Nutraceutical: Calcium

Indication: Bone mineral accretion (adolescent girls)

Source: Am J Clin Nutr, February 2008;87(2):455-462.

Research: A recent meta-analysis raised doubt as to whether calcium supplementation in children benefits spine and hip bone mineral density (BMD). In this study, researchers used measures of bone (fan-beam dual-energy X-ray absorptiometry and 4 bone turnover markers) to determine whether girls with low habitual calcium intake benefited from supplementation with a soluble form of calcium (calcium citrate malate dissolved in a fruit drink). The trial was an 18-month randomized trial of calcium supplementation (792 mg/d) with two years of follow-up after supplement withdrawal. Ninety-six girls (mean age: 12 years) with low calcium intakes (mean: 636 mg/d) participated in the study. The main outcome measure was change in total-body, lumbar spine and total hip bone mineral content (BMC) during supplementation and 2 years after supplement withdrawal. Changes in BMD and bone turnover markers were secondary outcome measures.

Results: The mean additional calcium intake in the supplemented group was 555 mg per day. Compared with the control group, the supplemented group showed significantly greater gains in BMC (except at the total hip site) over the 18-month study. BMD change was significantly greater for all skeletal sites, and concentrations of bone resorption markers and parathyroid hormone were significantly lower in the supplemented group than in the control group after 18 months. After 42 months, gains in BMC and BMD and differences in bone resorption were no longer evident. Researchers concluded that calcium supplementation enhances bone mineral accrual in teenage girls, but the effect is short-lived. The likely mechanism for the effect of the calcium is suppression of bone turnover, which is reversed upon supplement withdrawal.

Nutraceutical: Collagen hydrolysate

Indication: Joint discomfort

Source: Osteoarthritis Research Society International (OARSI) Congress

Research: In a study, carried out at the Faculty for Nutrition and Sports Nutrition in conjunction with the Faculty for Orthopedic Surgery and Rehabilitation at Penn State University, 147 students were treated. All the participants of the study suffered from joint symptoms caused by sporting activity, e.g. stress conditions, injury, post-surgical trauma, limited mobility and inflammation. The study was prospective, randomized, placebo-controlled and double-blind. The effects brought about by the administration of a daily dose of 10 grams of collagen hydrolysate over a period of 24 weeks on several joints were observed. The hip, knee, shoulder, ankle, wrist and elbow joints as well as neck and back of the participants, otherwise healthy and active in sports, were investigated. At the beginning of the study and subsequently every six weeks, changes in various pain parameters were objectively observed by a physician and subjectively by the participants with the help of a visual analog pain scale. These were then defined as primary parameters.

Results: The administration of collagen hydrolysate reduced joint symptoms brought about by mechanical stress. Significant improvement was demonstrated in the case of the knee, the joint most frequently affected by pain. The collagen hydrolysate group produced significantly better results. In addition, it was observed that, subsequent to completion of the study, a specific sub-group showed greater differences on average on the analog pain scale. This indicated a pronounced reduction in pain brought about by collagen hydrolysate compared with the other joints investigated.

Nutraceutical: Coccina cordifolia extract

Indication: Diabetes

Source: Diabetes Care, February 2008;31(2):216-20.

Research: Coccinia indica (synonym Coccinia cordifolia), an herb growing abundantly in India, has been used in the traditional treatment of diabetes. However, carefully controlled studies of its efficacy are lacking. This study aimed to evaluate the effectiveness of Coccinia cordifolia on blood glucose levels of incident type 2 diabetic patients requiring only dietary or lifestyle modifications. The study was a double-blind, placebo-controlled, randomized trial that included 60 incident type 2 diabetic subjects (aged 35-60 years) who were recruited from St. Johns Medical College Hospital, Bangalore, India. The subjects were randomly assigned into the placebo or experimental group and were provided with 1 gram alcoholic extract of the herb for 90 days. Anthropometric, biochemical, dietary, and physical activity assessment were carried out at baseline and were repeated at days 45 and 90 of the study. All subjects were provided with standard dietary and physical activity advice for blood sugar control.

Results: According to investigators, there was a significant decrease in the fasting, postprandial blood glucose and A1C of the experimental group compared with that of the placebo group. The fasting and postprandial blood glucose levels of the experimental group at day 90 significantly decreased, by 16% and 18%, respectively. There were no significant changes observed in the serum lipid levels. The researchers believe this study suggests that Coccinia cordifolia extract has a potential hypoglycemic action in patients with mild diabetes. However, further studies are needed to elucidate mechanisms of action.

Nutraceutical: Cranberry

Indication: Urinary tract infections (UTIs)

Source: Cochrane Library, Online January 22, 2008

Research: Analyzing 10 previous studies, researchers as­sessed whether or not cranberries can help prevent or treat urinary tract infections (UTIs). Researchers conducted a meta-analysis on all randomized controlled trials (RCTs) or quasi-RCTs of cranberry products for the prevention of UTIs in all populations. Information was collected on methods, participants, interventions and outcomes. The 10 studies—five cross-over, five parallel group—included 1049 subjects. Cranberry/cranberry-lingonberry juice versus placebo, juice or water was evaluated in seven studies, and cranberry tablets versus placebo in 4 studies (one study evaluated both juice and tablets).

Results: The authors believe there is some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12-month period, particularly for women with recurrent UTIs. However, its effectiveness for other groups is less certain. The large number of dropouts/withdrawals indicates that cranberry juice may not be acceptable over long periods of time. It is not clear what is the optimum dosage or method of administration (e.g. juice, tablets or capsules), which is why they suggest the need for properly designed studies with relevant outcomes.

Nutraceutical(s): Carotenoids and vitamins

Indication: Cataracts

Source: Arch Ophthalmol, January 2008;126(1):102-9.

Research: Researchers set out to examine the relationship between dietary intake of carotenoids and vitamins C and E and the risk of cataracts in women. Dietary intake was assessed at baseline in 39,876 female health professionals using a detailed food frequency questionnaire. A total of 35,551 women provided detailed information on antioxidant nutrient intake from food and supplements and were free of a diagnosis of cataract. The main outcome measure was cataracts, defined as an incident, age-related lens opacity responsible for a reduction in best-corrected visual acuity in the worse eye to 20/30 or worse based on self-report confirmed by medical record review.

Results: A total of 2031 cases of incident cataract were confirmed during a mean of 10 years of follow-up. Through these prospective observational data gathered from a large cohort of female health professionals, researchers concluded that higher dietary intakes of lutein/zeaxanthin and vitamin E from food and supplements were associated with significantly decreased risks of cataract.

Nutraceutical: Vitamin E

Indication: Physical decline (elderly)

Source: JAMA, January 2008;23;299(3):308-15.

Research: Maintaining independence of older persons is a public health priority, and identifying the factors that contribute to decline in physical function is needed to prevent or postpone the disablement process. The potential deleterious effect of poor nutrition on decline in physical function in older persons is unclear, so researchers set out to determine whether a low serum concentration of micronutrients is associated with subsequent decline in physical function among older men and women living in the community. This longitudinal study evaluated 698 community-living persons 65 years or older who were randomly selected from a population registry in Tuscany, Italy. Researchers measured their levels of several micronutrients, including serum folate and vitamins E, D, B6 and B12. Researchers then measured decline in physical function, as defined by a loss of at least one point in the Short Physical Performance Battery.

Results: The results provided empirical evidence showing that a low serum concentration of vitamin E is associated with subsequent decline in physical function, as brought on by oxidative stress, a situation that induces muscle fatigue. Clinical trials may be warranted to determine whether an optimal concentration of vitamin E reduces functional decline and the onset of disability in older persons.