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Alzheimer's Patients Low in B Vitamins
A Swedish study of 78 Alzheimer's patients found more than half had low levels of vitamin B12 and vitamin B9 (also known as folic acid). Researcher Hui-Xin Wang says they are not yet certain if poor nutrition causes the disease, although one theory speculates that insufficient vitamin intake increases levels of the amino acid homocysteine, which can destroy cells. High levels of homocysteine are associated with life-threatening clogged arteries—arteries above as well as below the neck.
It isn't clear whether folic acid in vitamin supplements can be absorbed efficiently, so researchers agree that higher intakes of whole grains, leafy green vegetables, beans, and peas are vitally important.
Wang HX, Wahlin A, Basun H, Fastbom J, Winblad B, Fratiglioni L. Vitamin B12 and folate in relation to the development of Alzheimer's disease. Neurology. 2001;56:1188-1194.
Viagra May Cause Blindness
We know that Viagra can cause temporary vision problems such as blue-green distortions, but now Howard Pomeranz, director of neuro-ophthalmology at the University of Maryland Medical Center, reports that he has found five men diagnosed with permanent vision loss after taking the drug.
The condition, called ischemic optic neuropathy, is caused when blood flow is cut off to the optic nerve. It usually occurs in people with diabetes, hypertension, and other vascular disorders—conditions that are not uncommon in the United States.
Presented at the American Academy of Ophthalmology Conference
HRT May Not Prevent Bone Breaks in Older Women
The main reason doctors prescribe hormone replacement therapy (HRT) for women over 60 is to reduce the risk of fractures. A major new study shows it may not work. Researchers in the United Kingdom analyzed 22 previous studies and published the results in the Journal of the American Medical Association. For women beginning HRT at age 60 or older, there was no significant reduction in overall fracture rates. For women starting HRT at younger ages, there was some reduction—about 30 percent—in fracture rates among those taking HRT.
Studies have also shown that HRT does not reduce the risk of heart problems either, as had been previously thought, and almost certainly increases the risk of breast cancer.
Torgerson DJ, Bell-Syer SEM. Hormone replacement therapy and prevention of nonvertebral fractures. JAMA. 2001;285:2891-2897.
Hulley S, Grady D, Bush T, et al. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. JAMA. 1998;280:605-613.
ALTERNATIVES TO ANIMAL EXPERIMENTATION
Human Fat Facilitates Stem Cell Research
Could the cure for a host of human illnesses come from human fat? Scientists from UCLA and the University of Pittsburgh say yes.
A half-pound of human fat contains as many as 100 million stem cells, the highly adaptable cells that act as a reserve for replacing a variety of cell types when the cells die. The researchers purified fat discarded after liposuction procedures, broke apart the cells with an enzyme treatment, and successfully grew bone, cartilage, and muscle tissue.
The research offers promise of cures for Alzheimer's disease, diabetes, Parkinson's disease, and a vast array of other conditions, without the controversial use of animals or aborted fetuses.
Zuk PA, Zhu M, Mizuno H, et al. Multilineage cells from human adipose tissue: implications for cell-based therapies. Tissue Eng. 2001;7:211-228.
Texas Tech University Offers Alternatives to Animal Dissection
After 18 months of negotiations, attorney Don Feare, working on behalf of student Megan Wampler, has persuaded Texas Tech University administrators to provide alternatives to animal dissection in its biological sciences curriculum.
Now students who attend the school can learn animal biology, human anatomy and physiology, genetics, and other sciences without harming animals.
Juice Is Sweet, but Breast Milk Is Best
Infants and toddlers love the taste of fruit juice, but too much can displace protein- and vitamin-rich breast milk and soy formulas, or even cause painful diarrhea or bloating, reports the American Academy of Pediatrics. The organization is calling for limits on how much juice children should drink.
The academy advises parents not to give fruit juice to infants younger than six months, not to offer it at bedtime, and to give one- to six-year-olds no more than 4 to 6 ounces per day. It also advises parents to encourage their children to eat whole fruits, which have fiber most juices lack.
Pediatrics. May 2001
Against the Grain?
A recent Gallup poll of 1,000 grocery shoppers revealed that most understand which foods are healthful, yet they often fail to eat them.
For example, 83 percent of respondents were aware that grain foods provide energy and more than 70 percent agreed that whole grains help prevent heart disease and cancer and encourage a healthy weight. However, barely half of Americans are getting enough of the fiber and complex carbohydrates they need for optimal health.
Cow's Milk Linked to Multiple Sclerosis
Dr. Michael Dosch and his colleagues at the Hospital for Sick Children in Toronto have discovered remarkable similarities in juvenile diabetes and multiple sclerosis patients in the way their immune systems respond to cow's milk, essentially by attacking the patients' own tissues. In both diseases, scientists believe there are silent years in which the immune system is doing damage before symptoms appear, and, in the test tube, it is difficult to differentiate the diseases.
Children who are genetically predisposed to diabetes are at greater risk of developing the disease if given cow's milk during infancy. An international trial will soon be underway to determine whether early intervention can help prevent both diseases.