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Enriched Environments, Epigenetics, and Offspring
Enriched environments produce epigenetic changes in young mice – both male and female – that affect the next generation, according to recent studies. Mice raised in an environment that encourages curiosity, exploration, social interaction, and physical activity produce offspring that are less stressed, have brain changes that promote memory and learning, and have higher birth weights compared with offspring from mice raised in isolation or conventional laboratory cages.
In a 2009 study, Junko A. Arai and colleagues exposed 15-day-old ras-grf mice to an enriched environment for two weeks. Ras-grf mice have defective long-term potentiation (LTP), "a form of synaptic plasticity that is known to be important for learning and memory." In previous studies, the researchers had observed that this temporary exposure to an enriched environment leads to normal LTP in these mice for about 2 months before dropping to defective LTP levels found in unexposed ras-grf mice. In this study, the researchers looked at the offspring of enriched mice that were conceived while LTP levels were still normal. They observed that the offspring of female rats exposed to an enriched environment during their adolescence displayed normal LTP even when raised in a conventional environment. Unlike the parents, however, the offspring's LTP levels declined before they were old enough to bear young; the genes themselves had not changed. Arai and colleagues say that environment affected the epigenetics; that is, how the genes are expressed. "The idea that the effect of enrichment in the mother can be passed on to offspring during embryogenesis is consistent with a behavior study from >20 years ago," write the authors, "which showed that exposure of pregnant rats to an enriched environment enhances the maze learning abilities of their offspring, even if the offspring are raised by non-enriched foster mothers" (Kiyono et al. 1985).
Early environment of male mice also has an effect on offspring, according to a 2012 study led by Rahia Mashoodh at Columbia University (New York). Paternal genes in rodents affect a pup's rate of ultrasonic vocalizations, suckling ability, and locomotor activity. These behaviors govern the amount of maternal care that a pup receives. In this experiment, female mice who mated with males raised in an enriched environment exhibited "significantly higher levels of pup nursing across the first week postpartum … and marginally higher levels of pup licking" than females mated with mice raised in isolation. At weaning, the weight of offspring from enriched males was 0.98 grams greater, on average, than isolated males' offspring. "This growth effect was observed in both male and female offspring and was significant after controlling for maternal care," say the authors.
We know that nutrition and exercise can affect gene expression. The quality of one's environment has epigenetic effects as well.
Arai JA, Li S, Hartley DM, Feig LA. Transgenerational rescue of a genetic defect in long-term potentiation and memory formation by juvenile enrichment. J Neurosci. February 4, 2009;29(5):1496–1502. Available at www.jneurosci.org/content/29/5/1496.long. Accessed November 14, 2013.
Mashoodh R, Franks B, Curley JP, Champagne FA. Paternal social enrichment effects on maternal behavior and offspring growth. PNAS. October 16, 2012;109(suppl.2):17232–17238. Available at www.pnas.org/cgi/doi/10.1073/pnas.1121083109. Accessed November 14, 2013.
Food Sensitivities, Elimination Diets, and Weight Gain
The idea that sensitivities to common foods such as wheat, dairy, eggs, and corn cause weight gain is gaining attention. British doctor John Mansfield in his book Six Secrets of Successful Weight Loss asserts that food sensitivities are "'by far the commonest single cause of weight gain. … '" The cover of The Virgin Diet, written by certified nutritionist J. J. Virgin, says "Why Food Intolerance is the Real Cause of Weight Gain." Virgin's program has seven foods to avoid: gluten, soy, dairy, eggs, corn, peanuts, and most sweeteners. Mansfield adds yeast, coffee, tea, potatoes, chocolate, oranges, onions, beef, and pork to the list of foods not tolerated by some people.
I was unable to find any research that links food sensitivity specifically to weight gain. Medical research is just beginning to allow the possibility that common foods can produce symptoms without inciting IgE antibodies. For example, a double-blind, randomized, placebo-controlled study, led by J. R. Biesiekierski, reported that gluten can cause gastrointestinal symptoms in people without celiac disease; but the authors had no idea why: "'Non-celiac gluten intolerance' may exist, but no clues to the mechanism were elucidated." So, the theory that food intolerance contributes to weight gain may be true; research studies have just not been performed.
The elimination diet is most valuable for people with chronic health problems or for those who feel fatigued and sluggish. The diet allows people to identify foods that cause symptoms or reactions. A February 2011 Lancet study, for example, showed that a strict elimination diet is a valuable technique for identifying foods that cause ADHD symptoms in children. The elimination diet also gets people off of processed foods – at least temporarily. Most processed foods contain one or more of the foods commonly linked to sensitivities. Could the weight loss attributed to elimination diets be the result of avoiding processed foods and eating whole foods instead?
Biesiekierski JR, Newnham ED, Irving PM et al. Gluten causes gastrointestinal symptoms in subjects without celiac: a double-blind randomized placebo-controlled trial. Am J Gastroenterol. March 2011;106(3):508–514. Available at www.researchgate.net. Accessed December 5, 2013.
Hodgekiss A. Food sensitivity could be stopping you lose weight, says doctor who also claims low-fat diets can make you HEAVIER. October 11, 2012. Daily Mail. Available at www.dailymail.co.uk. Accessed November 14, 2013.
Virgin JJ. The Virgin Diet. Don Mills, Ontario, Canada: Harlequin Enterprises; 2012.
Health care for all children begins with women's access to family planning and reliable contraception methods. "A woman's ability to space and limit her pregnancies has a direct impact on her health and well-being as well as on the outcome of each pregnancy," says the World Health Organization. Babies conceived at least 18 months (but less than 5 years) after a sibling's birth are less likely to be premature or be small for their gestational age, according to Mayo Clinic. Despite the importance of family planning, many medical schools do not include contraception, options counseling, or abortion procedures in their OB/GYN or family medicine residency programs. Medical Students for Choice is an organization that assists medical students who want to improve family planning instruction at their college (www.msfc.org).
Restricting access to family planning measures – whether through budget cuts or through law – has consequences beyond an infant's birth weight. When Romania restricted access to contraception in 1957, legal abortion rates soared, according to an article by Mihai Horga and colleagues: "By the mid-1960s, there were [1,100,000] abortions performed each year in Romania, a lifetime average of 3.9 per woman, the highest number ever recorded." Then Nicolae Ceausescu came to power and restricted abortion in October 1966 to women over age 45 years, those with four or more children, pregnancies resulting from rape or incest, pregnancies that threatened the woman's life, and pregnancies in which the fetus had a congenital defect. Abortion rates plummeted, and fertility rates nearly doubled from 1.9 to 3.6 births per woman in 1967–1968. Women who could not get birth control pills or condoms through the black market turned to illegal abortion. "Maternal mortality from unsafe abortion skyrocketed to an incredible 147 per 100,000 live births," say Horga and colleagues. By 1985–1986, the birth rate had declined to 2.3. When abortion was again legalized, maternal mortality fell within the first year, but abortion rates climbed. Family planning clinics and contraception became available in the 1990s, and abortion rates began to fall from 163.6 abortions per 1000 women in 1990, to 10.1 in 2010. Maternal mortality also decreased: 147 per 100,000 live births in 1989 to 5.2 in 2010.
"The reasons [US] women give for having an abortion underscore their understanding of the responsibilities of parenthood and family life," according to Guttmacher Institute. For many, it is an economic necessity. About 61% of the women already have one or more children, and most are low income: 42% of women obtaining abortions had income below the 2008 poverty level ($10,830 per single person plus $3600 for each additional person: http://aspe.hhs.gov/poverty/08poverty.shtml) and 27% made between 100% and 199% of the poverty level. About 75% of women decide to abort because having a baby (not to mention raising the child) would compromise their ability to work, continue school, or care for dependents. Marital difficulties and lack of support from the partner were other major reasons that women seek abortions. Most abortions (88%) occur in the first 12 weeks of pregnancy – long before the fetus is viable outside the womb. The best way to reduce abortions rates, as President Jimmy Carter realized, is to address the reasons that women choose abortions: lack of family planning resources and poverty.
Guttmacher Institute. Facts on induced abortion in the United States [Web page]. October 2013. Available at www.guttmacher.org. Accessed November 15, 2013.
Horga M, Gerdts C, Potts M. The remarkable story of Romanian women's struggle to manage their fertility. J Fam Plann Reprod Health Care. 2013;39:2–4. Available at www.west-info.eu/files/Report-Romania1.pdf. Accessed December 4, 2013.
Wind R. Services provided at family planning centers yield myriad public health benefits [online press release]. August 7, 2013. www.guttmacher.org/media/nr/2013/08/07/index.html. Accessed November 15, 2013.
———. New U.S. study highlights need to include men in strategies to prevent unintended pregnancy [online press release]. June 24, 2013. www.guttmacher.org/media/nr/2013/06/24/index.html. Accessed November 15, 2013.
World Health Organization. Family planning [Web page]. http://www.who.int/topics/family_planning/en. Accessed December 4, 2013.
Intermittent Fasting for Weight Loss
Monitoring calorie intake seven days a week becomes a constant battle for many who want to lose or maintain weight. Some people are finding intermittent fasting – in one form or another – to be a sustainable alternative. Intermittent fasting, as popularized by Dr. Michael Mosley's book The Fast Diet, consists of eating about one-fourth of the recommended calories in the form of nutritious foods (about 500 for women and 600 for men) on two nonconsecutive days and eating normally during the rest of the week. The program, the subject of a BBC documentary that appeared on US public television in April 2013, helped Mosley and his patients lose weight, improve glucose metabolism, and lower cholesterol. Mosley chose to undertake a fasting program because of scientific research that has shown its multiple health benefits. Studies, primarily with animals, show that fasting increases longevity; decreases oxidative stress and inflammation; and improves biomarkers linked to cancer, diabetes, cardiovascular disease, and dementia, according to a Canadian Medical Association article.
Another form of intermittent fasting for weight loss is to eat only during specific hours. The daily fast should last at least 16 hours to get the metabolic benefit. After 16 hours, the body begins to burn fat for energy, according to Mark Mattson, senior investigator for the National Institute on Aging. An example of this type of diet would be to eat only between 9 or 10 a.m. and 5 p.m.
During most calorie-restricting diets, muscle as well as fat is lost. Research by Dr. Krista Varady and by Dr. Michelle Hoffman found that 75% of weight lost with standard diets is from decreased fat and 25% is from decreased muscle, according to Mosley. With intermittent fasting, between 85% and 100% of weight lost is due to fat loss. Losing muscle, the body's biggest calorie burner, makes it more difficult to prevent weight gain.
Intermittent fasting is not recommended for people who are taking beta blockers or diabetes medication or for those with hypoglycemia or a history of eating disorders.
Collier R. Intermittent fasting: the science of going without. Can Med Assoc J. April 8, 2013. Available at www.cmaj.ca/content/early/2013/04/08/cmaj.109-4451.full.pdf. Accessed November 14, 2013.
Franklin NC. Different types of intermittent fasts [online article].
Answers. http://nutrition.answers.com/diets/different-types-of-intermittent-fasts. Accessed November 22, 2013.
Melnick M. Intermittent fasting: does it work? [online article]. Huffington Post. April 11, 2013. Available at www.huffingtonpost.com. Accessed November 14, 2013.
———. Michael Mosley: 'The Fast Diet" author on self-experimentation, fasting and coming to America [online article]. Huffington Post. March 29, 2013. Available at www.huffingtonpost.com. Accessed November 14, 2013.
Cytolytic vaginosis and lactobacillosis, two recently identified disorders characterized by Lactobacillus overgrowth, are often mistaken for vulvovaginal candidiasis. Symptoms include an odorless, white vaginal discharge; vulvar itching; and stinging/burning pain, particularly with urination. "These symptoms are often cyclical in nature, being more pronounced during the luteal phase and reaching a peak shortly before menses," writes Robin L. Hills, NP.
Accurate diagnosis requires microscopic examination and pH analysis. Cytolytic vaginosis has a low pH (3.5–4.5), a large number of intermediate epithelial cells, cellular debris from cytolyzed epithelial cells, and excessive lactobacilli. "Pseudohyphae, spores, trichomonads and clue cells are absent, and leukocytes are scarce or absent," says Hills. Lactobacillosis also has a low pH and a large number of intermediate epithelial cells but no cytolyzed cells or cellular debris. It also has long, segmented chains of lactobacilli.
Hills offers several measures for decreasing the numbers of lactobacilli, thereby increasing pH and relieving symptoms. Avoiding tampon use during menstruation is the first measure, since menstrual flow naturally raises pH. Sitz baths with baking soda will relieve symptoms. Douching with a baking soda solution can also help; but douching, particularly in the absence of symptoms, can alter the environment to the point of promoting bacteria vaginosis. Hills says that patients should refrain from sexual activity during initial treatment and when symptoms occur. If these self-care measures do not eliminate symptoms, beta-lactamase antibiotic therapy (Augmentin) or doxycycline (Doryx) can be prescribed.
Hills RL. Cytolytic vaginosis and Lactobacillosis. Adv NPs PAs. February 1, 2007;15(2):45. Available at http://nurse-practitioners-and-physician-assistants.advanceweb.com/Article/Cytolytic-Vaginosis-And-Lactobacillosis.aspx. Accessed November 10, 2013.
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