Guest guest Posted May 5, 2004 Report Share Posted May 5, 2004 ************************************** May 2004 issue of Dr. Michael Greger's Monthly Newsletter ******************************************************* CONTENTS (online at http://www.veganmd.org/newsletters.html) I. Latest Updates in Human Nutrition A. Mercury Contamination in Fish B. HIGH Carb Diet for Safe Weight Loss Without Hunger? C. Insulin Sensitivity and Vegetarianism D. Skim Milk Versus Soy Milk: Head to Head E. Iron Status of Young Vegan Women II. Mad Cow Disease: Comment deadline extended to May 7th III. Personal Update IV. MAILBAG: " I heard that a study showed that soy didn't prevent breast cancer " ******************************************************* I. LATEST UPDATES IN HUMAN NUTRITION -------------------------- A. Mercury Contamination in Fish Each year in the U.S., up to 600,000 children are born at risk for lower intelligence and learning problems due to mercury exposure because their mothers ate fish. That's the number of children the Environmental Protection Agency estimated to be at risk in an analysis published last month using data from the Centers for Disease Control. This is double the Agency's previous estimate.[1] This study follows on the heels of the joint FDA/EPA advisory in March, which warned young children, pregnant and breast-feeding women, or even women just planning to get pregnant to severely limit the consumption of many types of fish like canned tuna, and to stay away from some fish completely, like swordfish, mackerel, etc. Still, many scientists didn't think the advisory went far enough. After learning that the FDA was going to " disregard " science[2] and allow women to eat a whole can of albacore tuna once a week, one leading FDA advisory panel expert resigned in protest. University of Arizona toxicologist Vas Aposhian said the advisory should have put more stringent limits on all canned tuna and warned women who might get pregnant to avoid albacore tuna entirely, claiming that " The new recommendations are dangerous to 99 percent of pregnant women and their unborn children.[3] " It seems that one should be more concerned about the health of the future children of this country, " he said, " than the albacore tuna industry. " .[4] The hundreds of thousands of babies born every year in the U.S. to the one in six women with enough mercury in their blood to put their babies at risk suffer most often subtle losses in potential. Although mercury can cause irreparable damage to the human central nervous system and has been found to deform fetuses, more often, " It might reduce IQ by a few points, " says Dr. Michael Gochfeld, chairman of New Jersey's mercury task force. " It might reduce motor coordination, so that this child is someone we think of as a klutz. It might make them unmusical. " [5] Studies have shown that children born to mothers who ate a lot of fish were slower to talk, walk and develop fine motor skills and have weaker memories and attention spans. And the brain damage is apparently permanent. Follow-up studies over a decade later showed that their brains had not recovered. The tuna industry feels that tuna is being unfairly singled out and is quick to point out that " almost all ocean fish and seafood naturally contain trace levels of mercury. " [6] One such leading " natural " source is the smoke that pours from coal-burning plants across the U.S. And this past Earth Day it was the coal and power industry executives that were celebrating. Lost in Bush's " war on terror " is Bush's war on the Clean Air Act. As part of Bush's " Clear Skies Initiative, " the Bush White House proposed to weaken and delay efforts to clean up mercury emissions from America's power stations, thus saving millions for their corporate campaign contributors. The energy industry alone contributed $40 million to Republican election campaigns, including $1.3 million directly to Bush. And they got their money's worth. Last December as the EPA signed the first proposal ever to cut mercury emissions from coal plants, Bush was busy proposing mercury be delisted as a toxic air pollutant. The EPA was hoping to cut mercury emissions 90% by 2008. Bush had a better idea--how about 70% by 2018? Bush's plan would also allow coal plants to buy and sell pollution credits; in other words, bigger plants could buy the right to continue emitting mercury. At the same time, Bush is applauding Congress for passing the Unborn Victims of Violence Act, which makes harm to a fetus a federal crime separate from harm to the mother. Of course Bush's " Clear Skies Initiative " is going to mean harm for both. We have until June 29th to make our voices heard. Go to http://www.epa.gov/air/mercuryrule/ to submit comments to the EPA about their proposed Utility Mercury Reductions Rule. On a personal level, people can reduce their exposure to mercury by not eating fish. In a recent public relations blitz, Chicken of the Sea International was quick to point out the heart-healthy benefits of the omega 3's found in fish. Thankfully people don't need to choose between mercury poisoning or heart disease. For adults, mercury overload from eating fish can cause fatigue and memory loss--something we clinicians often call " fish fog " . Mercury poisons the heart and may double one's risk of dying from a heart attack. In fact, the mercury contamination in fish and fish oil may be so extensive that some recent data suggests that it may cancel out the benefits of the omega 3's in the fish. There are a number of studies, for example, showing increased mortality among fish-eaters, which we think is from the toxic mercury. Thankfully, plant-based sources of omega 3's provide a safe and healthy alternative. Our bodies convert some of the short chain omega 3's found in flax seeds, for example, into the long chain omega 3's found in fish fat, so one can choose to get omega 3's packaged with soluble fiber and antioxidants in flax, rather than getting them packaged with heavy metals and carcinogens in fish. I recommend everyone eat 2 tablespoons of ground flax seeds a day. For those who want to take supplemental long chain omega 3's directly, but don't want to be exposed to the high concentrations of PCBs and pesticides in fish oil capsules,[7] there are two vegan algae-based contamination-free supplements in veggie-caps currently on the market.[8] So when a fish-eating woman comes into my office, I've really got to just put my hand up and say, " Just the flax, maam. " -------------------------- B. HIGH Carb Diet for Safe Weight Loss Without Hunger? Any diet that restricts calorie intake can cause people to lose weight. Many fad diets accomplish this be being so restrictive or monotonous that people end up eating less. But lifelong weight control requires dietary changes people can safely and satisfactorily live with for a lifetime. And high carb diets may fit the bill. A recent study published in the Archives of Internal Medicine showed that people randomized to an all-you-can-eat high carbohydrate diet actually lost weight.[9] People were provided with piles of food, 50% more than they needed to cover daily caloric requirements and were specifically told to eat as much as they wanted. Not only did those eating the high carb diets lose weight, but CT scans of their thighs showed that while those eating the control diet increased their percentage body fat, those on the high carb diet lost thigh fat mass while preserving muscle mass. And all this despite exercising less than the control group (who ate unlimited amounts of a lower-carb, higher-fat diet). The researchers theorized that the explanation lay in the fact that carbohydrate-rich foods tend to be more satiating and less calorie-dense than higher fat foods. Proponents of low carb diets like the Atkins Diet claim that carbs stimulate insulin production, which leads to increased fat storage and decreased fat breakdown. Studies like this one in fact show exactly the opposite. Reputable scientific organizations like the American College of Sports Medicine, the American Heart Association, and the American Dietetics Association have all issued statements that high-protein high-fat low-carbohydrate diets are not only mostly ineffective, but may in fact cause harm. By eating a whole foods plant-based diet one can control one's weight without risking one's health. -------------------------- C. Insulin Sensitivity and Vegetarianism Impaired insulin sensitivity sets people up for a whole host of life-threatening problems, including obesity, hypertension, atherosclerosis, and diabetes. It is also thought to be at the heart of so-called syndrome X (now called metabolic syndrome) affecting 50 million Americans.[10] A new study in China compared the insulin sensitivity of vegetarians and meateaters, and even though the vegetarians were on average years older than the meateaters, the vegetarians were significantly more insulin sensitive. Yet another clue to explain why vegetarians have so much less cardiac mortality. And the longer the research subjects were vegetarian, the better their values became. The researchers summarize: " In conclusion, the vegetarian diets had significant beneficial effects on insulin sensitivity of subjects in a low-risk population. The degree of beneficial effects appeared to be correlated with years on a vegetarian diet. " [11] It seems vegetarians are sensitive in more ways than one. -------------------------- D. Skim Milk Versus Soy Milk: Head to Head Last month researchers in Brazil studied the effects of skim cow milk consumption compared to soy milk consumption using what's called a double-blind randomized crossover study. People were randomly split into two groups and given four cups of either soy milk or skim milk to drink every day. The milks were identically packaged and flavored such that neither the research subjects nor the researchers knew who was drinking which. Then at six weeks the skim milk group was secretly switched to soy and vice versa. So after 3 months each participant had spent 6 weeks on soy and six on skim in random order. The codes were broken and data tallied: Soy won hands down. When the subjects were drinking soy milk, their bad cholesterol went down and their good cholesterol went up (exactly the reverse of what happened when they were drinking milk from a cow). The amount of rancid fat circulating in their blood stream (a further risk factor for heart disease) was also reduced drinking the soy milk (and marginally higher drinking cow milk). The American Heart Association recommends people switch from whole milk to skim milk. But this new research suggests that it would be much healthier for people to wean themselves from bovine milk altogether and switch from veal milk to real milk--soy milk.[12] -------------------------- E. Iron Status of Young Vegan Women Iron deficiency is considered the most common nutrient deficiency in the world. In the United States, up to 1 in 25 menstruating women are so iron deficient that their bodies can't produce enough blood and they become anemic. The iron in animal blood is generally absorbed better in the digestive tract than the iron in plants, so there was a concern that people who didn't eat or drink blood - vegetarians -- would have higher rates of iron deficiency anemia. Thankfully the concern was unfounded, as vegetarians have been shown to generally have the same rates of iron deficiency anemia as blood-eaters. The latest from the German Vegan Study was just published and showed that 4% of vegan women had iron deficiency anemia,[13] the same rate of anemia we see generally here in the U.S.[14] But just because vegans don't have worse rates than meateaters here doesn't mean much, because meateaters have such crappy rates in the first place. All menstruating women, vegan or not, should be screened for anemia between 15 and 25 years of age. They should then consider getting rescreened once every 5 to 10 years, unless they have a lot of kids, frequently donate blood, have heavy periods, live in poverty or were previously diagnosed with iron deficiency anemia, in which case they should consider getting screened more frequently. ******************************************************* II. MAD COW DISEASE: Comment Deadline Extended to May 7th So if anyone missed a chance to send the USDA comments on their proposed mad cow regulations, the USDA announced that they were going to extend the deadline for comments until May 7th, 2004. So please go to http://www.organicconsumers.org/madcow/usdapubcom0304.cfm for information about the regulations and how to contact USDA. ******************************************************* III. PERSONAL UPDATE Just finished filming a new DVD on Friday -- a lecture/cooking show based on my " Stopping Cancer Before it Starts " talk. It's hard for me to gauge how well it went without an audience, but I should have it out and available by July and everyone can tell me how I did. I'm just so excited that it's done! I also have a mad cow talk DVD currently in press. Now that those are out of the way I've basically cleared the next few months to finish the vegan nutrition book whose writing was so rudely interrupted by the mad cow in Washington. A very generous activist is graciously welcoming me into their home in Massachusetts to spend the Summer writing. Then in July I'll be at Vegetarian Summerfest and AR2004 and, assuming the book is done, go back on the road speaking for another year or so starting in the Fall. I'm getting tired just thinking about it. ******************************************************* VI. MAILBAG: " I heard that a study showed that soy didn't prevent breast cancer " Back in February, there was this Dutch study published that followed thousands of women for a few years and found that those who ate the most phytoestrogens did NOT have lower rates of breast cancer, as might be expected. So a reader wrote me and asked why I didn't mention that study in any of my newsletters. Sometimes you have to really dig to discover flaws in experimental design; other times it's a bit more obvious. Phytoestrogen intake in the Netherlands? To study a nutrient you need a good range of intake levels. How much soy do Dutch women eat? Not much, it turns out. The group with the highest intake was eating 0.5mg of isoflavones a day; the group with the lowest intake was eating 0.3mg a day. That means they were comparing people who drank like a single spoonful of soy milk a day to people who drank like half a spoonful. Or comparing people who ate like 1.5 grams of tofu to people who only ate1 gram of tofu a day (a gram is the weight of a paper clip). And they're surprised they didn't find any difference in breast cancer rates? Listen to how this study was described in the press, though: " Dietary Isoflavones Not Linked to Breast Cancer " " High intake of isoflavones does not increase risk of breast cancer " [15] " Study Shows Reduction in Breast Cancer Risk Not Seen Even if Started at Early Age " " You may have heard that diets rich in soy that contain phytoestrogen help protect against breast cancer. Now, new research from The Netherlands indicatesŠ [no] protective effect. " [16] So always take media reports of studies with a grain of salt, or, at the very least shoot me an email and I'd be happy to check it out. ******************************************************* REFERENCES: (Full text of specific articles available by emailing article-request) [1] Environmental Health Perspectives 112(April 2004). [2] Connecticut Post (Bridgeport, CT). March 20, 2004. [3] The Boston Globe. March 20, 2004. [4] USA TODAY. March 22, 2004. [5] Milwaukee Journal Sentinel (Wisconsin). April 12, 2004. [6] Greenwire. March 22, 2004. [7] Times Newspapers Limited, January 11, 2004 [8] http://veganessentials.com/ and http://drfurhman.com/ [9] Archives of Internal Medicine 164(2004):210. [10] JAMA 287(2002):356. [11] European Journal of Clinical Nutrition 58(2004)312. [12] Nutrition 20(2004):200. [13] Annals of Nutrition and Metabolism 48(2994):103. [14] Centers for Disease Control MMWR 51(2002);897. [15] http://www.medscape.com/viewarticle/468113 [16] http://content.health.msn.com/content/article/81/96999.htm ******************************************************* If anyone missed previous months, check out my newsletter archive at http://www.veganMD.org/newsletters.html Until next month, peace, love, and kale, Michael -- (206) 312-8640 mhg1 http://www.veganMD.org To to my free monthly email newsletter send a blank email to: drgregersnewsletter- Four of my most popular talks are now online (free) at: http://www.veganmd.org/talks/ Check out my Vegetarian Nutrition DVD at: http://www.veganmd.org/dvd.html HEART FAILURE: Diary of a Third Year Medical Student (full text now available free): http://www.upalumni.org/medschool The thinker that most changed my life: Noam Chomsky http://www.zmag.org/chomsky/index.cfm The single article that most changed my life: http://www.petersingerlinks.com/famine.htm Please everyone donate money to Vegan Outreach http://veganoutreach.org/about/support.html Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.