Beauty Health for Life

Calcium or combination supplement reduces osteoporosis risk

While calcium supplements noticeably improved bone health in postmenopausal women, vitamin D supplements did not reduce bone turnover, according to a recent study accepted for publication in The Endocrine Societys Journal of Clinical Endocrinology & Metabolism (JCEM).

Bone turnover is the bodys natural process for breaking down old bone. In young people, the body forms enough new bone to replace what is lost. After age 30, however, bone mass in women begins to decline and the process speeds up after menopause. Osteoporosis develops when the body cannot replace bone as fast as it is broken down.

"Vitamin D and calcium interact to suppress bone turnover by decreasing parathyroid hormone levels," said the studys lead author, John Aloia, MD, of Winthrop University Hospital in Mineola, NY. "This can be beneficial in women who are vitamin D deficient. In women who already are receiving the recommended daily allowance of vitamin D, however, the study found there was no advantage to adding a vitamin D supplement."

The double-blind, placebo-controlled, parallel group, longitudinal factorial design study divided 159 postmenopausal women into four groups. One group received a combination of vitamin D and calcium, one was given 1,200 milligrams of calcium daily, one took 4,000 IU of vitamin D daily and the last group received placebos. To measure the effect supplements had on bone health, researchers measured bone turnover markers, such as parathyroid hormone levels in the blood, over the course of six months. In all, 120 women completed the study.

Researchers found a significant decline in bone turnover markers among women who were given daily calcium supplements. The vitamin D supplements did not have any effect on bone turnover markers, although the supplements did decrease parathyroid hormone levels.

"These findings suggest that vitamin D supplements over the recommended dietary allowance (RDA) do not protect bone health, whereas calcium supplements do have an effect," Aloia said. "Women do need to be cautious about the possibility of vascular side effects from too much calcium and should consult their physicians about whether their diet is adequate or whether they should take supplements at all."

University of Illinois scientists have evidence that lifelong exposure to genistein, a bioactive component in soy foods, protects against colon cancer by repressing a signal that leads to accelerated growth of cells, polyps, and eventually malignant tumors.

"In our study, we report a change in the expression of three genes that control an important signaling pathway," said Hong Chen, a U of I professor of food science and human nutrition.

The cells in the lining of the human gut turn over and are completely replaced weekly, she noted. "However, in 90 percent of colon cancer patients, an important growth-promoting signal is always on, leading to uncontrolled growth and malignancies. Our study suggests that the aberrant Wnt signaling during the development of colon cancer can be regulated by soy-rich diets."

"The good news is that a diet rich in soy genistein represses those signals through epigenetic modifications at the regulatory regions of those genes," said Yukun Zhang, a doctoral student in Chens laboratory.

Fish oil supplements may protect the heart in stressful situations, according to a recent study. Jason Carter, a researcher at Michigan Technological University, conducted the study with 67 healthy volunteer test participants in their 20s. Over a 2-month period, they were either given nine grams of fish oil pills or nine grams of olive oil as a placebo.

The test subjects were screened for heart rate, blood pressure and other related metrics. At the end of the test period, both groups took a mental arithmetic test that involved adding and subtracting numbers in their head. Their stress response was measured at that time.

“Those in the fish oil group showed blunted heart rate reactivity while they were stressed compared to those who took olive oil," said Carter. "Similarly, the total [muscle sympathetic nerve activity] reactivity to mental stress was also blunted in the fish oil group.” There was not much difference between the two groups at rest, however.
Results of the study were published in the May edition of the American Journal of Physiology – Regulatory, Integrative, and Comparative Physiology, published by the American Physiological Society. It is available online at http://bit.ly/10j0CSS