Posts Tagged ‘nutrition’

New estrogen-based compound suppresses binge-like eating behavior in female mice

“Previous data has shown that women who have irregular menstrual cycles tend to be more likely to binge eat, suggesting that hormones in women play a significant role in the development or prevention of the behavior,” said Dr. Yong Xu, assistant professor of pediatrics and senior author of the paper. “Previous data has also shown that in humans, there is a strong association between estrogen and binge eating. When estrogen is high, binge eating is inhibited, but when estrogen is low, binge eating becomes more frequent. Using mouse models, we set out to see what the effects of estrogen were on binge behavior in female mice.”

In this study, Xu and colleagues first found that estrogen can strongly inhibit binge eating in mice, which was consistent with data in humans.

“We can speculate that in women who develop binge eating who also happen to have irregular menstrual cycles, it is probably because their estrogen function is somehow damaged, which is what leads to the development of binge eating,” said Xu.

Xu and colleagues went further to determine what receptor was mediating the estrogen effect on binge eating and where this receptor was located. Using genetic mouse models, they found that the estrogen receptor-α, expressed by serotonin neurons in the brain, mediates the effect of estrogen to suppress binge eating.

“The significance is not only understanding the mechanism of how estrogen may modulate this behavior, but from a more therapeutic point of view, this would identify a potential target for estrogen therapy or modified estrogen therapy for treatment of this problem,” said Xu.

However, Xu notes that the current estrogen therapy in practice has been a problem because it produces detrimental effects, such as high risk of breast cancer.

“We thought, if we can understand where and how the estrogen acts to produce some benefits, maybe that will facilitate the development of an estrogen-based therapy that could be more specific and would just produce the benefits and bypass the side effects, such as breast cancer,” he said.

Around this same time, Xu’s collaborators at Indiana University developed a compound called GLP-1-estrogen, which was a conjugate between the peptide GLP-1 and estrogen. The idea was that GLP-1 would be used to carry the estrogen and deliver it to a region where there are GLP-1 receptors as well as estrogen receptors and the estrogen would be released there, producing a biological function. His collaborators at Indiana University published that this compound was good for body weight control and would not increase the risk of breast cancer because the compound did not deliver estrogen to the breast tissue.

Xu and colleagues used this compound to show that when a systemic injection of this compound is given in mice, there is increased activity of estrogen in the serotonin region of the brain, meaning the compound can deliver estrogen in the serotonin region where they believed binge behavior is regulated.

They further showed that the compound actually substantially inhibits binge eating in mice, and their data showed that part of this effect comes from the estrogen and the other part of the effect comes from the GLP-1.

“There are a few studies showing that binge patients tend to have decreased GLP-1 in their blood, but nobody had shown that GLP-1 suppresses binge eating in animals or humans until now,” said Xu. “We showed that these two things, estrogen and GLP-1, work together to decrease binge eating and that GLP-1 can carry estrogen to this specific site to produce a benefit, but bypasses the breast tissue.”

Xu notes that this provides a strong case for an interventional drug that specifically acts on estrogen receptor-α in the serotonin region of the brain to treat binge eating.

The next steps in Xu’s research will be to determine the mechanism by which estrogen regulates serotonin neurons. He and colleagues also hope to go downstream of serotonin to see if increasing serotonin release inhibits binge eating.

source : http://www.sciencedaily.com/releases/2014/08/140826205515.htm

Fighting prostate cancer with tomato-rich diet

With 35,000 new cases every year in the UK, and around 10,000 deaths, prostate cancer is the second most common cancer in men worldwide.

Rates are higher in developed countries, which some experts believe is linked to a Westernised diet and lifestyle.

To assess if following dietary and lifestyle recommendations reduces risk of prostate cancer, researchers at the Universities of Bristol, Cambridge and Oxford looked at the diets and lifestyle of 1,806 men aged between 50 and 69 with prostate cancer and compared with 12,005 cancer-free men.

The NIHR-funded study, published in the medical journal Cancer Epidemiology, Biomarkers and Prevention, is the first study of its kind to develop a prostate cancer ‘dietary index’ which consists of dietary components — selenium, calcium and foods rich in lycopene — that have been linked to prostate cancer.

Men who had optimal intake of these three dietary components had a lower risk of prostate cancer.

Tomatoes and its products — such as tomato juice and baked beans — were shown to be most beneficial, with an 18 per cent reduction in risk found in men eating over 10 portions a week.

This is thought to be due to lycopene, an antioxidant which fights off toxins that can cause DNA and cell damage. Vanessa Er, from the School of Social and Community Medicine at the University of Bristol and Bristol Nutrition BRU, led the research.

She said: “Our findings suggest that tomatoes may be important in prostate cancer prevention. However, further studies need to be conducted to confirm our findings, especially through human trials. Men should still eat a wide variety of fruits and vegetables, maintain a healthy weight and stay active.”

The researchers also looked at the recommendations on physical activity, diet and body weight for cancer prevention published by the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR).

Only the recommendation on plant foods — high intake of fruits, vegetables and dietary fibre — was found to be associated with a reduced risk of prostate cancer. As these recommendations are not targeted at prostate cancer prevention, researchers concluded that adhering to these recommendations is not sufficient and that additional dietary recommendations should be developed.

source : http://www.sciencedaily.com/releases/2014/08/140827100218.htm

Beating childhood cancer does not necessarily make survivors healthier adults, study shows

Childhood cancer survivors face different health-care challenges and are more susceptible to dying earlier than the general population. They have a higher risk of second cancers, heart disease, body weight disorders and psychosocial problems. Therefore the American Cancer Society Guidelines on Nutrition and Physical Activity encourages the efforts of cancer survivors to lead healthier lifestyles.

Because so little is known about how well cancer survivors adhere to these guidelines, Chloe Berdan and colleagues examined selected data from the Chicago Healthy Living Study participants. The University of Illinois investigative team led by Drs. Stolley and Sharp conducted structured health-focused interviews with 431 childhood cancer survivors and 361 people who never had the disease. The survivors, aged between 18 and 59 years old, were all diagnosed with a malignant cancer before their 21st birthdays.

No marked difference was found between how survivors and members of the control group adhered to the overall American Cancer Society guidelines. Survivors had on average a body mass index of about 1.2 kg/m² lower than that of members of the control group and smoked less. They consumed less fiber. In fact, only about one in every ten survivors (10.2 percent) met fiber recommendations, while only 17.7 percent ate five fruits or vegetables per day. Survivors were better at meeting the goal of at least five hours of moderate activity per week (60.5 percent) than to sticking to any of the other guidelines, and on average scored under 50 percent for the quality of their diets. The 0.7 percent of survivors who actually adhered fully to the guidelines tended to be women, non-smokers and people with a good view of their own health.

“There is still much room for improvement in educating and encouraging survivors to follow healthier diets and lifestyles,” says Berdan. “Adopting such behavior during early adulthood may have a lasting impact on their quality of life and overall survival.”

source : http://www.sciencedaily.com/releases/2014/08/140812163808.htm