A couple of glasses of wine a day really do help clear your mind

A couple of glasses a day to relax really does help clear the mind, a new study found.

The tipple not only help keeps down inflammation but helps flush the brain of toxins, including those associated with Alzheimer's disease and dementia.

Lead author Dr Maiken Nedergaard, co-director of the Centre for Translational Neuromedicine said: "Prolonged intake of excessive amounts of ethanol is known to have adverse effects on the central nervous system

"However, in this study we have shown for the first time that low doses of alcohol are potentially beneficial to brain health, namely it improves the brain's ability to remove waste."

The new study adds to a growing body of research that daily low amounts of alcohol is good for you.

While excessive drinking is harmful, many studies have linked lower levels of drinking with a reduced risk of cardiovascular diseases as well as a number of cancers.

Dr Nedergaard's research focused on the glymphatic system, the brain's unique cleaning process first described by her and her colleagues in 2012.

They showed how cerebral spinal fluid (CSF) is pumped into brain tissue and flushes away waste, including the proteins beta amyloid and tau associated with Alzheimer's disease and other forms of dementia.

Subsequent research showed the glymphatic system was more active while we slept, can be damaged by stroke and trauma, and improves with exercise.

The new study looked at the impact of both acute and chronic alcohol exposure.

The study by University of Rochester Medical Centre was conducted in mice who drank the equivalent of two-and-a-half drinks of wine a day.

Two and a half drinks the sweet spot

The NHS recommends men and women not to drink more than 14 units a week on a regular basis with one unit equal to 10ml or 8g of pure alcohol.

A standard 175ml glass of 12 per cent red, white or rose wine has 2.1 units.

The mice were given received low, intermediate, and high doses of alcohol at 0.5, 1.5 and 4g/kg.

When they studied the brains of animals exposed to high levels of alcohol over a long period of time, they observed high levels of a molecular marker for inflammation, particularly in cells called astrocytes which are key regulators of the glymphatic system.

They also noted impairment of the animal's cognitive abilities and motor skills.

Yet mice exposed to low levels of alcohol consumption, analogous to approximately two-and-a-half drinks per day, actually showed less inflammation in the brain.

Their glymphatic system was also more efficient in moving CSF through the brain and removing waste, compared to control "teetotal" mice.

Yet mice who drank low amounts also performed identically to the "teetotal" mice in cognitive and motor test.

Dr Nedergaard said: "We here investigated the effect of acute and chronic alcohol treatments on glymphatic function in mice, finding that acute alcohol intake potently alters glymphatic function in the awake state depending on the dosage.

"Intermediate dose alcohol exposure (1.5 g/kg), corresponding to 7.9 standard daily drinks daily (NIH definition; 12-ounce beers containing 5% alcohol, or 5-ounce glasses of wine containing 12% alcohol for a person weighing 70 kg), decreased glymphatic function following both acute and 30 days of chronic exposure.

"The suppression of glymphatic function was however not permanent, because glymphatic function was restored at 24 hours after termination of chronic moderate alcohol administration.

"A very high dose of alcohol (4 g/kg), corresponding to 21 standard drinks per day, also to acutely reduce glymphatic function.

"Unexpectedly, however, the low dose of alcohol (0.5 g/kg) significantly improved glymphatic activity, acutely and after 30 days of chronic exposure."

Dr Nedergaard added: "The data on the effects of alcohol on the glymphatic system seemingly matches the J-shaped model relating to the dose effects of alcohol on general health and mortality, whereby low doses of alcohol are beneficial, while excessive consumption is detrimental to overall health.

"Studies have shown that low-to-moderate alcohol intake is associated with a lesser risk of dementia, while heavy drinking for many years confers an increased risk of cognitive decline.

"This study may help explain why this occurs. Specifically, low doses of alcohol appear to improve overall brain health.

"In conclusion, the main finding of this study is that a low dose of ethanol, comparable to 2.6 daily drink equivalents (for a 70kg person) per day, increases glymphatic function in mice, which is expected to facilitate clearance of metabolic waste and potentially toxic proteins from the interstitial fluid."

The study was published in the journal Scientific Reports.