Lab Report

PUBLISHED : Monday, 19 May, 2014, 9:21am
UPDATED : Monday, 19 May, 2014, 9:21am

Too much intensive exercise puts heart at risk

Overdosing on high-intensity exercise may increase the risk of death from a heart attack or stroke in those with existing heart disease, according to a German study published online.

The frequency and intensity of physical activity of more than 1,000 people with stable coronary artery heart disease were tracked for 10 years. Most were in their 60s and all had attended a cardiac rehabilitation programme.

The least physically active were about twice as likely to have a heart attack/stroke as those who were regularly active and about four times as likely to die of cardiovascular and other causes. But those who did the most strenuous daily exercise were more than twice as likely to die of a heart attack/stroke.

Other studies have agreed with this, linking endurance training to an acute (reversible) pro-inflammatory state.

Two large meals beats six snacks

Research in Diabetologia suggests that two large meals (breakfast and lunch), rather than six small meals with the same calories, are better for controlling weight and blood sugar for type-2 diabetics.

The study assessed 54 patients (29 men, 25 women) aged from 30 to 70. They were asked to follow one of two regimens of a restricted calorie diet, each containing 500 calories less than the recommended daily amount. Half ate six small meals and the others two large meals - breakfast and lunch. After 12 weeks they swapped. The diets had the same macronutrient and calorie content. Liver fat content, insulin sensitivity and pancreatic beta cell (which release insulin) function were measured. The authors say: "Eating only breakfast and lunch reduced body weight, liver fat content, fasting plasma glucose, C-peptide and glucagon, and increased insulin sensitivity more than the same caloric restriction split into six meals."

Olive oil supplements for air pollution woes

Olive oil supplements may counteract some adverse vascular effects of air pollution, according to a recent study.

"Exposure to airborne particulate matter can cause the inner lining of blood vessels not to function normally," says lead author Dr Haiyan Tong. "Olive oil and fish oil are known to have beneficial effects on this endothelial function."

In the study, 42 adults took olive oil, fish oil or no supplements for four weeks, before two-hour exposures to filtered air. The next day they were exposed to particulate matter.

Significant reductions in flow-mediated dilation were observed in the control and fish oil groups, against a more minor decrease in the olive oil group. A protein involved in the breakdown of blood clots increased immediately after exposure in the olive oil group lasting for up to 20 hours.