A new research published in the British Medical Journal suggests that a high potassium diet as well as cutting down on salt will reduce blood pressure levels and the risk of stroke.
One study review found that eating an extra two to three servings of high potassium fruit or vegetables per day was beneficial.
A lower salt intake would increase the benefits further, researchers said.
While the increase of potassium in diets was found to have a positive effect on blood pressure, it was also discovered to have no adverse effects on kidney function or hormone levels, the research concluded.
A high potassium diet as well as cutting down on salt will reduce blood pressure levels and the risk of stroke
As a result, the World Health Organization has issued its first guidelines on potassium intake, recommending that adults should consume more than 4 g of potassium (or 90 to 100 mmol) per day.
The BMJ study on the effects of potassium intake, produced by scientists from the UN World Food Programme, Imperial College London and Warwick Medical School, among others, looked at 22 controlled trials and another 11 studies involving more than 128,000 healthy participants.
The results showed that increasing potassium in the diet to 3-4 g a day reduced blood pressure in adults.
This increased level of potassium intake was also linked to a 24% lower risk of stroke in those adults.
Researchers said potassium could have benefits for children’s blood pressure too, but more data was needed.
A separate study on salt intake, led by researchers at the Wolfson Institute of Preventive Medicine, Queen Mary, University of London, analyzed the results of 34 previous trials involving more than 3,000 people.
It found that a modest reduction in salt intake for four or more weeks caused significant falls in blood pressure in people with both raised and normal blood pressure. This happened in both men and women, irrespective of ethnic group.
Lower blood pressure levels are known to reduce the risk of stroke and heart disease.
Graham MacGregor, professor of cardiovascular medicine at Queen Mary, who led the study, said that the “modest reduction” in salt intake was equivalent to halving the amount of salt we consume each day.
“In the UK on average our dietary salt intake is 9.5 g, so we are talking about bringing this down to 6g, or if you’re very careful you can get it down to the recommended 5 g – but it’s very difficult because of the amount of salt already in the food we buy.
“Bread is the biggest source of salt in our diet.”
Prof. Graham MacGregor added that a further reduction in salt intake to 3 g per day would have a greater effect on blood pressure and should become the long-term target for population salt intake.
Getting people to eat more fruit and vegetables containing potassium was equally important, he said.
“Salt and potassium work in opposing ways. So a combination of lower salt and higher potassium in our diets has a bigger effect than changing just one of those factors alone.”
The WHO recommends that adults should not consume more than 5 g of salt a day (about one teaspoon).
Finnish researchers have found that a diet rich in tomatoes may reduce the risk of having a stroke.
They were investigating the impact of lycopene – a bright red chemical found in tomatoes, peppers and water-melons.
A study of 1,031 men, published in the journal Neurology, showed those with the most lycopene in their bloodstream were the least likely to have a stroke.
The Stroke Association called for more research into why lycopene seemed to have this effect.
The levels of lycopene in the blood were assessed at the beginning of the study, which then followed the men for the next 12 years.
They were split into four groups based on the amount of lycopene in their blood. There were 25 strokes in the 258 men in the low lycopene group and 11 strokes out of the 259 men in the high lycopene group.
The study said the risk of stroke was cut by 55% by having a diet rich in lycopene.
Dr. Jouni Karppi, from the University of Eastern Finland in Kuopio, said: “This study adds to the evidence that a diet high in fruits and vegetables is associated with a lower risk of stroke.
“The results support the recommendation that people get more than five servings of fruits and vegetables a day, which would likely lead to a major reduction in the number of strokes worldwide, according to previous research.”
He said lycopene acted as an antioxidant, reduced inflammation and prevented blood clotting.
A study published in the journal BMJ Open suggests that a simple drawing test may help predict the risk of older men dying after a first stroke.
Taken while healthy, the test involves drawing lines between numbers in ascending order as fast as possible.
Men who scored in the bottom third were about three times as likely to die after a stroke compared with those who were in the highest third.
The study looked at 1,000 men between the ages of 67 and 75 over 14 years.
Of the 155 men who had a stroke, 22 died within a month and more than half within an average of two- and-a-half years.
Taken while healthy, the test involves drawing lines between numbers in ascending order as fast as possible
The researchers think that tests are able to pick up hidden damage to brain blood vessels when there are no other obvious signs or symptoms.
Dr. Clare Walton, from the Stroke Association in UK, said: “This is an interesting study because it suggests there may be early changes in the brain that puts someone at a greater risk of having a fatal stroke.
“This is a small study and the causes of poor ability on the drawing task is not known. Although much more research is needed, this task has the potential to screen for those most at risk of a severe or fatal stroke before it occurs so that they can benefit from preventative treatments.”
Dr. Bernice Wiberg, lead author from Uppsala University in Sweden, said: “As the tests are very simple, cheap and easily accessible for clinical use, they could be a valuable tool – alongside traditional methods like measuring blood pressure (and) asking about smoking – for identifying risk of stroke, but also as a possible important predictor of post-stroke mortality.”
She also suggested it could help improve information given to patients and their family.
Researchers claim that eating oranges and grapefruit could cut your risk of stroke.
Both the whole fruit and breakfast juices appear to protect against having a “brain attack”, probably due to their high content of a certain type of antioxidant.
A new study looked at citrus fruit for the first time, rather than a range of fruit and vegetables which have been linked to stroke protection.
The study involved thousands of women taking part in the ongoing Nurses’ Health Study in the US, but experts believe the benefits may also apply to men.
A research team based at Norwich Medical School in the University of East Anglia in UK investigated the strength of protection from flavonoids, a class of antioxidant compounds present in fruits, vegetables, dark chocolate and red wine.
The study used 14 years of follow-up data provided by 69,622 women who reported their food intake, including details on fruit and vegetable consumption every four years.
The research team examined the relationship of the six main subclasses of flavonoids – flavanones, anthocyanins, flavan-3-ols, flavonoid polymers, flavonols and flavones – with risk of ischemic, hemorrhagic and total stroke.
The researchers did not find a beneficial association between total flavonoid consumption and stroke risk, as the biological activity of the sub-classes differ.
But women who ate high amounts of flavanones in citrus had a 19% lower risk of blood clot-related (ischemic) stroke than women who consumed the least amounts.
The highest level of flavanones was around 45 mg a day compared with 20 mg a day. A glass of commercial orange juice can provide 20-50mg depending on processing and storage conditions.
In the study, reported in the medical journal Stroke, flavanones came primarily from oranges and orange juice (82%) and grapefruit and grapefruit juice (14%).
Researchers claim that eating oranges and grapefruit could cut your risk of stroke probably due to their high content of a certain type of antioxidant
However, researchers recommended that consumers wanting to increase their citrus fruit intake should eat more whole fruit rather than juice, due to the high sugar content of commercial fruit juices.
Lead researcher Aedin Cassidy, professor of nutrition, said: “Studies have shown higher fruit, vegetable and specifically vitamin C intake is associated with reduced stroke risk.
“Flavonoids are thought to provide some of that protection through several mechanisms, including improved blood vessel function and an anti-inflammatory effect.”
A previous study found that citrus fruit and juice intake, but not intake of other fruits, protected against risk of ischemic stroke and intracerebral hemorrhage.
Another study found no association between yellow and orange fruits and stroke risk, but did link increased consumption of white fruits like apples and pears with lower stroke risk.
An additional study found that Swedish women who ate the highest levels of antioxidants – about 50% from fruits and vegetables – had fewer strokes than those with lower antioxidant levels.
More studies are needed to confirm the association between flavanone consumption and stroke risk, and to gain a better understanding about why the association occurs, said Prof. Aedin Cassidy.
Dr. Sharlin Ahmed, Research Liaison Officer at The Stroke Association said: “We all know that eating plenty of fresh fruit and veg is good for our health. This study suggests that eating citrus fruits in particular, such as oranges and grapefruits, which are high in vitamin C could help to lower your stroke risk.
“However, this should not deter people from eating other types of fruit and vegetables as they all have health benefits and remain an important part of a staple diet.
“More research is needed in this area to help us understand the possible reasons why citrus fruits could help to keep your stroke risk down.
“Everyone can reduce their risk of stroke by eating a healthy balanced diet that is low in saturated fat and salt, exercising regularly and ensuring that your blood pressure is checked and kept under control.”