MemoryA decline in memory and cognitive (thinking) function is considered by many authorities to be a normal consequence of aging. While age-related cognitive decline (ARCD) is therefore not considered a disease, authorities differ on whether ARCD is related to Alzheimer’s disease or other forms of dementia, or whether it is a distinct entity. ARCD usually occurs gradually. Sudden cognitive decline is not a part of normal aging. When people develop an illness such as Alzheimer’s disease, mental deterioration usually happens quickly. In contrast, cognitive performance in elderly adults normally remains stable over many years, with only slight declines in short-term memory and reaction times. Some older people have greater memory and cognitive difficulties than those of normal aging, but not so severe as to justify a diagnosis of Alzheimer’s Disease. Some of these people go on to develop Alzheimer’s disease; others do not. A qualified health professional should be consulted if memory impairment is suspected.
One of the most common indications of deteriorating brain function is memory loss. When many older people become aware of memory lapses, they jump to the conclusion that they are experiencing the early signs of Alzheimer's disease, when in fact their declining memory may be rooted in a nutritional deficiency. Experts today still tout the importance of B vitamins, particularly the following five (keep in mind that these vitamins are all water-soluble and should be taken together for maximum benefit):
- B1 (thiamine) helps convert glucose into energy. It also mimics acetylcholine (a neurotransmitter involved in memory) and plays a role in brain functions related to memory and cognition. Thiamine supplementation also appears to elevate mood. In another study, 120 young women took either placebo or 50 mg thiamine daily for two months. Before-and-after tests assessed mood, memory and reaction times. Women who took the thiamine supplements reported feeling significantly more clearheaded, composed and energetic.
- B3 (niacin) enhances the ability of red blood cells to carry oxygen. It is also vital to the formation and maintenance of many tissues, including nerve tissue.
- B6 (pyridoxine) is needed for the production of amino acid-derived neurotransmitters such as norepinephrine, serotonin and dopamine.
- B12 (cobalamin) plays an important role in the
formation of the myelin sheath around nerve fibers. It also helps the body transport and store folic acid. Deficiencies in cobalamin have also been linked to
depression, especially in the elderly.
Folic acid is necessary for DNA synthesis, hence it plays an essential role in all cell divisions and in the development of the fetal nervous system. Folic acid deficiency can lead to megaloblastic anemia and poor growth in children and can also contribute to various psychiatric disturbances including depression. As many as 31 to 35 percent of all depressed patients have folic acid deficiencies.
The following nutrients related to the B vitamins can
also enhance brain functioning:
- Choline, a component of lecithin, is critical to memory, learning and mental alertness. Manufacture of cell membranes and the neurotransmitter acetylcholine depend on it. Choline helps increase the amount of acetylcholine in the memory circuits of the temporal lobe. Although supplemental choline improves memory performance in younger people, it has failed to consistently help elderly adults who already suffer from memory loss or Alzheimer's disease.
- Inositol, although not officially a B vitamin, is recognized as part of the B complex. It occurs in cell membranes as phosphatidylinositol. The neurotransmitters serotonin and acetylcholine both require phosphatidylinositol for proper functioning. Phosphatidylserine is the major phospholipid in the brain. Present in cell membranes, it plays a major role in determining their integrity and fluidity. The brain generally makes enough, but deficiencies of essential fatty acids or vitamins such as folic acid and B12 can inhibit production. The potential benefits of phosphatidylserine on dementia and memory loss have been studied extensively.
- Docosahexaenoic acid (DHA), a polyunsaturated fatty acid also known as an omega-3 fatty acid, plays a critical role in infant brain development and vision. Before a child is born, DHA from the mother's blood
travels to the placenta where it is used for membrane development in the brain and retina. Research has also linked the rising rate of depression among adults to an imbalance in the ratio of omega-3 fatty acids to omega-6 fatty acids (arachadonic acid).
- Amino acids, the building blocks of protein, are
critical to the formation and functioning of neurotransmitters. Of the 20 amino acids, two are particularly important to brain function. These are L-tyrosine and L-tryptophan. L-tyrosine is one of the nonessential amino acids found in protein-rich foods such as meat, poultry, seafood and tofu. It's a
precursor to the neurotransmitters norepinephrine and dopamine--chemical messengers that promote mental acuity and alertness. Increased levels of these neurotransmitters can affect mood and behavior, fostering a tendency to think more quickly and react more rapidly.
- Iron, magnesium, calcium, copper and zinc all help
keep the body functioning smoothly. Proper balance of these minerals is especially critical to brain performance; even a slight imbalance may create psychological disturbances. Here are highlights of the most important mineral functions.
Iron is particularly critical to motor and mental development during infancy. An iron deficiency can adversely affect the ability to learn and understand new information and may result in poor concentration and attention span.
Calcium and magnesium regulate nerve impulses and aid in the formation of neurotransmitters. Excessive levels of calcium may result in mental changes--the extreme being stupor or even coma.
Zinc deficiency may contribute to dementing illnesses such as Alzheimer's disease. A small study suggests that supplemental zinc may provide benefits in cases of dementing illness.
The sophisticated chemistry of the brain depend on all of these nutrients, but further research is needed to elucidate the effects of supplementation on various central nervous system disorders.