The body-conscious may stop worrying to death over putting on tires. People with fat in their thighs and backsides may live longer, one more study shows.
The fat stored in those parts traps harmful fatty particles and actively secretes helpful compounds, according to a report published on Tuesday.
Fat on the bottom and thighs appears to store excess fatty acids, said Konstantinos Manolopoulos of Britain's University of Oxford. He reviewed published scientific studies for his report.
Pear-shaped people also appear to have lower levels of compounds called inflammatory cytokines -- signaling chemicals involved in the body's response to infection that also can play a role in heart disease and diabetes when they are inappropriately active.
Fat on the legs may also absorb fats from the diet, keeping them from overwhelming the body when people overeat, Manolopoulos said.
Cholesterol levels reflect a tricky balance between high density lipoprotein, the HDL or "good" cholesterol that removes harmful fats from the blood, and low-density lipoprotein, the "bad" LDL cholesterol that can harden and block the arteries.
Fat in the thighs may also be more stable, he said, with studies showing abdominal fat breaks down quickly during fasting or stress, releasing potentially harmful components from the fat.
"The exact regulatory mechanisms of fatty acid release and storage and their effect on short- and long-term fatty acid metabolism remain to be analyzed," Manolopoulos wrote.
Leg fat may also be better at producing hormones such as leptin, which are made by fat and affect appetite and metabolism -- although Manolopoulos said this is poorly understood.
Understanding all this could lead to better drugs for treating obesity and related disease such as diabetes and heart disease, Manolopoulos said.
A study published in the British Medical Journal in September last too had said
thigh size was an accurate marker of longevity and narrower thighs increase the risk of premature death.
Individuals whose thighs are less than 60 centimeters in circumference are at a greater risk of premature death. The risk is reported to be doubled in those with the thighs less than 55 centimeters.
"Additionally we found that the risk was more highly related to thigh circumference than to waist circumference," said lead researcher Professor Berit Heitmann, adding that the results are similar for both sexes.
Those with narrower thighs lack the muscle mass necessary to ensure proper glucose and lipid metabolism, a condition leading to type 2 diabetes and, in the long-run, heart disease.
Scientists believe thigh size could soon be used as a marker for identifying patients at-risk of early death or other serious health problems.