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Older people who use olive oil in their cooking and on their salads may have a lower risk of suffering a stroke, researchers reported Wednesday.

In a study that followed older French adults for five years, researchers found that those who regularly used olive oil were 41 percent less likely to have a stroke than those who never used the oil.

The findings, reported in the journal Neurology, hint that the well-known connection between olive oil and heart disease might extend to stroke as well. Olive oil is a key ingredient in the so-called Mediterranean diet. And some clinical trials have suggested that the diet helps control risk factors for heart disease, like high blood pressure, abdominal obesity and elevated levels of “bad” LDL cholesterol.

High olive oil intake is also linked to a lower risk of heart attack, and a longer lifespan among heart attack survivors. These latest findings support the general advice that people replace dubious dietary fats — namely, saturated fats and “trans” fats — with olive oil and other unsaturated fats, according to an expert not involved in the study. But he also stressed that the study does not prove that olive oil, per se, helps prevent strokes.

“We need to remember that this is an observational study,” said Dr. Nikolaos Scarmeas, a neurologist at Columbia University Medical Center in New York who wrote an editorial published with the study.

The study found a correlation between people’s olive oil use and their stroke risk, he told Reuters Health — but that doesn’t necessarily translate into cause-and-effect.

“People who use a lot of olive oil may be very different from people who don’t,” Scarmeas said.

Olive oil users may, for example, have higher incomes, eat better overall or exercise more often than people who never use the oil. The researchers on the new study, led by Cécilia Samieri of the French national research institute INSERM, tried to account for those differences. And after they did, olive oil was still linked to a lower stroke risk.

But it’s impossible to fully account for all those variables, Scarmeas noted. What’s needed, he said, are clinical trials where people are randomly assigned to use olive oil or not, then followed over time to see who suffers a stroke. Such clinical trials are considered the “gold standard” of medical evidence.

The current study included 7,625 French adults age 65 and older who reported on their diets and other lifestyle factors. People who said they used olive oil for both cooking and as a dressing were considered “intensive users.”

Over the next five to six years, those intensive users suffered strokes at a rate of 0.3 percent per year. That compared with just over 0.5 percent among non-users, and 0.4 percent among moderate users.

When the researchers factored in other diet habits, exercise levels and major risk factors for stroke — like high blood pressure and diabetes — heavy olive oil use was tied to 41 percent reduction in the odds of stroke.

Samieri’s team also took blood samples from another 1,245 older adults, measuring their levels of oleic acid — a monounsaturated fat that accounts for most of the fatty acids in olive oil. The one-third of participants with the highest oleic acid levels were 73 percent less likely to suffer a stroke than the one-third with the lowest levels.

The findings, according to Scarmeas, argue for more research into olive oil’s potential benefits against not only heart disease, but stroke and other neurological diseases as well.

For now, he suggested that people choose olive oil and other unsaturated fats over saturated fats (found largely in meat and dairy) and trans fats (found in some processed foods, like crackers, cookies and chips).

“It’s better to rely on this type of fat for your overall health,” Scarmeas said.

That said, no single food is consumed in isolation, he points out in his editorial. Olive oil is one part of the Mediterranean diet that has been tied to heart benefits. The diet also boasts plenty of fruits and vegetables, legumes, whole grains, fish and moderate amounts of red wine.

SOURCE: Neurology, online June 15, 2011

Older adults at risk for stroke have significantly increased risk for some types of cognitive decline, according to a multicenter study led by University of California scientists.

The study, which involved 73 older women and men who had not had a stroke and did not have dementia, showed that participants had substantially greater risk for decline in some aspects of “executive function” – specifically in verbal fluency and the ability to ignore irrelevant information. Verbal memory and short term, or “working memory,” were not affected.

The finding is reported in a poster session at the American Academy of Neurology annual meeting on Tuesday, April 12, 2011.

Elevated risk factors for coronary artery disease previously have been linked to a decline in cognitive function in non-demented older adults. However, few studies have examined specific aspects of neuropsychological functioning in individuals with a wide range of risk for coronary artery disease and stroke.

The goal of the current study was see if risk for these conditions was associated with declines in specific neuropsychological functions. The team asked the question, ‘if a study controlled for age, education and gender, would the risk for coronary artery disease be associated with a decline in executive function or memory?’

They assessed participants’ risk for coronary artery disease using the widely used Framingham Coronary Risk Score, which incorporates coronary artery disease risk factors – age, cholesterol levels, blood pressure, presence of diabetes, and smoking status – to generate a person’s risk of stroke within 10 years.

The participants underwent testing for executive function – the ability to engage in goal-directed behavior, such as remaining attentive, multitasking, thinking flexibly, inhibiting attention to irrelevant sensory information and generating ideas – and memory, through a series of neuropsychological tests.

The results showed that those at a higher risk for stroke performed worse on verbal fluency, a test designed to measure a person’s ability to quickly generate verbal information. It also showed that higher risk for stroke, as well as age, accounted for a significant portion of decline in the ability to ignore irrelevant information.

“The findings reveal that if you control for age, education and gender, participants with higher risk for stroke perform significantly more poorly in verbal fluency and in inhibition, even when controlling for a history of stroke and dementia,” said the lead author of the study, Jonathan Gooblar, a research associate in the UCSF Memory and Aging Center.

At the same time, the research “suggests that treating stroke risk factors potentially could decrease decline in executive function in otherwise healthy patients,” said the senior author of the study, Joel H. Kramer, PsyD, UCSF clinical professor of neuropsychology and the director of the neuropsychology program at the UCSF Memory and Aging Center.

The study involved women and men with a mean age of 78 who live independently. They were recruited as part of the ongoing “Aging Brain: Vasculature, Ischemia and Behavior” study involving researchers at UCSF, University of Southern California and University of California, Davis. The principle investigator of the NIH-funded study is Helena Chiu, MD, of USC.

The study also looked at the cohort in a different way – by dividing the participants up into high and low risk groups according to a cutoff widely used (15 percent risk of stroke in 10 years for women and 20 percent for men). “We showed that this common method of dividing up populations didn’t detect cognitive impairment as well as treating risk as a continuous factor,” said Gooblar. “Even people with a ‘lower’ risk score according to that dichotomy (12 percent for example) were more likely to have cognitive impairment than lower risk scores.”

Kramer said he suspects that coronary risk factors cause cerebrovascular damage that will be detected in neuroimaging scans and will correlate with cognitive decline. The team has conducted scans, but has not yet analyzed the data for this particular study.

Looking ahead, he said, the team plans to focus on participants who have elevated heart risk factors, in order to identify the mechanisms of cognitive change. “Within that group, there probably will be some who have early Alzheimer’s disease and some who don’t. We want to understand the relationship between vascular risk factors and Alzheimer’s disease, as well as the relationship between vascular risk factors and cognitive change that’s purely associated with vascular changes in the brain resulting from heart disease risk factors.”

Other co-authors of the study are Wendy J. Mack, PhD, of USC, and Charles DeCarli, MD, Dan Mungas, PhD and Bruce R. Reed, PhD, of UC Davis.

Researchers say strategies do not consider ethnicity, a leading risk factor for heart disease

TORONTO, Ont., March 17, 2011 — Major clinical studies that evaluate prevention strategies for heart disease and stroke fail to consider a participant’s ethnicity, a factor that can more than double the rate of death in some groups, according to research led by St. Michael’s Dr. Joel Ray.

The study, published online in the Quarterly Journal of Medicine, reviewed 45 major clinical trials on prevention strategies. Researchers found that only 1 in 4 studies reported on the ethnicity of participants. None included information about whether a participant was an immigrant. When ethnicity is reported, it is often superficial in scope.

“On the one hand, some immigrant groups to Canada have lower rates of chronic diseases than Canadian-born residents,” Ray explains. “But, at the same time, some ethnic groups — like those from South Asia, including India and Pakistan — have dramatic early onset of heart disease and stroke. And, not all ethnic groups respond to preventive treatments in the same manner, such blood pressure medications among persons of Afro-Caribbean decent.”

In Canada, 17 per cent of citizens are of a visible minority. Heart disease costs accounts for 17 per cent of hospitalizations each year. Rates of heart disease and stroke are highest among South Asians, one of the largest and fastest growing ethnic groups in Canada, the USA and the U.K. South Asian immigrants have up to a four times higher risk of death from heart disease compared to native-born populations.

“This makes it important to consider ethnicity when conducting research studies so that we can better target prevention strategies to different ethnic groups,” says Ray.

The researchers say some ethnic groups may also be reluctant to enrol in clinical trials because consent forms tend to be in English and French. Others may shy away from committing to participating in research because of cultural norms, they add.

“Most of our scientific research on heart disease and prevention stems from studies conducted in the industrialized world, and among predominantly White populations,” Ray said. “Future studies must both recruit and report on ethnic and immigrant status of their study groups to ensure we are treating these patients in the best way possible. This must become a priority concept for researchers and funding agencies such as the Canadian Institutes of Health Research and the Heart and Stroke Foundation of Canada.”

ST. PAUL, Minn. – Stroke survivors who have an irregular heartbeat called atrial fibrillation may be at higher risk of developing dementia than stroke survivors who do not have the heart condition, according to research published in the March 8, 2011, print issue of Neurology®, the medical journal of the American Academy of Neurology.

Atrial fibrillation affects more than two million Americans, and it is more common as people age. About 15 percent of strokes occur in people with atrial fibrillation. The heart’s two upper chambers do not beat effectively in the condition, resulting in an irregular heart rhythm.

The research analyzed all of the available studies where people with atrial fibrillation were compared to people without atrial fibrillation and followed to determine who developed dementia over time.

A total of 15 studies were analyzed, with 46,637 participants with an average age of 72. The research found that stroke survivors with atrial fibrillation were 2.4 times more likely to develop dementia than stroke survivors who did not have the heart condition. About 25 percent of patients with stroke and atrial fibrillation were found to have developed dementia during follow-up.

“These results may help us identify potential treatments that could help delay or even prevent the onset of dementia,” said study author Phyo Kyaw Myint, MD, of the University of East Anglia in Norfolk, U.K. “Options could include more rigorous management of cardiovascular risk factors or of atrial fibrillation, particularly in stroke patients.”

Myint noted that the research on whether people who have atrial fibrillation but have not had a stroke have any greater risk of dementia was not conclusive.

The American Academy of Neurology, an association of more than 22,500 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, brain injury, Parkinson’s disease and epilepsy.

A study by researchers in Denmark revealed that increasing levels of non-fasting triglycerides are associated with an increased risk of ischemic stroke in men and women. Higher cholesterol levels were associated with greater stroke risk in men only. Details of this novel, 33-year study are now available online in Annals of Neurology, a journal published by Wiley-Blackwell on behalf of the American Neurological Association.

According to the World Health Organization (WHO) cardiovascular diseases are the number one cause of death globally—responsible for an estimated 17.1 million deaths worldwide ( 2004), with 5.7 million due to stroke. The American Stroke Association states that stroke is the third leading cause of death in the U.S. and 87% of all cases are attributed to ischemic stroke, occurring when the supply of blood to the brain is obstructed. The obstruction or blockage is typically caused by the build-up of fatty deposits inside blood vessels (atherosclerosis).

Medical evidence suggests that elevated non-fasting triglycerides are markers of elevated levels of lipoprotein remnants, particles similar to low density lipoprotein (LDL), or bad cholesterol, both of which are thought to contribute to plaque build-up. “Interestingly, current guidelines on stroke prevention have recommendations on desirable cholesterol levels, but not on non-fasting triglycerides,” said lead study author, Dr. Marianne Benn from Copenhagen University Hospital. “Our study was the first to examine how the risk of stroke for very high levels of non-fasting triglycerides compared with very high cholesterol levels in the general population.”

The Danish team followed 7,579 women and 6,372 men who were enrolled in the Copenhagen City Heart Study, all of whom were white and of Danish decent. Participants had non-fasting triglycerides and cholesterol measurements taken at baseline (1976-1978) and were followed for up to 33 years. A diagnosis of ischemic stroke was made when focal neurological symptoms lasted more than 24 hours. During the follow-up period, completed by 100% of participants, 837 women and 837 men developed ischemic stroke.

Results confirmed in both women and men, stepwise increasing levels of non-fasting triglycerides associated with increased risk of ischemic stroke. In women, triglycerides levels of 1-2 mmol/L (89-177 mg/dL) carried a relative risk of 1.2 and levels of 5 mmol/L (443 mg/dL) or greater were associated with a 3.9-fold greater risk, compared with women whose triglycerides levels were less than 1 mmol/L (89 mg/dL). At similar triglyceride levels men had a relative risk that ranged from 1.2 to 2.3. Increasing cholesterol levels did not associate with greater risk of ischemic stroke, except in men whose cholesterol levels were equal to 9 mmol/L (348 mg/dL) or more (relative risk of 4.4).

“Our findings suggest that levels of non-fasting triglycerides should be included in stroke prevention guidelines which currently focus on total cholesterol and LDL cholesterol levels,” concluded Dr. Benn.

AMA Press Release February 1 2011

If you’re a woman and your mother had a stroke, you may have a risk of heart attack in addition to a higher risk of stroke, according to new research on family history and heart disease published in the American Heart Association journal
Circulation: Cardiovascular Genetics.

In a study of more than 2,200 patients, female heart patients were more likely to have mothers who had suffered a stroke than fathers who did.

“Our study results point towards sex-specific heritability of vascular disease across different arterial territories — namely coronary and cerebral artery territories,” said Amitava Banerjee, M.R.C.P., M.P.H., the study’s lead author and Clinical Research Associate in the Stroke Prevention Research Unit at the University of Oxford in the United Kingdom.

The Oxford Vascular Study included patients who had suffered a stroke or transient ischemic attack (TIA), or had experienced a heart attack or chest pain known as unstable angina. It’s the first study in which researchers investigated the link between a relative’s stroke and heart disease risk by sex of the patient and sex of the relative.

In a previous study of the same group, researchers found that women face a higher risk of heart attack before age 65 if their mothers have also had a heart attack at an early age. Other research has linked a mother’s history of stroke to a daughter’s stroke risk.

Understanding such gender-specific risk factors is important because women, despite their lower odds of suffering a heart attack, are more likely than men to die from one, Banerjee said.

“Moreover, traditional risk factors such as high blood pressure, smoking and diabetes don’t account for heart attack risk as clearly in women as in men, and tools to gauge risk in women are inadequate,” Banerjee said. “There is clearly room for improvement in predicting heart attack risk in women.”

The study also found:

• About 24 percent of the heart attack and angina patients, and roughly the same percentage of the stroke patients, had at least one first-degree relative who had a history of stroke. This indicates that stroke history in these relatives — which included siblings and parents — is as important to a person’s risk of heart attack or angina as it is to risk of stroke, Banerjee said.
• The female patients who had heart attacks or unstable angina, conditions known collectively as acute coronary syndromes, were more likely to have had any female relative than any male first-degree relatives with stroke history. Male patients were the opposite.
• Parents’ stroke history didn’t help predict where patients’ heart disease showed up on coronary angiography, or whether disease was present in multiple blood vessels. This suggests that whatever family influence is occurring doesn’t directly affect the heart’s anatomy or dictate where dangerous plaques build up in the coronary arteries. Instead, family history might influence a more general tendency toward thrombosis, or clot production.

The new findings can’t be attributed to genetics alone because shared environmental factors such as relatives’ wealth or poverty can also influence disease risk, Banerjee said.

The study used multiple avenues to comprehensively identify patients in a six-and-a-half-year period who had a diagnosis of stroke, TIA or acute coronary syndromes.

Researchers gathered data throughout the study rather than retrospectively and the subjects were a more representative group recruited through general practitioners. However, because the subjects are all from the United Kingdom, it’s unclear whether the findings would apply to populations in other countries. Ninety-four percent of the population in the Oxford Vascular Study is white, 3 percent Asian, 2 percent Chinese, and 1 percent Afro-Caribbean.

To gather family histories, researchers relied on patients’ reports rather than direct interviews with relatives. But studies have shown these reports are generally accurate and are what doctors most often rely on in the clinic.

“Existing tools to predict heart attack risk ignore family history or include it simply as a yes or no question, without accounting for relevant details such as age, sex and type of disease in patients compared with their relatives,” Banerjee said. “Family history of cardiovascular disease is under-used in clinical practice.”

Co-authors are: Chris C.S. Lim, M.B.B.S.; Louise E. Silver, R.G.N., B.Sc., M.Sc.; Sarah J.V. Welch, R.G.N., B.Sc., M.A.; Adrian P. Banning, M.D.; and Peter M. Rothwell, M.D., Ph.D.

Author disclosures are on the manuscript.

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Statements and conclusions of study authors published in American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect the association’s policy or position. The association makes no representation or guarantee as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content.

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