Nutrition

Archive for Nutrition

What (if anything) does “natural” mean?

"When I use a word," said Humpty Dumpty said in a rather scornful tone, "it means just what I choose it to mean -- neither more, nor less." Lewis Carroll, "Through the Looking Glass"

“When I use a word,” said Humpty Dumpty in a rather scornful tone, “it means just what I choose it to mean — neither more, nor less.”
Lewis Carroll, “Through the Looking Glass”

What does the term “natural” mean on a label? Does it mean anything? Should it mean anything? Good questions. And complicated ones, judging from the list of questions the FDA needs your help in answering.

The FDA has resisted defining “natural” in food product labeling, including whether foods that are genetically engineered, or contain genetically engineered ingredients, can use the term. Back in 1991, the agency set out to issue regulations but abandoned the effort and has since held to an informal policy that “natural” means

nothing artificial or synthetic (including color additives regardless of source) has been included in, or has been added to, a food that would not normally be expected to be in the food.

The only official legal requirement for using the description “natural” on a food label is that it not be misleading or false, which is forbidden by the Food, Drug & Cosmetics Act of 1938. In that appetite-suppressing way of statutory language, “food” is defined by the Act as

articles used for food or drink for man or other animals, chewing gum, and articles for used for components of any such article.

For regulatory purposes, dietary supplements are also considered foods in most cases. (more…)

Posted in: Genetically modified organisms (GMOs), Legal, Nutrition, Politics and Regulation

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Questioning the Evidence for Breastfeeding

Breastfeeding_baby
Six years ago I wrote about the evidence for breastfeeding. I questioned an article that claimed 900 babies’ lives could be saved every year in the US if 90% of mothers breastfed for at least 6 months. I didn’t think that was true, but I did think the evidence supported the claim that breastfeeding was clearly better for babies. Now I’m not so sure we can trust that evidence.

A new study reevaluated the evidence from previous studies and found that the studies hadn’t adequately ruled out significant confounders. There are social, cultural and economic factors that contribute to the choice to breastfeed, factors that may have skewed the results of those studies to favor breastfeeding. The new study tried to correct for these issues.

Results from standard multiple regression models suggest that children aged 4 to 14 who were breast- as opposed to bottle-fed did significantly better on 10 of the 11 outcomes studied. Once we restrict analyses to siblings and incorporate within-family fixed effects, estimates of the association between breastfeeding and all but one indicator of child health and wellbeing dramatically decrease and fail to maintain statistical significance. Our results suggest that much of the beneficial long-term effects typically attributed to breastfeeding, per se, may primarily be due to selection pressures into infant feeding practices along key demographic characteristics such as race and socioeconomic status.

(more…)

Posted in: Nutrition

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Organic vs Conventional Meat and Milk

cow-eating-grassTwo recently published meta-analyses, one on meat and another on milk, conclude that levels of polyunsaturated fatty acids (PUFA) and omega-3 fatty acids are higher in the organic versions of both. This is being widely reported as evidence that organic meat and milk is healthier, but a closer look at these two studies shows a different picture.

The organic false dichotomy

I am going to start with what I consider to be the biggest problem with how both studies are being presented and reported. This relates to a deeper issue – the false dichotomy of organic vs conventional. In my opinion, we should use whatever farming techniques prove to be best (for the quality of the food, sustainability, cost-effectiveness, and environmental impact) regardless of whether or not they are considered organic.

While proponents of organic farming claim that for them food quality and sustainability are the real issue, they aren’t. Organic techniques are based on the appeal to nature, not an evidence-based approach to best practices. (more…)

Posted in: Nutrition

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Prenatal Multivitamins and Iron: Not Evidence-Based

prenatal-vitamins small
When I was pregnant, I obediently took the iron pills and prenatal vitamins prescribed by my obstetrician. And I prescribed them for every pregnant patient I took care of as a family physician. I never questioned the practice. It seemed intuitively obvious that it was a good thing; we know pregnancy makes extra nutritional demands and depletes iron stores. It never occurred to me to question what I had been taught, because it seemed perfectly logical. I did question other things I was taught that didn’t seem so logical. In my internship, we were ordered to do episiotomies on every patient (the rationale was that it made birth less traumatic for the baby and prevented uncontrolled perineal tearing in the mother). I was severely chastised for omitting an episiotomy on a patient who begged me not to do one. She had had several babies and was stretchy enough to deliver easily without an episiotomy. In this case, my common-sense clinical judgment was vindicated by further research in the years after my internship; new evidence showed that routine episiotomies were of no benefit, practice changed in response to the new evidence, and episiotomies are no longer done routinely.

That was a long time ago. I have long since learned that even the most reasonable assumptions can be wrong. I happened to be right about episiotomies, but I might just as well have been wrong; and the only way to know whether a belief is true is to test it in controlled scientific trials. As Will Rogers said, “It isn’t what we don’t know that gives us trouble, it’s what we know that ain’t so.” It turns out that routine multivitamin and iron supplementation is not supported by any convincing evidence from scientific studies. And practice is changing. Recently, when one woman asked her OB what she should do about prenatal vitamins he pulled his wastebasket out from under his desk and said “put them there.” (more…)

Posted in: Herbs & Supplements, Nutrition, Obstetrics & gynecology

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More Trouble for Antioxidants

Antioxidants are better acquired through food than pills.

Antioxidants are better-acquired through food than pills.

Antioxidants are now an iconic example of premature hype making its way into marketing and the public consciousness long before the science is adequately understood. There are multiple lessons to be learned in this story, and a new study just emphasizes those lessons further.

A brief history of antioxidants

One of the unavoidable consequences of metabolism (burning food for energy) is the creation of oxygen free radicals, or reactive oxygen species (ROS). These are molecules that are highly reactive. They essentially contain oxygen with an extra electron, which can react with another molecule, breaking bonds and causing damage.

As you might expect, the body has natural antioxidants which react with ROS to form benign molecules.

In the 1990s it became increasingly apparent that oxidative stress was playing an important role in cell damage, even sometimes triggering apoptosis, or programmed cell death. Many degenerative diseases, like Alzheimer’s disease, were shown to be driven in part by oxidative stress. In addition, it seemed that ROS play a role in aging.

(more…)

Posted in: Herbs & Supplements, Nutrition

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The Clean Eating Delusion

eating-clean-november-400px

While some parts of the world are concerned with eating, because of food insecurity, the “worried and well-fed well” are increasingly obsessed with so-called “clean eating.”

This is nothing new, but like every cultural phenomenon, it seems, has increased partly due to the easy spread of misinformation over the internet. If you are anxious about your health, and who isn’t to some degree, your anxiety is fed by a steady diet of pseudo-experts, con-artists, and internet personalities telling you about all the things you eat that adversely affect your health.

This phenomenon is increasingly being recognized as a health issue among experts. In 1996 Dr. Steven Bratman proposed a formal disorder he calls orthorexia nervosa. He writes:

For people with orthorexia, eating healthily has become an extreme, obsessive, psychologically limiting and sometimes physically dangerous disorder, related to but quite distinct from anorexia.

(more…)

Posted in: Nutrition

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The one thing you need to know before you detox

detox will to live small

New Year, New You, right? Here’s a perennially popular post, revised for 2016.

With 2016 upon us, it’s finally time get serious about your health. You’re resolving to eat better and exercise more. But first, you need to reset your body – and purge yourself of all of your lifestyle and dietary overindulgences. But how? The options seem limitless, and everyone has advice: There’s Dr. Oz, Gwyneth, and even your favourite Kardashian has advice: They’re all telling you how it’s essential to “detox”, “cleanse” and “flush” away all of your toxins. Your local pharmacy has an ever-growing section of products promising a newer, more pure you: supplements, homeopathy, ear candles, and an entire aisle of “detox kits” all promise to suck toxins out of your body. Don’t forget your local naturopath who sells IV vitamin drips as the detoxification solution to your problems. The approaches may differ but all the advocates are completely convinced of one fact: Detoxing will deliver a renewed body and better health. Not only will you look better, you’ll feel better. It is a new year. Wouldn’t a purification from last year’s habits (dietary and otherwise) of last year be the best way to start? Well before you pull out your credit card, there is one fact that “detox” advocates are reluctant to tell you. (more…)

Posted in: Health Fraud, Herbs & Supplements, Naturopathy, Nutrition

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Guess who pioneered chemoprevention through diet?

Listen to your science: Eat your vegetables.

This is an expansion of a post I did over on the Society for Science-Based Medicine blog about this time last year. The original post, which got far more traffic than is usual for the SFSBM, is a good example of how science works and the good that it can do. The hard work of real science illustrated here serves as a striking counterpoint to the slap-dash system of pseudoscience, which churns out fake diseases, causes, and cures by the dozen based on a fuzzy understanding of real science fueled by a healthy dose of imagination.

Naturopaths and “functional medicine” practitioners would have the public believe that they are the true experts on nutrition and health. Even though their nutritional advice contains a large serving of hooey and a big helping of dietary supplements, which they are happy to sell to patients.

So it was with great interest that I read the obituary of Dr. Lee Wattenberg in the New York Times.

Dr. Wattenberg published a landmark paper in the journal Cancer Research that reviewed 36 years of animal studies on the effects that certain compounds had on the development of cancer. The paper laid the framework for understanding how these compounds work. . . .

He showed that cabbage, brussel sprouts, cauliflower and broccoli inhibit the development of carcinogens. He isolated a compound in garlic that decreased “by a factor of three” the chances that animals injected with cancer agents would develop that cancer. He found two chemicals in coffee that neutralize free radicals, which are harmful chemicals commonly implicated in the onset of cancer.

(more…)

Posted in: Cancer, Herbs & Supplements, Naturopathy, Nutrition, Science and Medicine

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Intermittent Fasting

fasting
Fasting can mean anything from total abstinence from food and beverages to restricting specific foods or the hours of food intake. Many religions have traditions of fasting, with various restrictions. There is a good summary of those traditions on Wikipedia. The reason for religious fasting is not to improve health, but for other reasons like improving discipline and demonstrating devotion.

There are many health claims for different fasting regimens. Daily calorie restriction has been demonstrated to prolong lifespans in several organisms, from yeast and worms to mice and monkeys, although the evidence for monkeys is equivocal and there is no evidence for humans. There is some evidence that intermittent fasting can forestall and even reverse cancer, cardiovascular disease, diabetes, and neurodegenerative disorders in mice. In humans, there is some evidence that it might help reduce obesity, hypertension, asthma, and rheumatoid arthritis. How good is the evidence? (more…)

Posted in: Nutrition

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