Why you're better off eating FULL fat dairy

People who drink skimmed milk are more likely to develop Parkinson's disease, research suggests.

A major study by US experts at the Harvard University found a significant link between regular consumption of low-fat dairy - such as yogurt, milk and cheese - and development of the neurological condition.

The researchers, who assessed data from 130,000 people tracked over 25 years, found people who drank skimmed or semi-skimmed milk more than once a day were 39 per cent more likely to develop Parkinson's than people who did so less than once a week.

Crucially, the same link was not seen for consumption of full-fat milk.

The team also analysed how often people ate other forms of low-fat dairy, including low-fat cheese, yogurt and cottage cheese.

When looking at all forms of low-fat dairy, the researchers found those who consumed at least three servings a day had a 34 per cent greater chance of developing Parkinson's than people who consumed less than one serving per day.

Around 127,000 people in the UK are believed to have Parkinson's, which causes tremors, slow movements and muscle rigidity.

It is a progressive neurological condition that destroys cells in the part of the brain that controls movement.

There is currently no cure and no way of stopping the progression of the disease.

Experts suspect all dairy products have the potential to raise the risk of Parkinson's, because it is thought to reduce levels of protective chemicals in the body.

But they think eating full-fat forms lessens this impact, as saturated fat seems to counteract the process by which these protective molecules - called urates - are driven out of the body.

Researcher Katherine Hughes, of the Harvard T.H. Chan School of Public Health in Boston, said: 'Our study is the largest analysis of dairy and Parkinson's to date.

'The results provide evidence of a modest increased risk of Parkinson's with greater consumption of low-fat dairy products.

A recent study provides more evidence that Parkinson's disease starts in the gut.

The neurodegenerative disease appears to be triggered by a protein in the stomach and spreads to the brain via the vagus nerve.

The nerve extends from the abdomen to the brainstem and controls unconscious body processes like heart rate and food digestion.

Patients who underwent surgery to remove the trunk of the nerve were 40 percent less likely to develop Parkinson's than those who hadn't, according to researchers from Karolinska Instituet in Stockholm, Sweden.

'These results provide preliminary evidence that Parkinson's disease may start in the gut,' said study author Bojing Liu.

'Other evidence for this hypothesis is that people with Parkinson's disease often have gastrointestinal problems such as constipation that can start decades before they develop the disease.'

A December 2016 study from the California Institute of Technology found a conclusive link between gut microbes and the development of Parkinson's-like movement disorders in mice.

'Such dairy products, which are widely consumed, could potentially be a modifiable risk factor for the disease.'

Experts stressed that although the relative increased risk was significant, very few people would actually develop Parkinson's.

Of the 77,864 people in the study who consumed less than one serving per day of low-fat dairy, 483 people, or 0.6 per cent, developed Parkinson's.

Among those who ate more than three servings a day, the risk increased to 1 per cent.

But the authors said even this risk demands further investigation, particularly in relation to the impact of urates - tiny crystals thought to protect against Parkinson's but which raise the risk of gout.

Writing in the Neurology medical journal, they said: 'A substantial body of evidence suggests that urate may be protective against Parkinson's disease.

'Milk proteins and intact milk have been shown to reduce serum urate levels in healthy individuals, and consumption of low-fat, but not high-fat, dairy has been associated with a reduced risk of gout.

'The lack of association with full-fat dairy products could be due to counteracting effect of saturated fats.'

Another theory suggests pesticides which get into dairy may be to blame, although this does not explain the specific link to low-fat products.

Claire Bale, head of research at Parkinson's UK, said last night: 'It's really important to point out that the risk of developing Parkinson's was still very low - around one in 100 - even in those who consumed lots of dairy, so there is no reason for people to make changes to their diet based on this research.

'Previous research has suggested that traces of pesticides in dairy products might be involved, and more recently there have been a number of studies suggesting that bacteria living in the gut may play a role, but there is much more research needed in this area.

'If we can understand more about how and why dietary factors influence Parkinson's, it could reveal exciting opportunities for developing urgently needed treatments that can slow, stop or even prevent the condition.'

Dr Anne Mullen, director of nutrition at The Dairy Council, said: 'We must remember that the factors that cause Parkinson’s disease are not clearly understood, but they are believed to have genetic and environmental components.

'Generally, dietary factors are not at all well investigated in relation to the major causes of Parkinson’s disease, so the results here should not be over-interpreted.’

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