So the good news: eggs, including egg yolks, in moderation (which is defined as 1 a day or 7 eggs/week) are safe and healthy and you don’t have to be scared of them:
The other important thing to clear up is that, often in health news, you hear about being careful with your cholesterol, HDL, LDL levels — “too high” of LDL, and that’s bad.
It’s then easy then to assume that “eating” cholesterol is bad for you.
But there’s surprisingly little evidence to support that assumption. In fact, it appears that there is no link between eating lots of cholesterol, and giving you heart disease.
That is what I concluded after I read a review article written by Harvard professors Frank Hu, Joanne Manson, Walter Willet, who are respected principal investigators of large-scale studies on nutrition, preventive medicine, such as the Women’s Health Initiative, and the Nurses Health Study. I highlighted some of the passages in that article if you were more interested (for the full article, click here Fat, eggs and heart disease):
In controlled metabolic studies conducted in humans, dietary cholesterol raises levels of total and LDL cholesterol in blood, but the effects are relatively small compared with saturated and trans fatty acids, and individuals vary widely in their responses. A significant positive association between dietary cholesterol and CHD was found in some epidemiologic studies, but not in others. In a pooled analysis of four studies [5–7,11], the relative risk of CHD was 1.30 (1.10 –1.50) for a difference of 200 mg/1000 kcal in dietary cholesterol . But this analysis included only those studies with positive findings. The Nurses’ Health Study found a weak and nonsignificant positive association between dietary cholesterol and risk of CHD (relative risk for each increase of 200 mg/1000 kcal 5 1.12, 95% confidence interval 0.91–1.40).
Surprisingly, there is little direct evidence linking higher egg consumption and increased risk of CHD…The null association between egg consumption and risk of CHD observed in these studies may be somewhat surprising, considering the widespread belief that eggs are a major cause of heart disease. One egg contains about 200 mg cholesterol, but also appreciable amounts of protein, unsaturated fats, folate, B vitamins and minerals. It is conceivable that the small adverse effect caused by cholesterol is counterbalanced by potential beneficial effects of other nutrients.
These findings do not suggest that one should go back to the traditional high cholesterol Western diet. Instead, they suggest that among healthy men and women, moderate egg consumption can be part of a nutritious and balanced diet. Because eggs are excellent and relatively inexpensive sources of essential amino acids and certain vitamins, they can substitute for other animal products such as red meat. These results also illustrate the danger of judging health effects of a food by single nutrients or components contained in the food.
Again, apologies for taking so long to update the blog. Right now, we’re in the midst of finals week, preparing for dermatology, rheumatology, orthopedics, respiratory and cardiovascular pathophysiology. It’s going to be a fun week of studying in the snow! (There’s a snow storm in Boston right now).
Going back to the fish story and omega-3’s — apparently it’s a lot more complicated than what I originally anticipated. There are two extreme views on fish. One side, argued by many nutrition professors, is that fish is really good because of the omega-3’s, and the more you eat, the better for your heart and brain, and the better you feel, so eat your fish at every meal! (Okay, that’s a bit of an exaggeration, but you get the gist). Another side, argued by environmentally-oriented scientists, and a few nutrition professors like Marion Nestle, is that fish is for the most part, a dangerous food. Big fish are loaded with mercury and all farmed fish—big and small—are loaded with PCBs and dioxin. So unless you can buy fresh wild coho salmon that costs 15 dollars per pound at Whole Foods, or unless you live in Alaska – you should pretty much just forget about seafood.
Huge fights have erupted between both sides – nasty language thrown about back and forth, words that you thought would only be in political campaigns. One side has said that telling people fish is dangerous is equivalent to causing the premature deaths of hundreds of thousands of people. The other side retorted by saying that these “scurrilous attacks” don’t help anybody and that instead of blaming the fish truth-tellers, the real problem is the industrial polluter who poisons our earth.
There have even been serious conflict of interest issues, with the tuna and fish industry influencing researchers and FDA fish safety policy. I was surprised to read about this (Marion Nestle talks about this in-depth in her book, What to Eat) but in hindsight, I guess I shouldn’t have been…
It’s a tough story to figure out because both sides have written several articles published in top medical and science journals arguing that fish is good and that fish is bad. I took about 15 hours trying my best to sort through the data. What I concluded is that, somewhere in the middle of both extremes is where the answer lies: fish is truly a healthy, “power” food, if you eat the right kinds of fish, and the right amounts. So how much should I eat? When, and what should I eat? What kind of fish oil supplements are the safest? To answer some of those questions, I made two handouts (Fish and Fish oil Recommendations, Fish recommendations part II), with references, that hopefully will help guide your shopping in the future.
Wow very sorry for not writing in such a long time. It’s been a little difficult these days as second-year medical school has been much busier than I thought it would be. I wanted to post up this table from Dr. Michael Holick’s New England Journal of Medicine review article (N Engl J Med 2007;357:266-81) on Vitamin D defiency and how to prevent it. Basically, many many people we care about — 1 billion worldwide, have vitamin D deficiency. It’s very sad, because not having enough vitamin D can contribute to many diseases — like osteoporosis, and even common cancers, autoimmune disease, infectious disease and heart disease. Please if you get a chance, read the Holick article (http://www.uvadvantage.org/portals/0/pdf/NEJournalofMedicine.pdf). And check out the following table, which is from that article, which can help you make some of your decisions together with your doctor.
This is a quick note, so, poorly written, but I’ve been looking up the safety of fish,and I think the take home message seems to be that lots of fish are unsafe — unfortunately.Marion Nestle’s book, What To Eat, talks about this in detail. She reports that a studycame out in Science (2004) which looked at the PCB levels of 700 samples of salmon from all over the world.
Salmon is typically known as one of the safest fish out there, and one of the mostnutritious. Unfortunately, this report found that these salmon all were contaminatedwith unsafe levels of PCBs. Only salmon from Chile and Washington State were deemedacceptable. Fish from everywhere else? The study found those other salmon simply had unacceptable levels of PCBs.
Moral of the story? It seems like this would be an argument whyone would want to use fish oil supplements — from a good brand which has taken outall the dioxins, PCBs and methylmercury. Only five brands — omegabrite,nordic naturals, olay, vitamin shoppe and coromega have allowed themselves to be independentlytested for dioxins, PCBs and methylmercury (source: www.consumerlabs.com).These are just drafts of thoughts, so more on this later — but I wanted to just let you all about this sooner, as opposed to later.
If I had to pick one nutrient to tell you about, I’d probably start with fish oil and omega-3 fatty acids: get yourself a good bottle, or eat some flaxseeds, or wild deep sea fish! Now.
But before I go on, you should know that I’m heavily biased. Right now, I’m in a pediatric surgery lab at the Children’s Hospital of Boston, and the team here has seen firsthand how fish oil can save babies with short gut. Plus, Dr. Bruce Bistrian, an esteemed professor of medicine and clinical nutrition, has been very kind to take about three hours explaining to me how fish oil works biochemically. So, I guess you could expect that I’d be excited about fish oil. But I am also aware that when people get excited, they can get incredibly carried away, like some authors of “superfoods” or “miraculous detox” books that you bump into at a bookstore.
That said, special things do happen, and I wanted to tell you a short story about it. But I hope I don’t get carried away, and I hope can be objective…
Prior to 2005, children with short gut, or more formally, “short bowel syndrome,” had a very difficult life. Many of them couldn’t eat because their guts were too short, due to birth defects or injury. Because their intestines weren’t functioning, nutrients had to be given intravenously through a process called “parenteral nutrition.” Everyday, the children had to live with needles stuck into their veins in order to receive liquidized food formula – it was highly unpleasant.
The hope was that, while on parenteral nutrition, the babies’ guts could get healthy enough to start absorbing food. Ever so often, however, the gut just never recovered, at which point the baby would have to rely on parenteral nutrition for an indefinite period of time.
When that happens, the outlook immediately dims. Patients on long-term parenteral nutrition often develop serious liver problems that lead to death from liver failure. The only option at that point would be a liver transplant. It’s an option, but not a cure, and waiting on the transplantation list can be excruciating for parents. If the babies did not get the transplant, they would die; this was the conventional wisdom for decades.
But when 2005 came around, a medical team here in Boston with an inclination for fish decided they were going to give babies none other than…fish oil. You might be wondering, where in the world did they get that idea? And if it’s such a great idea, why did it take so long to figure out? The team did previously test the idea on mouse models, which showed promise. But perhaps more importantly, when faced with an emergency, you find new avenues of inspiration?
I’m not sure what was the catalyst, but what I do know was that the fish oil worked. Once the medical team started pumping omega-3 fatty acids into the babies’ veins, their livers started to heal — so much so that even extremely ill patients who were waiting for liver transplantations no longer needed transplants!
All of the above that I said is true, and, at least for me, it’s exciting to learn about. But I did want to take a step back and point out that more research needs to be done — randomized controlled trials, larger studies. And I think it’s important to point out that patients with short gut — even if they are on fish oil and are doing much better than anyone could ever expect — still have to fight courageously. Their families still have to be very supportive, and sadly, some patients, regardless of their omega-3 fatty acid status, will pass away from other health complications related to their short gut problems.
Nevertheless, things are encouraging. It’s not often that you’ll find a serious article, published in a serious medical journal, begin with the word “reversal” when describing the effectiveness of a treatment. Typically, treatments don’t “reverse” disease. They “ameliorate,” or “improve outcomes.” Editors are usually careful to save lofty words for only the most dramatic encounters. In this case, when it came time to submit the report of fish oil for publication, this was the title: “reversal of parenteral nutrition–associated liver disease.”
And without any changes, the editors accepted it.
I saw Urgelt’s video (http://www.youtube.com/watch?v=ld1azzZrfGQon) on probiotics which I thought was very interesting and it made me think of a story I wanted to share but didn’t quite know the context of how to do so — until I saw his video. Alright, so here goes:
Last month, I went to a grand physiology rounds led by the Chief of Gastroenterology, Dr. Thomas Lamont, at Beth Israel Deaconess Medical Center. We talked about a patient who had clostridium difficile colitis — an inflammed colon — and I remember distinctly that the patient sadly passed away.
For the patient’s treatments, we only discussed antibiotic therapies — hard-hitting antibiotics like vancomycin and metronidazole that kill nasty bacteria like clostridium difficile. Unfortunately, though, for some patients who relapse, the drugs don’t do the job. In these cases, long-term suffering or death is not uncommon. Such instances make you wonder about the patients’ treatment: could there have been a better way?
Back in high school, I had read in a health magazine how probiotics, like the harmless bacteria found in yogurt, were good for serious problems of the gut. Six years later, I was now in med school — at a grand physiology rounds no less — and I had the chance to ask an expert, “why?”
But I was hesitant. Dr. Lamont’s a distinguished-looking man in his 60’s with a crisp tie and few tufts of white hair. In medical school, professors with his kind of gravitas tend to think about treatment in strictly four modalities: drugs, chemotherapy, surgery and angiogenesis inhibitors. Probiotics didn’t belong in these categories. In fact, they fell way outside — somewhere in the territory of Hawaiian yoga and herbal healing centers. The chance he’d know about them? Tiny.
Or so I thought. I approached him gingerly and braced myself for a curt response. “Uh, Dr. Lamont, what’s your, uh, take on probiotics?” He paused for a moment, contemplating. Meanwhile, my face felt hot. He’s just going to think you’re a silly student, I thought to myself.
Suddenly, he nodded. “I think probiotics will be one of the frontiers of future research. The gut microbes are a poorly understood area with vast clinical significance if we can understand the mechanisms behind it.”
I was startled. I didn’t just hear what I heard — did I?
Lamont continued, “You know, there’s this guy in Minnesota who transplants gut flora from one person to another.”
“Yes, through stool transplantation. What you need is to freeze dry the stool from a family member, administer using an enema.”
My mind raced wildly. What? I didn’t quite comprehend what he just told me, but I sensed it was profound. Or profoundly weird. Or both. I wondered for a second whether I was actually in medical school, actually talking to the Chief of Gastroenterology of a famous hospital.
Lamont went on. “You have to understand, it sounds nuts, but there may be a case for that. Healthy people who have never taken a single antibiotic in their lives, can occasionally develop spontaneous ulcerative colitis, which suggests a disruption in the gut flora.”
I studied the creases on Lamont’s face carefully — he was all seriousness. No joke, only complete earnestness. What he was referring to, after I had time to process it, is that there are trillions of healthy bacteria in our intestines that keep us going. They help us digest, absorb food, protect us from the bad germs. But sometimes, there’s an imbalance between the good versus bad bacteria. When “bad” wins, we get problems like diarrhea, or colitis (inflammatory colon).
When is there an imbalance? Most often it’s when people take antibiotics, which kill the good, the bad and the ugly — altogether and all at the same time. During this vulnerable state, certain bad bacteria like Clostridium difficile can overwhelm the good germs, causing the human host all kinds of complications and even death.
Dr. Lamont explained that most of the time, people only get clostridium difficile complications when they take antibiotics. Yet, there can be rare instances of colitis without antibiotics, which suggest that there’s more to the gut flora story than we originally thought there was. For some reason or another, with or without antibiotics, the fine balance between good and bad bacteria can be broken, and stool transplantation might be the last option. It could also be one of the most promising.
That “Minnesota guy” who does the transplant turns out to be Dr. Johannes Aas. Journalists love him. Gene Weingarten from the Washington Post wrote a dialogue about him (which I adapted for my video below) and Aas was featured in blogs like “News of the Weird.” Everybody else though — besides his patients — probably thinks he’s nuts.
But the craziest thing of all, might just be that he’s not nuts. For example, his published case reports on stool transplantation were featured in a prestigious speciality journal called Clinical Infectious Disease. This is a journal that’s peer-reviewed, with a high impact factor, meaning that it goes through a rigorous editorial review process and gets read and cited by lots of specialists.
I looked up this paper and read it. The langauge certainly seemed “scientific,” capped off with a stern enough title: “Recurrent Clostridium difficile Colitis: Case series involving 18 patients treated with donor stool administered via a nasogastric tube.” But the real litmus test, as far as I know, involve the letters to the editor. Getting published in a prestigious journal is great — but bad studies do occasionally get published in great journals. When that happens, the letters to the editor can be swift and furious. Experts weigh in, critique this, critique that — in these letters, you can find some most insightful viewpoints.
After perusing through the entire National Library of Medicine database, I found one published letter to the editor. It was in electronic form, so I had to click a few links to get to the page. Oh boy, moment of truth, I thought. This was it.
I felt a faint dread — as I approached the link to the response on stool transplants, I readied myself for disappointment. Was this the letter that was going to expose the flaws of Aas? A cynical sneer of a report, tearing us apart the way Vioxx did to people’s hearts last year?
I held my breath. Suddenly, the paper title popped open:
” ‘It lacked aesthetic appeal.’
- i’m back! (for a bit)
- a “new” take on eggs — they’re not bad!
- More fish, fish oil, omega 3
- What fish and what fish oil should I eat?
- Strategies to Prevent and Treat Vitamin D Deficiency
- Follow up to Omega-3’s
- Fish Oil Saves Babies
- Youtube Video on Omega-3 and Fatty Acids
- References for Blog Entry Titled, “Fish Oil Saves Babies with Short Gut”
- Hey I’m Back!
- Youtube Summary of Probiotics
- Professor Lamont, Doctor Aas, and the Bacteria