Monday, May 31, 2010

Go to Health –Blueberries

Most of us know that blueberries are healthy – but what do we know to back up this claim? Blueberries were an important food source for Native American tribes in the east; berries, leaves and roots were also considered medicinal. In the last 10 years there has been an increasing research in compounds in blueberries that may prevent disease. Wild blueberries have been found to have a higher antioxidant capacity than cranberries, strawberries, plums, and raspberries. Here is some of the data.

The Brain: blueberries contain ‘anthocyanins’ - pigments found in red/purplish fruits and vegetables – such as purple cabbage, beets, blueberries, cocoa, cherries, raspberries and purple grapes. These pigments are antioxidant and anti-inflammatory, helping to protect brain cells and enhance their ability to signal one another. Researchers at the University of Cincinnati worked with a small group of older adults with early memory changes. Those who drank 2 cups of blueberry juice per day showed improved memory and learning, reduced depression and improved glucose levels after 3 months. Similar results have been found in experimental animals. A study from Reading University in England on people of all ages showed that people taking 200 gm (2 cups) of blueberries in a morning smoothie did better on mental tasks 5 hours later compared to people having a smoothie without blueberries. Two cups is a large (and expensive) amount of blueberries. Strawberries, cocoa and raspberries were said to have similar effects on the brain. A study at Tufts University in Boston on experimental animals showed that blueberries improved motor and navigational skills.

Cancer prevention: Studies at the University of Illinois have looked at 3 phases of cancer development – initiation, promotion and proliferation (metastasis). Various compounds in wild blueberries are helpful in prevention all 3 phases, Researchers at several universities have looked at the ability of blueberry extracts to inhibit the growth of prostate, colon, breast and cervical cancer cells. The work looks promising, but is still laboratory-based and preliminary.

Urinary Tract infections: Rutgers University has a Blueberry-Cranberry Research Center; they have found that both fruits prevent bacteria from adhering to urinary tract tissues, and this help prevent urinary tract infections. A half-cup of blueberries a day may be sufficient for this benefit.

Heart Health: A study on rats at Tufts University and the National Institute on Aging showed that when the animals had a major artery to their hearts tied off, those on a blueberry enriched diet had less damage to their hearts than those on a control diet, and were less likely to develop heart failure. Several studies in Canada and at UC Davis have shown that blueberries can reduce LDL Cholesterol (the kind that can lead to heart attack and stroke).

Diabetes: The anthocyanins in blueberries have been found to reduce blood sugar levels in rodents bred to develop diabetes, according to studies at North Carolina State University. This may mean that blueberries and their juice are safe for people with diabetes. People with high blood sugar should proceed with caution and check their levels. This may be a helpful fruit.

Blueberries and their European cousin, bilberries, are now being grown all over the world. There is said to be a blueberry juice craze in Japan, with the idea that blueberries reduce eyestrain. This has also been studied with bilberries in Europe. Most markets carry frozen blueberries all year, and fresh ones in the summer. They are a good investment.
Sadja Greenwood, MD, MPH Back issues here. Leave me a message!

Monday, May 10, 2010

Go to Health: The Second Brain in Your Gut!

We have an extensive network of nerve cells (neurons) lining our guts – some call it ‘the second brain’. This nervous system contains about 100 million neurons, more neurons than the spinal cord or the peripheral nervous system (sensory and motor nerves relaying impulses all over the body). The second brain consists of sheaths of neurons embedded in the long tube of our gut, from the esophagus to the anus, It gives the necessary stimuli for mechanical mixing of food in the stomach, breaking down particles, chemical processing, and rhythmical muscle contractions that move food down the intestinal tract. We can feel the inner world of our gut when we pay attention, especially if it gives us pain from malfunction (think of the cramps of dysentery, the discomfort of gas or the pain of appendicitis). Think of ‘butterflies in the stomach’ when you are anxious, or in love, or a ‘knot’ in your midsection when you are asked to do something you don’t want to do! Sudden fear, often felt in the belly, will stop digestion to route blood to your muscles for flight or fight. These feelings can come on before the brain in your head has understood the situation. The second brain works fast!

The second brain makes many neurotransmitters, just like the brain in our heads. Over 80% percent of the body’s serotonin is located in the gut, where it is made from tryptophan (an amino acid found in the proteins we eat). Serotonin regulates intestinal movements. If irritants are present in our food, gut nerve cells release more serotonin, making the gut move faster to get rid of the noxious substance. It can also induce vomiting. Gut serotonin is regularly released into the blood stream, where it is taken up and stored by blood platelets, and used to help in the clotting process when a cut or wound occurs. Serotonin is also important in the regulation of mood, appetite, sleep, muscle contraction and some cognitive processes.

The SSRI antidepressants (Prozac, Paxil, Zoloft, Celexa, Lexapro and others) increase serotonin levels and are highly effective for some people to alleviate depression and anxiety. However they can also can affect the gut and bone strength. Some, but not all, users have abdominal symptoms with these drugs. Serotonin’s role in bone strength is under study - bones get weaker in the presence of more serotonin. Users of SSRIs have been shown to have greater rates of bone loss than average, and should be extra careful to protect their bones with exercise, vitamin D and special medications if needed.

In addition to serotonin, the brain in the gut also makes the neurotransmitters dopamine, glutamate, norephinephrine and nitric oxide, and two dozen small brain proteins, called neuropeptides. Endorphins, that relieve pain, are also made in the gut, as well as tranquilizing substances. The food-mood connection is real.

You can keep your gut happy and healthy by some simple daily habits. Take a probiotic every morning (keep it refrigerated) to ensure a predominance of healthy bacteria in your colon. Eat plenty of simple plant food to ensure good levels of fiber, vitamins, minerals and other plant nutrients. Go for dried figs, dates or bananas instead of cake and candy. You know the rap! Have you tried dried bananas? Wow!
Sadja Greenwood, MD, MPH back columns on this blog. Leave me your thoughts.

Wednesday, May 5, 2010

Go to Health: Important Updates on Vitamin D and Chocolate

Vitamin D
Researchers at the University of Copenhagen have just published an important paper - explaining the mechanisms by which vitamin D helps our immune systems fight off viral and bacterial infections. T cells, the cells that detect and kill foreign pathogens must be triggered into action by vitamin D. When the T cell meets a clump of bacteria or viruses, it extends a signaling device - an antenna - known as a vitamin D receptor. If it finds enough vitamin D in the blood, it is transformed into a ‘killer’ cell that will attack and destroy all cells carrying traces of a foreign pathogen, or into a ‘helper’ call that assist the immune system in acquiring ‘memory’. This memory enables the immune system to recognize the pathogen at the next encounter and launch an enhanced response. If vitamin D blood levels are low, T cells are less likely to be transformed into killer or helper cells.

Prior studies have shown that people with higher blood levels of vitamin D are less likely to get respiratory infections. The Copenhagen group has found a mechanism that may explain this. Many local residents suffered from prolonged colds and coughs this winter – getting adequate D is good preventive medicine and may help from now on..

We are heading into summer and the sun is back – so you can get D from safe sun exposure as well as from pills. While the majority of dermatologists discourage exposing skin to sunlight without sunscreen of 15 spf or higher, a few say that 10 minutes a day of exposure of the arms, legs and back is safe and can result in good levels of vitamin D being formed. Avoid sun exposure on your face by wearing sunscreen and a hat, because of skin damage and wrinkles. Get a blood level of 25 hydroxy vitamin D at the clinic, and aim for 35-40 ng/ml by taking vitamin D3 pills as well as safe sun exposure. Most doctors are now suggesting 1000-2000 IU of D daily in pill form.

A recent study from the University of South Carolina, funded by the National Institutes of Health, showed that pregnant women who took 4000 IU of vitamin D daily, starting at three months of pregnancy, had half the usual risk of premature delivery and ‘small for dates’ babies, and a 25% lower risk of respiratory infections, vaginal infections and gum problems. The pregnant women also had less diabetes, high blood pressure and ‘eclampsia’ - a dangerous complication. The university is now studying extra vitamin D for nursing mothers. (If you are pregnant or nursing, check with your doctor!)

Chocolate
In a previous column on chocolate, I wrote that chocolate increases 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. Another protective effect of NO is its inhibition of blood clotting and the adhesion of white blood cells to the lining of blood vessels. These findings tie in with a joint Swedish-US study that showed that heart attack patients who had eaten chocolate at least twice a week during the year before their attack were 66% less likely to die at that time from cardiac causes. Over the following 8 years, the risk of cardiac mortality went down as chocolate consumption went up – there was a 44% reduction of risk associated with eating chocolate up to once a week. The authors of this study cautioned that chocolate is not a health food, being high in sugars and fats. However, there are healthy ways to eat it. Buy unsweetened cocoa powder (Green and Black is organic and fair trade) and put it in a shake, sweetened with a date or two, pomegranate concentrate, banana, xylitol or stevia. Mash a banana and some peanut butter, add unsweetened cocoa powder, and eat it right away, or put it on toast.

Here’s another benefit – researchers at the University of Barcelona put 47 men and women (age 55 and older) on diets including 1/4th cup unsweetened cocoa powder and skim milk , to be taken twice a day, and found, after a month, that those who drank cocoa had lower levels of inflammatory markers associated with heart disease, and significantly higher HDL cholesterol (the good kind). People sensitive to caffeine should be careful with these amounts of cocoa, as they give a stimulant effect.

Dear readers – I hope your spirits are rising with the sun and the wonderful green plants in your gardens and all around you.
Sadja Greenwood, MD,MPH - back issues at on this blog. Leave me a message!

Tuesday, April 27, 2010

Methamphetamine – What YOU can do to stop the labs

We used to worry about meth labs in West Marin, even in Bolinas, picturing a cluttered house stocked with tubing, tanks of explosive chemicals, and a stove with bubbling beakers of a toxic brew. It’s gotten a lot simpler in recent years. Meth is now made in cars. There is a faster, cheaper and simpler method of making small amounts of meth. The ingredients – pills with the decongestant pseudoephedrine (Sudafed) and household chemicals are shaken in a 2 quart soda bottle. No flame is required. The back seat of a car or a bathroom stall are the new makeshift labs. The batches of meth are much smaller, so the addicts who make them are harder to apprehend. According to the NYTimes (4/15/10) roadsides throughout the country are littered with discarded pop bottles and chemicals from these car labs. Cleanup is dangerous and time-consuming, and addicts in cars are hard to apprehend. They are also very dangerous drivers.

The basis for meth production is pseudoephedrine, made in labs in Mexico, China and other countries, often from petroleum-based compounds. The chemical comes into the country illegally. However, most of the new car-based labs use pseudoephedrine pills known as Sudafed, Actifed or Contac. In California, these drugs are no longer directly available over the counter, and a limited amount is sold at any one time. However, drug addicts and dealers employ ‘smurfers’ - people who travel to various pharmacies, using different names, to buy as much Sudafed as possible
States are trying out different techniques to stop the new car labs. Oregon has gone the farthest, with a 2006 law that makes medicines with pseudoephedrine available only with a prescription. The state has seen a marked decrease in seizures of meth labs and in property crime,. Identity theft and child abuse are also linked to meth use. A similar law has been proposed in California, opposed by drug companies and chain drug stores. Oregon’s Senator Ron Wyden has introduced a bill in the US Senate called the Meth Labs Elimination Act, which would take Oregon’s law nationwide. This proposed legislation has been targeted and opposed by drug companies eager to protect their $500 million allergy and cold care business.

Sudafed and related drugs cause stimulation of the central nervous system, including sleeplessness, excitability, dizziness and anxiety. In certain people they can cause blood pressure elevation, a very rapid or irregular heart beat, and stroke.

There are safer ways to deal with nasal congestion due to colds or allergies. Work on eliminating allergens in your home. Rinse your nose with a solution of 4 ounces warm water, ¼ teaspoon salt and 1/8 teaspoon baking soda, using a bulb syringe or a neti pot. Alternatively, you can buy a Sinus Rinse kit in local pharmacies. Use an antihistamine such as Benadryl or Chlor-trimeton, being aware that these drugs can make you sleepy, or Claritin. Vitamin C in high doses is a natural antihistamine; many people take a gram of C every 3-4 hours when they have a runny nose due to a cold or allergy, and get relief without fatigue as a side effect.

But back to meth – here are some steps you can take for the safety of your family and the wider world. Call Jared Huffman, our assemblyman: 415-479-4920. Ask him to support the Wright bill, a measure that would require a prescription for drugs containing pseudoephedrine, which can be made into methamphetamine. Also call Mark Leno, our state senator, 479-6612, with the same message. Take your activism a step further and call Lynn Woolsey, our Congresswoman – 507-9554, and Senators Feinstein -393-0707, and Boxer – 403-0100. These are all local numbers. Ask these congresswomen to support Senator Ron Wyden’s bill to require a prescription for drugs containing pseudoephedrine.

Meth is not a benign recreational drug; it is a killer drug that threatens our youth and also our budgets. If you have any doubts about this, read Tweak, by Nic Sheff, a local youth whose life was profoundly disturbed by methamphetamine. Annual costs for meth detection, cleanup and health care in the US exceed $23 billion. It’s time to try what worked in Oregon to combat this drug.
Sadja Greenwood, MD, MPH - back issues on this blog.

Monday, April 5, 2010

Biological Exuberance; a new view of animal homosexuality

In his 1999 book Biological Exuberance – Animal Homosexuality and Natural Diversity – the biologist Bruce Bagemihl writes about same-
sex behaviors in a wide variety of primates, other mammals and in many bird species, explaining homosexual courtship, affection, sex, pair bonding and parenting. Same-sex behavior has been documented in over 450 species of animals; biologists point out that only a fraction of the more than a million species known to exist have been studied in any depth, so the number may be far larger. Bagemihl writes that western science has overstressed the importance of heterosexual sex for passing on genes and failed to notice many other kinds of sexual behavior – such as same sex mounting, necking (among male giraffes), oral sex and masturbation- mutual and solo.

Bonobos – pygmy chimpanzees (with whom we share over 99% of our genes) - are predominantly bisexual; females and males have frequent hetero and same-sex contact with each other, including with juveniles. Females also have sex during their pregnancies. Clearly their ‘exuberant’ sexual behavior has meanings beyond reproduction – anthropologists see it as beneficial to the group by creating tribal cohesion and preventing fights over food. These animals truly do make love not war.

Bagemihl points out that western science has attempted to explain animal homosexuality for over two hundred years but has had problems explaining behavior that is non-reproductive. However, from the point of view of biological exuberance, natural systems are driven as much by abundance as by limitations and practicality. Seen in this light, homosexuality and non-reproductive heterosexuality are “expected occurrences” – they are one manifestation of an overall “extravagance” of biological systems that has many other expressions.
Bagemihl. 1999. (Think of the peacock’s tail.)

In 2006, the Natural History Museum in Oslo opened the first-ever museum exhibition dedicated to gay animals. The exhibit , titled Against Nature?, showed photographs of the more than 1500 species (their count)where homosexuality has been observed – from insects to mammals. The curators stated that a greater understanding of how extensive and common this behavior is among animals could help to demystify homosexuality among people. You can see a few of the outstanding photographs of this exhibit by going to google : Against Nature? Exhibition in Oslo.

In today’s New York Times Magazine, April 4, 2010, the article The love that Dare Not Squawk its Name concerns new studies on animal homosexuality, mostly among seabirds. Careful observation of the Laysan Albatross, who nest in Hawaii, reveals that a third of nesting pairs are made up of two females. One or both mate briefly with a male and then return to their female nest-mate, with whom they may bond for many years. Taking off from Bagemihl’s theories, scientists are thinking that homosexuality must be seen as having different ‘purposes’ or manifestations in each species - it is a byproduct of reproductive sex, but cannot easily be explained by our current Darwinian model. New thinking is needed about the possible benefits of homosexuals to the family or the group, and also about homosexuality and bisexuality being a by-product of exuberant desire for sexual play.

Scientists studying animal sexual behavior have generally been careful not to extrapolate their findings to human society, but of course their findings have had an impact on the wider world. After publishing, the authors have been reviled by homophobes and cheered by many liberals and the GLBT community. The culture wars go on – and will undoubtedly be affected by new findings from other animals.
Sadja Greenwood, MD – back issues on this blog

Tuesday, March 30, 2010

Magnesium - for your bones, energy and brain

Magnesium is in the center of the chlorophyll molecule – just as iron is in hemoglobin. How impressive is that!

Magnesium is abundant in green vegetables (think chlorophyll), beans, whole grains, nuts, edible seeds such as pumpkin and sunflower, bananas, chocolate and many other unrefined plant foods. How can it be that a recent report from the US Department of Agriculture indicated that only 32% of us were getting adequate magnesium in our diet? Perhaps this is because we are not following Michael Pollan’s rule “If it came from a plant, eat it; if it was made in a plant, don’t.” A lot of us are filling up on things our ancestors would not recognize as food.


Bones: Magnesium is stored in bones; if there is not enough, bones become more brittle. A study from Tufts University of 900 elderly men and women found higher dietary magnesium intakes were associated with increased bone mineral density at the hip. Eating an unrefined plant based diet gives abundant magnesium as well as potassium, and will help bone strength by creating a more alkaline urine, thereby minimizing calcium loss.

Energy: The body provides energy for all metabolic processes by transforming carbohydrates and fats into a molecule called ATP, which exists as a complex with magnesium. A study from the Agricultural Research Service in North Dakota showed that people with inadequate levels of magnesium need more oxygen during exercise, and tire more quickly, than those with adequate levels.
Heart: Magnesium helps to maintain a normal heart rhythm. Magnesium supplements are sometimes suggested by cardiologists for people with intermittent atrial fibrillation or with cardiac failure. Studies have shown that a high dietary intake of magnesium (lots of unrefined plant food) may decrease blood pressure. This kind of diet is also rich in potassium and calcium, so it is difficult to sort out the factors involved.

Brain: An international study Tsinghua University in Beijing, University of Toronto, MIT, and Tel Aviv University showed that increased levels of magnesium in the brain enhanced learning and memory (in rats). The researchers used a new supplement that passed the blood-brain barrier and entered the brain. While this supplement is not available, they stated that people should get their magnesium from dietary sources – noting that half of all people in industrialized countries have magnesium deficiencies.. A better, plant-based diet may delay the cognitive impairment of aging.

Getting Enough Magnesium (Mg) It’s easy to get plenty of magnesium by eating green vegetables, beans, nuts, seeds and whole grains. Taking Mg as a supplement can be dangerous for people with kidney disease – especially for older people - so check with your doctor. The Institute of Medicine has set a ‘tolerable upper intake’ for Mg pills at 350 mg/day, and many women take that amount with their calcium supplements. Higher levels can cause diarrhea and gastrointestinal discomfort. Magnesium citrate is commonly used as a safe supplement in sensible doses. Two forms of Mg are laxatives and should not be taken regularly – magnesium sulfate (Epsom salts) and magnesium hydroxide (Milk of Magnesia).. Final word – here's another reason to go for the greens!
Sadja Greenwood MD, MPH Back issues on this blog

Sunday, March 21, 2010

Important Supplements

IMPORTANT SUPPLEMENTS
Dear readers: this is a summary of a talk I gave at Commonweal on March 7, 2010. Below are some suggested supplements that may help to give you maximum health. However, eating a good diet is the first key to health. Here in West Marin we are blessed to have great organic farmers giving us wonderful vegetables and fruits. Have these every day, along with local diary products and eggs, and small amounts of poultry, fish and meat. Walk, run or bike - spring is on its way. And remember to give thanks to your local farmers, especially organic farmers, for their hard work and provisions.

WOMEN 18-50
*Multivitamin (for folic acid) in case of pregnancy. Folic acid helps prevent birth defects. Multis should contain iron because of menstrual blood loss.
*Calcium - 600-1000 mg daily – to get 1200 mg from pills and diet. Calcium helps bone strength and may help with premenstrual tension.
*Magnesium 300 – 350 mg daily. Magnesium helps bone strength and has numerous positive effects on the body.
*Vitamin D – 1000 – 2000 IU – or enough to keep blood level of 25 hydroxy vitamin D 35 – 40 ng/ml. People with darker skin may need more D to get to these levels. Vitamin D helps with bone strength, prevention of infection and cancer and keeps your brain sharp.
*Vitamin C - 500 mg daily – taking 250 twice a day is ideal
*Fish oil capsule – or eat fish 2-3 times a week. The omega-3 fatty acids in fish oil help your heart and are important for your brain and mood.
*Probiotic on arising – these contain beneficial bacteria that help your immune system fight off colds, and infections of the vagina and bladder

WOMEN OVER 50
*Multivitamin without iron – if diet is haphazard
*Calcium and magnesium as above
*Vitamin D, Vitamin C, Probiotic -the same as for women under 50.
*Fish Oil capsules 2 daily
*Vitamin B12 500-1000 mcg sublingually once or twice a week. A level of 500pg/ml is desirable. As you get older, you may not absorb this essential vitamin from the meat, fish, dairy or eggs that you eat. B12 prevents anemia and keeps your brain sharp. Letting it dissolve under your tongue will take it directly into your bloodstream.

MEN 18-50
*Multivitamin without iron–if diet is haphazard
*Vitamin D – 1000 IU -2000- or enough to keep blood level of 25 hydroxy vitamin D 35 - 40 ng/ml. People with darker skin may need more D to get to these levels.
*Vitamin C - 500 mg daily – taking 250 twice a day is ideal
*Fish oil capsule - or eat fish 2-3 times a week
*Probiotic on arising

MEN OVER 50
*Multivitamin without iron–if diet is haphazard
*Vitamin D , Vitamin C, Probiotic, the same as for men under 50
*Fish oil capsules 2 daily
*Vitamin B12 500-1000 mcg sublingually once or twice a week. A level of 500 pg/ml is desirable
As you get older, you may not absorb this essential vitamin from the meat, fish, dairy or eggs that you eat. B12 prevents anemia and keeps your brain sharp. Letting it dissolve under your tongue will take it directly into your bloodstream.
Sadja Greenwood, MD, MPH back issues on this blog

Sunday, January 24, 2010

Folic acid: an essential B vitamin with a warning on overdose

Folate is the naturally occurring form of vitamin B9, while folic acid is the synthesized form. This vitamin is essential in the synthesis and repair of DNA, in the production of red and white blood cells, in the synthesis of important amino acids, and in any period of rapid cell growth, such as childhood and pregnancy.

The urgent need for Folate in pregnancy Neural tube defects are among the most dreaded birth defects, affecting 1 in 1500 births in the US today. The baby is born without a major portion of its brain and skull (and dies shortly after birth) or with incomplete closure of the spinal cord in the back, leading to some degree of paralysis, pain, and problems with bowel and bladder function. Insufficient folate in the diet (along with genetic and unknown factors) plays a role in this problem, and supplementation of the mother’s diet can decrease the incidence of neural tube defects by more than 70%. The folic acid supplement, as well as adequate dietary intake of folate, should start even before the beginning of pregnancy, as the neural tube starts developing in the first month. It is extremely important for young women to take a multivitamin containing 400 micrograms (mcg) of folic acid on a regular basis; even if she does not plan to become pregnant (at least 50% of pregnancies are unplanned; in celibate or lesbian women the multi will also help with a possibly haphazard diet.) More folate is needed during pregnancy and lactation. Because not all girls and young women take vitamins, the FDA mandated the fortification of refined grain products (white flour, pasta, breakfast cereals) with folic acid in 1998. It is estimated that young women get about 100 mcg a day of folic acid from fortified cereal grains – which is an improvement, but insufficient. An excellent diet and/or a multivitamin is still important. Studies show an approximate 50% reduction in neural tube defects in the US since fortification in 1998. Similar programs of fortification have taken place in Costa Rica and many European countries. Other problems in pregnancy, such as fetal cleft lip, premature delivery and serious bleeding at delivery from placental detachment, have been associated with folate deficiency. See http://www.nytimes.com/2010/01/03/opinion/03kristof.html for Nicolas Kristof’s opinion page article on the benefits of micronutrient enrichment of foods in Honduras and elsewhere.

Homocysteine: Homocysteine is an amino acid that used to be associated with higher rates of heart disease amd stroke; it can be lowered by conversion into methionine (another amino acid) by folic acid, vitamins B6 and B12. However, studies from two Canadian Universities in 2006 showed that lowering homocysteine levels with these B vitamins did not decrease the risk of heart attack or death from heart disease, but did significantly decrease the risk of stroke. Studies also show that lowering homocysteine levels with B vitamins in people with former strokes lowers their risk of hip fractures.

Anemia: People with a low intake of folate from food, or with chronic alcoholism, can develop a kind of anemia characterized by large, malformed red blood cells. This anemia is akin to ‘pernicious anemia’ related to vitamin B12 deficiency, and can have serious consequences. Medical care is essential.

Cancer: There is growing controversy over the effects of giving high dose folic acid supplements to prevent cancer or other diseases, since recent clinical trials have shown an increase in lung cancer and polyps of the colon. Animal experiments show that small amounts of folic acid supplements can decrease cancer risk, and high amounts can increase it. However, no amount of folate in foods is dangerous and studies show a decreased cancer risk, including breast cancer, among those with the highest dietary intakes.

Foods containing folate: All forms of green leafy vegetables, broccoli, avocado, asparagus, peas, beans of all kinds, lentils, peanuts, wheat germ, oranges and other citrus fruits, and many other whole foods contain folate. You will benefit from folate by making vegetables and fruits the center of your diet. Cooking can destroy folate, so it is best to steam or stir fry vegetables lightly, or cook them in a microwave. Avoid boiling in abundant water.

What’s the bottom line with folate and folic acid supplements?
Keep eating as many vegetables and fruits as possible, and include raw salads in your daily fare. You will be ingesting plenty of folate, which is a very good thing. Young women who might become pregnant should take a daily multi with 400 mcg of folic acid and special vitamins during pregnancy. Adult multivitamins with 400 mcg of folic acid should be taken by people with high risk of stroke or a prior stroke, and by those dependent on alcohol. For other adults, a multi is probably safe, if it contains no more than 400 mcg of folic acid. Who said it would be simple?
Sadja Greenwood, MD, MPH past issues on this blog

Thursday, January 21, 2010

Selenium: Take a Supplement, or a Brazil Nut?

Selenium is an element that is essential in the human diet in small amounts, but toxic at high levels. All animals require selenium, since we evolved from the sea where it is abundant. Plants do not appear to require selenium for survival, but incorporate it into their structures. Edible plants contain differing amounts of selenium, as the element is found in varying amounts in rocks and soil throughout the world. The element is found in higher amounts where there were inland seas.

Thyroid hormone: While iodine is essential for the synthesis of thyroid hormone, a selenium dependent enzyme must be present to activate this hormone, which in turn regulates normal growth, development and metabolism.

Sperm development: a recent study from Vanderbilt University showed that a protein containing selenium is essential for normal sperm development and male fertility.

Viral Infection: selenium deficiency appears to enhance the virulence of some viral infections, by inducing mutations in the expression of some viral genes. In a region of China where soils are very low in selenium, young women and children develop a disease of the heart muscle; this seems to be worsened by a change in a common virus that affects the heart. Selenium supplementation can protect against this, but cannot reverse the damage to the heart muscle.

Cancer – a mixed picture: Chronic infection with viral hepatitis B or C increases the risk of liver cancer; selenium supplements given in China in an area with a high incidence of hepatitis B and liver cancer reduced the incidence of this cancer. Similar findings were seen in Taiwan. A study in Finland showed that low selenium status in creased the risk of lung cancer: the association was more pronounced in smokers. On the other hand, a prospective study of more than 60,000 female nurses in the US found no association between selenium levels and total cancer risk. The data on prostate cancer are confusing – several studies have shown lower selenium levels in men with prostate cancer, but a recent large study from the National Cancer Institute, following 295,344 men who were cancer free on enrollment, found that excessive multivitamin use (more than 7 times per week) increased the risk of fatal prostate cancer compared with never users. The positive association with prostate cancer and excessive multivitamin use was strongest in men with a family history of prostate cancer or in men who took supplemental selenium, zinc, or beta-carotene. Further studies are needed to understand whether selenium levels in the body are linked to prostate cancer, and several are underway. Selenium supplements (200 micrograms daily) increased the risk of squamous cell skin cancer in a study from Memorial Sloan-Kettering, and did not alter the incidence of basal cell skin cancers.

HIV/AIDS: Declining selenium levels are found in HIV infected people and are markers of disease progression and severity. A randomized control trial of HIV positive men and women from the University of Miami found that selenium supplements (200 micrograms a day) taken for 2 years significantly decreased the rates of hospitalization. A further study showed a decreased viral load and more CD4 cells with the same dose of selenium.. Proteins containing selenium negatively affect the replication of the AIDS virus. Many AIDS patients in the US take selenium supplements, and it is also used in some African countries/
Who needs selenium supplements? Based on the information currently available, it is wise for most people to get this trace element in their diet, and not from supplements. Supplemental selenium should be considered by people with HIV infections, and by those with severe gastrointestinal problems such as Crohn’s disease or surgical removal of part of the stomach or intestines.

Food Sources of Selenium: Organ meats, shellfish and other healthy (non-endangered) fish are the important sources of selenium in our diets. Whole grains are also important sources (avoid white flour and white rice), as are sunflower seeds, and other nuts. Whole grains grown in Nebraska and the Dakotas have high levels (but who knows the origin of the wheat in our daily bread?) Brazil nuts grown in areas of Brazil with selenium-rich soil may provide 50 to 100 mcg in one nut, which is an excellent daily amount for adults. However, Brazil nuts grown on selenium-poor soil may provide 10 times less – another ‘who knows?’ conundrum. Studies from New Zealand have shown that the selenium in Brazil nuts improves serum selenium levels as effectively as supplements. My final conclusion from all this is that adults can benefit from a daily Brazil nut! You can give a few Brazil nuts a week to children over age 9. Good news - it seems that the cultivation of Brazil nuts will improve conditions in the rainforests of Brazil; the nut is not suitable for growth in plantations and can only grow in the rainforest itself.
Sadja Greenwood, MD back issues onsadjascolumns.blogspot.com

Wednesday, January 13, 2010

Is there a Supreme Bean?

Go to Health: Is there a Supreme Bean?
Some insist that it’s coffee, but for many it’s the soybean, which nourishes hungry people throughout the world; its balance of essential amino acids makes soy a plant protein as valuable as eggs or meat.  Soy has been grown in China for some 5000 years, to enrich the soil (like other beans it has bacteria on its roots that fix nitrogen), and for human consumption.
Heart Disease Prevention:  Following studies showing significant decreases in serum cholesterol, LDL cholesterol (the ‘bad’ kind) and triglycerides, the FDA granted a health claim for soy in 1999: “25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”  HDL, (‘good cholesterol’) did not increase.  Recently, new studies have challenged the ‘heart healthy’ claim for soy protein per se, but concede that soy milk, tofu, soy nuts and some soy burgers should be beneficial to heart health because of their polyunsaturated fats, fiber, vitamins and low content of saturated fat.  The American Heart Association said: “Using these soy foods to replace foods high in animal protein that contain saturated fat and cholesterol may confer benefits to cardiovascular health.” 
Breast Cancer:  Genistein and daidzein (so called phytoestrogens,  or plant estrogens) are substances in soy that are similar structurally to human estrogen but act differently in the human body.  They have much lower biologic activity than human estrogens and in some cases may function as anti-estrogens.  A recent study on breast cancer and soy from Vanderbilt University was encouraging.   The researchers looked at 5000 Chinese women in Shanghai, ages 20 -75, who were breast cancer survivors. They found those who ate the most soy (15 grams or more of soy protein daily) had a 29% lower risk of dying than those who consumed the least (5 grams or less).  A similar benefit appeared for breast cancer recurrence risk regardless of tamoxifen use.  The benefits of soy increased up to 11 grams of soy protein daily, and then leveled off or reversed, so more was not necessarily better.  The women ate mainly tofu and whole soy beans. The researchers warned that similar benefits can not be extrapolated to dietary supplements containing soy (pills, bars or foods containing isolated soy protein). The associations did not vary with menopausal status, cancer stage, or estrogen receptor status of a woman’s cancer.
Vitamin K2 & Hip Fracture: a recent study from the University of Tokyo School of Medicine showed that natto, a Japanese fermented soybean food, contains large amounts of Vitamin K2; there is increasing evidence that Vitamin K plays a positive role in bone strength and osteoporosis prevention.  Serum concentrations of vitamin K2 were significantly higher in frequent natto eaters, and the incidence of hip fracture was correspondingly lower, in every prefecture of Japan.
Soybean foods in the US: Today about 90% of soybeans grown in the US are genetically modified to make the plant resistant to the herbicide Roundup. Ninety percent of these beans are turned into soy oil and defatted soy meal that is fed to chickens, turkeys and pigs.  The abundance of soy meal, as well as corn, makes possible the new and very problematic industrial farming of these animals.  The US, Brazil and Argentina are major growers and exporters of soybeans, and the Brazilian crop has been responsible for a considerable loss of rainforest. Some soybeans, including organic soybeans, made into human foods in the US are imported from Brazil and China, where organic standards may differ from ours. Most Silk soymilk is no longer organic; the company was bought over by Dean Foods and switched many of their products to “natural” rather than organic. Edensoy products are made from organic soybeans grown in the US; Westsoy, Wildwood and others also have organic soy products.  If you care about this issue, read labels!   To get the benefits of soy, nutritionists advise people to eat whole soy products, such as tofu, tempeh, soy milk and soy nuts, rather than manufactured foods containing isolated soy protein.   Happy New Year, dear readers, and let us all appreciate the natural foods stores and organic farmers in West Marin.
Sadja Greenwood, MD, back issues at sadjascolumns.blogspot.com