To Your Health
September, 2011 (Vol. 05, Issue 09) |
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A Walk in the Park
Previously sedentary middle-aged men and women who walked 10,000 steps (about 5 miles) daily demonstrated marked improvement in insulin sensitivity.
Terry Dwyer, from the Murdoch Children's Research Institute (Australia), and colleagues investigated the relationship between daily step count and both adiposity (obesity) and insulin sensitivity. The team studied 592 non-diabetic adult men and women, average age 50-51 years at the study's start, for a five-year period. Many participants were already overweight (57.4 percent of men, 36.9 percent of women) or obese (17.7 percent of men, 16.0 percent of women) at the outset and then gained additional weight over the five-year study period.
During the study period, most subjects became more sedentary as well, with 65 percent showing a decline in step counts. The researchers found that sedentary individuals who changed their habits to walk an extra 2,000 steps (about 1 mile) a day might expect to shave 0.16 kg/m2 off their body mass index (BMI) and boost insulin sensitivity by 2.76 units. Further, a relatively inactive person who achieves 10,000 steps (about 5 miles) per day could expect their BMI to drop 0.83 kg/m2 and their insulin sensitivity to rise 13.85 units – a 12.8 percent increase from the average for men and 11.5 percent for women. The team calculated that sedentary individuals who reach 10,000 steps per day might improve their insulin sensitivity threefold compared with increasing daily activity to 3,000 steps five days a week.
Get Your Omega-3s
Consumption of omega-3 fatty acids may help to improve key markers of insulin resistance, thereby reducing the risk of diabetes. Giuseppe Derosa, from the University of Pavia (Italy), and colleagues studied 167 subjects, each of whom received either 1 gram of omega-3s (concentrated EPA and DHA), or 1 gram of placebo (a capsule containing sucrose, mannitol, and mineral salts) three times a day, during meals, for six months. The team found that the group which consumed the omega-3 capsules showed improvements in HDL cholesterol and plasma triglyceride markers compared to placebo. After challenging the subjects with an oral fat load, the researchers found that the group taking omega-3 capsules showed an improvement in all parameters, include insulin resistance biomarkers, while there was a neutral effect with placebo.
Amino Acids on the Way
L-carnitine is an amino acid (building block for protein) that helps the body to produce energy. The nutrient is also important for proper heart and brain function, muscle movement, and a number of other body processes. Stuart Galloway, from the University of Stirling (Scotland), and colleagues enrolled eight lean and eight overweight / obese men in a 14-day study. The men received 3 grams of L-carnitine or 3 grams of glucose per day with their meals. Subjects then underwent an oral glucose tolerance test, which involved feeding them 75 grams of glucose and then measuring the effects. The team found that blood sugar levels were significantly lower in the L-carnitine group of lean men as compared to the glucose-fed lean men 30 minutes after ingestion. Blood glucose levels were also higher in the group of overweight / obese subjects 90 minutes after ingesting L-carnitine compared to placebo.
Defend With Dairy
Circulating levels of trans-palmitoleic acid, the fatty acid contained in dairy products, may reduce the risk of type 2 diabetes. Trans-palmitoleic acid is a naturally occurring fatty acid in dairy fats, and on a biological basis it may mimic its counterpart, cis-palmitoleic acid, a fatty acid produced in the body that protects against diabetes. Dariush Mozaffarian and colleagues, from Harvard School of Public Health in Massachusetts, examined data from a study that followed 3, 3736 adults enrolled in a cardiovascular health study. The researchers found that those adults with the highest circulating levels of trans-palmitoleic acid had the lowest risk of type 2 diabetes. Specifically, those subjects with the highest levels of trans-palmitoleic acid were found to be at 60 percent lower risk of developing diabetes compared to the subjects at the bottom 20 percent.
