The consumption of sea fish and nuts does not support memory and does not prevent memory damage, especially in old age. However, the omega-3 polyunsaturated fatty acids contained in them protect against Alzheimer’s disease and reduce the risk of sudden cerebral hemorrhages occurring in younger and younger people.
A team of scientists from the University of Iowa, led by Dr. Eric Ammann, investigated the health-promoting properties of unsaturated fatty acids, found in large amounts in oily sea fish (e.g. salmon) and nuts. The result was not exactly what was expected. Currently, there is great interest in omega-3 acids as substances that can prevent or reverse cognitive decline. However, our research did not show the expected effects of these acids in women, especially in the menopausal and postmenopausal periods, the researchers said.
Sea fish and nuts are a great alternative to a junk food and red meat diet rich in saturated fatty acids. However, it cannot be stated with certainty that the omega-3 fatty acids in these foods can improve memory performance or prevent memory damage, especially in old age. However, scientists have detected the positive effects of this type of acid on blood vessels, heart and arteries and will continue their research in this direction.
During the completed experiment, 2157 women of various ages, from 25 to 80 years of age, were examined, with the largest group being postmenopausal women – from 65 to 80 years of age. During 6 years, all participants of the research performed annual memory and association tests. Blood tests were also performed to determine the levels of omega-3 fatty acids in the test participants both before and during the test.
The researchers found no significant differences between the women who had high levels of unsaturated fatty acids at the beginning of the experiment and those who had low levels of it. Differences in association speed and cognitive decline between these groups, determined depending on age groups, were also not significant.
Fish against Alzheimer’s
However, according to another research group, if the effect of unsaturated fatty acids is not visible in healthy people, it may be because omega-3 counteracts more serious damage at the level of brain cells – this hypothesis was tested by a team of scientists from Columbia University Medical Center in New York at led by Dr. Nikolaos Scarmeas. As it turned out, this was true – eating sea fish, white meat and nuts helps protect against neurodegenerative diseases like Alzheimer’s disease.
As noted in previous studies, the formation of neurodegenerative diseases is caused by debris not removed from neuronal cells, especially beta-amyloid protein, which forms deposits. Meanwhile, a high level of omega-3 fatty acids correlates with a low level of beta-amyloid, and the lower the level of omega-3, the more deposits of this harmful protein increase.
The level of beta-amyloid deposits – the most harmful form of this protein – is determined by measuring the level of beta-amyloid in the blood, which is directly related to its presence in brain cells, Dr. Scarmeas noted.
1219 people aged 25 and over participated in this study. The group with the most significant risk of Alzheimer’s disease, i.e. over 65, free from signs of dementia, was asked to record information about their diet and pass it on to scientists. Before the start, during and at the end of the study, measurements were made for the concentration of beta-amyloid in the blood. Scientists were most interested in 10 dietary ingredients containing omega-3 and omega-6 poly and monounsaturated fatty acids, saturated fatty acids, vitamins B12, D, E and C, beta-carotene and folic acid
Consuming a gram of pure omega-3 acid a day (half a salmon fillet a week) will decrease your blood beta-amyloid levels by 20 to 30 percent. According to the researchers, only some people in the study group – as it turned out, all over the age of 65 – achieved this level of omega-3 consumption. Only two people particularly fond of fish and nuts exceeded this dose of omega-3 twice. Their blood tests showed that beta-amyloid levels were 60-66 percent lower than the median for the group as a whole! The results were not dependent on age, gender, education, daily calories, ethnicity, and even the presence of the APOE gene, considered a serious risk factor in Alzheimer’s disease.
The best natural source of omega-3, scientists found, is fatty sea fish, mainly salmon and nuts. White chicken also contains a good amount of these unsaturated fatty acids. The results of these studies establishing the relationship between the level of omega-3 and other nutrients and the level of beta-amyolide in the cerebrospinal fluid and brain cells are important because they contribute to the definition of the diet in Alzheimer’s disease and dementia, and in the case of brain damage at an earlier age, he noted. Dr. Scarmeas.
Nuts and fish protect against stroke
Meanwhile, an international research team consisting of scientists from the University of Eastern Finland and scientists working for American government institutions – National Heart, Lung and Blood Institute and the National Institute of Neurological Disorders, led by Prof. Dariusha Mozaffariana found that the high concentration of long-chain polyunsaturated fatty acids in the blood reduces the risk of small cerebral hemorrhages and heart attacks, both in old and young age. They are extremely dangerous – in the older age they mean a rapid worsening of dementia, in the younger age they can cause exclusion from normal activities even for years. Cases of such strokes have already been observed in Poland over 35 years of age.
They are called silent because they do not produce any indicative symptoms and only their effects can be assessed. In order to assess the possibility of their occurrence and methods of prevention, 3660 people in various age groups were examined, with the largest group being people over 65 years of age. The examination was carried out with the use of magnetic resonance imaging devices. They were repeated 5 years later on a group of 2313 people from the previous volunteers. The volunteers’ diets were also carefully examined, paying attention to foods that may increase blood pressure, build up cholesterol deposits and, consequently, strokes, and those that reduce blood pressure, regulate and accelerate cholesterol metabolism, and reduce the risk of cholesterol build-up.
The researchers found that the concentration of long-chain polyunsaturated fatty acids in the blood significantly reduces the risk of small cerebral hemorrhages and heart attacks. This applies to both older and younger people, although paradoxically, the older the respondent, the greater the decrease in this risk. The high concentration of unsaturated omega-3 fatty acids for people over the age of 65 reduced the risk of such a silent stroke or heart attack by as much as 40 percent, while after the age of 30, the high concentration of omega-3 fatty acids reduced this risk by 30 percent.
Scientists have undertaken a program to produce a drug based on salmon meat isolates, containing a concentrate of such long-chain omega-3 fatty acids. According to researchers, it is supposed to be a natural drug, on the one hand, so that it is easily absorbed, and on the other hand, that it can easily penetrate into the blood. It is supposed to prevent silent strokes and, referring to the research of scientists from the University of Iowa, also facilitate the elimination of betra-amyloid deposits. Probably based on the omega-3 drug, it will be tested next year, and it will appear in medicine in about 2-3 years
Tekst: Marek Mejssner