Free radicals, produced during normal metabolic processes, cause oxidative stress. Oxidative stress has been implicated both in the aging process and in the pathological changes associated with Alzheimer’s disease. Antioxidants help provide protection against free radical damage. In this study, investigators examined the association between blood levels of antioxidants, including vitamins A, C and E, and selenium, and memory in a multiethnic population of senior citizens. The researchers examined 4,809 people aged 60 or older between 1988 and 1994. They found a connection between poor memory and low blood levels of vitamin E. Overall, 7% of the group had poor memory. These people were at least twice as likely to report problems managing their money or preparing meals. Among those with vitamin E levels lower than 4.8 per unit of cholesterol, 11% had poor memory. In contrast, just 4% of people with levels higher than 7.2 had memory problems. Increasing levels of vitamin E were associated with better memory performance for this ethnically diverse elderly population. Among those who said they did not eat enough food or skipped meals, almost 20% had poor memory, as opposed to 7% among people who ate regularly. The researchers report that they found no connection between the other antioxidants and memory loss. Most previous studies have not found a link between vitamin deficiencies and memory. However, the researchers noted, many of these studies had a limited range of subjects who were mostly Caucasian, well-educated and higher income levels — all factors linked to better memory retention.
Source: LE Magazine September 1999
Full source: American Journal of Epidemiology 1999;150:37-44