High levels of omega-3 fatty acids in the blood are associated with a lower risk of dementia and Alzheimer's, according to the largest population study developed in this field, co-led by the Hospital del Mar. Its authors recommend incorporating rich foods into the diet. in these substances, such as oily fish or nuts.
“In all associations we have found at least a 10% risk reduction. There are cases in which this decrease is even somewhat higher, especially in men, people who are a little older, over 60 years old, and when other types of omega-3 were tested,” explains Aleix Sala-Vila, risk researcher. vascular and nutrition of the hospital del Mar.
“Reducing Alzheimer's by 10%, if one imagines the costs, not only emotional, but resources that public health dedicates to each patient, without taking into account all the care that is given at home, means a brutal saving,” points out the doctor.
Never before had there been such an extensive sample in a work in this field, nor had previous works been directed at the appearance of the disease. The researchers, who have published the results in Nutrients, have analyzed blood metabolite data from 260,000 people from the British Biobank base.
In addition to examining associations between different types of omega-3, the authors have been able to include younger population groups than those traditionally studied, which are those over 60 years of age. These are the main novelties of a work that, according to Sala-Vila, has served to “study whether having high levels of omega-3 at age 50 can help us prevent dementia many years later.”
The study concludes that high levels of omega-3 in the blood imply lower risk for all age groups (from 40 years old), for men as well as for women and in both diseases (dementia and Alzheimer's). It is also proven that the benefits do not come from types of omega-3 other than DHA, which oily fish provides.
Therefore, the idea is reinforced that “there are some foods, which do not necessarily have to be fish, such as walnuts, that could be beneficial for brain health,” says Sala-Vila.
The results do not establish a direct causality between fatty acid levels and the risk of dementia, but they help define future studies with volunteers on dietary supplementation with omega-3. “For this, many millions and years of follow-up are necessary,” says the doctor. “Hopefully we will see a good study on supplementation within two decades.”
Meanwhile, researchers think it's never too late or too early to improve your diet. “The sooner the better, but don't let anyone think that I'm too old and I won't have time for it to take effect. You can be old and you will surely have a benefit by improving your diet.”
In Sala-Vila's opinion, the same thing will happen with Alzheimer's and dementia as with cardiovascular disease: years ago no one thought that it could be so influenced by diet. "Within a while it might be possible for no one to doubt that fatty acids are one of the elements to avoid the possibilities of dementia."
“There is more and more evidence that not only diet, but lifestyle, knowing how to sleep well, avoiding tobacco, managing emotions well, socializing, doing physical activity, doing what we call cognitive stimulation (playing an instrument, reading) , learning a language), ends up being beneficial for the brain.” “You have to be as trained as possible for when it is time for the changes that lead to the onset of the disease to appear,” says Sala-Vila.
In addition to the Hospital del Mar research institute, scientists from the Fartty Acid Research Institute (USA) and the CIBER for the pathophysiology of obesity and nutrition have participated in the work. The Hospital del Mar group is now working with researchers from the Pasqual Maragall Foundation to identify the small changes that occur in the brain just before dementia appears.
