Wednesday, July 30, 2014

Update on Magnesium

Magnesium is an important mineral in the human body, involved in essential metabolic reactions such as energy production in mitochondria, synthesis of DNA and RNA, the conduction of nerve impulses, normal heart rhythm, wound healing et al. Along with calcium, it plays an important structural role in bone,. Magnesium is at the center of the chlorophyll molecule, so it is abundant in many plant foods, such as leafy greens, beans, nuts and unrefined grains.

Low serum levels of magnesium have been found in people with asthma, diabetes, osteoporosis, and alcoholism. However, treatment with supplemental magnesium has not been uniformly found to be as helpful as a healthy lifestyle and diet. Here are some recent studies on magnesium.

Diabetes – diets with higher amounts of magnesium are associated with a significantly lower risk of Diabetes. This is based on large cohort studies over 4-20 years in length. People with the highest intake of magnesium in food were found to have up to a 20% lower risk of diabetes compared to those with the lowest intake. This association achieved significance only in people who were overweight. Some studies, but not all, show that taking magnesium supplements may help with blood sugar control.

Blood Pressure: A study from the University of Hertfordshire in England found that magnesium supplements offer small but clinically significant reductions in blood pressure. The researchers looked 22 trials involving 1,173 people, and found systolic pressure reduced by 4mmHG and diastolic by 2-3mmHG.

Brain Function: Research at the Center for Learning and Memory at Tsinghua University in Beijing found that using a new form of magnesium as an oral supplement, magnesium-L-threonate (MgT), could increase many different forms of learning and memory in both young and aged rats. The authors concluded that since many people in industrialized countries have a magnesium deficit, increasing magnesium intake might prevent or reduce cognitive decline. Similar studies from MIT, Tel Aviv University and the University of Toronto confirmed these findings, and showed that animals given the new oral magnesium compound (MgT) had an increase of synapses in the brain – connective nerve endings that carry memories in the form of electrical impulses from one part of the brain to the other. The researchers also concluded that most of today’s over-the-counter supplements don’t get into the brain effectively.

MgT as a supplement is now commercially available, and can be found on-line from several sources (such as Amazon and supplement companies like iherb). However – there are so far no real studies on its safety in humans – remember that the studies have been done on rats! At least one human study is underway. It is probably prudent to wait for validation of its safety. Discuss this with your doctor.

Taking the usual forms of supplemental magnesium (magnesium oxide, citrate, chloride) in reasonable doses (up to 350 mg daily) is safe for most people, but not everyone. People with kidney problems should confer with their doctor before taking magnesium supplements, as magnesium is excreted through the kidneys – as well as in feces. Too high a serum level can be dangerous.
Many people are taking magnesium citrate or other forms of the mineral to help them relax and sleep. Unless you have kidney disease this is probably safe, but users should be aware of the guidelines as indicated below.

The recommended dietary allowance for magnesium for adults 19-30 years old is 400 milligrams/day for men and 310 milligrams/day for women. For adults 31 and older, it is 420 milligrams/day for men and 320 milligrams/day for women. Pregnant women should get slightly more – from food and prenatal vitamin-mineral supplements. When women take calcium supplements, it is advisable to take half as much magnesium as calcium – for example 500 mg of calcium with 250 mg of magnesium.

In 2011, the Food and Drug Administration issued a safety announcement that long-term use - longer than one year - of prescription proton pump inhibitor (PPI) drugs (such as Nexium and Prilosec) may cause low serum magnesium levels. Treatment usually involves magnesium supplements, but in about 25% of cases the PPI has to be discontinued. Over the counter doses of these same drugs are lower, and their use is advised for no more than 15 days up to 3 times a year.

Fortunately, magnesium is found in some wonderful foods easily available, such as leafy greens. beans, nuts and whole grains. Fresh green beans are in season!
Sadja Greenwood MD, MPH – past issues on this blog

Tuesday, July 8, 2014

Autism - Why the Increase?

Autism and autism spectrum disorder (ASD) are terms for a group of complex disorders of brain development, characterized by difficulties in social interaction, verbal and non-verbal communication and repetitive behaviors. There are multiple causes of ASD, although most are not yet known. The learning, thinking, and problem-solving abilities of people with ASD can range from gifted to severely challenged - ASD begins before the age of 3 and last throughout a person's life, although symptoms may improve over time.

The rise in the diagnosis of autism among young children has been rapid and alarming.  Broadening the diagnosis of the disease and increased surveillance may be a factor, but do not explain what has happened.  Prior to 1990 the estimates of autism prevalence were about 3 per 10,000.  In 2000 and 2002 the autism estimate was about 1 in 150 children. Two years later, 1 in 125 8-year-olds was believed to have autism. In 2006, the number grew to 1 in 110, and then the number went up to 1 in 88 based on 2008 data. Currently, one in 68 U.S. children has an autism spectrum disorder (ASD), according the Centers for Disease Control and Prevention. This newest estimate is based on the CDC's evaluation of health and educational records of all 8-year-old children in 11 states: Alabama, Wisconsin, Colorado, Missouri, Georgia, Arkansas, Arizona, Maryland, North Carolina, Utah and New Jersey. The incidence of autism ranged from a low of 1 in 175 children in Alabama to a high of 1 in 45 in New Jersey, according to the CDC. Children with autism continue to be overwhelmingly male. According to the new report, the CDC estimates 1 in 42 boys has autism, 4.5 times as many as girls (1 in 189).

Clearly, we are experiencing a huge, unprecedented problem.  Here is an abbreviated version of current thinking on causation.  The theory that mercury (thiomersal) in vaccines causes autism has been investigated extensively and discredited. The clinical symptoms of mercury poisoning differ significantly from those of autism. In addition, multiple population studies have found no association between thiomersal and autism, and rates of autism have continued to increase despite removal of thiomersal from vaccines.  
Studies of twins suggest that heritability is 0.7 for autism and as high as 0.9 for ASD, and siblings of those with autism are about 25 times more likely to be autistic than the general population. However, most of the mutations that increase autism risk have not been identified. A recent study involving 13 institutions around the world showed that mutation in ‘an autism specific gene’ could lead to autism marked by gastrointestinal disorders, and sleep disturbances.  Mutations in this gene would account for a very small number of cases, but the finding was the harbinger of discoveries to come. 

A recent study from Denmark (a small country with excellent statistical records) showed that both maternal and paternal age are associated with a greater risk of ASD in the offspring, depending on combinations of parental age categories. For mothers younger than 35 years, the risk of ASD increased with increasing father's age. For fathers younger than 35 years, the risk of ASD increased with increasing maternal age.

A study just reported from UC Davis showed that pregnant women who lived in close proximity to fields and farms where chemical pesticides were applied experienced a two-thirds increased risk of having a child with ASD or other developmental delay. The study examined associations between specific classes of pesticides, including organophosphates, pyrethroids and carbamates, applied during the study participants' pregnancies, and later diagnoses of autism and developmental delay in their offspring. This study validates the results of earlier research that has reported associations between having a child with autism and prenatal exposure to agricultural chemicals in California," said lead study author Janie F. Shelton, a UC Davis graduate student who now consults with the United Nations. "While we still must investigate whether certain sub-groups are more vulnerable to exposures to these compounds than others, the message is very clear: Women who are pregnant should take special care to avoid contact with agricultural chemicals whenever possible. In the early developmental gestational period, the brain is developing synapses, the spaces between neurons, where electrical impulses are turned into neurotransmitting chemicals that leap from one neuron to another to pass messages along. The formation of these junctions is really important and may well be where these pesticides are operating and affecting neurotransmission.”

A 2013 report from Harvard School of Public Health was the first large national study to examine links between autism and air pollution across the U.S. Exposure to diesel particulates, lead, manganese, mercury, methylene chloride and other pollutants are known to affect brain function and to affect the developing baby. Women in the U.S. exposed to high levels of air pollution while pregnant were up to twice as likely to have a child with autism as women who lived in areas with low pollution.

Writing this column has made me ever more concerned that our crowded, industrialized world has created conditions dangerous for human life, as well as the lives of other animals and plants. Changing directions will take enormous commitment and political will. Awareness of the damage we are doing to children should give us a powerful incentive to find new ways to live. 
Sadja Greenwood, MD, MPH  leave me a message, and I’ll answer you!

Wednesday, July 2, 2014

Oxytocin - An Amazing Hormone

Oxytocin is produced in the hypothalamus (above the pituitary gland, behind the eyes) and stored in the pituitary gland.  It is also produced in other body parts, including the sex glands of men and women.

Oxytocin has been called the love hormone or the bonding hormone because its release contributes to the social bonding that occurs between lovers, friends and colleagues.  A study from Bar-llan University in Israel showed that fathers living with their partner and newborn had as much oxytocin in their blood as mothers, at one week postpartum and at 6 months.  Mothers with high oxytocin levels provided more affectionate parenting, and fathers with high levels encouraged more exploration and attention to objects.  The researchers were not sure whether these differences reflected cultural role expectations or were ‘indicative of distinct circuit effects of oxytocin in the male and female brain.’  The amounts of oxytocin found in each couple tended to be similar, although most people differ in the amount they produce. 

The oxytocin that is released during sex and orgasm, and also in handholding, hugging and eye-gazing plays a role in keeping couples together, and keeping men attracted to their partners, according to studies at the University of Bonn in Germany and also at Emory University in Atlanta.  There is an evolutionary benefit here for offspring survival.
(Another school of thought – not related to oxytocin - is that men are primed to have as many affairs as possible to spread their DNA.  Examples of both these theories may be found in the course of a man’s life.  Women have their own variation on these themes, but it’s exhausting to think of the numerous pregnancies that could occur with a variety of mates if evolution had its way.  Fortunately, there’s birth control.)

Oxytocin is released in large amounts during labor; it causes uterine contraction and thereby facilitates  delivery. A synthetic form of oxytocin, known as pitocin, is frequently given intravenously if labor is too slow. Oxytocin is produced during stimulation of the nipples by the infant’s mouth, and it produces milk release.  Intravenous pitocin has been considered an important drug in the treatment of hemorrhage after birth, although newer drugs are taking its place. 

Research into wound healing and oxytocin was carried out at Ohio State University.  This unusual study was done with 37 couples admitted to a hospital for 24 hours. Participants were given small blister wounds on the arm. Each couple was then given instructions on how to interact, and asked to avoid topics that could cause marital dissension.   Follow up of wound healing was done for 8 days.  They found that people with higher levels of oxytocin had more rapid wound healing than others.

A relationship between addiction and oxytocin has been found at the University of Adelaide.  Researchers looked at why there is a high level of variability in people’s oxytocin levels – they think that adversity early in life may be key.  Oxytocin exists in the newborn and helps to create bonding with the mother.  A difficult birth, disturbed bonding or abuse, deprivation or severe infection might act to prevent normal development of the oxytocin system by age 3.  Later in life, people with low oxytocin levels may be more attracted to drugs and alcohol when under stress.

Here’s one of the latest and most amazing studies on oxytocin.  Researchers at UC Berkeley have found that oxytocin helps to prevent muscle wasting with age and even osteoporosis. The study was done in mice, but is believed to be applicable to humans. The mice with osteoporosis had had their ovaries removed to mimic menopause.  The animals with muscle wasting were given oxytocin injections under the skin, and regeneration to about 80% of the muscle strength seen in young mice occurred fairly rapidly.  The title of the paper from Berkeley summarizes their findings: Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regerneration.

What are the take home messages of this discussion of oxytocin? Keep your relationships with significant others as happy as possible, with plenty of hugs, snuggles and massage.  Do things that make you happy, like listening to your favorite music, or playing an instrument, singing, making art, walking outside, or getting a massage. See you on the trail. 
Sadja Greenwood, MD, MPH  past issues at on this blog
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