Vitamins & minerals
A two-year study which involved metabolic testing of 50 people, suggests that Alzheimer's disease consists of three distinct subtypes, each one of which may need to be treated differently. The finding may help explain why it has been so hard to find effective treatments for the disease.
The subtypes are:
An 11-week trial involving 54 young, healthy men and women engaging in an endurance training program, has found that markers for the production of new muscle mitochondria only increased in the group not taking vitamin C and E supplements. It’s possible that high doses of vitamins C and E act as antioxidants and take away some of the oxidative stress needed to develop muscular endurance.
http://www.eurekalert.org/pub_releases/2014-02/w-vca013014.php
A new study from the Women's Health Initiative has found that calcium and vitamin D supplements after menopause can improve women's cholesterol profiles, with much of that effect tied to raising vitamin D levels. Taking the calcium and vitamin D supplements was especially helpful in raising vitamin D levels in women who were older, women who had a low intake, women who had levels first measured in the winter, and women who didn’t smoke and who drank less alcohol.
Like us, guinea pigs can’t make vitamin C, but must obtain it from their diet. This makes them a good model for examining the effects of vitamin C deficiency.
The study involved 104 healthy older adults (average age 87) participating in the Oregon Brain Aging Study. Analysis of the nutrient biomarkers in their blood revealed that those with diets high in omega 3 fatty acids and in vitamins C, D, E and the B vitamins had higher scores on cognitive tests than people with diets low in those nutrients, while those with diets high in trans fats were more likely to score more poorly on cognitive tests.
The newborn brain may be particularly vulnerable to vitamin C deficiency, which has been found in rodent studies to lead to a marked decrease in the number of brain cells in the hippocampus. Although there is no clear evidence that vitamin C supplements on their own improve memory or brain function in adults, two large studies of older adults have found that taking both vitamin C and vitamin E supplements significantly reduced the risk of Alzheimer's. Other indications suggest the efficacy of these vitamins may depend on whether they are taken in through food or through supplements (food is better), and whether the individual has the "Alzheimer's gene" (better not to).
It's been proposed that vitamin E might help prevent Alzheimer's, because of the role that oxidative stress plays in the development of the disease. Vitamin E is an antioxidant. It has been found in cultured cell studies that vitamin E does help protect against the effects of oxidative stress, and results in significantly fewer neurons dying. At the level of the organism, results are not so clearcut. One study of older adults found those eating the most vitamin E-rich foods had a lower risk of developing Alzheimer's, provided they didn't have the 'Alzheimer's gene'. Supplements did not have the same effect. Another, larger, study found that those with high intakes of vitamins E and C were less likely to develop Alzheimer's, regardless of gene status. This was especially true for smokers.
Research indicates that choline is a crucial ingredient in a pregnant woman's diet, for brain development in the fetus. Among older adults, choline, particularly in conjunction with omega-3 fatty acids and uridine (not available from food), has been found to improve memory in those cognitively impaired. Top sources of choline are eggs, peanuts, and meat. Fish and soy are also good sources. A choline food database is available at: www.nal.usda.gov/fnic/foodcomp
Research with rats indicates that increasing magnesium levels in the brain improves learning and memory, apparently through its effects on synaptic density and plasticity. Unfortunately, traditional supplements have little effect on magnesium levels in the brain, but the researchers developed a new compound that was effective. Magnesium deficits are common in the population of industrialized countries, and increase with age. Good sources of magnesium are dark green leafy vegetables (such as spinach), some nuts (almonds and cashews are particularly good), beans, seeds and whole unrefined grains (especially buckwheat). See here for a list of magnesium-rich foods.
Zinc has been linked to cognitive and motor function in very young children and adults, and one small study has found zinc supplements improved cognition, especially attention, in adolescents, who are particularly at risk of zinc deficiency. Red meats, fish and grains are good sources of zinc.
A study involving 676 children (7-9) in rural Nepal has found that those whose mothers received iron, folic acid and vitamin A supplementation during their pregnancies and for three months after the birth performed better on some measures of intellectual and motor functioning compared to offspring of mothers who received vitamin A alone. However, there was no significant benefit for those whose mothers received iron, folic acid and zinc (plus vitamin A), or multiple micronutrients.
Another study has come out showing that older adults with low levels of vitamin D are more likely to have cognitive problems. The six-year study followed 858 adults who were age 65 or older at the beginning of the study. Those who were severely deficient in vitamin D were 60% more likely to have substantial cognitive decline, and 31% more likely to have specific declines in executive function, although there was no association with attention.
A study involving 236 persons with multiple sclerosis has found that only 7% of those with secondary-progressive MS showed sufficient vitamin D in their blood, compared to 18.3% of patients with the less severe relapsing-remitting type, and that higher levels of vitamin D3 and its byproducts were associated with better scores on cognitive tests (especially reasoning and planning), and less brain atrophy and fewer brain lesions. Lower-than-normal vitamin D status is known to be associated with a higher risk of developing MS
Seventh graders given 20 mg zinc, five days per week, for 10 to 12 weeks showed improvement in cognitive performance, responding more quickly and accurately on memory tasks and with more sustained attention, than classmates who received no additional zinc. Those who received only 10mg a day did not improve their performance. Previous studies have linked zinc nutrition to motor, cognitive and psychosocial function in very young children and adults, but this is the first study of its effect in adolescents.