How olive oil and nuts can boost brain power:

Mediterranean diet halts decline in memory and attention span

• Mediterranean diet has been shown to improve heart and brain health
• Study: Adding extra olive oil or nuts halts decline in memory and thinking
• This was compared to a group of people who ate a low fat diet for 4 years
• Significant drop in brain function scores was seen in those on a low fat diet

Swapping to a Mediterranean diet – with added extra virgin olive oil or mixed nuts – may boost ageing brain power better than a low-fat diet.

Just four years of eating like the Spanish and Italians who use olive oil rather than less healthy fats can improve brain function in older people, says a new study.

The Mediterranean diet is regarded as the classic eating habits of populations from countries in southern Europe, even though fewer inhabitants follow it today.

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 study shows further benefits, with people eating more olive oil or nuts gaining higher scores in tests of memory, attention span and abstract thinking.

The research involved 447 men and women aged 67 years on average.

They were regarded as high risk heart patients who were already taking part in the Prevencion con Dieta Mediterranea (PREDIMED) study.

They were all regarded as ‘brain healthy’ at the start of the study, which compared a Mediterranean diet supplemented with olive oil or nuts with a low-fat control diet.

Altogether 155 people were assigned to supplement a Mediterranean diet with one litre of extra virgin olive oil per week.

Another 147 were assigned to supplement a Mediterranean diet with 30 grams per day of a mix of walnuts,almonds and hazelnuts.

And 145 individuals were assigned to follow a low-fat control diet typically recommended to prevent heart attack and stroke.

After an average of four years, they were tested for signs of cognitive decline using a range of tests to assess memory, and functions such as working memory, attention span, and abstract thinking.

Follow-up results were available for 334 people, with 37 cases of mild cognitive impairment, a more severe form of normal memory loss that comes with aging, says a report online in JAMA Internal Medicine.

Of these, 17 (13.4 per cent) were in the Mediterranean diet plus olive oil group; eight (7.1 per cent) in the Mediterranean diet plus nuts group; and 12 (12.6 per cent) in the low-fat control group.

No dementia cases were found in patients who completed study follow-up.

The study found people assigned to the low-fat control diet had a significant drop in brain function scores.

Compared with the control group, the memory scores improved significantly in the Mediterranean diet plus nuts.

Other scores of brain function improved in the Mediterranean diet plus olive oil group.

The study was led by Dr Emilio Ros, of the Institut d’Investigacions Biomediques August Pi Sunyer, Hospital Clinic, Barcelona.He said:

‘Our results suggest that in an older population a Mediterranean diet supplemented with olive oil or nuts may counter-act age-related cognitive decline.The Mediterranean diet 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.

The lack of effective treatments for cognitive decline and dementia points to the need of preventive strategies to delay the onset and/or minimise the effects of these devastating conditions.

The present results with the Mediterranean diet are encouraging but further investigation is warranted.’

Dr Simon Ridley, head of research at Alzheimer’s Research UK, said: ‘The results of this trial appear to be encouraging but the effects seen were very subtle and as the researchers themselves point out, more work is needed to understand these findings fully.

‘It’s important to note that the people in this study did not have dementia, and this trial does not tell us whether a Mediterranean diet could prevent the condition.

‘These findings suggest a need for much larger trials to understand better the effects of changes in diet on memory, thinking and dementia risk.

‘While there is currently no certain way to prevent dementia, evidence suggests the risk can be lowered with a healthy lifestyle including a balanced diet, regular exercise, not smoking, and keeping weight and blood pressure in check.’