Dr Dingle's Blog / children
Evidence from animal studies shows that prenatal exposure to bisphenol A (BPA), a ubiquitous endocrine-disrupting chemical, is associated with adverse reproductive outcomes in females and males. In females exposure during early gestation, a critical period for reproductive development, is of particular concern. The Anogenital distance (AGD) is a sensitive biomarker of the fetal hormonal balance and a measure of reproductive toxicity in animal studies. In some studies, the daughters of BPA-exposed dams have shorter AGD than controls.
The results of this study showed BPA was detectable in 94% of women. In analysis of the 381 eligible subjects, maternal BPA concentration was inversely associated with infant AGD-AC
In support of animal studies this human study shows that BPA may have toxic effects on the female reproductive system in humans, as it does in animal models. Higher first-trimester BPA exposure was associated with significantly shorter AGD in daughters, suggesting that BPA may alter the hormonal environment of the female fetus.
Bisphenol A (BPA) is a synthetic chemical widely used in consumer products, including food and drink containers, thermal receipts, medical equipment, and other plastic products. BPA is detectable in over 90% of the population in the United States, and may act on the endocrine system in numerous ways, including binding to and activating numerous nuclear and membrane endocrine receptors, and stimulating changes in estrogen, androgen, progesterone, and thyroid hormone activity.
Dozens of studies in humans have examined BPA exposure in relation to a wide range of health end points, including reproductive, perinatal, and pediatric outcomes. Many animal studies and in vitro studies show that many tissues and organ systems (including the mammary gland, prostate gland, adipose tissue, reproductive system, and brain) are sensitive to BPA. In animal and human studies, BPA can cross the placenta to enter fetal circulation. Because fetal development is a period of rapid cell proliferation and differentiation, tissue development, and organ growth, prenatal exposure to environmental chemicals such as BPA may be of particular concern.
Many studies have now shown that nut consumption has consistently been found to be associated with a reduced risk of cardiovascular diseases (CVD) and mortality. In this meta-analysis they combined 10 trials involving 374 participants and showed nut consumption significantly improved FMD (This is an indicator of the endothelial tissue on the inside of the arteries). Further analyses showed the real benefits were from the walnuts.
Nuts are a rich source of nutrients (eg, vitamin E, magnesium, folate, essential fatty acids, fiber, and protein) and phytochemicals.
Walnuts and other nutrient-rich nuts have been found to contribute to satiety, which can help control appetite and total caloric intake and have been associated with healthy weight and weight loss despite the fat and calorie content.
Chronic overconsumption of sugar-sweetened beverages (SSBs) is amongst the dietary factors most consistently found to be associated with obesity, type 2 diabetes (T2D) and cardiovascular disease (CVD) risk in large epidemiological studies. Studies have shown that SSB overconsumption increases intra-abdominal obesity and ectopic lipid deposition in the liver, and also exacerbates cardiometabolic risk. Similar to the prevalence of obesity and T2D, national surveys of food consumption have shown that chronic overconsumption of SSBs is skyrocketing in many parts of the world,
SSB overconsumption is also particularly worrisome among children and adolescents. SSBs typically include carbonated soft drinks, juice drinks (with added sugars), sports drinks, energy drinks, milkshakes, and iced tea or coffee.
The epidemics of obesity, type 2 diabetes (T2D), and cardiovascular diseases (CVD) are affecting most if not all developed countries around the world. While the prevalence of overweight, obesity, and T2D remain high in North America and Western Europe, obesity rates and T2D rates are increasing at a stunning pace in developing countries. In Mexico City inhabitants aged between 35 and 74 years, the excess mortality associated with previously diagnosed T2D accounted for one third of all deaths between 1998 to 2004.
In some countries such as the Unites States, sugar-sweetened beverages (SSBs) account for almost half of the added sugar consumed nationally and consumption around the world has reached unprecedented proportions, and the rise in the prevalence of cardiometabolic risk factors in children such as abdominal obesity and insulin resistance has increased in parallel.
A recent modelling study performed by the Global Burden of Diseases Nutrition and Chronic Diseases Expert Group (NutriCoDE) estimated that up to 184,000 deaths per year could be attributed to the chronic overconsumption of SSBs . Similar to the prevalence of obesity and T2D, studies analysing national surveys of food consumption have shown that the chronic overconsumption of SSBs is also skyrocketing in many parts of the world.
SSBs are the single greatest source of added sugars in most Western countries. SSBs are typically sweetened with high-fructose corn syrup (HFCS) in the US or sucrose. Sucrose, also often referred to as table sugar, is a disaccharide composed of glucose and fructose linked via a glycoside bond.
One study showed in a six-month parallel intervention study of 47 overweight individuals that the consumption of 1 L/day of sucrose-sweetened beverages (cola) significantly increased visceral adipose tissue and hepatic fat accumulation compared to the consumption of 1 L/day of semi-skimmed milk or water. Although not associated with increases in body weight or total fat mass, the consumption of cola was linked with increases in plasma triglyceride and cholesterol levels. Interestingly, daily total energy intake did not appear to differ across subgroups, thereby suggesting that energy included in beverages could have been compensated for by reductions in energy from other sources.
HFCS is produced by industrial processing of corn starch. It contains two monosaccharides, free fructose, and glucose in various proportions. Both fructose and glucose have different metabolic fates, an observation that has encouraged many to suggest that fructose may have a unique role in the pathogenesis of cardiometabolic diseases. This hypothesis has been supported by well-designed controlled studies
In a 10-week randomized clinical trial fed an ad libitum diet with 25% of calories originating from glucose- or fructose-sweetened beverages. Although both diets increased body weight, only participants in the HFCS group had increased visceral adipose tissue accumulation at the end of the trial. Insulin levels during a 3-h oral glucose tolerance test increased by 27% in the fructose group (significant) and by approximately 14% in the glucose group (nonsignificant). Similarly, 24-h post-meal triglyceride and fasting apolipoprotein B levels, as well as small, dense low-density lipoprotein (LDL) levels and triglyceride levels all increased in the fructose but not in the glucose group following the intervention.
About a dozen large prospective epidemiological studies have documented the association between SSB consumption and the risk of cardiometabolic diseases such as obesity, metabolic syndrome, T2D, and CVD.
A meta-analysis on 2013 that included 25,745 children and adolescents from 15 prospective studies and 174,252 adults from in seven prospective studies suggest that a one serving per day increase in SSB is associated with a 0.06 unit increase in body mass index (BMI) per year in children and adolescent and with a 0.12 to 0.22 kg yearly weight gain in adults. The same group also published evidence that SSBs overconsumption is linked with the onset of the metabolic syndrome (a constellation of CVD and T2D risk factors associated with abdominal obesity and insulin resistance) and T2D.
Residential proximity to agricultural pesticide use has been associated with many adverse health conditions including neural tube defects and autism.
In a long term study of 283 mothers and children 7 years old living in an agricultural area in the US researchers found a decrease of 2.2 points in Full-Scale IQ and 2.9 points in Verbal Comprehension for each increase in toxicity-weighted use of organophosphate pesticides. In separate analysis, they observed similar decrements in Full-Scale IQ with each standard deviation increase of use for two organophosphate pesticides (acephate and oxydemeton-methyl) and three neurotoxic pesticide groups (pyrethroids, neonicotinoids, and manganese fungicides).
As a part of this ongoing research earlier studies from the same research group identified higher levels of organophosphate urinary metabolites or dialkylphosphate (DAP) levels were ∼40% higher than those in a representative sample of U.S. women of childbearing age and had observed a relationship between prenatal maternal DAP concentrations and children’s performance at 2 y measures of attention at 5 y and Intelligence at 7 years. Several studies in other populations have similarly reported adverse associations of prenatal exposure to OP pesticides and child neurodevelopment
This is part of a long list of studies now showing that exposure to these neurotoxic pesticides are linked with poorer neurodevelopment in children even at moderately low exposures. All pesticides are bioactive agents designed to kill.
Bisphenol A (BPA) is a high-production-volume chemical that is used to produce polycarbonate plastics and resins used in some food can linings and other consumer products around the home and everyone is exposed predominantly from their diet.
There is growing evidence that prenatal BPA exposure increases the risk of neurobehavioral disorders in children. Some experimental studies in rodents suggest that prenatal BPA exposure is associated with behavior problems and that these effects may be sex-specific.
Prenatal exposure to BPA may increase the risk of neurobehavioral disorders by affecting thyroid or gonadal hormones or neurotransmitter systems, which are both necessary for proper brain development.
BPA may also affect the production or metabolism of gonadal hormones, which are an important determinant of sexually dimorphic brain development; thus, BPA may differentially affect neurodevelopment in males and females.
Several epidemiological studies have reported that maternal urinary BPA concentration during pregnancy is associated with adverse behavioral outcomes. In addition, some studies have reported that child sex modifies the association between BPA and neurobehavior. Studies in animals also show that gestational BPA exposure may affect specific aspects of cognition, such as memory and learning.
In this study increasing BPA concentrations in the mother at the birth of the child was associated with lower memory ability at 3 years of age but only in boys.
Environ Health Perspect; DOI:10.1289/EHP984
Associations of Prenatal Urinary Bisphenol A Concentrations with Child Behaviors and Cognitive Abilities
There is increasing evidence emerging from the scientific community which suggests that mass-medication in the form of water fluoridation is in fact having a serious and adverse effect on the public’s health. A recent report from the US National Research Council 1 concluded that adverse effects of high fluoride concentrations in drinking-water may be of concern. Animal studies have shown Fluoride may cause neurotoxicity, including effects on learning and memory 2,3. Recent experiments where the rat hippocampal neurons were incubated with various concentrations of sodium fluoride showed that fluoride neurotoxicity may target hippocampal neurons.
Fluoride readily crosses the placenta exposing the developing brain, which is much more susceptible to injury caused by toxicants than is the mature brain, may possibly lead to damage of a permanent nature 4
In a study conducted by Tianjin Medical University in China, a comparison in the Intelligence Quotient (IQ) was measured between 60 children living in a high fluoride area and 58 children living in a low fluoride area. The IQ of the 60 children living in the high fluoride area was lower than that of the 58 children living in the low fluoride area. 21.6% of the children in the high fluoride area were retarded compared to 3.4% of retarded children living in the low fluoride area 5.
In a study at Tokyo University Medical School, water fluoridation was linked to Down syndrome. The study found that - as well as the aging of mothers - the number of excess Down syndrome births caused each year by water fluoridation was estimated to be several thousand cases throughout the world 6.
In the most recent meta analysis of 27 eligible epidemiological studies found that children in high fluoride areas had significantly lower IQ scores than those who lived in low fluoride areas 7. The conclusions of the study “support the possibility of an adverse effect of high fluoride exposure on children’s neurodevelopment.”
Some of the other adverse health effects of fluoride include lowered levels of collagen synthesis, depleted energy reserves and lowered immunity, irritable bowel syndrome,thyroid disorders, Skeletal fluorosis, Osteosarcoma, Osteoporosis and bone fractures as well as Alzheimer's disease.
Exercises on television shows like “the biggest losers“ give a false impression of the role of exercise. Exercise, unless it is extreme in the case of the biggest losers who have cameras and personal trainers and doctors etc. plays a relatively lesser role in weight loss and may even backfire in people who over do it. That doesn’t mean you don’t do anything because being active is critical for many aspects of your overall health and wellbeing were just saying you don’t have to be a gym junkie to get to your optimal weight. A lot of evidence shows that aerobic exercises which are great for the heart are minimally effective for weight loss, although they have multiple other benefits including reducing your risk of all forms of chronic illness. The problem is that, in general terms, exercise does not burn tons of calories (unless we’re doing heroic amounts of it). It doesn’t usually take much additional eating to wipe out any calorie deficit induced through exercise. For example the energy burned while walking 30 minutes (170 calories) each day will only lose you around one kilogram after 50 days. In the study, 23 overweight and healthy men engaged in a 6-month programme of exercise 108 minutes of exercise a week changed the expression of about a third of the genes in the fat cells, including some that relate to the risk of type 2 diabetes and the development of obesity. As well as changes in waist circumference, waist-to-hip ratio, diastolic blood pressure (the lower of the two blood pressure readings), resting heart rate and levels of HDL-cholesterol. However, weight only declined by 1 kg on average and appeared to be no less fat for their efforts.
In a meta analysis of children’s weight loss, Physical activity interventions were not associated with reductions of BMI. However, there was an association between the interventions and reduction of blood pressure. In a study of overweight people expending either 300 or 600 calories a day exercising for 12 weeks twice the exercise did not translate into improved weight loss. Those doing 300 calories of exercise lost an average of 2.7 kg compared to 3.6 kg for the 600 calorie exercise group. Double the exercise lead to a 30% extra loss of weight. Of interest those exercising for about half an hour a day (300 calories) had a more positive attitude to exercise. Doing larger amounts of exercise are harder which is a barrier to maintaining the exercise.
On the positive side exercise is great for keeping weight off. The more you are active the less likely you are to put on excess weight. In a study of 25 639 men and women an increase in weight was associated with higher risk of being inactive 10 years later. Compared with stable weight, a gain in weight of more than 2 kg per year is associated with physical inactivity
Exercising for weight loss
But don’t stop exercising if you like exercising just yet because the level of exercise also has a large impact on your Resting Metabolic Rate and thermogenesis. There are certain things you can do to improve your weight through exercise. The first is to increase your muscle mass through anaerobic, muscle building exercise. The more muscle you have the higher your resting metabolic rate. That is the more you burn excess fuel while you are resting
You can also use exercise and physical activity to increase your thermogensis at critical times, in a sense tricking you body into burning calories before it is stored around your waist. Insulin is a major contributor to weight gain. The more insulin released with a carbohydrate dense meal the more weight you put on around the waste. However, increasing physical activity soon after a meal, even just standing up increases the cells requirements for the sugar without releasing extra insulin. Within seconds of any physical activity one of the non-insulin sugar pathways into the cells, the Glut 4 transporters are activated to remove sugar from the blood. This reduces blood glucose levels and improves insulin sensitivity (very good for diabetics). That is less insulin does more work. Regular exercise also increases the number of Glut 4 transporters. The more you exercise the more Glut 4 transporters your body will make. Any diabetic will tell you that as soon as they exercise their blood sugar levels goes down straight away. This means less to be stored as fat around the waist. In a study of thirteen obese-patients with type-2 diabetes post-dinner resistance exercise improved both postprandial glucose and glycation-end products, the damage caused by sugar. Post meal physical activity takes the sugar out of the blood before it can cause harm and build up around the waist. Associated with the increase in Glut 4 transporters is that exercise also increases the production of mitochondria which are the energy burning factories of the cells, and a lack of exercise causes numbers to deteriorate.
Exercise for your hunger genes
Like the different foods exercise can also alter how hungry you feel. In its natural environment your body is in perfect balance and everything feeds back on itself to constantly bring it back into balance. While being more active and exercising generally sends messages to eat more, to keep it all in balance you can also use exercises to suppress your appetite and trick the body. Exercise can suppress appetite, subsequent energy intake, and alter appetite-regulating hormones for a period of time post-exercise. Most people experience appetite suppression following an acute bout of exercise as exercise reduces your immediate feelings of hunger. In a study of 9 women who had fasted for some time before the experiment. They found that appetite ratings of the subjects in the exercise group fell for up to 2 hours after they had been placed on a treadmill for 30 minutes. Similar results have been found with different types of workouts and generally the exercise with greater metabolic and mechanical demand (weight-bearing exercise) showed greater immediate appetite suppression. So if you are reducing your calorie intake it is worth being active before a meal as well to reduce those immediate hunger pangs.
There is just no down side to physical activity unless you try to do too much too quickly like the biggest losers.
Standing up for weight loss
Sitting for any length of time may not be good for us, as more and more evidence shows that sedentary behaviours including sitting, watching television, using a computer, and driving a car are risk factors, independent of physical activity, for adverse chronic disease in adults such as obesity, diabetes, heart disease and much more. You can do a long run every night, but if you sit too long during the day you still increase your risk of these chronic conditions. In a study of 2,761 women and 2,103 men without clinically diagnosed diabetes, sitting time was detrimentally associated with waist circumference, BMI (body mass index), weight gain, blood pressure, fasting blood fats, HDL cholesterol, two-hour postload plasma glucose, and fasting insulin. A sure way to put on weight. In a meta-analysis using 48 studies, a consistent relationship of sedentary behaviour with mortality was found with weight gain from childhood. That is, the greater the sedentary time in childhood, the greater the weight gain.
It appears that any type of brief, yet frequent, muscular contraction throughout the day—such as standing or moving—may create healthy epigenetic signals which positively alter the body’s biochemistry and metabolism. One of these is a particular muscle chemicals, lipoprotein lipase (LPL), a protein enzyme has been studied in depth because this enzyme has a central role in several aspects of fat metabolism. Experimentally reducing movement by sitting had a much greater negative effect on LPL regulation than a positive effect of adding vigorous exercise training on top of the normal level of non exercise activity. In rat studies the amount of time spent sedentary influences how our bodies process fats given that leg muscles only produce the lipase lipoprotein (LPL) fat-processing molecule when they are being actively flexed, either standing or moving. What this shows is that by simply standing up more frequently you increase your muscle activity to reduce sugar and fats in the blood. To achieve even better effects you can stand up after a meal rather than sitting down and watching Television. In support of this one study reported that independent of total sedentary time and moderate-to-vigorous intensity activity time, increased breaks in sedentary time were beneficially associated with waist circumference, body mass index, triglycerides, and 2-hour plasma glucose. While in a study of 70 adults involving sitting for nine hours, regular activity breaks lowered plasma insulin levels and lowered plasma glucose when compared with prolonged sitting, even when compared with physical activity. While physical activity lowered plasma triglyceride more with regular activity breaks, activity breaks were more effective than continuous physical activity at decreasing negative blood sugar and insulin levels in healthy, normal-weight adults.
Overall, there is a compelling case for sitting reduction to be included in clinical preventive advice as a key component of “active living,” where adults and children are encouraged to “stand up, move more and sit less” across different settings and locations throughout the day. Just standing up every 20 or 30 minutes can have a remarkable health benefit reducing your risk of many chronic illnesses. How simple is that. The results of these studies suggest that, at a minimum, we need to be breaking up our sitting time every 20 to 30 minutes.
Another study adds to evidence that environmental chemicals can contribute to obesity. The study examined prenatal and early childhood exposure to BPA and found children at 7 years of age put on significant more weight if there mother was exposed to BPA. However, the researchers did not see an association between body fat and BPA levels in the children at ages three or five. The researchers suggest that this may be a time of heightened vulnerability to the chemical.
The results of this study suggest that prenatal BPA exposure may contribute to developmental origins of adiposity and findings are consistent with several prior studies, raising concern about the pervasiveness of BPA. Other human studies have found a similar link between BPA exposure and signs of child obesity. BPA has been shown to alter the body’s metabolism, increasing weight gain and making it difficult to lose weight. In a study of 1,326 children, girls between ages 9 and 12 with high BPA levels had double the risk of being obese than girls with low BPA levels, validating previous animal and human studies. The chemical can alter the body’s metabolism and make it harder to lose weight. Girls with high levels of BPA, two micrograms per litre or more, were twice as likely to be obese as girls with lower levels of BPA in the same age group. Girls with very high levels of BPA, more than 10 micrograms per litre, were five times more likely to be obese, the study showed.
Animal studies have found prenatal BPA exposure linked to offspring obesity. When pregnant rats are exposed to BPA it increased the fat mass in offspring, even later in life. In animal experiments, a mother’s exposure to BPA is produced the same outcomes that we see in humans born light at birth: an increase in abdominal fat and glucose intolerance. However, BPA affects rodent fat cells at very low doses, 1,000 times below the dose that regulatory agencies presume causes no effect in humans.
BPA, a common plastic additive, can leach out of can linings and into the food and studies show that just about everyone has traces of the chemical in their body. Ninety-four percent of the women in this study had BPA in their urine.
Parabens are one of the most widely and heavily used antimicrobial preservatives, which until recently, were found in up to 99% of cosmetics and toiletries. Typically, more than one paraben is used in a single product and they are often used in combination with other chemical preservatives and are commonly used in facial moisturisers, lipsticks, eye‑shadow and mascara, body sprays, deodorants, hair removal creams, shaving gels, body lotions, face creams, sunscreens, toothpastes, cleansers and shampoos. It is probably easier to say what they are not found in.
Unfortunately, multiple studies have also identified parabens in most of the personal care and cosmetic products analysed even if they were not mentioned on the label. In a study of personal care products methyl paraben was detected most frequently and at the highest concentrations. The highest concentration was in an “alternative” sunscreen. Of the 11 conventional samples with detectable parabens, 10 included products with “paraben” on the label. Nevertheless, in “alternative” products, the study found parabens in 7 products, including 3 sunscreens, that did not list parabens on the label. One study of the 215 common cosmetic products tested 93% contained parabens. Not only are they not be listing parabens on the label but manufactures may hide the chemical under the word ‘fragrance’, a collective term which covers over two thousand chemicals (Williams, 2004) or as the research shows they may not even label them as ingredients.
Parabens can be absorbed through application on the skin and able to enter the blood based on their fat loving (lipophilic) properties. As the vast majority of cosmetic products containing parabens are usually applied to the skin, it can be a major source of exposure. Average exposure to parabens is estimated to be around 76 mg per day which includes 1 mg daily from food, 50 mg from cosmetics and 25 mg from pharmaceuticals. Between 20 and 50 times more is taken in through the skin than food. As a result, extensive distribution of parabens in human samples, including milk, urine, semen, breast tissue and blood, has been reported over the past decade and widespread studies have now shown 2 or 3 or more paraben in 99% of the general population in many countries around the world.
Paraben absorption can also be enhanced by the presence of other chemicals such as ethanol, menthol and propylene glycol, which occur in a many commonly used cosmetic products Because parabens tend to accumulate they can be found in elevated concentrations in some tissues. In one study after eight hours of contact with skin 60% of methylparaben, 40% of ethylparaben and 20% of propylparaben were found to have permeated across the skins surface.
A number of studies have now shown higher paraben concentrations with increasing use of PCPs used in the past 24 hours. In particular, the use of colognes and perfumes has been associated with increased methylparaben concentrations in both adults and 8–13 year old children. Other PCPs associated with increased methylparaben concentrations include lotions, colored cosmetics (hair dye, foundation, blush, eye shadow, eye liner, or mascara), aftershaves and nail polish in adults and hair care products and deodorants (girls only) in children.
Many studies have now linked parabens to reproductive, endocrine, respiratory and other health problems including cancer, birth defects, infertility, contact allergies, and a host of other problems. Many studies have suggested possible chronic health effects of parabens, including increased risk of breast cancer and prostate cancer through estrogenic activity, and possibly increased risk of skin cancer. Parabens have also been linked increases in estrogenic activity in children, leading to decreased fertility in males early puberty in females including early breast development.
Natural estrogens act in target cells by binding to estrogen receptors which function to regulate gene expression. However, parabens have the ability to remain longer within the body and accumulate than their short‑lived natural counterparts. Studies have also found the estrogenic effects of parabens at doses at the same levels reported in many studies.
A number of studies have suggested that products containing parabens that are regularly used around the breast area, are contributing to the increase in breast cancers. In particular, products such as deodorants and anti-perspirants applied to, and left on the underarm area for long periods, thus able to absorb through the skin and accumulate in the underlying tissue. Studies show that around 54% of incidences of breast cancer were located around the underarm area.
In addition, an analysis of breast tissue samples collected during mastectomy performed for primary breast cancer showed that at least one paraben was detectable in virtually all samples (99%) because estrogen is known to play a central role in the development, growth, and progression of breast cancer. The mechanisms by which parabens contribute to breast cancer is now well established and shows they enable multiple cancer steps. Of great concern is also that combinations of different parabens can produce additive effects on proliferation and most paraben containing products have multiple parabens in them. They can act synergistically to increase breast cancer gene expression and the presence of multiple estrogen receptors and other areas where they can bind in breast tissues may even increase the activity of parabens.
The influence of paraben on estrogen activity may be exacerbated by the fact that many personal care products containing parabens are applied directly around the breast area, as is the case with underarm deodorants and body moisturisers. Clinical studies over the last decade have indicated the majority of breast cancers occur in the upper‑outer quadrant of the breast near to the underarm area where products are applied. Not only are these products then able to be directly absorbed but regular re-application can promote the bioaccumulation of paraben in breast tissue. Underarm cosmetics can penetrate the skin more efficiently as they are applied to an area which usually has nicks and abrasions, caused by shaving and other forms of hair removal. The frequent application of these PCPs and the fact that they are left upon the skin of the breast region means that the dermal area is constantly and regularly exposed leading to accumulation in the underlying tissues.
Studies as early as 1983 have suggested links with negative reproductive effects. This study found that six preterm infants had significant concentrations of methyl paraben and its metabolites present in their urine. While more recent studies have found that exposing pregnant female mice to small levels of environmental estrogens could lead to a termination during early pregnancy.
Male bits and Mens issues
In recent decades reproductive and developmental problems have become more prevalent—for example, data from the Centers for Disease Control and Prevention (CDC) show that male reproductive problems, including undescended testicles and hypospadias, doubled between 1970 and 1993. A rising concern has emerged regarding possible adverse effects of chemicals in cosmetics and PCPs on human reproduction outcomes. In developed countries about 15% of human couples are affected by infertility, almost half of these cases attributed to men, through low sperm motility or/and sperm count. Since they tend to mimic female hormones, these compounds especially affect male reproductive function.
Products containing parabens have been linked to negative effects on the male reproductive system and that exposure to paraben, particularly butyl paraben, while in the womb and in young males can lead to decreased testosterone levels and reduced sperm counts. Parabens appear toxic to the mitochondria and adversely affect mitochondrial function in the testes. The daily sperm production and the efficiency in the testes decreased dramatically in the test groups who received parabens. The sperm counts in the studies decreased in a dose dependent manner, that is the higher the paraben levels the lower the sperm counts. Other studies have also shown exposure to pregnant female rats led to male offspring with decreased testes, seminal vesicle and prostate gland weights, as well as decreased sperm count and motility.
Parabens have also been associated with allergic reactions (sensitisation); commonly rashes, swelling and itchiness and contact dermatitis (skin inflammation). An extensive range of adverse effects on the skin have been reported, including changes to cell structure, changes to gene expression, protein synthesis and cell death, following one month daily application of paraben based formulations. Studies are also showing chronic skin application of parabens may lead to prolonged estrogenic effects in skin. Estrogens are very important hormonal regulators in the skin and function to preserve collagen content, which supports and maintains elasticity thickening of the skin and wound healing. Daily application of products containing methylparaben to the skin found that the methylparaben remained unmetabolised on the skin and affected the ability of the skin act as a protective barrier so dermatological disorders, skin irritation and skin allergies often follow. Short term application to the skin of animals resulted in edema, which is swelling due to a collection of fluids, desquamation, which is a shedding of the skin, and erythema, which is a reddening of the skin due to dilation of the blood vessels. Similar affects have also been observed in human studies.
Overall this is a group of chemicals that we really do need to avoid but even reading the labels does not guarantee there will be no parabens.