Mediterranean diet can cut risk of developing age-related brain disorders, says new study (?)
Diet questionnaires are about as low-grade data as you can get. This proves nothing. Being conducted in Manhattan, there could have been in this study a sub-population of Ashkenazi Jews in the sample and they are known for good health into late old age despite smoking and other "incorrect" behaviours. If anything, it may simply be their diet that was being detected and associated with good mental functioning -- which they tend to have anyway
Eating a Mediterranean-style diet helps keep the brain healthy, reducing age-related damage, say researchers. Brain scans suggest a diet rich in plant foods and fish, along with moderate drinking, cuts the risk of developing lesions that are linked to the development of cognitive disorders including Alzheimer’s.
The Mediterranean diet is regarded as the classic eating habits of populations from countries such as France, Greece, Spain and Italy.
It has been thought to improve heart health and stave off cancer because it is high in fruit, vegetables, fish, nuts, whole grains and ‘healthy’ fats such as those in olive oil, while low in red meat and dairy products.
But a new US study shows further benefits to the brain where it is linked to lower levels of white matter hyperintesity volume, a marker of damage to the small vessels.
Some researchers believe the diet keeps the grey cells healthy by cutting inflammation, while others say the high intake of antioxidant vitamins may also protect the brain.
A report in the Archives of Neurology medical journal examined for the first time the relationship between the Mediterranean diet and lesions in the brain, known as white matter hyperintensities (WHM).
Study leader Hannah Gardener of the University of Miami Miller School of Medicine, and colleagues looked at data on almost 1,000 people with an average age of 72 years taking part in the Northern Manhattan Study.
Participants were given a food frequency questionnaire to assess dietary patterns during the previous year, and answers were used to determine a score from 0-9 indicating how much they stuck to a Mediterranean diet, with a higher MeDi score showing greater compliance.
The volume of chronic age-related white matter damage was measured using brain MRI scans.
Results of the survey showed that 11.6 per cent of participants scored 0 to 2 on the MeDi scale, 15.8 per cent scored 3, 23 per cent scored 4, 23.5 per cent scored 5, and 26.1 per cent scored 6 to 9.
Women had lower scores than men and those engaged in moderate to heavy levels of physical activity had higher scores. Those scoring 6 or higher also had lower Body Mass Index scores, suggesting healthier weights.
The results show a lower burden of WMHV among people sticking to a Mediterranean diet, even after allowing for risk factors including physical activity, smoking, blood lipid levels, hypertension, diabetes, history of cardiac disease and BMI.
The only component of the MeDi score showing independent benefit with less brain damage was higher consumption of monounsaturated fat such as olive oil compared with saturated fat, including butter.
Dr Gardener said ‘Although diet may be an important predictor of vascular disease, little is known about the possible association between dietary habits and WMHs.
‘Studies have suggested that consumption of a Mediterranean Diet is associated with a reduced risk of the metabolic syndrome, coronary heart disease, stroke and cognitive disorders, but no studies to date, to our knowledge, have examined the association with WMH volume.’
She said: ‘In summary, the current study suggests a possible protective association between increased consumption of a MeDi and small vessel damage.’
The results suggests the overall dietary pattern, rather than any of the individual components, was the most important factor, said the report. Eating healthy monounsaturated fats such as olive oil is known to lower the risk of cardiovascular disease, but in the UK higher levels of animal or saturated fats are eaten.
Olive oil contains omega-6 fats, a form of ‘healthy’ polyunsaturates which blocks the body’s response to inflammation in chronic conditions such as heart disease and arthritis. It also reduces blood pressure and improves the ratio of good to bad blood fats.
Dieticians say the Mediterranean diet also appears to improve vascular function, the flexibility of cells lining the walls of blood vessels, particularly in the heart and circulatory system.
The diet is known to fight inflammation and repair oxygen-related cell damage.
Previous research has found strict adherence to a Mediterranean diet could help stave off memory loss and Alzheimer’s. Even those people already suffering from memory loss were half as likely to develop full-blown Alzheimer’s if they stuck to a Mediterranean-style diet.
Few of us need too much encouragement when it comes to heading off to the curry house. But scientists have come up with one of the best excuses ever: a spicy ingredient in curry could be an effective treatment for Alzheimer's disease.
Tests on fruit flies with a nervous disorder similar to the neurodegenerative illness found those given curcumin - the key chemical in turmeric used in everything from mild Kormas to the hottest Vindaloos - lived 75 per cent longer.
Alzheimer's is linked to the build up of knots of protein in the brain called amyloid plaques, damaging the wiring in brain cells.
The findings, published in the journal PLoS One, could help explain why rates of dementia are much lower among the elderly in India than in their Western peers. Previous research has found Alzheimer's affects just one per cent of people over the age of 65 living in some Indian villages.
Drugs with similar properties to curcumin could potentially be used as preventative treatments.
In the study Professor Per Hammarstrom and colleagues also found five groups of fruit flies genetically engineered to develop Alzheimer's-type symptoms manipulations maintained their mobility longer when given curcumin.
The scientists saw no decrease of amyloid in the brain or eyes of the insects.
Curcumin did not dissolve the plaque, but accelerated the formation of nerve fibres by reducing the amount of their precursor forms, known as oligomers, from which they were formed.
Prof Hammarstrom, of Linkoping University in Sweden, said: 'The results confirm our belief that it is the oligomers that are most harmful to the nerve cells.'
Several theories have been established about how oligomers can instigate the disease process. According to one hypothesis they become trapped at nerve junctions inhibiting impulse signals. Others claim they destroy brain cells by puncturing membrane.
Curcumin is extracted from the root of turmeric and has been used as medicine for thousands of years. It aids digestion, helps fight infection and guards against heart attacks. More recently it has been tested against pain, thrombosis and cancer.