Abstract
Research suggests regular drinking of coffee could reduce the risk of stroke in women.
Researchers based at the Karolinska Institute (Stockholm, Sweden), have reported that drinking more than one cup of coffee a day gives a 22–25% lower risk of stroke in women. The study, reported in Stroke: Journal of the American Heart Association also indicated that consumption of no or low amounts of coffee is associated with a increased risk of stroke.
It has previously been suggested that coffee could have an effect on the cardiovascular system, but whether the effects were beneficial or detrimental were undecided. Research that has been previously carried out on the association has been inconclusive. Coffee is one of the most popular beverages in the world; “Therefore, even small health effects of substances in coffee may have large public health consequences,” comments Susanna Larsson, the lead author of the study.
The inspiration for the study came from previous research performed by the group, “Our research group has previously observed an inverse association between coffee consumption and risk in Finnish male smokers, we wanted to assess the situation in women” explains Larsson. The research followed 34,670 women, aged from 49 to 83 years, for an average of 10.4 years, to establish whether there was a cardiovascular effect from coffee consumption.
The study was performed on women who were participating in the long-running Swedish Mammography Cohort, an epidemiology study that aims to investigate the association between diet, lifestyle and disease development. At the start of the study in 1997, none of the women who participated had cardiovascular disease or cancer.
Data were collected on women who experienced their first stroke between 1 January 1998 and 31 December 2008. The researchers collected data on 1680 strokes, of which 1310 were cerebral infarctions or ischemic strokes, 154 were intracerebral hemorrhages, 79 were subarachnoid hemorrhages and 137 were unspecified.
The results indicated that regular consumption of coffee was associated with a significantly lower risk of stroke, cerebral infarction and subarachnoid hemorrhage. The results were adjusted accordingly for other risk factors.
“Some women have avoided consuming coffee because they have thought it is unhealthy,” comments Larsson. “In fact, increasing evidence indicates that moderate coffee consumption may decrease the risk of some diseases such as diabetes, liver cancer and possibly stoke.” The reasons for the possible reduced risk of stroke remains to be determined. However, coffee consumption may reduce subclinical inflammation, reducing oxidative stress and improving insulin sensitivity.
The researchers noted that although the results are currently too preliminary to advise a change in coffee drinking habit, the results could ease the health concerns of women who consume coffee on a regular basis. Further research is required to determine whether there is a strong link between drinking coffee and a reduced risk of stroke in women.
Sources: Larsson SC, Virtamo J, Wolk A: Coffee consumption and risk of stroke in women. Stroke 42(4), 908–912 (2011); www.sciencedaily.com/releases/2011/03/110310173204.htm.
Possible link between hot flashes and reduced stroke risk
The early onset of menopausal symptoms, such as hot flashes and sweats, could mean a lower risk of heart disease, stroke and death.
Research that has been performed at the Northwestern Memorial Hospital (IL, USA), suggests there is a link between the risk of heart disease and stroke, and the onset of menopausal symptoms. Women who experience hot flashes and sweats when they begin the menopause were found to be at lower risk, however, women who started symptoms later in the menopause, or did not experience any symptoms appear to be at greater risk of cardiovascular disease.
“While they are certainly bothersome, hot flashes may not be all bad. Our research found that despite previous reports suggesting that menopause symptoms were associated with increased levels of risk markers for heart disease, such as blood pressure and cholesterol the actual outcomes tell a different story,” said Emily Szmuilowicz, the lead author of the study. “We found that women who experienced symptoms when they began menopause had fewer cardiovascular events than those who experienced hot flashes late in menopause or not at all.”
The study utilized data collected from the Women's Health Initiative Observational Study, which compiles data from 60,027 postmenopausal women. The women were followed for 10 years, allowing the researchers to investigate the links between the time of onset of menopausal symptoms, in relation to the start of the menopause, and the risk of a cardiovascular events.
The participants were separated into four groups; those who had no symptoms throughout the menopause, those who experienced symptoms at the start of the menopause (but not upon enrollment in the study), those who experienced symptoms at the start of the menopause and at study enrollment, and those who did not experience symptoms until after the menopause. The data was adjusted accordingly to take into account other risk factors associated with cardiovascular disease.
The results demonstrated a lower risk of heart disease and stroke in women who had experienced an early onset of symptoms during the menopause, when compared with the group of women who had experienced no symptoms throughout the menopause. “It is reassuring that these symptoms, which are experienced by so many women, do not seem to correlate with increased risk of cardiovascular disease” enthuses Szmuilowicz. However, women who experienced a late onset of symptoms were found to have an increased risk of heart disease and stroke when compared with those who had no symptoms throughout.
Szmuilowicz comments that menopausal symptoms, such as hot flashes “will never be enjoyable, but perhaps these findings will make them more tolerable.” The team hope to perform further research to establish whether menopausal symptoms can be used as an effective predictive value for cardiovascular risk.
Sources: Szmuilowicz ED, Manson JE, Rossouw JE et al.: Vasomotor symptoms and cardiovascular events in postmenopausal women. Menopause doi: 10.1097/gme.0b013e3182014849 (Epub ahead of print) (2011); Northwestern Memorial Hospital press release: www.nmh.org.
Energy and protein consumption in postmenopausal women and reducing stroke risk
Researchers have discovered a link between the consumption of energy and protein and a reduced risk of ischemic stroke in postmenopausal women.
Research carried out at the Fred Hutchinson Cancer Research Centre (Washington DC, USA) suggests a positive association between energy and coronary heart disease that could be correlated to body mass accumulation.
The study involved the assessment of 80,370 postmenopausal women who were enrolled in the Dietary Modification Trial or the prospective Observational Study in the Women's Health Initiative. The women were aged 50–79 years at the time of enrollment. The women completed food frequency questionnaires and were assessed for the incidence of cardiovascular disease by a physician. In addition to the collection of data from the food frequency questionnaires, urinary recovery biomarkers of energy and protein were collected from 544 of the women.
The results indicated that energy consumption was positively correlated to the incidence of coronary heart disease, after biomarker correction. In addition, protein density was found to be inversely associated to coronary heart disease. The results appeared to indicate that the positive association with energy resulted from body fat accumulation. The incidence of ischemic stroke was demonstrated to be inversely associated with consumption of energy and protein, but not with protein density.
The study concludes that the direct association between energy consumption and the risk of coronary heart disease is a result of increased body mass. However, the consumption of energy and protein and this inverse risk of ischemic stroke may be due to links between consumption of this diet and physical activity.
Source: Prentice RL, Huang Y, Kuller LH et al.: Biomarker-calibrated energy and protein consumption and cardiovascular disease risk among postmenopausal women. Epidemiology 22(2), (2011).
Women may develop less infarcted tissue than men following ischemic stroke
A study suggests that women may develop lesions half the size of their male counterparts following ischemic stroke.
Researchers based at Harvard Medical School (MA, USA) have investigated whether there is a relationship between gender and tissue outcome in ischemic stroke. The aim of the study was to determine whether the proportion of tissue that was initially ischemic prior to becoming infarcted was different between men and women who had suffered an ischemic stroke.
The scientists studied 141 consecutive patients who had suffered an acute ischemic stroke and who had been imaged using MRI to establish a baseline of damaged tissue within 12 h of the onset of symptoms. A follow up MRI was conducted 4 days or later after the original image. The images obtained were compared to establish the percentage of infarcted tissue by using mean time mismatch in comparison to the original image. The growth of the lesion was calculated as the percentage of tissue that had undergone infarction in the follow-up MRI.
The results indicated that there was not a significant difference in the median percentage mismatch lost between men and women. However, the results indicated that the combined effects of gender and age had a significant impact on the tissue outcome after ischemic stroke. Women less than 70 years of age were found to develop approximately 50% less infarcted tissue that male counterparts.
The findings highlight the well-known concept that age and gender have a significant effect on stroke incidence, mortality and outcome of function.
Source: GoKcay F, Arsava EM, Baykaner T et al.: Age-dependent susceptibility to infarct growth in women. Stroke 42, 947–951 (2011).