Some vitamins such as vitamin C and E, and minerals such as selenium are known to possess antioxidant activity. Oxidative damage to the brain is responsible for a progressive decline in the ability to perform mental functions in old age. A recent study in France examined the role of some antioxidant vitamins and minerals in preventing the cognitive decline associated with oxidative damage in people aged between 45 and 60 years. The study revealed that those who were provided with active antioxidant supplementation performed better in memory tests compared to those who were given placebos.
The incidence of dementia in old age has been increasing in recent years. The main reason for dementia is Alzheimer’s disease, which occurs because of the death of neurons in a particular part of the brain. Although the symptoms of this disease can be reduced to some extent, there is no cure for this disease. Hence, a constant search for substances that would prevent the occurrence of this disease or at least retard its progression is going on across the world. Studies on the association between antioxidant consumption and improvement in cognitive functions are scarce. Therefore, the present study was conducted to assess the long-term benefits of the consumption of regular doses of antioxidant minerals and vitamins in the cognitive performance of healthy middle-aged adults.
* The participants of the present study were originally recruited for another large study known as the Supplementation in Vitamins and Mineral Antioxidants (SU.VI.MAX) study, in which the role of antioxidants in preventing heart diseases and various cancers was being analyzed. Six years after the completion of the original study, the participants were requested to participate in the present study. In this study, 6,850 participants, aged between 45 and 60 years, agreed to take part. Of these, only 4,447 completed the study.
* The participants were categorized into two groups – those who were given antioxidants and those who were given placebos. Cognitive, neuropsychological and memory tests were carried out in both the groups. Data on their sociodemographic and lifestyle characteristics, such as smoking habits and physical activity, were collected.
* Blood samples were collected to measure the levels of various antioxidants in the blood. The consumption of various vitamins and minerals through food was measured by using food frequency questionnaires.
* There were no major differences in the sociodemographic and lifestyle characteristics of both the groups.
* Memory tests showed that the memory levels were higher in participants who regularly consumed antioxidants for six years.
* The study also revealed that antioxidant supplementation improved verbal memory skills in non-smokers. In contrast, antioxidant supplementation was found to have a harmful effect on smokers.
* The beneficial effects of antioxidant supplementation were higher in participants who had higher levels of vitamin C in their blood.
The cognitive capacity of participants was not assessed before supplementation with vitamins and minerals, because evaluating their cognition was not the actual intention of the main study. Moreover, memory was measured by using a self-reported questionnaire, which is not very accurate. In addition, since a mixture of antioxidants was given to the participants, it is difficult to identify which one of them actually produced the beneficial effect.
This study has shown that when several antioxidants are used in combination regularly, for a long time, they can help in preventing the deterioration of cognitive function, as age progresses. This study is unique because unlike other studies, where high doses of antioxidants were administered, in the present study, only routine nutritional doses of antioxidants were given to the participants. The findings of this study are consistent with similar studies in the past, which studied the effects of beta carotene on cognitive performance. From this study, it can be inferred that an adequate supplementation of antioxidant vitamins and minerals in the diet is significantly helpful for the preservation of verbal memory and cognitive function.
For More Information:
French Adults’ Cognitive Performance after Daily Supplementation with Antioxidant Vitamins and Minerals at Nutritional Doses
Publication Journal: American Journal of Clinical Nutrition, July 2011
By Emmanuelle Kesse-Guyot; Léopold Fezeu; Université Paris, Bobigny, France