above that, with the increase of total activity from 9000 to 12,000 MET minutes/week yielding only an additional 0.6% diabetes reduction.

Overall, compared with insufficiently active individuals (total activity < 600 MET minutes/week), the risk reduction for those in the highly active category (≥ 8000 MET minutes/week) was 14% for breast cancer; 21% for colon cancer; 28% for diabetes; 25% for ischemic heart disease; and 26% for ischemic stroke

Credit: Medscape

Another study that found benefits to dog ownership. The study authors concluded that: "Our study provides evidence that dog owners are at a lower risk for ischemic stroke, hemorrhagic stroke and heart failure." This could be to daily exercise, or that dog ownership results in less stress or better psychosocial health, or even some other reason (perhaps dog owners are healthier to start with).   Note: myocardial infarction (MI) is commonly known as a heart attack. From Medscape:

Canine Companions Appear to Help Heart Health: Swedish Study

Middle-aged and older dog owners were less likely to die from cardiovascular heart disease (CVD) or all causes, and those who lived alone were less likely to have an MI (myocardial infarction) or stroke, during a decade of follow-up in a large study based on Swedish national registry data[1]. The findings suggest that "especially for those who live alone, dog ownership makes a significant difference . . . in health status," Dr Mwenya Mubanga (Uppsala University, Sweden) told Heartwire from Medscape.....

Dog owners get daily exercise from walking their dogs, and canine companions can reduce stress, which might explain these findings, the researchers speculate....Similarly, Dr Gang Hu (Pennington Biomedical Research, Baton Rouge, LA).....pointed out that the dog owners do more exercise (by walking their dogs), which may contribute to having a lower body weight, lower blood pressure, and possibly good lipid levels and a lower risk of diabetes—which may all act to lower mortality. Having a dog may also reduce the chances of having depression, which might partly explain the more striking findings in the people who lived alone, he added.

Since 2001, dog owners in Sweden have been required by law to register their dogs, and an estimated 83% of dogs were registered that year with the Swedish Board of Agriculture and/or the Swedish Kennel Club dog registries, Mubanga and colleagues explain. They examined the Swedish national registry data to see how dog ownership was related to new CVD events or mortality.....This included 162,091 dog owners (4.8% of the population) and 3,195,153 people who were not dog owners.

Dog owners who lived alone or with at least one child or adult were less likely to die of CVD or all causes during follow-up compared with those who did not own a dog, but the relationships were stronger for solitary dwellers. Among dog owners, solitary dwellers (but not others) were also significantly less likely to have an MI or stroke than people who did not have a dog.

The possibility of lowering the risk of ischemic stroke (and poor recovery from it) is a good reason to try to increase vitamin D levels - by supplements and/or sunlight. Note that an ischemic stroke occurs when a blood vessel that supplies blood to the brain is blocked by a blood clot. From Medical Xpress:

Low vitamin D predicts more severe strokes, poor health post-stroke

Stroke patients with low vitamin D levels were found to be more likely than those with normal vitamin D levels to suffer severe strokes and have poor health months after stroke, according to research presented at the American Stroke Association's International Stroke Conference 2015. Low vitamin D has been associated in past studies with neurovascular injury (damage to the major blood vessels supplying the brain, brainstem, and upper spinal cord).

"Many of the people we consider at high risk for developing stroke have low vitamin D levels. Understanding the link between stroke severity and vitamin D status will help us determine if we should treat vitamin D deficiency in these high-risk patients," said Nils Henninger, M.D., senior study author and assistant professor of neurology and psychiatry at University of Massachusetts Medical School in Worchester.

Henninger and colleagues studied whether low blood levels of 25-hydroxyvitamin D, a marker of vitamin D status, is predictive of ischemic stroke severity and poor health after stroke in 96 stroke patients treated between January 2013 and January 2014 at a U.S. hospital. They found:

  • Overall, patients who had low vitamin D levels –defined as less than 30 nanograms per milliliter (ng/mL) – had about two-times larger areas of dead tissue resulting from obstruction of the blood supply compared to patients with normal vitamin D levels.
  • This association was similar among patients who suffered lacunar strokes (in which the small, intricate arteries of the brain are affected) and patients with non-lacunar strokes (such as those caused by carotid disease or by a clot that originated elsewhere in the body).
  • For each 10 ng/mL reduction in vitamin D level, the chance for healthy recovery in the three months following stroke decreased by almost half, regardless of the patient's age or initial stroke severity.