People with high levels of certain vitamins and omega 3 fatty acids in their blood do better in cognitive tests, and are less likely to have brain shrinkage associated with Alzheimer’s disease, according to US researchers.
A study published in the journal Neurology investigated a range of nutrients in people’s blood, instead of the usual approach of using questionnaires to assess people’s diets. The researchers said their method gave a more accurate picture of a person’s food intake, because it did not rely on memory or honesty when answering questions about diet.
Researchers at the Oregon Health and Science University studied blood samples from 104 healthy older people with an average age of 87, who had few known risk factors for Alzheimer’s.
They found those whose blood contained more vitamin B, C, D and E were the best performers in cognitive tests, while people with higher levels of omega 3 fatty acids also had high scores in these tests. Conversely, people whose blood had higher levels of trans fats had the worst cognitive scores.
The researchers also analysed MRI scans from 42 of the participants, and found those whose blood had higher levels of vitamins and omega 3 were also more likely to have bigger total brain volume. In comparison, those with more trans fats in their blood had less brain volume.
Dr Simon Ridley, head of research at Alzheimer’s Research UK, said: “It’s important to note that this study looked at a small group of people with few risk factors for Alzheimer’s disease, and did not investigate whether they went on to develop Alzheimer’s at a later stage.”
But he added: “Although there is no sure-fire way of preventing Alzheimer’s yet, we know that risk factors for heart disease and stroke can also increase the risk of dementia.
“The best advice at the moment is to eat a balanced diet with plenty of fruit and vegetables, and keep healthy by not smoking, taking regular exercise and keeping blood pressure and cholesterol in check.”