Zinc
Zinc helps children thinkApril 10, 2005 Eleven-year-olds that took zinc supplements for five days each week had better mental performance after three months than their classmates, said researchers yesterday.
The children taking an extra 20mg of zinc responded more quickly and accurately on memory tasks and with more sustained attention than classmates who did not take the mineral.
Beneficial effects were seen regardless of the youngsters’ previous zinc status, said the researchers led by Dr James Penland from the US Agricultural Research Service’s Grand Forks Human Nutrition Research Center in North Dakota.
The findings, presented at the Experimental Biology meeting this week, suggest that there could be new demand for fortified foods and supplements for this age group.
Although zinc nutrition has been related to motor, cognitive and psychosocial function in very young children and adults, this is the first study of its effect in adolescents.
Zinc deficiency is not uncommon, even in nations such as the United States, and the risk is particularly high in adolescents, said Dr Penland, because they are undergoing rapid growth and often have poor eating habits. They may not consume enough zinc-rich foods like red meat, fish and grains.
Moreover the current recommended daily allowance is only 15mg for adults in the US, and up to 9.5 mg a day for men and 4-7 mg a day for women in the UK.
In the study, 111 girls and 98 boys consumed four ounces of fruit juice containing either 0, 10 or 20 mg of zinc gluconate each school day for 10 to 12 weeks. Students, their parents and teachers did not know who was receiving which, if any, zinc supplementation.
At the beginning and end of the study, students performed a battery of tasks designed to measure mental and motor skills, like attention, memory, problem-solving and hand-eye coordination.
Students, their parents, and teachers filled out questionnaires about the students’ mental, physical and social abilities and skills, school performance, and problems in any of these areas to provide a measure of psychosocial function.
Blood samples measured zinc status before and after the treatment.
Compared to the students who received no additional zinc, students who consumed an additional 20 mg zinc each day decreased reaction time on a visual memory task by 12 per cent versus 6 per cent; increased correct answers on a word recognition task by 9 per cent versus 3 per cent; and increased scores on a task requiring sustained attention and vigilance by 6 per cent versus 1 per cent.
Those who received only 10 mg a day, the US Recommended Dietary Allowances (RDA) for this age group, did not significantly improve performance, however.
Supplementation at either the 10 mg or 20 mg did not appear to improve motor and social skills, although girls receiving the placebo experienced a 10 per cent increase in conduct problems during the study while the behaviour of girls receiving any level of zinc supplementation remained unchanged, reported the researchers.
Previous studies have shown that zinc is needed for growth and immune function and may be important for eye-hand coordination and reasoning in very young children. It also appears to influence memory, muscle strength and endurance in adults.
Pine Bark Extract Boosts Heart Health
Pine Bark Extract Boost Diabetics’ Heart Health May 13, 2008
Supplements of extracts from French maritime pine bark reduce blood pressure and the use of blood pressure medication among diabetics, concludes results from a new study.
Blood pressure control was achieved in 58 per cent of study participants, and a halving of the use of medication, among 48 participants randomly assigned to daily supplements of pine bark extract or placebo for 12 weeks. The results of the new study, published in the May issue of the journal Nutrition Research, is of particular importance for diabetics who are reportedly two to four times more likely to suffer from heart disease than non-diabetics “”These data confirm the hypothesis that pine bark extract improves diabetes control, reduces antihypertensive medicine use, and may favour a reduction in cardiovascular disease risk in individuals with type 2 diabetes,”" wrote lead author Sherma Zibadi from the University of Arizona. Indeed, previous studies have reported potential health benefits for the extract, including hypertension, asthma, chronic venous insufficiency, osteoarthritis, deep vein thrombosis, diabetes management, and diabetic leg ulcers. The new study recruited diabetic subjects with an average age of 60 and randomly assigned them to receive daily supplements of pine bark extract (125 mg) or placebo for 12 weeks in a randomized, double-blind, placebo-controlled trial with parallel-group design. All subjects were receiving pharmaceutical anti-hypertension treatment (angiotensin- converting enzyme [ACE] inhibitors). At the end of the study, Zibadi and co-workers report that 58.3 per cent of subjects in the pine bark extract group experienced blood pressure control, defined as attaining a stable systolic blood pressure, compared to 20.8 per cent in the placebo group. Moreover, use of ACE inhibitors was reduced by 50 per cent in the group receiving the pine bark extract Improvements in measures of diabetes control were also recorded, with a 23.7 mg/dL reduction in fasting blood glucose levels in the pine bark extract group, compared to only 5.7 mg/dL in the placebo group. Improvements in LDL-cholesterol, a marker of cardiovascular health, were recorded in the pine bark extract-supplemented group. After eight and 12 weeks of supplementation, decreases of 11.6 and 12.7 mg/dL were observed, respectively, compared with placebo. Mechanism of Action In attempting to understand the benefits of the pine bark extract on cardiovascular health of the diabetics, the researchers noted that the blood pressure lowering effects may be due to a suppression of serum endothelin-1, a protein that restricts blood vessels and reported to be found in higher levels than normal in type 2 diabetics and hypertensives. On the other hand, the authors could not rule out the potential of an inhibitory effect on ACE, which could improve blood flow and subsequently blood pressure. Finally, other studies have reported a potential benefit from pine bark extract on the production of the potent vasodilator, nitric oxide (NO). Limitations About 26.5 million people are affected by diabetes in the European Union, United States, and Canada equal to four per cent of the total population. This figure is projected to increase to 40 million by 2030. In the US, there are over 20 million people with diabetes, equal to seven per cent of the population. The total costs are thought to be as much as $132 billion, with $92 billion being direct costs from medication, according to 2002 American Diabetes Association figures.
Source: Nutrition Research (Elsevier) May 2008, Volume 28, Issue 5, Pages 315-320 “”Reduction of cardiovascular risk factors in subjects with type 2 diabetes by Pycnogenol supplementation”" Authors: S. Zibadi, P.J. Rohdewald, D. Park, R.R. Watson