Different types of food are linked
to risks of different types of stroke, according to the largest study to
investigate this, published in the European Heart Journal ).
Until now, most
studies have looked at the association between food and total stroke (all types
of stroke combined), or focused on ischaemic stroke only. However, the current
study of more than 418,000 people in nine European countries investigated
ischaemic stroke and haemorrhagic stroke separately.
The study found
that while higher intakes of fruit, vegetables, fibre, milk, cheese or yoghurt
were each linked to a lower risk of ischaemic stroke, there was no significant
association with a lower risk of haemorrhagic stroke. However, greater
consumption of eggs was associated with a higher risk of haemorrhagic stroke,
but not with ischaemic stroke.
Ischaemic stroke
occurs when a blood clot blocks an artery supplying blood to the brain or forms
somewhere else in the body and travels to the brain where it blocks blood flow.
Haemorrhagic stroke occurs when there is bleeding in the brain that damages
nearby cells. About 85% of strokes are ischaemic and 15% are haemorrhagic.
Stroke is the second leading cause of deaths worldwide.
Dr Tammy Tong,
the first author of the paper and a nutritional epidemiologist at the Nuffield
Department of Population Health, University of Oxford (UK), said: “The most
important finding is that higher consumption of both dietary fibre and fruit
and vegetables was strongly associated with lower risks of ischaemic stroke,
which supports current European guidelines. The general public should be
recommended to increase their fibre and fruit and vegetable consumption, if
they are not already meeting these guidelines.
“Our study also
highlights the importance of examining stroke subtypes separately, as the
dietary associations differ for ischaemic and haemorrhagic stroke, and is
consistent with other evidence, which shows that other risk factors, such as
cholesterol levels or obesity, also influence the two stroke subtypes
differently.”
The total amount
of fibre (including fibre from fruit, vegetables, cereal, legumes, nuts and
seeds) that people ate was associated with the greatest potential reduction in
the risk of ischaemic stroke. Every 10g more intake of fibre a day was
associated with a 23% lower risk, which is equivalent to around two fewer cases
per 1000 of the population over ten years.
Fruit and vegetables
alone were associated with a 13% lower risk for every 200g eaten a day, which
is equivalent to one less case per 1000 of the population over ten years. No
foods were linked to a statistically significant higher risk of ischaemic
stroke.
Based on UK
estimates, two thick slices of wholemeal toast provide 6.6g of fibre, a portion
of broccoli (around eight florets) provides about 3g, and a medium raw,
unpeeled apple provides about 1.2g of fibre. The European Society of Cardiology
(ESC) and the World Health Organization Regional Office for Europe recommend
consuming at least 400g of fruit and vegetables a day; the ESC also suggests
people should consume 30-45g of fibre a day.
The researchers
found that for every extra 20g of eggs consumed a day there was a 25% higher
risk of haemorrhagic stroke, equivalent to 0.66 extra cases per 1000 (or around
two cases per 3000) of the population over ten years. An average large-sized
egg weighs approximately 60g. Egg consumption in the EPIC study was low overall,
with an average of less than 20g eaten a day.
The researchers
say the associations they found between different foods and ischaemic and
haemorrhagic stroke might be explained partly by the effects on blood pressure
and cholesterol.
Dr Tong and her
colleagues analysed data from 418,329 men and women in nine countries (Denmark,
Germany, Greece, Italy, The Netherlands, Norway, Spain, Sweden and the United
Kingdom) who were recruited to the European Prospective Investigation into
Cancer and Nutrition (EPIC) study between 1992 and 2000. The participants
completed questionnaires asking about diet, lifestyle, medical history and
socio-demographic factors, and were followed up for an average of 12.7 years.
During this time, there were 4281 cases of ischaemic stroke and 1430 cases of
haemorrhagic stroke.
Food groups
studied included meat and meat products (red meat, processed meat and poultry),
fish and fish products (white fish and fatty fish), dairy products (including
milk, yogurt, cheese), eggs, cereals and cereal products, fruit and vegetables
(combined and separately), legumes, nuts and seeds, and dietary fibre (total
fibre and cereal, fruit and vegetable fibre).
Major strengths
of the study include the large numbers of people studied in several different countries
and long follow-up period. Most types of food were included in the study,
although information on diet was collected at only one point in time, when the
participants joined the study. As the study is observational it cannot show
that the foods studied cause an increase or decrease in risk of ischaemic or
haemorrhagic stroke, only that they are associated with different risks.
Information on medication use (including statins) was not available.
Journal article: https://academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehaa007/5748325
No comments:
Post a Comment