A new research has found that eating oily fish may boost women’s heart health more than men’s.
The oils – found in fish like salmon, mackerel and tuna – are known to improve chances of surviving a repeat heart attack.
But a new study suggests women could benefit more from their effect on the heart.
Researchers at the University of Reading, UK, found fish oils have a direct impact on the muscle cells that control the elasticity of our blood vessels.
In tests, women got double the benefit compared with men as elasticity improved four-fold in women compared with two-fold in men.
In fact the beneficial effect of the fish oil in women was as potent as that of drugs that are prescribed to people with poor blood vessel elasticity, such as those with diabetes.
Study leader Professor Christine Williams, the University’s first Hugh Sinclair Professor of Nutrition and Pro Vice-Chancellor for Research and Innovation, said: “Studies examining women’s heart health are much less common than those which study men, partly because the studies are harder to carry out in women due to the varying effects of hormones during the menstrual cycle.
“In addition, many believe men are the only ones to suffer from heart disease.
“However nearly 40,000 women die of coronary heart disease each year in the UK and we do not yet know whether all the diet recommendations which we currently advise are as effective for women as for men.
“The good news here is that current recommendations that we should all eat more oily fish appears to be more effective for women than men.”
However, two thirds of Britons never eat oily fish even though official guidelines recommend its consumption at least once a week.
In the study around 60 people, half men and women, were given test drinks containing either saturated fats or a combination with omega 3 fish oils, equivalent to a 200 g portion of oily fish.
Imaging was used to check the reaction of the blood cells to the different drinks, says a report in the Journal of Lipid Research.
Prof. Christine Williams said: “As well as discovering the effect of fish oils is greater in women we also found that people with a gene variation that produces the protein eNOS, which helps to increase blood flow, also benefitted more.
“Our study showed that people who carry the rarer form of the protein, which is about 10 per cent of the UK population, respond twice as well to fish oils, suggesting they would particularly benefit from additional oily fish intake.
“This research supports the view that the effects of diets vary, being more effective in certain genders and genotypes. Our study was very carefully designed to include equal numbers of men and women and also equal numbers of people with the two types of gene variants, so that the results are very unlikely to be due to chance.”
Although the responses varied, all the subjects in the study benefitted from taking fish oils with a meal.
“However, for women and those with the gene variant, the responses were very marked indeed, and when it comes to their diet could give them considerable health benefits in the future.”
The work was funded by the Biotechnology and Biological Sciences Research Council.
Fish oil is known to increase the release of nitric oxide from the lining of the blood vessel wall which causes relaxation of the vessel and increases blood flow.
However, the researchers found that some of the relaxation effect on the blood vessel wall may be due to direct actions of the fish oil acting on the muscle cells themselves, rather than on the cells lining the blood vessel wall.
Prof. Christine Williams added: “This is an exciting discovery which gives us a new way of looking at how our diet affects the health of our blood vessels, and possibly more effective ways of improving heart health in the future.”
The best dietary source of omega 3 fatty acids is oily fish because the human body cannot produce omega-3 fatty acids.
There has been an explosion in the number of foods fortified with omega-3 oils, such as chickens, margarine, eggs, milk and bread, but they contain only small amounts.
Types of fish that contain high levels include tuna, salmon, mackerel, herring, sardines, and anchovies.
White fish is also a healthy food including cod, haddock and plaice although it contains lower levels of essential fatty acids.
Fish oil supplements are recommended as protection against repeat heart attacks, with regular fish eaters a third more likely to survive a heart attack.
Fish oil supplements are approved for prescribing on the NHS to patients after a heart attack, or who have metabolic syndrome or high triglycerides – unhealthy blood fats.
Omacor, which is licensed for post-heart attack treatment, has been shown in clinical trials to cut the risk of sudden death by up to 45%.
Omega-3 fats are important throughout adult life for mental wellbeing but in particular help heart patients, and those with arthritis, by blocking the body’s response to inflammation.
They work in several ways to reduce heart attack risk by cutting blood fats, reducing the chances of a blood clot and blocking dangerous heart rhythms that might otherwise prove fatal.
Having a highly demanding job, but little control over it, could be a deadly combination, British researchers have found.
They analyzed 13 existing European studies covering nearly 200,000 people and found “job strain” was linked to a 23% increased risk of heart attacks and deaths from coronary heart disease.
The risk to the heart was much smaller than for smoking or not exercising, the Lancet medical journal report said.
The British Heart Foundation said how people reacted to work stress was key.
Job strain is a type of stress. The research team at University College London said working in any profession could lead to strain, but it was more common in lower skilled workers.
Doctors who have a lot of decision-making in their jobs would be less likely to have job strain than someone working on a busy factory production line.
Having a highly demanding job, but little control over it, could be a deadly combination
There has previously been conflicting evidence on the effect of job strain on the heart.
In this paper, the researchers analyzed combined data from 13 studies.
At the beginning of each of the studies, people were asked whether they had excessive workloads or insufficient time to do their job as well as questions around how much freedom they had to make decisions.
They were then sorted into people with job strain or not and followed for an average of seven and a half years.
One of the researchers, Prof. Mika Kivimaki, from University College London, said: “Our findings indicate that job strain is associated with a small but consistent increased risk of experiencing a first coronary heart disease event, such as a heart attack.”
The researchers said eliminating job strain would prevent 3.4% of those cases, whereas there would be a 36% reduction if everyone stopped smoking.
Prof. Mika Kivimaki said the evidence of a direct effect of job strain on the heart was mixed.
He said job strain was linked to other lifestyle choices that were bad for the heart: “We know smokers with job strain are more likely to smoke a bit more, active people with job strain are more likely to become inactive and there is a link with obesity.
“If one has high stress at work you can still reduce risk by keeping a healthy lifestyle.”
Prof. Peter Weissberg, medical director at the British Heart Foundation, said: “We know that being under stress at work, and being unable to change the situation, could increase your risk of developing heart disease.
“This large study confirms this, but also shows that the negative effect of workplace strain is much smaller than, for example, the damage caused by smoking or lack of exercise.
“Though stresses at work may be unavoidable, how you deal with these pressures is important, and lighting up a cigarette is bad news for your heart. Eating a balanced diet, taking regular exercise and quitting smoking will more than offset any risk associated with your job.”
Dr. Bo Netterstrom, from Bispebjerg Hospital in Denmark, said other stresses at work such as job insecurity “are likely to be of major importance”.
He said job strain was “a measure of only part of a psychosocially damaging work environment”.
An analysis of 20 studies showed that eating dark chocolate daily resulted in a slight reduction in blood pressure.
The Cochrane Group’s report said chemicals in cocoa, chocolate’s key ingredient, relaxed blood vessels.
However, there are healthier ways of lowering blood pressure.
The theory is that cocoa contains flavanols which produce a chemical in the body called nitric oxide. This “relaxes” blood vessels making it easier for blood to pass through them, lowering the blood pressure.
An analysis of 20 studies showed that eating dark chocolate daily resulted in a slight reduction in blood pressure
However, studies have thrown up mixed results. The Cochrane analysis combined previous studies to see if there was really an effect.
There was a huge range in the amount of cocoa consumed, from 3 g to 105 g a day, by each participant. However, the overall picture was a small reduction in blood pressure.
A systolic blood pressure under 120 mmHg (millimetres of mercury) is considered normal. Cocoa resulted in a 2-3 mmHg reduction in blood pressure. However, the length of the trials was only two weeks so the longer term effects are unknown.
Lead researcher Karin Ried, from the National Institute of Integrative Medicine in Melbourne, Australia, said: “Although we don’t yet have evidence for any sustained decrease in blood pressure, the small reduction we saw over the short term might complement other treatment options and might contribute to reducing the risk of cardiovascular disease.”
High blood pressure is both common and deadly. It has been linked to 54% of strokes worldwide and 47% of cases of coronary heart disease.
However, chocolate packs plenty of fat and sugar as well as cocoa so is not the ideal way of lowering blood pressure.
There has also been a warning in the Lancet medical journal that dark chocolate may contain fewer flavanols than you might think. Dark chocolate contains a higher cocoa count than milk chocolate so should contain more flavanols, however, they can also be removed as they have a bitter taste.
Researchers warn that extreme exercise, such as marathons, may permanently damage the heart and trigger rhythm abnormalities.
They say the safe “upper limit” for heart health is a maximum of an hour a day – after which there is little benefit to the individual.
A review of research evidence by US physicians says intensive training schedules and extreme endurance competitions can cause long-term harm to people’s hearts.
Activities such as marathons, iron man distance triathlons, and very long distance bicycle races may cause structural changes to the heart and large arteries, leading to lasting injury.
Lead author Dr. James O’Keefe, of Saint Luke’s Hospital of Kansas City, said exercise was generally beneficial for health but could tip into becoming harmful when taken to excessive lengths.
Dr. James O’Keefe said: “Physical exercise, though not a drug, possesses many traits of a powerful pharmacologic agent.
“A routine of daily physical activity can be highly effective for prevention and treatment of many diseases, including coronary heart disease, hypertension, heart failure, and obesity.
“However, as with any pharmacologic agent, a safe upper dose limit potentially exists, beyond which the adverse effects of physical exercise, such as musculoskeletal trauma and cardiovascular stress, may outweigh its benefits.”
A review of research evidence by US physicians says intensive training schedules and extreme endurance competitions can cause long-term harm to people’s hearts
A review published in the medical journal Mayo Clinic Proceedings (must credit) looked at studies detailing the mechanisms, pathophysiology, and clinical manifestations of cardiovascular injury from excessive endurance exercise.
Dr. James O’Keefe and colleagues said research suggests that extreme endurance training can cause transient structural cardiovascular changes and elevations of cardiac biomarkers, all of which return to normal within one week.
But for some individuals, over months and years of repetitive injury, this process can lead to the development of patchy scarring of certain areas of the heart, and abnormal heart rhythms.
In one study, approximately 12% of apparently healthy marathon runners showed evidence for patchy myocardial scarring, and the coronary heart disease event rate during a two-year follow up was significantly higher in marathon runners than in runners not doing marathons.
The review said it had been known that elite-level athletes commonly develop abnormal electrocardiogram readings.
However, studies now show that changes to the heart triggered by excessive exercise can lead to rhythm abnormalities.
Endurance sports such as ultramarathon running or professional cycling have been associated with as much as a five-fold increase in the prevalence of atrial fibrillation, or abnormal heart rhythms.
Chronic excessive sustained exercise may also be associated with other heart problems including artery wall stiffening.
Dr. James O’Keefe said lifelong vigorous exercisers generally have lower death and disability rates compared with non-exercisers, but it was becoming important to detect intense exercisers whose regime might put them at risk.
The phenomenon has been dubbed Phidippides cardiomyopathy – after the fatal heart damage suffered by the original marathon runner.
The young Greek messenger in 490BC died suddenly after running 175 miles in two days, with the last leg of 26.2 miles from Marathon to Athens.
His death was the first report of a sudden cardiac death of a long distance runner.
Dr. James O’Keefe stressed the review findings should not undermine the message that physical exercise was good for most people.
He said: “Physically active people are much healthier than their sedentary counterparts. Exercise is one of the most important things you need to do on a daily basis.
“But what this paper points out is that a lot of people do not understand that the lion’s share of health benefits accrue at a relatively modest level.
“Extreme exercise is not really conducive to great cardiovascular health. Beyond 30-60 minutes per day, you reach a point of diminishing returns.”
Government guidelines recommend adults take aerobic exercise five times a week for 30 minutes or more for maximum health benefits.
Children should have at least 60 minutes of moderate to vigorous exercise a day, including taking part in sports, brisk walking and running.
Aerobic exercise is achieved through sports such as jogging, running, cycling, tennis and swimming.
The level of aerobic exertion should be enough to raise the heart rate to 120 beats a minute or higher, which includes a brisk walk and swimming. But taking a stroll or even gardening is also regarded as healthy activity.
British scientists suggest that about 4,600 lives in England could be saved by reducing alcohol intake to just half a unit a day.
The Oxford University report warned that alcohol consumption is a risk factor for many chronic diseases.
The government recommends that men drink no more than three to four units per day and women no more than two to three.
But the current guidelines are “not compatible with optimum protection of public health”, the researchers said.
Ill health linked to alcohol is estimated to cost the NHS in England £3.3 billion ($5 billion) every year.
British scientists suggest that about 4,600 lives in England could be saved by reducing alcohol intake to just half a unit a day
The Oxford University team used data from the 2006 General Household Survey looking at weekly drinking patterns of 15,000 adults in England.
The researchers used a mathematical model to study death rates from 11 illnesses known to be linked to long-term alcohol use, the British Medical Journal reported.
These included coronary heart disease, stroke, high blood pressure, diabetes, cirrhosis of the liver, epilepsy and five cancers.
Dr. Melanie Nichols, lead author of the paper, said: “Over 4,000 deaths from cancer, heart disease, stroke and liver disease in England could be prevented if drinkers reduced their average level of alcohol consumption to half a unit per person per day – a level much lower than current UK government recommendations.
“Half a unit of alcohol is as little as a quarter of a glass of wine, or a quarter of a pint.”
But the researchers said they were not trying to lecture people, just give them the information so they could make an informed decision.
They added there was a widespread belief that alcohol protects against heart disease.
Alcohol Concern chief executive Eric Appleby said that government guidelines must offer the public a realistic way of reducing the risks associated with drinking.
“As alcoholic drinks have started to vary in strength we use ‘units’ to measure alcohol intake but it can be very difficult for people to understand what this means in practical terms.”
But Henry Ashworth, chief executive of the Portman Group, which also represents UK drinks producers, said: “78% of people in the UK drink within recommended low risk guidelines – as set by the chief medical officers.
“Drastically cutting everyone’s consumption to half a unit a day (i.e. one large glass of wine a week) is not the way to reduce harms in the smaller groups who are misusing alcohol and need specific and targeted help”.