Even short-term smoking can lead to cardiovascular disease by affecting the heart-protecting high density lipoprotein cholesterol (HDL-C), according to a study in the Journal of the American Medical Assn. HDL-C is thought to play an important role in preventing cardiovascular disease.
For the study, researchers measured blood levels of high density lipoprotein cholesterol in children 12 to 14 in Berlin and Bremen, Germany, before they began to smoke. This data then was compared to HDL-C levels in the children after they became light (one to 39 cigarettes per week) or moderate (more than 40 per week) smokers and with the levels of children who didn't smoke.
The researchers found that HDL-C levels decreased in children who smoked, compared to those who didn't.
"Exposure to even low concentrations of cigarette smoke for relatively short periods of time may contribute to vascular damage that is difficult to reverse," the authors conclude.
The study was done by researchers at the Institute for Health Promotion and Disease Prevention Research, USC School of Medicine, and colleagues in Germany and Switzerland.
Fish Oil--The current fondness for fish oil, the result of links between it and reduced cardiac death, may not be particularly healthy for some people. Non-insulin dependent diabetics should not take fish oils to lower cholesterol, according to a report in the Annals of Internal Medicine, because fish oils increase sugar levels and impair insulin secretion in these individuals.
Researchers at UC San Diego and the Veterans Administration Medical Center in La Jolla conducted a one-month study of dietary supplementation with an extract rich in omega-3 fatty acids on patients with non-insulin dependent diabetes. They did so because there has been interest in using these fatty acids for problems seen in diabetes. Also, studies have shown a low prevalence of non-insulin dependent diabetes in populations consuming large quantities of marine fats.
Researchers found a "consistent and marked deterioration of glucose tolerance" in patients taking the omega-3 fatty acid supplements for one month. But this was reversed when the fish oil supplements were stopped.
"We examined only a few patients in an unblinded study," the researchers said. "However, because of the consistent and marked deterioration of glucose tolerance observed, it was unreasonable to continue these studies in more patients."
There is no evidence that the usual dietary intake of fish has any adverse metabolic effects, the study said.