HEALTH NEWS TODAY
From BBC Health News:
Why some just cannot resist food
A typical
image shown to volunteers
|
They used scans to show the reward centres in some people's brains are particularly sensitive to food advertising and product packaging. Greater stimulation of this area by food images is likely to encourage over-eating, and obesity.
The study, published in the Journal of Neuroscience, was
carried out by the Medical Research Council's Cognition and Brain
Sciences Unit.
This helps explain why some
individuals are more vulnerable to developing certain disorders like
binge-eating 
The researchers showed people pictures of highly appetizing foods (eg chocolate cakes), bland foods (eg broccoli), and disgusting foods (eg rotten meat).
At the same time, they measured brain activity using a sophisticated fMRI scanner.
After testing, the study participants completed a questionnaire that assessed their general desire to pursue rewarding items or goals.
The results showed that the participant's scores on the reward sensitivity questionnaire predicted the extent to which the appetizing food images activated their brain's reward network.
False assumptions
Lead researcher Dr John Beaver said: "Previous studies in this area have assumed that brain activation patterns are similar in all healthy individuals.
"But the new findings demonstrate that, even in healthy individuals, some people's brain reward centres are more sensitive to appetizing food cues.
We need to move away from a
position of simply blaming patients
"This helps explain why some individuals are more vulnerable to developing certain disorders like binge-eating.
"This is particularly pertinent in understanding the rapidly increasing prevalence of obesity, as people are constantly bombarded with images of appetizing food items in order to promote food intake through television advertising, vending machines, or product packaging."
According to Dr Beaver the findings may also have broader implications for understanding vulnerability to multiple forms of addiction and compulsive behaviours.
He said: "Research demonstrates that an individual's reward sensitivity may also relate to their vulnerability to substance abuse, and the brain network we have identified is hyper-responsive to drug cues in addicts."
Industry responsibility
Dr Ian Campbell, an expert in obesity from Nottingham and medical director of the charity Weight Concern, said appetite control was notoriously difficult and most dieters regularly fail to control their food intake.
"This research this shows that it's not simply explained by a loss of will power or greed. It's much more complicated.
"An involuntary exaggerated neurophysiological response to pictures of desirable food presented through clever advertising makes it incredibly difficult for some affected individuals to resist.
"The message is clear. While individuals must retain a responsibility to do their best to control their intake of high fat high sugar foods this responsibility must be shared by the food manufacturers and advertisers.
"We need to move away from a position of simply blaming patients to one of greater understanding, and support."Grapefruit link to breast cancer
Eating too much grapefruit could increase risks
of breast cancer
|
A study of 50,000 post-menopausal women found eating just a quarter of a grapefruit daily raised the risk by up to 30%.
The fruit is thought to boost levels of oestrogen - the hormone associated with a higher risk of the disease, the British Journal of Cancer reported.
But the researchers and other experts said more research was still needed.
This
is an interesting study, but is simply a piece of the jigsaw that will
eventually help us to understand how our diets affect our health
The women had to fill in questionnaires saying how often they ate grapefruit and how big their portions were.
Oestrogen important
The researchers, at the universities of Southern California and Hawaii, found that women who ate one quarter of a grapefruit or more every day had a higher risk of breast cancer than those who did not eat the fruit at all.
Previous studies have shown that a molecule called cytochrome P450 3A4 (CYP3A4) is involved in metabolising oestrogen hormones.
And grapefruit may boost blood oestrogen levels by inhibiting this molecule, allowing the hormones to build up.
The researchers found that in women who ate at least a quarter of a grapefruit daily, levels of oestrogen were higher.
They said: "It is well established that oestrogen is associated with breast cancer risk.
"Therefore, if grapefruit intake affects oestrogen metabolism leading to higher circulating levels, then it is biologically plausible that regular intake of grapefruit would increase a woman's risk of breast cancer."
More research
And they said this was the first time a commonly eaten food had been linked to an increased risk of breast cancer in older women.
However, they warned that more research was needed to confirm the findings which may have been affected because they only took into account intake of the fruit, but not grapefruit juice.
Breast cancer accounts for almost a third of all cancers in women, and previous lifestyle factors linked to the disease include drinking alcohol and being overweight.
Dr Joanne Lunn, a nutrition scientist at the British Nutrition Foundation said: "This is an interesting study of a large group of post-menopausal women whose diet and health have been followed for many years.
"However, this study is simply a piece of the jigsaw that will eventually help us to understand how our diets affect our health.
"Although we are beginning to get a better awareness of how our diets can modify the risk of diseases such as cancer, we are still a long way from identifying particular foods that might specifically increase or decrease risk."
However, she said that some dietary patterns are associated with a reduced risk of certain cancers and that a diet rich in a variety of different fruits and vegetables could help reduce the risk of heart disease and some cancers.
An Old Cholesterol Remedy Is
New Again
Perhaps you heard it? The wail last month from the labs of heart researchers and the offices of Wall Street analysts?
Pfizer Inc., the pharmaceutical giant, halted late-stage trials of a cholesterol drug called torcetrapib after investigators discovered that it increased heart problems — and death rates — in the test population.Torcetrapib wasn’t just another scientific misfire; the drug was to have been a blockbuster heralding the transformation of cardiovascular care. Statin drugs like simvastatin (sold as Zocor) and atorvastatin (Lipitor) lower blood levels of LDL, the so-called bad cholesterol, thereby slowing the buildup of plaque in the arteries.
But torcetrapib worked primarily by increasing HDL, or good cholesterol. Among other functions, HDL carries dangerous forms of cholesterol from artery walls to the liver for excretion. The process, called reverse cholesterol transport, is thought to be crucial to preventing clogged arteries.
Many scientists still believe that a statin combined with a drug that raises HDL would mark a significant advance in the treatment of heart disease. But for patients now at high risk of heart attack or stroke, the news is better than it sounds. An effective HDL booster already exists.
It is niacin, the ordinary B vitamin.
In its therapeutic form, nicotinic acid, niacin can increase HDL as much as 35 percent when taken in high doses, usually about 2,000 milligrams per day. It also lowers LDL, though not as sharply as statins do, and it has been shown to reduce serum levels of artery-clogging triglycerides as much as 50 percent. Its principal side effect is an irritating flush caused by the vitamin’s dilation of blood vessels.
Despite its effectiveness, niacin has been the ugly duckling of heart medications, an old remedy that few scientists cared to examine. But that seems likely to change.
“There’s a great unfilled need for something that raises HDL,” said Dr. Steven E. Nissen, a cardiologist at the Cleveland Clinic and president of the American College of Cardiology. “Right now, in the wake of the failure of torcetrapib, niacin is really it. Nothing else available is that effective.”
In 1975, long before statins, a landmark study of 8,341 men who had suffered heart attacks found that niacin was the only treatment among five tested that prevented second heart attacks. Compared with men on placebos, those on niacin had a 26 percent reduction in heart attacks and a 27 percent reduction in strokes. Fifteen years later, the mortality rate among the men on niacin was 11 percent lower than among those who had received placebos.
“Here you have a drug that was about as effective as the early statins, and it just never caught on,” said Dr. B. Greg Brown, professor of medicine at the University of Washington in Seattle. “It’s a mystery to me. But if you’re a drug company, I guess you can’t make money on a vitamin.”
By and large, research was focused on lowering LDL, and the statins proved to be remarkably effective. The drugs can slow the progress of cardiovascular disease, reducing the risk of heart attack or other adverse outcomes by 25 percent to 35 percent.
But recent studies suggest that the addition of an HDL booster like niacin may afford still greater protection.
After analyzing data from more than 83,000 heart patients who participated in 23 different clinical trials, researchers at the University of Washington calculated this month that a regimen that increased HDL by 30 percent and lowered LDL by 40 percent in the average patient would reduce the risk of heart attack or stroke by 70 percent. That is far more than can be achieved by reducing LDL alone.
Other small studies have produced similarly encouraging results, but some experts caution that the data on increased HDL and heart disease are preliminary.
Researchers at 72 sites in the United States and Canada are recruiting 3,300 heart patients for a study, led by Dr. Brown and financed by the National Institutes of Health, comparing those who take niacin and a statin with those who take only a statin. This large head-on comparison should answer many questions about the benefits of combination therapy.
Many cardiologists see no reason to wait for the results. But niacin can be a bitter pill; in rare instances, the vitamin can cause liver damage and can impair the body’s use of glucose. High doses should be taken only under a doctor’s supervision.
A more frequent side effect is flushing. It becomes less pronounced with time, and often it can be avoided by taking the pills before bed with a bit of food. Doctors also recommend starting with small doses and working up to larger ones.
Extended-release formulations of the vitamin, taken once daily, are now available by prescription, and in many patients they produce fewer side effects. And a new Merck drug to counteract niacin-induced flushing is being tested in Britain. If it works, the company plans to bundle the drug with its own extended-release niacin and with Zocor, its popular statin.
Until then, consider this: If it means preventing a heart attack, maybe it is better to put up with flushing than to wait for the next blockbuster.
“If you can just get patients to take niacin, HDL goes up substantially,” said Dr. Nissen of the Cleveland Clinic. “Most of the evidence suggests they’ll get a benefit from that.”
From BBC Health
News:
Vitamin pill for prostate cancer
Prostate
cancer is a major killer
|
Exposure to Vitamin D from sunlight is known to improve the prognosis of certain cancers.
US drug company Novacea has produced a pill which delivers a concentrated dose of the vitamin without running the risk of side-effects from an overdose.
Chemistry and Industry magazine reports that if clinical trials of the drug - Asentar (DN-101) - are successful it could be available by 2009.
This drug has shown
potential in early trials
Cancer Research UK
The drug would be given to patients in the advanced stages of the disease, along with chemotherapy drugs.
Professor Nick James, a cancer expert at the University of Birmingham, said the drug had produced impressive results in preliminary phase two trials.
He said patients taking the drug lived for an average of an extra nine months longer than those taking another chemotherapy drug - taxotere - alone.
Professor James said: "On average, patients in the advanced stage of the disease survive about 18 months, so an extension of nine months would be very significant in my view."
Asentar provides levels of vitamin D 50 to 100 times higher than normal.
Patients would be expected to take one tablet once a week with their weekly regime of taxotere for three weeks out of every four.
No guarantees
However, Professor James said it was far from certain that the phase three trials would repeat the success of the earlier tests.
The phase II trial used a less than optimal taxotere regime so the survival rate may have been artificially inflated.
Professor James said vitamin D was known to play a key role in the regulation of several tissues, including the prostate and breast.
He said laboratory work had shown that cancer cells had lost the ability to respond in the normal way to vitamin D, and carried on dividing in an uncontrolled fashion.
Data shows that rates of prostate cancer are higher in countries further away from the equator, where there is less exposure to sunlight.
Professor James said it was possible that the new drug helped to increase the sensitivity of cancer cells to the effect of other chemotherapy drugs.
Dr Julie Sharp, of the charity Cancer Research UK, said: "We would welcome any improvements in the treatment for men with advanced prostate cancer and this drug has shown potential in early trials.
"But the results of the much larger study are needed to fully establish if this treatment is both effective and safe."
Prostate cancer is the second leading cause of cancer death in men. It kills one man every hour in the UK.
From Reuters Health News:
Cola consumption linked to weaker bones in women
Tue Oct 10, 1:55 PM ET
Women who want to keep their bones strong may want to keep their cola consumption to a minimum, a new study suggests.
In a study of more than 2,500 adults, Dr. Katherine L. Tucker of Tufts University in Boston and colleagues found that women who consumed cola daily had lower bone mineral density (BMD) in their hips than those who drank less than one serving of cola a month.
"Because BMD is strongly linked with fracture risk, and because cola is a popular beverage, this is of considerable public health importance," the authors write in the American Journal of Clinical Nutrition.
Studies in teen girls have tied heavy soft drink consumption to fractures and lower BMD, the researchers note, but it is not clear if this is because they're drinking less milk, or if it is due to any harmful effects of soda itself.
To investigate this question in adults, the researchers measured BMD in the spine and at three points on the hips in 1,413 women and 1,125 men participating in a study of the bone-thinning disease osteoporosis.
While there was no association between soft drinks in general and BMD, the researchers found that women who drank the most cola had significantly less dense bones in their hips. The greater their intake, the thinner the bones, and the relationship was seen for diet, regular, and non-caffeinated colas.
Cola consumption had no effect on BMD in men.
Women who drank more cola did not drink less milk, but they did consume less calcium and had lower intakes of phosphorus in relation to calcium. Cola contains phosphoric acid, the researchers note, which impairs calcium absorption and increases excretion of the mineral. Caffeine has also been linked to osteoporosis, they add.
"No evidence exists that occasional use of carbonated beverages, including cola, is detrimental to bone," they note. "However, unless additional evidence rules out an effect, women who are concerned about osteoporosis may want to avoid the regular use of cola beverages."
SOURCE: American Journal of Clinical Nutrition, October 2006.
Vitamin D halves pancreatic cancer risk
Wed Sep 13, 8:06 AM ET
People who take vitamin D tablets are half as likely to get deadly pancreatic cancer as people who do not, U.S. researchers reported on Wednesday.
Now they are checking to see if getting the vitamin from food or sunlight also cuts the risk.
The study suggests one easy way to reduce the risk of pancreatic cancer, the fourth-leading cause of death from cancer in the United States. This year, the American Cancer Society estimates that 32,000 new cases of cancer will be diagnosed, and only 5 percent of patients will survive more than five years.
"Because there is no effective screening for pancreatic cancer, identifying controllable risk factors for the disease is essential for developing strategies that can prevent cancer," Halcyon Skinner of Northwestern University in Chicago, who helped lead the study, said in a statement.
"Vitamin D has shown strong potential for preventing and treating prostate cancer, and areas with greater sunlight exposure have lower incidence and mortality for prostate, breast, and colon cancers, leading us to investigate a role for Vitamin D in pancreatic cancer risk."
Working with colleagues at Harvard University, Skinner's team examined data from two large, long-term health surveys involving 46,771 men aged 40 to 75 and 75,427 women aged 38 to 65.
They found that people who took the U.S. Recommended Daily Allowance of Vitamin D, 400 IU a day, had a 43 percent lower risk of pancreatic cancer.
Those who took doses of less than 150 IU per day had a 22 percent reduced risk of cancer.
Writing in the journal Cancer Epidemiology Biomarkers & Prevention, the researchers said taking more than 400 IU a day did not reduce the risk further.
Vitamin D is produced by the body when sunlight hits the skin, but most Americans do not get enough sunlight to produce the needed amount. Milk, both dairy and soy, is fortified with the vitamin. Some foods such as fish, eggs and liver also contain vitamin D.
"In concert with laboratory results suggesting anti-tumor effects of Vitamin D, our results point to a possible role for Vitamin D in the prevention and possible reduction in mortality of pancreatic cancer," Skinner said.
"Since no other environmental or dietary factor showed this risk relationship, more study of Vitamin D's role is warranted."
Copyright © 2006 Reuters Limited.
Pomegranate juice may be cancer weapon
By Lisa RichwineSat Jul 1, 11:41 AM ET
A daily glass of pomegranate juice showed potential for slowing the growth of prostate cancer in a small study but more evidence is needed before doctors recommend it, U.S. scientists said on Saturday.
A study funded by a juice maker found men who drank the beverage had a longer time until doubling of their blood levels of PSA -- a protein that indicates the presence of prostate cancer. Patients with short doubling times are more likely to die from the cancer.
In the study, the time until PSA doubling after treatment extended to 54 months on average when the men started drinking eight ounces of pomegranate juice a day. Before drinking the juice, PSA doubled in an average of 15 months.
"That's a very big difference. ... It's an indicator of how quickly the cancer is growing," said Dr. Allan Pantuck, a urologist at UCLA Jonsson Cancer Center and the study's lead author.
Each of the 50 men who took part had radiation, surgery or other treatment for prostate cancer before enrolling in the study. No major side effects were reported from drinking the juice.
"It's too early to tell people with prostate cancer they should drink pomegranate juice" because the evidence is preliminary, Pantuck said in an interview.
A larger study is under way to try to confirm the findings, with results expected in two years, he said.
While he does not expect pomegranate juice to cure prostate cancer, Pantuck said it could delay or prevent the need for other therapies with harsh side effects including hot flashes, fatigue, depression and impotence.
Pomegranate juice "is a very non-toxic treatment that, if it really did have that effect on doubling time, could prevent many people from going on to metastatic disease and hopefully from dying of prostate cancer," he said.
The research team said substances known as polyphenols or other ingredients in the fruit juice may be able to fight prostate cancer, but exactly how is unclear. The benefits probably come from a combination of ingredients, they said.
The findings were published in the peer-reviewed journal
Clinical Cancer Research and funded by a trust established by
the owners of Pom Wonderful, a brand of pomegranate juice. Pom
Wonderful supplied the juice used in the study.
Click
here to go to our Pomegranate Juice Concentrate -
From BBC Health
News:
A daily drink 'only good for men'
Drinking alcohol every day protects against heart disease in men but not in women, Danish research shows.A study of 50,000 people found that men who drank daily had a 41% reduced risk of coronary heart disease compared with a 7% drop in men who drank once a week. In women, the risk of heart disease fell by a third with a weekly drink but did not fall further in daily drinkers. Experts warned the results, published in the British Medical Journal, should not be used to justify heavy drinking.
Previous research has shown that moderate alcohol intake is associated with a lower risk of heart disease, but up until now most studies have been in men. Men and women aged 50-65 who took part in this study were questioned on their drinking behaviour and then followed for an average of six years.
"One or two drinks in men or one drink a day in women would be sufficient for heart disease - you wouldn't get any more beneficial effects from drinking more" - Professor Morten Gronbaek, Study leader
Women drank an average of five and a half drinks a week, and men consumed 11. In men, the risk of heart disease fell significantly with increased frequency of drinking - with men who drank a little every day having the lowest risk. But for women, although drinking on at least one day a week was associated with a 36% reduced risk of heart disease compared to those who drank more rarely, the risk was the same whether women had one drink a week or drank moderately each day. The researchers said how much women drank may be more important for protection against heart disease than how often they drank.Gender difference
The researchers said there could be several explanations for the differences found between men and women. It may be hormonal, or related to the type of alcohol consumed or there may be differences in the way men and women's bodies process alcohol.
Lead researcher Professor Morten Gronbaek from the National Institute of Public Health in Denmark said: "It has been shown that frequency of drinking has a larger role than amount but this points towards the fact there is a gender difference." He added that the benefits of alcohol had to be weighed against the increased risk of cancer and liver damage. "One or two drinks in men, or one drink a day in women, would be sufficient for heart disease - you wouldn't get any more beneficial effects from drinking more."
In an accompanying editorial, Dr Annie Britton, senior lecturer at University College London warned that the study participants had a high risk of heart disease because of their age, and added that the study had a low response rate and so may not have been fully representative. She said: "We do not yet know whether cardioprotective effects accrue over a lifetime or whether, purely from a health perspective, we should defer drinking alcohol until older age, when heart disease is manifest."
Judy O'Sullivan, medical spokesperson for the British Heart Foundation (BHF) said: "This study does not change the fact that alcohol should be enjoyed in moderation only, both by men and women. "If you are teetotal you should not start consuming alcohol in order to reduce your risk of developing coronary heart disease. However, if you enjoy alcohol you should be aware that the risks of drinking large quantities significantly outweigh any potential benefits."
Small changes 'add years to life'
Blair (PA)
Making small changes to your lifestyle can have a significant impact on how long you will live, research has shown.
The Cambridge University study looked at over 25,000 people. It found that stopping smoking, exercising more and eating better could give you the life expectancy of a person 11 to 12 years younger. The government is backing the research, and launching an initiative to encourage people to make small changes to improve their health.
This is about showing people that there are everyday, simple
choices they can make in their lives which will have a direct impact on
their health
- Caroline Flint, Health minister
The study, carried out in Norfolk, is part of the European Prospective Investigation and Nutrition (Epic) study, involving over half a million people in 10 European countries. The UK arm of the study is following 25,663 men and women aged between 45 and 79 years old since 1993, looking at their diet, environment, lifestyle and health. The participants have regularly filled in questionnaires about their diet, lifestyle and health and had periodic check-ups from nurses.
These latest results from the study showed eating five portions of fruit and vegetables a day can give you the life expectancy of someone three years younger. Not smoking turned the clock back by four to five years. Even increasing exercise by a moderate amount can take up to three years off.
But the amount of exercise someone would need to do to achieve that depends on their job. An office worker would need to do one hour of exercise, such as swimming or jogging, every day, while a person with a moderately active job, such as a hairdresser, would need to take 30 minutes exercise a day. People with active jobs, including nurses and bricklayers, do not need to do any extra exercise - as their work is strenuous enough.
'Daunting prospect'
Professor Kay-Tee Khaw, who led the study, said: "Many of us find it difficult to change our usual lifestyle. "However, there is increasing evidence that even relatively small changes can make a big difference to our health and well being." Government ministers highlighted the research as they launched an initiative called Small Change Big Difference, aimed at showing people how to improve their health by making small easily available changed to lifestyle.
Prime Minister Tony Blair has vowed to make lifestyle changes such as using the stairs instead of the lift, visiting the gym more often and boosting his intake of fruit and vegetables. Public Health Minister Caroline Flint said: "We all know that we should eat more fruit and veg and get more exercise to improve our health, but sometimes improving our own health can be daunting. "This is about showing people that there are everyday, simple choices they can make in their lives which will have a direct impact on their health. "Eating an extra piece of fruit or walking up the stairs can help people add years to their lives." James Johnson, chairman of the British Medical Association, said: "Today's campaign is to be welcomed. "But we would also like to see funding questions urgently addressed if the agenda is to make a sustained difference to the health of our communities."
Obesity is on the rise across the developed world
Scientists believe it could be possible to treat obesity by altering levels of fatty acids in a key area of the brain. They found reducing fatty acid levels in the hypothalamus caused rats to overeat and become obese. The study, by a team at Albert Einstein College of Medicine in New York, was featured in Nature Neuroscience. It suggests that a therapy which restores fatty acid levels in the hypothalamus may be a promising way to treat obesity. However, UK experts warned that appetite regulation was a complex area.
"Work like this does help to increase our understanding of obesity, and does help us work towards new treatments" Dr Ian Campbell
Obesity is a growing problem across the developed world. In the UK, it is thought that 40% of men, and a third of women are either obese or overweight. Carrying too much weight is linked to a range of health problems, including a greater risk of heart disease and cancer.
The hypothalamus keeps track of the body's nutritional status by monitoring the blood levels of several different hormones and nutrients. Taking this information into account, it regulates both appetite, and the speed at which the body breaks down nutrients.
Injected virus
The Einstein team had already shown that glucose is one of the substances closely tracked by the hypothalamus. Now they have found that fatty acids too are on the organ's checklist. The researchers focused on a particular fatty acid molecule called malonyl CoA. They injected a virus on to which was attached an enzyme known to break down malonyl CoA into the hypothalamus of lab rats. The injections caused a drop in malonyl CoA levels, which led to the rats gorging themselves. The effect lasted for at least four months. Lead researcher Dr Luciano Rossetti said: "We showed in this study that disrupting malonyl-CoA levels in this region of the brain impairs the nutrient-sensing mechanism by which the hypothalamus modulates food intake to maintain normal weight. Figuring out a way to re-adjust malonyl-CoA levels in the human hypothalamus could lead to innovative therapies not only to treat obesity but to help prevent diabetes and other consequences of being overweight."
Complex issue
Dr Ian Campbell, a weight management expert and former chairman of the UK National Obesity Forum, told the BBC News website that research of this kind underlined just what a complex issue obesity was. "It is not just about greed and laziness," he said. "There seem to be many underlying physiological factors. Clearly we are a long way off being able to prescribe a drug based on this research. "But work like this does help to increase our understanding of obesity, and does help us work towards new treatments." Dr Campbell stressed that the best way to combat obesity was to control one's weight through exercise and a sensible diet.Professor Ian MacDonald, of the University of Nottingham, agreed that it was simplistic to draw too many conclusions from one piece of research. He said it would be difficult to produce a drug that targeted its effect specifically at the hypothalamus, and that any effect on human appetite that could be produced was likely to be minimal.
Exercise now to cut dementia risk
The exercise should be enough to make you sweaty and breathless. Exercising for half an hour at least twice a week during midlife can significantly cut a person's risk of dementia later, say researchers. People in their late 40s and early 50s who do this could reduce their risk of dementia by about 50%, according to a study reported in Lancet Neurology. Those who are genetically prone to Alzheimer's disease could see a reduction of about 60%, it adds. The Swedish team said the findings had large disease prevention implications.
Protective effect
"If an individual adopts an active lifestyle in youth and at midlife, this may increase their probability of enjoying both physically and cognitively vital years in later life," they said. Past studies have also suggested regular exercise might guard against dementia, however, this is one of the first to look at the effects over a long time scale - about two decades. The authors say this is important because dementia takes many years to develop and is typically quite advanced when it is diagnosed.
The study involved nearly 1,500 men and women, of whom nearly 200 developed dementia or Alzheimer's disease between the ages of 65 and 79. The researchers looked back at how physically active the study participants had been up to 21 years earlier, when they would have been in their late 40s and early 50s. Those who developed Alzheimer's disease or another form of dementia were far less likely to have been active when they were middle-aged than those who remained free of dementia.
Good for the brain
The amount of exercise that appeared to be necessary to be protective was physical activity which lasted 20-30 minutes at least twice a week and which was enough to cause breathlessness and sweating. People are generally recommended to take moderate aerobic exercise for 20-30 minutes three to five times a week for a healthy heart and lungs. Dr Miia Kivipelto and colleagues said there were many reasons why exercise might be good for the brain as well as the rest of the body. For example, regular exercise could help keep the small blood vessels of the brain healthy as well as protecting against other conditions that might make dementia more likely, such as high blood pressure and diabetes.
Memory
Exercise might also reduce the amount of the protein amyloid that builds up in the brain in Alzheimer's disease. Physical activity also affects genes and compounds important for maintaining good cognition and memory. It might be that people who exercise tend to live healthier lifestyles in general, such as drinking less alcohol and refraining from smoking, they said. However, when they took into account such health risk factors, the findings remained the same, suggesting that exercise per se is beneficial for the brain. A spokeswoman from the Alzheimer's Research Trust said: "This study backs up the evidence so far. "Studies seem to suggest that leading a healthy lifestyle - exercising regularly and eating a balanced diet - helps protect against dementia." She said more research was needed, particularly as the condition was becoming increasingly common since the proportion of older people in society was increasing.
A few cigarettes a day 'deadly'
Doctors warn that any amount of smoking is dangerous
Smoking just one to four cigarettes a day almost triples a person's risk of dying of heart disease, according to Norwegian researchers. Their work suggests the health impact is stronger for women and that even "light" smokers face similar diseases to heavier smokers, including cancer. The team tracked the health and death rates of almost 43,000 men and women from the mid 1970s up to 2002. Their findings appear in the journal Tobacco Control.
Lung cancer
Compared with those who had never smoked, the men and women who smoked between one and four cigarettes a day were almost three times as likely to die of coronary artery disease. Among women, smoking one to four cigarettes daily increased the chance of dying from lung cancer almost five times. Men who smoked this amount were almost three times as likely to be killed by lung cancer. However, due to the relatively small number of men that this applied to in the study sample, this finding could have been due to chance."There is no safe level of smoking" Amanda Sandford from ASH
So-called "light" smokers were also found to have a significantly higher risk of dying from any cause - 1.5 times higher generally - than those who had never smoked, when researchers looked at deaths among those studied over the duration of the research. Death rates from all causes rose as the number of cigarettes smoked every day increased.Sporadic smoking
The researchers believe their conclusions are accurate, even though they had to estimate the projected impact of smoking one to four cigarettes for five years in those light smokers who had smoked for less time. This indicated that the risk of death from coronary artery disease for both sexes would have been 7% higher, and the risk of lung cancer would have been 47% higher in women. A significant proportion of the light smokers had also increased their daily consumption over the period of the study. However, this had not exceeded nine cigarettes a day.
"The only way to protect smokers from heart disease, cancer and other killer diseases is to quit completely" A spokesman from the British Medical Association
Author Dr Kjell Bjartveit also pointed out that it was not possible to tell from the findings what impact sporadic smoking - such as a few cigarettes on a Saturday night out - might have on health. Dr Ken Denson of the Thame Thrombosis and Haemostasis Research Foundation questioned the validity of the figures. He said other large studies had not found that smoking fewer than 10 cigarettes daily increased the risk of heart disease.
'No safe level'
Amanda Sandford from Action on Smoking and Health said the conclusions were clear. "This study should dispel the myth once and for all that smoking just a few cigarettes a day won't do you any harm. "Quite simply, there is no safe level of smoking."
A spokesman from the British Medical Association said: "All smokers are putting their health on the line when they smoke - even if they only define themselves as social smokers. "The only way to protect smokers from heart disease, cancer and other killer diseases is to quit completely." The Department of Health estimates 106,000 people die every year in the UK as a direct result of smoking. It said quitting was the only way to avoid the serious health risks. Jean King of Cancer Research UK said: "Although more research is needed, this study suggests that the health implications for 'light smokers' are much more serious than previously thought. "This is particularly worrying as a third of smokers in the UK - an estimated 3.7 million people - smoke less than 10 cigarettes a day."