Chocolate - A Holiday Update

 

The first people known to have made chocolate from the cacao tree were members of the ancient cultures of Mexico and Central America. The Maya and Aztec people took the tree from the rainforest - they harvested, fermented, roasted and ground the seeds into a paste. When mixed with water, chile peppers, cornmeal and other ingredients, this paste made a frothy spicy chocolate drink. The word ‘chocolate’ comes from a combination of the terms ‘choco’ (foam) and ‘atl’ (water).

*Nitric Oxide (NO) Dr. Norman Hollenberg at Harvard University has studied the ability of cocoa to increase the amount of nitric oxide (NO) in the body. NO is a gaseous ‘signaling molecule’ that crosses membranes and freely diffuses between cells. It signals the muscular coating around arteries to relax, thus improving blood flow and lowering blood pressure. Several medicines are based on this effect - nitroglycerin is a vasodilator because it is converted to NO in the body and Viagra stimulates erections by the effects of NO on blood vessels in the penis. Another protective effect of NO on the cardiovascular system is its inhibition of blood clotting and the adhesion of white blood cells to the lining of blood vessels.

*Flavonoids – Flavonoids are a group of compounds found widely in plants that produce healthy effects on animals who eat them. Many flavonoids activate the nitric oxide system. Cocoa is one of the richest sources of flavonoids (although current processing techniques reduce the content). Dr. Hollenberg and colleagues in Panama studied the Kuna Indians who live off the coast of Panama; the Kuna drink lightly processed cocoa as their main beverage and therefore have one of the world’s richest diets in flavonoids. The Kuna do not show an increase of blood pressure with aging, or decline in kidney function. Their death rates from heart disease, stroke, diabetes and cancer are markedly lower than those of genetically similar Kuna in mainland Panama, where cocoa is replaced by local foods. The researchers wrote a paper on the Kuna, concluding that “the comparatively lower risk among Kuna in the San Blas islands from the most common causes of morbidity and mortality in much of the world, possibly reflects a very high flavanol intake and sustained nitric oxide synthesis activation. However, there are many risk factors and an observational study cannot provide definitive evidence.”

In the Dutch Zutphen Study, cocoa intake specifically was associated with a 50% reduced risk of cardiovascular mortality between the highest and lowest quintile of intake in 470 elderly men. These epidemiologic data led to the hypothesis that the health benefits of cocoa may be linked to its flavonoids. Both the flavonoid content and the total antioxidant capacity have been shown to increase in plasma after cocoa consumption.

*The University of Michigan has summarized the benefits of dark chocolate as follows:

*Decreases LDL (“bad”) cholesterol oxidation

*Reduces the risk of blood clots

 *Increases blood flow in arteries and the heart

*May lower high blood pressure

*Cocoa may have a beneficial effect on cholesterol levels because it consists mainly of stearic acid and oleic acid. Stearic acid is a saturated fat, but unlike most saturated fatty acids, it does not raise blood cholesterol levels. Oleic acid, a monounsaturated fat, does not raise cholesterol and may even reduce it.

*May improve mood and pleasure by boosting serotonin and endorphin levels in the brain

*Regular intake is associated with better cognitive performance in the elderly

*Contains a number of minerals, including calcium, magnesium, and potassium

*CocoaVia by Mars The Mars company has been studying the health benefits of chocolate for over a decade, and has isolated the particular flavonol in cocoa that relaxes blood vessels and inhibits clotting. Their formula for this - a trade secret - is in their chocolate bar CocoaVia, along with plant substances (sterols) that lower cholesterol. CocoaVia is available in some stores and on line, in an unsweetened version as well as in a bar.  As far as I know, CocoaVia products are not labeled as organic or fair trade. 

*Theobromine Chocolate has a mild stimulating effect due to theobromine, a substance similar to caffeine. People sensitive to caffeine and parents of young children should be cautious about this, and avoid chocolate close to bedtime.  Do not let your dog eat chocolate – dogs cannot metabolize theobromine and can develop epilepsy, have a heart attack or die from eating it.

*Oxalates – Chocolate is a source of oxalates, which can be a problem for people who have had calcium oxalate kidney stones.  If you are at risk, talk to your doctor – and drink lots of water!

*Healthy Chocolate for You! You can buy organic, fair trade, dark chocolate bars locally, and in many markets.  Look for a bar that has 70% cocoa or higher.  Note the caloric content if you are watching your weight.  You can also find unsweetened cocoa powder, and make sure it is not ‘dutch processed’, which will lower its flavonoid content. Make a cocoa drink with 1% milk, soy or nut milk, or hot water, and sweeten it with xylitol (a healthy sugar that’s good for your teeth!) or stevia or both. You can skip sugar by mashing a banana with unsweetened cocoa powder, and add peanut or almond butter if desired. You can make a shake with your favorite ingredients and add cocoa powder and pomegranate concentrate for sweetness. Purists can buy organic, fair trade cocoa nibs and eat them with raisins for sweetness. Buying ‘fair trade’ cocoa or chocolate bars is important, because cocoa producers in Latin America are often badly underpaid and in Africa child labor is a serious problem. The fair trade label ensures that the cocoa workers are decently treated.

Sadja Greenwood, MD, MPH  back issues on this blog

Sleep Apnea - What is it? What can help? The Didgeridoo?

Each time you breath in, muscles in your throat, chest and diaphragm help you inhale; air flows from your nose and mouth into your lungs  - the breath of life.  During your waking hours your breathing is usually regular and automatic, unless you suffer from asthma or other lung diseases.  Throat muscles are important, although we are generally not aware of their action, by keeping the  airway open and stiff so inhalation is easy. When you sleep, these throat muscles may relax, narrowing your airway.  Normally, this narrowing doesn’t prevent air flow in and out of your lungs.  But if you have sleep apnea, your airway can become partially or fully blocked because of factors like these: 

*Your throat muscles and tongue relax more than normal.  Aging may play a role here.

*Your tongue and tonsils may be large compared to the opening into your windpipe.

*Overweight may cause extra fat tissue to thicken the wall of the windpipe, narrowing it and making it harder to keep open.

*The shape of your head and neck may result in a smaller airway size. 

Apnea is a word that means the suspension of breathing.  During sleep apnea, when the opening to the windpipe is narrowed or closed, people snore loudly and/or stop breathing for a time. Breathing may stop for up to a minute. Blood oxygen levels drop, triggering the brain to disturb sleep.  This helps to tighten airway muscles and open the windpipe.  Normal breathing starts again, often with a snorting sound.  When this happens repeatedly during the night, drops in oxygen levels and constant waking can result in the release of stress hormones.  A risk of high blood pressure, heart attack, stroke and irregular heartbeat is increased.  People with this condition often have excessive daytime fatigue because of sleep disturbance.  They often do not experience REM sleep and do not have dreams. 

Sleep apnea can be greatly helped by  a device called CPAP – continuous positive airway pressure, as well as by certain dental devices.  Many people with sleep apnea have used these treatments, which are important and helpful.  However, it is not easy for everyone to get used to these treatments and use them regularly. Weight loss is also helpful for some people with sleep apnea.

Since the human mind is infinitely inventive, new treatments that involve breathing techniques were bound to emerge. Instructors teaching the didgeridoo noted that their students reported reduced daytime sleepiness and less snoring after practicing the instrument for several months.  In Zurich, a group of doctors, respiratory therapists and sleep therapists decided to test the proposition that training the upper airway by digeridoo playing would reduce daytime sleepiness, due to training the muscles of the upper airways that control airway dilation and wall stiffening.  The recruited 25 patients, average age 50, who had moderate sleep apnea and were willing to learn the didgeridoo.  Half the patients became a control group, who had to wait for 4 months before taking the didg training.  The patients had weekly lessons, and were told to practice for 20 minutes 5 times a week.  They were instructed in circular breathing.  Apparently the practice was enjoyable, as compliance was excellent – the subjects practiced 6 days a week, and there were no dropouts.  The same was true of the control group, who started didg playing 4 months later.  The study found that patients had reduced daytime sleepiness and snoring – the effectiveness of didg playing was slightly less than that of regular CPAP use, but still notable.  The study was published in the British Medical Journal in 2006.

A study in Australia looked at the effectiveness of didgeridoo playing on boys with asthma.  The comparison group was singing lessons for girls.  Asthma is a problem for 15% of Austrian Aborigines, probably because of poverty and poor living conditions.  Girls are not supposed to play the didgeridoo in public for cultural reasons.  Asthma relief was more pronounced for the didg players than the singers. Playing the didg has a pronounced effect on lung capacity, relaxation and the ease of controlled breathing.  The study was published in Music and Medicine in 2013.

I have been taking classes in didgeridoo playing in Petaluma, and have found playing the instrument to be calming, mesmerizing, and helpful for my lungs. I love the sound of the low vibrations. Other people in the classes have found improvement with their sleep apnea.  The teacher, Elise Peeples, will be giving an introductory class in January as well as continuing lessons.  The classes will take place on Saturday morning in Petaluma.  I plan to post fliers about the classes and also give them to local doctors who may want to refer their patients.  Feel free to contact me if you are interested.  Full disclosure – I am crazy about wind instruments. 

Sadja Greenwood, MD, MPH  Back issues on this blog!

The Color Purple

I ‘m not referring to the amazing novel by Alice Walker, which won the 1983 Pulitzer Prize and the National Book Award for fiction.  I’m not writing about the movie with Whoopi Goldberg, Danny Glover and Oprah Winfrey, directed by Steven Spielberg, although I am planning to see it again.  I’m writing about (you guessed it) the benefits of purple foods, such as, purple cabbage, the skin of eggplant, purple corn, black rice, raspberries, cherries, blueberries, blackberries, cranberries, blood oranges, dark grapes and red wines. The dark red and purple color in these foods contain a pigment known as anthocyanin, which may appear red, purple or blue depending on the pH. 

Anthocyanins occur in the leaves, stems, flowers, fruits and roots of many plants.  Their colors attracts pollinators and other animals, enhances the scattering of seeds, and also protect plants from sun damage. 

Researchers at Ohio State University have done studies on human colon cancer cells and in rats, to determine what gives anthocyanins cancer –protective properties.  Extracts derived from purple corn were the most potent, with chokeberry and bilberry extracts also effective in reducing colon cancer cell growth in laboratory dishes. The researchers said that only small amounts of anthocyanin is absorbed by the blood stream in animals, but a large portion travels through the gastro-intestinal tract, where tissues absorb the compound. Anthocyanins may also help with esophageal cancers.   The researchers also noted that plant pigments such as anthocyanins could be used instead of synthetic dyes to color foods and enhance their health-promoting properties.

A comprehensive review of anthocyanin consumption and human health was published by an Italian research center in 2013.  They cited papers showing that anthocyanins  can protect against heart disease, obesity and diabetes, and gave rodent pancreatic cells increased insulin secretion.  Anticancer activity was found in leukemia cells, colon cancer cells, oral cancer cells, and other forms of cancer.  Laboratory studies have shown that anthocyanins can inhibit malignant cell growth, and stimulate apoptosis (tumor cell death).  The authors cited studies showing potent anti-oxidant activity of anthocyanins, which is enhanced by the other phytonutrients and vitamins in fruits.  Studies have shown neuroprotective  activity in animals with brain injuries, memory problems and visual decline with aging.  Recent studies also indicate that anthocyanins can inhibit the growth of some pathogenic bacteria, and may enhance the growth of healthy bacteria in the intestinal tract. 

What inspired me to write this column were the purple yams now on sale at the Bolinas People’s Store.  They are deep in color and amazingly good.  I also recall that Dr. Donald Abrams, an integrative oncologist at UCSF’s Osher Center, has said that he eats a yam every day of the year.   My advice:  Try those yams and also purple potatoes.  Once you plant the little Peruvian potatoes in your yard (gopher proof area) they will keep on giving, I have some ready to plant – call me if you want a few.  They are hardy in the winter. Include berries in your diet as often as possible, including frozen berries during the winter months.  Stock up on the cranberries now in season, and freeze some for later.  Eat prunes – they are purple plums and are high in anthocyanins.  Get purple popcorn and black rice at a natural food store.  Just think of the color purple; it’s powerful. 

Sadja Greenwood, MD, MPH – back issues on this blog

Artificial Sweeteners Can Undermine Your Diet

All those non-caloric packages of saccharin, aspartame, or neotame (lots of different trade names – Splenda, Equal, etc) you may have been putting in your coffee have been found to make changes in your intestinal bacteria  - changes that can actually move you towards diabetes.  The same is true for sugar free colas and other diet drinks.  Researchers at the Weizmann Institute of Science in Israel started working with mice, and showed that the artificial sweeteners induced glucose intolerance – which occurs when the body cannot cope with the amount of sugar in the diet.  They found that the gut bacteria, known as the gut microbiome, were involved – reacting to the sweeteners even though the body does not recognize these substances as food.  The artificial sweeteners changed the composition of bacteria in the microbiome, and induced glucose intolerance.  The new microbial functions are known to infer a propensity to obesity and diabetes.

The researchers then enlisted a group of human volunteers who did not generally use artificially sweetened food or drink, and had them consume them for a week.  Many, but not all of the volunteers began to develop glucose intolerance after a week.  The composition of their gut microbiome explained the differences.  The researchers found two different populations of gut bacteria – one that induced glucose intolerance when exposed to artificial sweeteners and one that had no effect either way.  They believed that certain bacteria in the guts of those who developed glucose intolerance reacted to the chemical sweeteners by secreting substances that provoked an inflammatory response similar to sugar overdose, promoting changes in the body’s ability to utilize sugar.

Here’s how Dr. Elinav of the Weizmann Institute summarized his findings:  “Our relationship with our own individual mix of gut bacteria is a huge factor in determining how the food we eat affects us.  Especially intriguing is the link between use of artificial sweeteners – through the bacteria in our guts – to a tendency to develop the very disorders they were designed to prevent; this calls for reassessment of today’s massive, unsupervised consumption of these substances.”

What is a person to do with this new information if s/he uses artificial sweeteners?  Here are some answers I found on the internet:  add cinnamon to your coffee, or a little unsweetened cocoa.  Try milk, cream, Almond Milk or unsweetened coconut milk.  Many people use Stevia - from the leaf of a tropical plant. Only a drop is needed, though some find it has a bitter aftertaste.  Not enough research has been done to tell if Stevia can alter the microbiome.  I have used xylitol and concentrated pomegranate juice to sweeten cocoa.  Xylitol is a sugar made from hardwood trees, corncobs or other plants, with 33% fewer calories than sucrose per gram.  It has dental health properties, as it increases saliva production and is not metabolized by mouth bacteria.  Bacteria are unable to produce as much acid in the presence of xylitol, so that the teeth are less damaged by acid and plaque.  Many toothpastes are sweetened with xylitol.  This would be my recommendation for people who want sweeteners in their coffee or tea – carry a little home made packet of xylitol. Chew xylitol gum during the day as well if you have problems with cavities (talk to your dentist first!).  You can get xylitol at the Palace Market, the Bolinas People’s store, and most natural food stores.  A xylitol gum called Spry is also available at markets and on the internet.    If your passion is diet soft drinks, try substituting plain carbonated water with slices of lemons and oranges.

Good luck – it takes time to change a habit, but it can be done. 

Sadja Greenwood, MD, MPH   back issues on this blog

The Obesity Dilemma & Good News About Tomatoes

We are the fattest country in the world, in terms of the proportion of our citizens who are overweight or obese – about 70% of adults and 32% of children.  Data from 1988 to 2010 showed that obesity increased in this time period, but average daily calorie intake was more stable.  The proportion of adults who did not engage in physical activity increased markedly  - from 19% to 52% in women and from 11% to 44% in men. 

The impacts of this trend on individual well-being, the incidence of diseases such as diabetes, heart disease and many cancers, and the cost of medical care and medical insurance are huge.  Prevention is needed, and must be aimed at increasing the space and time for people to walk and play, and decreasing the desirability of sugar-laden drinks, salty snack food and junk food with empty calories.  While it is easy to say this, public health officials and thinkers are struggling to come up with ways to reverse the trend. 

University of Illinois researchers have written that easy access to junk food, even when vegetables are available and people exercise, is a major cause of the obesity epidemic.  They think that reducing calorie intake from sweetened beverages and salty snacks would be more effective than convincing people to eat more vegetables.  How can this be done? We live in a society that questions and dislikes regulations , and we are inundated with advertising for easily purchased fattening foods.    Attempts to remove sweetened soda drinks from schools have not been successful nationwide, both because of school resistance (sales are a source of income) and because children buy the drinks elsewhere.  Our local schools are an exception!

In general, taxes on sweetened soda drinks have failed at the ballot box- Richmond, CA tried to pass a soda tax in 2012 but the nay vote was 67%. 

Michelle Obama has been working with the U.S. Department of Agriculture to formulate nutrition standards for schools with predominately low income students.  Starting this summer, these schools will receive financial aid to implement healthy breakfasts and lunches.  These recommendations set limits on calories, salt, sugar and fat in foods and beverages, and also promote snack foods with more whole grains, low-fat dairy and fruits and vegetables.  This is a start, especially if children are given instructions on food, cooking and gardening, and can raise some food at school. 

It is also important to provide school activities beyond competitive sports, such as dancing, theater, martial arts, gym workouts and hiking.  This will allow shy or ‘non-athletic’ students to find a way to be active that they can enjoy and pursue for a lifetime. 

Cities must have sidewalks and parks, including pocket parks, and encourage the placement of markets and farmers’ markets where there are food deserts. 

California is doing better than 45 other states with regard to the epidemic, but it’s hard to be satisfied with our rate of adult obesity of 24%.  We have abundant produce and a beautiful out-of-doors.    Something is drastically wrong.  Food is a survival issue, a huge source of pleasure and of course an emotional  issue – but it can kill us as well as nourish us.  We are swayed by powerful financial interests to buy and eat or drink the wrong things for our bodies.  Solving this problem will take many approaches, including a return to ancient wisdom and age old methods of cooking and eating found in each culture.  

And now for some good news – about tomatoes and watermelon.

Lycopene is one of more than 600 carotenoids found in vegetables and fruits – it is the red pigment in tomatoes and watermelons.  It is an antioxidant that substantially lowers the risk of many diseases.  A study from Harvard showed that women with the highest blood levels of lycopene had a 50% lower risk of  heart disease when followed for 5 years.  Lycopene also lowers the risk of developing  many cancers, including prostate, cervix, skin, bladder, breast, lung and digestive tract.  It’s tomato season, so go for the deep red kind;  include a little fat in your meal to help you absorb the lycopene – such as olive oil on your salad.  Watermelon for dessert or in salad is another good choice for lycopene.  In the winter, tomato paste or tomato sauce will give you abundant lycopene.  Put a little, or a lot, in all your dishes.  Tomatoes will give your dish 3 of the 5 tongue tastes – sweet, sour and umami flavor.  (Salty and bitter are the other tastes in the mouth.) Umami taste is considered to be ‘meaty’ or ‘brothy’.  It’s also found in mushrooms and meat, fish and poultry.    We are so lucky to have great tomatoes this year.

Sadja Greenwood, MD, MPH   back issues on this blog

Flaxseed can help lower blood pressure

Flax plants, used for food and to make textiles (linen) have been used for thousands of years.  Flax fibers spun into clothing have been found in a cave in the Republic of Georgia and dated as made 30,000 years ago.  Modern science has found that flax seeds contain a plant form of omega-3 fatty acid (alpha linolenic acid) as well as lignans - substances that act as plant estrogens. Lignans are also found in lower amounts in rye, wheat, oats, barley, soybeans, sesame seeds, cruciferous vegetables and in certain fruits such as strawberries and apricots.  Flax seeds, but not flax seed oil by itself, has been found to be associated with a lower risk for breast cancer.  A study from Duke University showed an association of flax seed with slower growth of prostate cancer.  

A recent study from St. Boniface Hospital Research Center in Manitoba showed that people with high blood pressure and resultant leg pain from constricted blood vessels were helped by supplementing their diets with ground flax seeds.  They took 30 grams a day, which is about 4 tablespoons, put into muffins and bars or eaten as plain ground flax.  The flax seed provided abundant fiber, and the subjects did not gain weight during the 6 month trial.  Subjects in the comparison group, also with high blood pressure, were given food enhanced with almonds and other  ground nuts.  Their blood pressures did not change during the 6 month study.  The blood pressure reductions seen in the flaxseed group were impressive - systolic blood pressure was 10 mm Hg lower and diastolic 7 mm Hg lower after 6 months.  In subjects with initial systolic blood pressure readings of  140 mmHg or higher, there was a reduction of 15 mm Hg systolic and 7 mm Hg diastolic.  These figures compare favorably with the reductions seen with many blood pressure medications.  It should be noted that subjects in this study continued their prescribed medications for blood pressure reduction.  The authors cautioned that people trying flaxseed meal should remain under their doctor’s care and not change their meds unless advised to do so.  

A study from the University of Saskatchewan in 2009 showed that men, but not women, had reduced scores of factors in the ‘metabolic syndrome’ when they took flax seed components and engaged in a walking program.  The metabolic syndrome is a cluster of conditions: increased blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol levels.  These factors can lead to an increased risk of heart disease, stroke and diabetes.

This article has given the reader several good reasons to try adding flax seeds to your diet.  It’s easy to do so, and the taste is nutty and pleasant.  You can grind your own (with a spice or coffee grinder) from organic flax seed from many stores, or buy it already ground.  Be sure to refrigerate the ground flax.  Put it on oatmeal, salad, stir fries  or in shakes.  Incorporate it into baked goods.  There are lots of recipes for this on line. Ground flax adds fiber to your diet and can relieve constipation. Be sure to drink more fluids if you start using flax.  

Post-menopausal women may enjoy the slight increase in safe plant estrogens from the flaxseed lignans,  However, flax has not been shown to relieve hot flashes.

Sadja Greenwood, MD   back issues on this blog

Get Fitter Faster with Interval Training

Interval training is a fitness practice that anyone can use, no matter what their level of activity.  You alternate periods of light exercise, or even rest, with periods of relatively intense exercise - depending on your fitness level. You can do this when walking, running, biking, swimming, or using a stationary bike or other aerobic gym machine. If you don’t enjoy exercise ‘that much’, but know you should do it, of if you are short on time, the big advantage of interval training is that you can get results quite quickly.  According to Martin Gibala, professor of Kinesiology at McMaster University in Ontario, 20 minutes three times a week is the usual time commitment. In these 20 minutes, you alternate recovery periods with hard effort.  The protocol used by Gibala involves speeding up to 85-90% of your maximum heart rate for one minute, and then slowing down for one minute - you keep doing this 10 times during the 20 minutes.  

So far, trials of this method have shown that interval training makes the heart a better pump, makes blood vessels more elastic, and makes muscles better at using oxygen.  Average blood sugar levels were reduced after two weeks of interval training, in people with and without diabetes.  This happens because exercised muscles have greatly enhanced ability to take up blood glucose.  

People rode stationary bikes in the McMaster studies, because of the safety of this exercise, and the relative ease on joints.  It’s important to realize that people can start interval training at any level of fitness.  If your usual exercise is walking around the block, or around your neighborhood, try alternating faster walking for a minute with slower for the next minute, and keep this up for 20 minutes.  You don’t have to sprint if you are not used to doing so!  

You should talk to your doctor or nurse practitioner about any proposed new exercise program if you have been inactive.  Remember - it’s also risky to sit on the couch all day!

A recent study from the University of Copenhagen in Denmark showed that for people with diabetes- alternating levels of walking intensity could be much more effective than walking at constant speed to help manage blood sugar.  They measured insulin secretion after a glucose infusion, and did skeletal muscle biopsies, before and after a 4 month training period.  Only the people who had been given interval walking training showed improved blood sugar control and increased insulin sensitivity in in skeletal muscle.  People who walked a comparable amount of time without interval training were the comparison group.

I love to walk and daydream, sing to myself, or talk with friends as I stroll.  Whatever activity you like to do - carry on. Interval training can be effective if done only 3 times a week.   “If it’s physical, it’s therapy” were the words on a  t-shirt I  saw long ago in Golden Gate Park.  Here are some other great t-shirt slogans:

I got my shit together with a Clivus Multrum.

Fighting terrorism since 1492 (a group of Indians with long rifles)

Some Day my Prince will Come - and I wanna  come too. 

But I digress.  See you on the road, looking at your stopwatch.

Sadja Greenwood 

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

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!

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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Can Aspirin Help to Prevent Cancer? - the pros and cons

Can Aspirin Help Prevent Cancer? - the pros and cons

Two physicians at Harvard Medical School, Drs. Michelle Holmes and Wendy Chen, recently wrote in the New York Times about the apparent ability of regular aspirin use to prevent death in women with breast cancer.  They called for a randomized trial of aspirin, enrolling 3000 women with stage 2 and 3 breast cancer for five years, which they estimate would cost $10 million.  They have repeatedly tried to raise these funds through federal grants, and have been rejected.  It is possible that the publicity from their article will result in funding from the government, private foundations or private individuals.  The first randomized clinical trial of aspirin is now going on in Britain, funded by a nonprofit group.  They are looking at 4 cancers - colorectal, breast, gastro-esophageal, & prostate - with results expected by 2025.  

Evidence so far:  Many studies in the past 20 years have shown that taking aspirin is associated with the prevention of colon cancer.  A recent study helped to refine the findings - people with high amounts of an enzyme known as 15-PDGH in their gut lining had a 50% lower risk of colon cancer than those with a low level, if they took the equivalent of 2 regular strength aspirins a week.  A regular strength aspirin is 325 mg, and a ‘baby’ aspirin is usually 81 mg.  (2 x 325=650, and 7 X 81=567 - close enough). The test for 15-PDGH is not yet available.  People at high risk for colon cancer - a diet low in vegetables and whole grains, high in red meat and processed meat, inactivity, obesity, smoking, family history of colon cancer - should talk to their doctor about the pros and cons of low dose aspirin.  (People with these habits might also want to make some life-style changes.)

Breast cancer: a Columbia University study published in 2004 showed that women who took aspirin regularly (the 325 mg or 81 mg dose was not distinguished) were 20–30% less likely to develop hormone positive breast cancer.  Aspirin did not decrease the risk of hormone negative breast cancer. The proposed mechanism is that by a series of physiologic steps, aspirin decreases hormone biosynthesis in the body.  The researchers also discussed the anti-inflammatory properties of aspirin, which may reduce cancer risk overall.  NSAIDS such as ibuprofen were also associated with slightly decreased cancer risk, but not as great as aspirin.  Acetaminophen (Tylenol) did not show a protective effect.  Another study, published in 2010 by the authors of the recent NYTimes article, looked at data from The Nurses Health Study in the US.  It found that in women living at least 1 year after a breast cancer diagnosis, aspirin use was associated with a decreased risk of distant recurrence and breast cancer death.

A recent study from the National Cancer Institute showed that daily aspirin use may reduce the risk of ovarian cancer by 20%.  About 20,000 women in the US will be diagnosed with ovarian cancer in 2014, and more than 14,000 will die of this disease, which is hard to diagnose early enough for a cure.  Early symptoms are non-specific, such as abdominal bloating, pelvic or abdominal pain, feeling full quickly, and urinary frequency.    

Many people take aspirin to prevent heart disease, especially if they have already had a heart attack - to prevent another.  Paramedics regularly give aspirin to a heart attack patient on the way to the hospital. Heart attacks and strokes occur when the blood supply to a part of the heart muscle or brain is blocked by ‘plaque’, a buildup of cholesterol, fatty substances, cellular waste products and calcium.  Aspirin helps to prevent blood clotting in the presence of plaque. The dose to take should always be discussed with your health care provider. 

There are side effects of aspirin use, which is why it cannot be recommended to everyone to reduce the risk of cancer or heart disease.  Aspirin can be irritating to the stomach and can cause serious bleeding in the gastrointestinal tract.  It can also cause bleeding in the brain, known as a hemorrhagic stroke. 

Here’s the real message of this column: it looks as though a simple medicine - aspirin - could be very important in the prevention of many common cancers.  However, because of the possible side effects and dangers of aspirin, randomized studies are greatly needed to show its efficacy and safety.  Funding is needed for this, and it will not come from pharmaceutical companies, as aspirin is such a common and inexpensive drug.  The recent publicity about this subject has stirred great interest.  Hopefully there will soon be such studies -with answers coming more quickly than the British study due to be finished in 2025!  

Sadja Greenwood, MD,MPH   back issues on this blog

What's the Connection between Sleep, Exercise and the Immune System?

When we get sick – with an infection, other illness or traumatic event – we want to sleep more.  It’s a natural reaction seen in other animals as well.  Recent research at the University of Pennsylvania showed that sleep helps to facilitate the immune response by increasing resistance to infection and survival after infection.  This research was done on fruit flies – but don’t discount it too quickly.  The genetic pathways found in these insects are preserved in mammals.  The take-home message from this work is that when you get sick – sleep as much as your body tells you to.

Research at the Finnish Institute of Occupational Health showed that healthy young adults restricted to 4 hours of sleep per night for 5 days  showed marked changes in their immune systems, with pro-inflammatory changes and an increase in allergic reactions and asthma.  Sleep deprivation also affects metabolism, leading to obesity, heart disease and diabetes. 

What are some natural ways to get enough sleep?  If you work at home and can’t sleep well at night, try a nap during the day – any time from 10 to 30 minutes may revive your day.  Regulate your 24 hour (circadian) rhythms by exposing yourself to bright light n the morning – sunlight or a ‘happylight’ during foggy days or the winter.  Before bedtime, wear blue-blocking glasses for an hour, while you read, compute, play music or watch television.  When you block the short blue wavelengths of the light spectrum with these orange colored glasses, you prevent the suppression of your natural melatonin. Melatonin is a hormone produced by the brain’s  pineal gland, located behind your eyes.  Melatonin outflow promotes good sleep. As an anti-oxidant, it has many salutary effects on the body, which we have suppressed with the artificial light of light bulbs, televisions, tablets et al.  Go to the website LowBlueLight.com to read about the benefits of normal melatonin release - by wearing the glasses for an hour or more before bedtime.  You can get a pair that will fit over your regular glasses and allow you to read, compute, or watch TV.  You can also take 1-3 mg of melatonin as a sleeping pill - start with the lowest dose.  This is safer than prescription sleeping pills such as Ambien or Valium.

Exercising  is another way to induce melatonin release and help sleep.   Morning exercise may be the most effective in increasing melatonin secretion in the evening, but exercise at any time of day can work for many people.  Here’s another benefit of exercise – a recent study from UCLA showed that maintaining muscle mass through resistance exercise (or plain hard work such as lifting, or farming) is more important than BMI (body mass index) in determining the risk of death from any cause.  So – turn your compost, get out those weights, take a Pilates class or do pushups to increase your muscle mass.

I will be away for a few weeks; my column will resume on Monday, May 26^th. Keep eating those colorful vegetables and fruits, a brassica vegetable every day, herbs, olive oil, pre and probiotic foods, and nosh on nuts.  Get some blueblocking glasses for evening use, and thereby improve your sleep. They are widely available on the Internet; I think the ones at LowBlueLight are the best – but more expensive. If you are sleep deprived at night, remember that taking a daytime nap does not mean you are lazy  - just look at your dog or cat..  Write me a comment and I’ll reply. 

Sadja  Greenwood, MD – back issues on this blog