Among healthy people over the age of 75 who have the genotype associated with higher risk for Alzheimer’s, low levels of vitamin B-12 are associated with significantly worse performance on memory tests.
Scientists already knew of a genetic predisposition for Alzheimer’s disease, and that low levels of two B vitamins — B-12 and folic acid — were also linked to problems. However, few had examined nutrition and genotype together relative to cognition, to reflect what real people carry into old age – a mix of inborn traits and environmental factors such as nutrition, including undiagnosed vitamin B deficiencies.
Researchers studied 167 healthy older people, averaging nearly 83 years old. First, they checked blood samples for vitamin levels and genotype. Some 82 participants had low B-12. The researchers then tested episodic memory, varying the test conditions to make them as sensitive as possible to the underlying disorder.
Among carriers of the high-risk gene, people with normal B-12 levels recalled a greater number of words than those with low levels. A significant difference showed up in the experiment’s most demanding condition, when participants had just two seconds to encode words. In that situation, the high-risk genotype plus low B-12 levels was significantly associated with poorer memory.
According to the authors, those at higher risk for Alzheimer’s “may derive relatively greater cognitive benefits from B-12 and [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][folic acid]. Supplement treatment is relatively inexpensive and may be required as part of preventive health regimes for older persons.”
American Psychological Association, Apr 4, 2004