Thursday, April 12, 2012

Eating berries can cut men's risk of Parkinson's disease by 40 per cent

It's encouraging to see that the authors undertook some validation of their food frequency questionnaire but as I spent a large part of my 20 year research career validating questionnaires, I know the possibilities there and I cannot see that they would be able to rule out the likely social class biases that probably lie behind the results reported below.  Middle class people are more likely to follow diet advice (or say they do) and also tend to be healthier. I think  we are just looking below at yet another proof that middle class people have a pervasive health advantage.

One might also note that high IQ people are more healthy and take more notice of official advice so the result could be an IQ effect alone.  IQ and higher class do correlate but there is a substantial non-overlap of variance nonetheless

In the end diet questionnaires are the weakest form of data and results from them must be taken with much salt  -- iodized preferably

Particularly salt-demanding is the fact that the finding was observed in men only.  The physiology of male and female  brains is not that different

Reliance on extreme quintiles is also a mark of desperation.  It leaves out the majority of the data!  Much ado about nothing would be my summary of the paper

Eating strawberries, blue- berries, blackcurrants and blackberries could help to protect against Parkinson’s disease, researchers suggest.  Men who ate the fruits along with other foods rich in flavonoids were found to be 40 per cent less likely to develop the brain disease.

And those who ate berries at least once a week could cut their risk of developing the disease by a quarter compared with those who never ate them, the study by British and U.S. experts also found.

Flavonoids – which are also found in tea and red wine – are antioxidants which can offer protection against a range of diseases including heart disease, some cancers and dementia.

The research is the first large-scale study looking at the effect of  flavonoids in protecting against  Parkinson’s disease, a progressive neurological condition which affects 125,000 Britons.   It causes tremors and muscular rigidity or stiffness, and affects all kinds of movement in the body.  About 10,000 new sufferers are diagnosed each year. There is no cure, but drugs and surgery can help control symptoms.

About 130,000 men and women took part in the research, published in the journal Neurology, of whom 800 had developed Parkinson’s disease during 20 years of follow-up.

It involved an analysis of their diets and, adjusting for age and lifestyle, men volunteers who ate the most flavonoids were shown to be 40 per cent less likely to develop the disease than those who ate the least. The study found no similar link for total flavonoid intake in women.

Antioxidants help to neutralise free radicals – destructive by-products of metabolism in the body that can damage cell membranes and DNA.  Brain cells are particularly sensitive to free radicals – which may help to explain the benefits revealed by the study.

It found the main protective effect came from higher intakes of anthocyanins – a type of flavonoid – present in berries and other fruits and vegetables such as aubergines.

Men who ate one or more portions of berries each week were 24 per cent less likely to develop Parkinson’s disease, relative to those who did not eat the fruits, the experts said.

Dr Xiang Gao of Harvard School of Public Health, one of the study leaders, said the findings suggest that anthocyanins ‘may have neuro- protective effects’.   He added: ‘Given the other potential health effects of berry fruits, such as lowering risk of hypertension as reported in our previous studies, it is good to regularly add these fruits to your diet.’

His colleague Professor Aedin Cassidy, of Norwich Medical School at the University of East Anglia, described their findings as ‘exciting’.


Habitual intake of dietary flavonoids and risk of Parkinson disease

X. Gao, MD et al.


Objective: To prospectively examine whether higher intakes of total flavonoids and their subclasses (flavanones, anthocyanins, flavan-3-ols, flavonols, flavones, and polymers) were associated with a lower risk of developing Parkinson disease (PD).

Methods: In the current analysis, we included 49,281 men in the Health Professional Follow-up Study and 80,336 women from the Nurses' Health Study. Five major sources of flavonoid-rich foods (tea, berry fruits, apples, red wine, and orange/orange juice) were also examined. Flavonoid intake was assessed using an updated food composition database and a validated food frequency questionnaire.

Results: We identified 805 participants (438 men and 367 women) who developed PD during 20–22 years of follow-up. In men, after adjusting for multiple confounders, participants in the highest quintile of total flavonoids had a 40%lower PD risk than those in the lowest quintile (hazard ratio [HR] = 0.60; 95% confidence interval 0.43, 0.83; p trend = 0.001). No significant relationship was observed in women (p trend = 0.62) or in pooled analyses (p trend = 0.23). In the pooled analyses for the subclasses, intakes of anthocyanins and a rich dietary source, berries, were significantly associated with a lower PD risk (HR comparing 2 extreme intake quintiles were 0.76 for anthocyanins and 0.77 for berries, respectively; p trend < 0.02 for both).

Conclusions: Our findings suggest that intake of some flavonoids may reduce PD risk, particularly in men, but a protective effect of other constituents of plant foods cannot be excluded.


The politics of fat in the 21st century

Acceptance is the new buzzword among some participants in the great weight debate, but how far can they push it?

When Regina Benjamin was made US Surgeon-General in July 2009 she ran into a storm of criticism.  But it wasn't just the usual political point-scoring that any new appointee has to weather.

Many of the attacks on Benjamin were because she is overweight - by 20 kilograms or possibly more.

What message was the country's top health administrator sending, wondered her critics. And they were the polite ones. Even more bluntly, some asked, was she too fat for the job?

Benjamin, a formidable personality by all accounts, wasted little time returning fire. "I exercise regularly, at least four days a week," she was reported as saying. "I tend to stay on the elliptical as long as other people. I'm not out of breath. You can be healthy and fit at different sizes. The real message is that you don't want to limit yourself by your dress size."

The furore around Benjamin's appointment brought into sharp relief a controversial approach being promoted by a small but growing group of doctors and academics, cheered on by "fat acceptance" activists.

It is possible to be fat and healthy, they say. Further, they believe that the constant focus on shedding weight and staying slim may actually be doing more harm than good.

Needless to say, this is a hugely controversial area - a potent stew of emotion, prejudice, guilt and politics. There is also a range of positions, from hardline "fat pride" activists through to doctors and other health professionals who, while they accept being overweight is often unhealthy, believe focusing exclusively on patients' weight can be counterproductive.

The official measure of whether a person is overweight is the Body Mass Index. If you have a BMI of 25 or more, you are overweight. Get up to a BMI of 30-plus and you are clinically obese.

(The BMI itself is a controversial tool, often criticised for producing anomalous results in all but the most "average" body types.)

Anyone with a BMI of 25 or more who visits their GP will almost certainly be told to lose weight. They'll probably be given a diet sheet, counselling on exercise and may even be referred to a dietitian before being sent on their way.

And, while many of those patients will manage to lose some excess weight, most solid studies show the vast majority (up to 95 per cent) will regain all the weight they have lost within one to two years. Many will even "overshoot", ending up heavier than their starting weight.

Dr Rick Kausman is the author of a book called If Not Dieting, Then What? and widely recognised as a pioneer of healthy weight management without dieting.

"There is no question that weight-loss dieting does not work," he says. "The way I define a weight-loss diet is anything that tells us what, when and/or how much to eat for the purpose of weight control.

"Weight-loss dieting also increases the risk of eating disorders and immune problems and physical health issues." Kausman says some doctors understand the complexities of the problem but don't have enough time to deal with it in "a 10-minute consult", and others "just think it's a matter of telling people to eat less and exercise more and it's the person's fault that they are not able to do that".

Regardless of individual doctors' reasoning, however, it has been pointed out that if any other treatment of "intervention" had a failure rate of up to 95 per cent, we'd almost certainly be looking for a different approach.

Dr Linda Bacon is an American physiologist and psychologist, and the main standard bearer for the "health at every size" (HAES) movement.

"HAES teaches people to rely on internal regulation, a process dubbed 'intuitive eating'," Bacon writes in a recent paper. "HAES teaches people to make connections between what they eat and how they feel in the short and medium term, paying attention to food and mood, concentration, energy levels, fullness, ease of bowel movements, comfort eating, appetite, satiety, hunger and pleasure as guiding principles."

And while Kausman tends to talk about individuals being at their "most healthy weight" rather than "health at every size" he shares Bacon's focus on mindful eating.

In particular, he says, it's important to "check" whether you are hungry before eating. "Dieting makes it more difficult for people to know when they are hungry or full because dieting says, 'Don't trust your body, follow our rules and forget whether you are hungry or not'," he says. "When I see people who have dieted on and off for 20 or 30 years, I'm almost retraining them to start trusting their body again."

But activists such as Bacon go much further, asserting that promoting weight loss is counterproductive and it is possible to be fat and fit.

There is some research to show being fit is more important than being thin and that being overweight (though not obese) may actually offer some health benefits.

But both these points remain controversial, flying in the face of mainstream medical thinking.

Lyn Roberts, chief executive of the Heart Foundation, says it is dangerous to think that being overweight is OK. "It's almost like we have normalised being overweight and obese in Australia," she says. "That is a concern because of the very direct link between overweight and obesity and the fact that it increases your risk of heart disease. We also know it's a risk for diabetes and arthritis and some types of cancer as well.

"There are people who are overweight who may be very fit and who may not have high cholesterol and high blood pressure and who may not go on to develop diabetes, but there are a lot of people who are overweight who really do have a range of other problems."

Roberts admits losing weight is extraordinarily tough for most people, which is why the Heart Foundation also emphasises prevention. "We really want to encourage people not to put on that weight in the first place because it is so much more difficult to lose it once it's on," she says.  "I have enormous sympathy and regard for people that are out there trying to lose weight because it is not an easy thing to do."


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