Women: Something to Consider Regarding BF%

I'd read that extended breast feeding could help prevent osteoporosis because, as with a broken bone, your body over compensates when replacing the lost calcium. I don't know if that's up-to-date information or not, but it certainly won't prevent me from breastfeeding as long as I feel appropriate.

I've also read one source that suggested that some of the effects of a low body fat percentage were actually effects of eating too little, but that was livestrong.com or something similar, so not necessarily reliable.

I do worry that the chart publicised by ACE is partly to blame, as women aim for 'essential' or 'athlete', rather than 'fitness', as they are all presented as positives.

http://www.builtlean.com/2010/08/03/ideal-body-fat-percentage-chart/

'Wrong'-Time Eating Reduces Fertility in Fruit Flies: Study Points to Fertility-Metabolism Connection

ScienceDaily (June 8, 2011) — Dieticians will tell you it isn't healthy to eat late at night: it's a recipe for weight gain. In fruit flies, at least, there's another consequence: reduced fertility.

That's the conclusion of a new study in Cell Metabolism by researchers at the Perelman School of Medicine at the University of Pennsylvania, in which they manipulated circadian rhythms in fruit flies and measured the affect on egg-laying capacity.
Lead author Amita Sehgal, PhD, John Herr Musser Professor of Neuroscience, stresses, though, that what is true in flies grown in a lab does not necessarily hold for humans, and any potential link between diet and reproduction would have to be independently tested.

"I wouldn't say eating at the wrong time of the day makes people less fertile, though that is the implication," says Sehgal, who is also a Howard Hughes Medical Institute Investigator. "I would say that eating at the wrong time of the day has deleterious consequences for physiology."

It's All Connected
Many aspects of animal biology cycle over the course of a day. Sleep and wakefulness, activity and rest, body temperature, and more, all fluctuate in a pattern called a circadian rhythm. Disruption of these rhythms has been shown to negatively affect physiology. Shift workers, for instance, often suffer from psychological and metabolic issues that colleagues on normal hours do not. Rodents with disrupted circadian rhythms are more likely to develop obesity.

For a while, Sehgal explains, researchers believed animals had a single master molecular clock, located in the brain, that controlled activity throughout the body. In recent years, however, they have come to understand that some individual organs also have their own, independent clocks, like townspeople who wear a wristwatch and keep it synchronized with the clock in city hall.

The mammalian liver is one organ that has its own independent clock. In 2008, Sehgal's team discovered that the fruit fly equivalent of the liver, called the fat body, has its own clock, which controls eating and food storage. They wanted to know what would happen if the fat body clock became desynchronized from the master clock in the brain.

Decoupling Clocks
First, her team asked which fly genes are controlled specifically by the fat body clock. Using gene chip microarrays, they identified 81 genes related to lipid and carbohydrate metabolism, the immune system, and reproduction that fit those criteria.
Next, the researchers attempted to decouple the fat body and central clocks by keeping the flies in constant darkness (to eliminate effects of light on these clocks) and feeding them at times when they don't normally eat. They found the two clocks could be desynchronized: disrupting the animals' feeding cycles altered the cycling of genes controlled by the fat-body clock, but not those regulated by the central clock itself itself.

Finally, the team addressed the functional consequences of this desynchronization, by counting the number of eggs the flies laid under different conditions. Flies fed at the "right" time of the day deposited about 8 eggs per day, compared to about 5 when they fed at the "wrong" time.

"Circadian desynchrony caused by feeding at the 'wrong' time of day leads to a defect in overall reproductive capacity," the authors wrote.

The next question to pursue, Sehgal says, is finding the molecular mechanism that controls this phenomenon: How does the fat body communicate with the ovaries. And, more importantly, is this effect restricted to fruit flies, or does it also occur in higher organisms, including humans.

The research was funded by the Howard Hughes Medical Institute and the National Institute of Neurological Disorders and Stroke and the National Heart, Lung, and Blood Institute.
Other authors include Penn postdoctoral fellows Kanyan Xu, Justin R. DiAngelo, and Michael E. Hughes, as well as John B. Hogenesch, associate professor of Pharmacology

Gum Disease Can Increase the Time It Takes to Become Pregnant

ScienceDaily (Aug. 1, 2011) — Professor Roger Hart told the annual meeting of the European Society of Human Reproduction and Embryology that the negative effect of gum disease on conception was of the same order of magnitude as the effect of obesity.

Periodontal (gum) disease is a chronic, infectious and inflammatory disease of the gums and supporting tissues. It is caused by the normal bacteria that exist in everyone's mouths, which, if unchecked, can create inflammation around the tooth; the gum starts to pull away from the tooth, creating spaces (periodontal pockets) that become infected. The inflammation sets off a cascade of tissue-destructive events that can pass into the circulation. As a result, periodontal disease has been associated with heart disease, type 2 diabetes, respiratory and kidney disease, and problems in pregnancy such as miscarriage and premature birth. Around 10% of the population is believed to have severe periodontal disease. Regular brushing and flossing of teeth is the best way of preventing it.

Prof Hart, who is Professor of Reproductive Medicine at the University of Western Australia (Perth, Australia) and Medical Director of Fertility Specialists of Western Australia, said: "Until now, there have been no published studies that investigate whether gum disease can affect a woman's chance of conceiving, so this is the first report to suggest that gum disease might be one of several factors that could be modified to improve the chances of a pregnancy."

The researchers followed a group 3737 pregnant women, who were taking part in a Western Australian study called the SMILE study, and they analysed information on pregnancy planning and pregnancy outcomes for 3416 of them.

They found that women with gum disease took an average of just over seven months to become pregnant -- two months longer than the average of five months that it took women without gum disease to conceive.

In addition, non-Caucasian women with gum disease were more likely to take over a year to become pregnant compared to those without gum disease: their increased risk of later conception was 13.9% compared to 6.2% for women without gum disease. Caucasian women with gum disease also tended to take longer to conceive than those who were disease-free but the difference was not statistically significant (8.6% of Caucasian women with gum disease took over one year to conceive and 6.2% of women with gum disease).

Information on time to conception was available for 1,956 women, and of, these, 146 women took longer than 12 months to conceive -- an indicator of impaired fertility. They were more likely to be older, non-Caucasian, to smoke and to have a body mass index over 25 kg/m2. Out of the 3416 women, 1014 (26%) had periodontal disease.

Prof Hart said: "Our data suggest that the presence of periodontal disease is a modifiable risk factor, which can increase a woman's time to conception, particularly for non-Caucasians. It exerts a negative influence on fertility that is of the same order of magnitude as obesity. This study also confirms other, known negative influences upon time to conception for a woman; these include being over 35 years of age, being overweight or obese, and being a smoker. There was no correlation between the time it took to become pregnant and the socio-economic status of the woman.

"All women about to plan for a family should be encouraged to see their general practitioner to ensure that they are as healthy as possible before trying to conceive and so that they can be given appropriate lifestyle advice with respect to weight loss, diet and assistance with stopping smoking and drinking, plus the commencement of folic acid supplements. Additionally, it now appears that all women should also be encouraged to see their dentist to have any gum disease treated before trying to conceive. It is easily treated, usually involving no more than four dental visits.

"The SMILE study was one of the three largest randomised controlled trials performed in Western Australia. It showed conclusively that although treatment of periodontal disease does not prevent pre-term birth in any ethnic group, the treatment itself does not have any harmful effect on the mother or fetus during pregnancy."

Prof Hart said that the reason why pregnancies in non-Caucasian women were more affected by gum disease could be because these women appeared to have a higher level of inflammatory response to the condition.

How Fast Is Your Biological Clock Ticking?
Submitted by Bilyana Petrinska on 2011, August 10


It won’t be long before science is able to accurately predict the duration of a woman’s fertility. Experts from the Universities of St. Andrews, Edinburgh and Glasgow, carried out a survey of healthy women, which revealed the normal range of the levels of the anti-Mullerian hormone (AMH) considered most vital for a woman’s fertility. in relation to age.

The findings of the study will prove helpful for younger women in finding out whether they are in for an early or late menopause, including the duration of their fertility.

The AMH hormone by reflecting the activity of a woman’s ovaries during her lifetime, provides an estimate of her remaining egg supply.

Researchers in a bid to find out the average levels of the AMH hormone looked at 3,200 samples from healthy girls and women. Fertility experts will now be able to tell how AMH hormone levels compare with the average age of a woman.

According to Tom Kelsey, who teaches at the School of Computer Science at St. Andrews, despite knowing high AMH levels were necessary for conception, there was no statistical backing, which the current study has now provided.

Scientists already knew that when AMH hormone levels fell below a certain level, the infertility treatment in vitro fertilization (IVF) became less successful. The new findings by offering a benchmark will prove helpful in providing a more accurate prediction of a successful IVF outcome.

According to Richard Anderson, Professor of Reproductive Medicine at the University of Edinburgh, assessment of AMH is already being widely used in IVF treatment.

The findings of this survey it is hoped will prove helpful in developing test for predicting the reproductive life span of a woman. AMH hormone levels are measured via blood tests, however researchers are also investigating the possibility of determining the levels of this hormone via urine.