High insulin levels enhance breast cancer risk

Elevated insulin levels in the blood seem to raise the risk of breast cancer in post-menopausal women, according to a new study.

Increased breast cancer risk for post-menopausal women has previously been linked to obesity and diabetes. Both conditions involve insulin resistance, which causes increases in circulating levels of insulin.

Since insulin is known to promote cell division and enhance breast tumour growth in animal models, Einstein College of Medicine scientists reasoned that relatively high insulin levels may contribute to breast cancer risk in women.

"Up to now, only a few studies have directly investigated whether insulin levels are associated with breast cancer risk, and those studies have yielded conflicting results," says Geoffrey Geoffrey Kabat, senior epidemiologist at Einstein and the study's co-author.

"Those other studies were based on just a single baseline measurement of insulin, while our study involved analysing repeated measurements of insulin taken over several years - which provides a more accurate picture of the possible association between insulin levels and breast cancer risk."

Kabat and colleagues analysed data on 5,450 women enrolled in the Women’s Health Initiative, a large multi-centre study investigating the influence of a number of factors on women's health.

Most of the women had participated in the clinical trial part of the study and provided fasting blood samples at its start (baseline) and then at years one, three and six.

The remaining women, who were enrolled in a separate "observational" component of the study, provided fasting blood samples at baseline and at year three of the study. Among all these women, 190 cases of breast cancer were identified over eight years of follow-up.

The analysis revealed a strong association between elevated insulin levels and increased risk for breast cancer, said an Einstein release. These findings were published in online in the International Journal of Cancer. –The Times of India

A diet that predisposes baby to obesity

High-fat diet during pregnancy produces permanent changes in the offspring's brain that lead to increased appetite and obesity early in life, a study in rats has shown.

The surprising new research by Rockefeller University scientists has been reported in the Nov. 12 issue of the Journal of Neuroscience. The research provides a key step toward understanding mechanisms of fetal programming involving the production of new brain cells that may help explain the increased prevalence of childhood obesity during the last 30 years. "We've shown that short-term exposure to a high-fat diet in utero produces permanent neurons in the fetal brain that later increase the appetite for fat," says senior author Sarah F. Leibowitz, who directs the Laboratory of Behavioral Neurobiology at Rockefeller. "This work provides the first evidence for a fetal program that links high levels of fats circulating in the mother''s blood during pregnancy to the overeating and increased weight gain of offspring after weaning,” the expert added.

Research in adult animals by Leibowitz and others has shown that circulating triglycerides stimulate brain chemicals known as orexigenic peptides, which in turn spur the animals to eat more. Scientists also have shown that obese and diabetic mothers produce heavier children and that exposure to fat-rich foods early in life leads to obesity in adulthood.

These studies suggested that food intake and body weight may be programmed during fetal development. But little was known about the mechanism underlying this programming.

ref: thetimesofindia

Obese kids risk thyroid damage

Good morning friends. Obese kids out there. Being fat is not good. You may be looking healthy but the truth is it has a it's not good and it creates damage.

Obesity may cause inflammation that damages the thyroid, which secretes hormones to regulate metabolism and other important functions, Giorgio Radetti of the Regional Hospital of Bolzano in Italy and colleagues said.

They evaluated 186 overweight and obese children for about three years, testing thyroid hormone levels and thyroid antibodies and imaging the thyroid gland using ultrasound.

“We found an association between body mass index and thyroid hormone levels which suggests that fat excess may have a role in thyroid tissue modification,” Radetti said.

ref: thetimesofindia

Exercise, calorie restricted diet 'lowers postmenopausal women's breast cancer risk'

Good morning friends. After reading news I want to share it to everyone specially to women out there. It's important.

Regular exercise and reduced-calorie diet can significantly cut breast cancer risk in postmenopausal women, suggests a new study.

The research team from University of Texas at Austin have identified pathways by which calorie restriction and exercise can modify a postmenopausal woman's risk of breast cancer. They found that both caloric restriction and exercise affect pathways leading to mTOR, a molecule involved in integrating energy balance with cell growth. Dysregulation of the mTOR pathway is a contributing factor to various human diseases, including cancers.

Diet and exercise reach mTOR through different means, with calorie restriction affecting more upstream pathways, which could explain why caloric restriction is more efficient in delaying tumour growth than exercise in animal models. "One of the few breast cancer modifiable risk factors is obesity," said lead author Leticia M. Nogueira, Ph.D., a research graduate assistant at the University of Texas.

"Our study may provide a good scientific basis for medical recommendations. If you're obese, and at high risk for breast cancer, diet and exercise could help prevent tumour growth," she added.
The research suggests that inducing a so-called "negative energy balance" (where less energy is taken in than expended) through eating a low-calorie diet or increasing exercise levels, decreases the postmenopausal breast cancer risk associated with obesity. Increased levels of leptin and decreased levels of adiponectin have been associated with breast cancer risk.

For eight weeks, they administered a high-fat diet to 45 mice that had their ovaries surgically removed to model the post-menopausal state.

During week nine of the study, the diet-induced obese mice were randomly assigned to one of three groups: a control group, permitted to eat at will; a group fed a diet reduced in calories by 30 percent; and a group that was permitted to eat at will but exercised on a treadmill for 45 minutes a day, five days a week. At week 16, researchers collected tissue from the mice for analysis.
The study showed that blood levels of leptin, a hormone that plays a role in fat metabolism, were significantly reduced in the calorie-restricted mice while blood levels of adiponectin showed an increase.

She also found that the key proteins found downstream of mTOR activation were less active in both the calorie-restricted and exercised mice compared to the controls. "These data suggest that although exercise can act on similar pathways as caloric restriction, caloric restriction possesses a more global effect on cell signaling and, therefore, may produce a more potent anti-cancer effect," Nogueira said.

The study was presented at the American Association for Cancer Research's Seventh Annual International Conference on Frontiers in Cancer Prevention Research. (ANI)