Elderly people with higher levels of vitamin B12 had lower risk for dementia and mental (cognitive) impairment in a new study. Researchers from the University of Michigan, Ann Arbor, followed 1,405 Mexican-Americans, aged 60 to 101, for an average of 4.5 years and found that those who had higher levels of vitamin B12 had lower levels of a risk factor—homocysteine—for Alzheimer’s disease, dementia, and cognitive impairment. Those who had high homocysteine levels were 139% more likely to develop dementia and cognitive impairment, and those who had both high homocysteine levels and low vitamin B12 levels had even greater risk of cognitive decline.

Reference: American Journal of Clinical Nutrition; 2007, Vol. 85, 511-7

Folic acid (folate, or vitamin B9) slowed the decline in hearing that occurs with age in a new study. Researchers from The Netherlands recruited 728 men and women, aged 50 to 70, with healthy middle ears (the part of the ear that transfers sound energy from the air to the liquid of the inner ear), who had not lost hearing separately in the left or right ear, and who had no ear condition that was not part of normal aging. The scientists also screened out those who had high levels of a hearing risk factor—homocysteine, an inflammatory signal—and those who had low levels of vitamin B12, which may increase homocysteine.

During the three-year double-blind trial, participants took a placebo or 800 mcg of folic acid per day. Doctors tested hearing in the range of sound frequencies of the normal speaking voice. By the end of the three-year period, those who had taken folic acid could hear low frequencies—such as the voice of a bass or baritone singer—better than those who had taken the placebo. Hearing in both groups declined, but the placebo group needed a louder noise—13.4 decibels on average—before being able to hear low-frequency sound, compared to those in the folic acid group, who on average could hear low frequencies at 12.7 decibels, or 0.7 decibels softer than the placebo group.

At the beginning of the study, all participants heard low-frequency sound at an average of 11.7 decibels. By the end of the study, the placebo group needed a 15% increase in sound volume compared to a 9% increase in the folic acid group. Folic acid did not affect the decline in hearing high-frequency sounds, such as those of a tenor or soprano singer, which participants heard at an average of 34.2 decibels at the beginning of the study. Researchers noted that some countries, including The Netherlands, do not require food manufacturers to fortify foods with folic acid, and that the average blood level of folate at the beginning of the study was 50% lower than the average level in the U.S., which does fortify foods with folic acid.

Reference: Annals of Internal Medicine; 2007, Vol. 146, No. 1, 1-9.

Folic acid (vitamin B9), vitamin B12, magnesium, and potassium citrate improved bone health in several new studies on men, women, and children. A study in the European Journal of Clinical Nutrition found that folic acid combined with vitamin B12 reduced homocysteine, a chemical compound that doctors believe increases risk for bone disease (osteoporosis) and fracture. Researchers reporting in the New England Journal of Medicine followed nearly 2,000 patients with osteoporosis, aged 59 to 91, for 17.5 years and found that women and men with the highest homocysteine levels were twice as likely, and four times as likely, respectively, to have a hip fracture than were women and men with the lowest levels.

Scientists from the University of California, San Francisco, studied 80 elderly women, average age 71, and found that women with the highest blood-fluid (serum) levels of vitamin B12 had significantly more hip bone mineral density (BMD) than women with the lowest levels.

In one of the first bone studies on children, reported in The Journal of Clinical Endocrinology & Metabolism, 120 Caucasian girls aged 8 to 14 volunteered to keep diet diaries. Girls whose daily diets had less than 220 mg of magnesium took 300 mg of elemental magnesium oxide per day, separately in two 150 mg capsules, or a placebo, for 12 months. Researchers measured bone mineral content (BMC) of the hip, thigh (femoral neck), and lower (lumbar) spine at the start and end of the study and found that compared to placebo, girls who took magnesium before, during, and in the late stages of puberty had significantly increased hip BMC without side effects.

Researchers from the University of Basel, Switzerland theorized that modern diets have fewer fruits and vegetables, and more dairy, grains, and meats, which may cause chronic, mildly elevated blood acidity and lower BMD. In this new 12-month study, post-menopausal women, average age 59, who took 1,173 mg of potassium citrate—a non-acidic (alkaline) form—per day had a one-percent increase in BMD of the lumbar spine, a result similar to pharmaceutical treatments, and lower blood acidity.

Reference: Journal of the American Society of Nephrology; 2006, Vol. 7, No. 11, 3213-22.