The straight dope on nutrition myths, trends, and fads
In the chaos surrounding the novel coronavirus, there is a lot of information swirling around about foods and nutrients that can “boost your immune system.” Some of it is not terribly accurate. In this Live Q&A, I answer your questions about specific supplements and highlight the most effective things you can do to keep yourself and your family safe.
Related listening:
An advocacy group called Friends of the Earth has been publicizing the results of a new study demonstrating that when people switch from a regular diet to one containing only organic foods, their exposure to pesticides is reduced.
The study recruited four families from different corners of the country. Each family ate a non-organic diet for six days and an all-organic diet for six days. The researchers found that the organic diet “rapidly and dramatically reduced exposure to pesticides.”
That’s not terribly surprising. In fact, it’s so unsurprising, it’s a little hard to imagine why the researchers felt the need to do this study.
The far more important question (not answered in this study) is: Is this something we need to worry about?
In reporting their findings, the Friends of the Earth present the difference in exposure in relative terms. “Levels of all detected chemicals dropped an average of 60.5 percent with a range of 37 percent to 95 percent depending on the compound.”
But they don’t give us any information about the absolute levels of exposure. This is at least as important as the relative exposure. Celery has 40 times as much sodium as cucumber. It’s still a low sodium food.
Did those higher levels of exposure pose any sort of threat? Or were they (as I suspect) well below the threshold of concern?
Secondly, the coverage repeatedly talks about the “pesticide levels in the bodies” of the subjects. But the study didn’t test the subjects’ blood or tissues. They tested their urine, which is where the body discards things it doesn’t want or need. Furthermore, what they found in the urine were compounds formed when the pesticides were broken down by the liver.
In other words, what they found was evidence that the body’s detoxification systems were working exactly as they are supposed to, breaking down and excreting potentially harmful compounds. The pesticides these families were being exposed to by eating a non-organic diet were apparently being eliminated from their bodies.
So I have to ask once again: Is this really something that we need to worry about?
The organization points out that one of the pesticides monitored in this study is frequently linked to farmworker poisonings. That’s a great argument for farmers using more care when working with agricultural chemicals (and that goes for synthetic as well as organic chemicals). But it doesn’t really have anything to do with risks that families might be exposed to by eating conventional produce. And yet, by juxtaposing these two facts in the press release, it implies that eating non-organic foods increases your risk of chemical poisoning. There is absolutely no data to support this implication.
Meanwhile, the press reports don’t mention that a third of the compounds they were testing for were undetectable in the urine samples after the non-organic diet. You have to wonder whether they were, perversely, somewhat disappointed by this. They certainly didn’t seem very eager to publicize the fact that some of the most common pesticides used in conventional agriculture apparently pose little risk to eaters.
So, what’s the upshot of all this?
The Friends of the Earth concludes that “these results show that eating organic works.” Works how, exactly? Yes, eating organic reduces your exposure to certain (but not all) pesticides. But does it reduce your risk of disease or harm? I don’t see any evidence of that here.
Lest you think I am pro-pesticide, or anti-organic, let me assure you I’m not. I’m just against this sort of sloppy communication and manipulative “science.”
Conventional farmers don’t use pesticides because they’re lazy, ignorant, or uncaring. They use them, as sparingly as they can get away with, in order to maximize yields and lower the cost of food. If they can figure out a way to use less, they are eager to do so.
Organic farmers use pesticides and herbicides, too, by the way. Some of these organic pesticides are highly toxic to beneficial insects and, if mishandled, can be harmful to humans, as well. But organic farmers are also working to increase yield and reduce the cost of their products. And pest control is part of that.
Instead of pitting organic growers (and eaters) against conventional, why not work together to make progress on all of these important fronts? Let’s use the best technology, the best practices and, yes, the best chemistry, to create a safer, more abundant, and more sustainable food supply.
To that end, let’s assess the risks and impacts of chemical use (both synthetic and organic). Let’s weigh the costs and benefits of various options. But let’s debate the issues on their scientific merits instead of resorting to sensational, misleading, and manipulative “research” and rhetoric.
This is not an us vs. them situation. We’re all us.
In this week’s Nutrition Diva podcast, I talk with protein researcher Douglas Paddon Jones about whether or not there’s any benefit to combining complementary plant-based protein sources at the same meal.
Contrary to a lot of the conventional wisdom, which claims that it’s sufficient to get all of the essential amino acids over the course of a single day, Dr. Paddon Jones argues that a meal-based approach to protein nutrition will enhance the ability to build and maintain lean muscle tissue.
This doesn’t mean you have to tally up and micro-manage each individual amino acid. The following chart shows how to choose meal components that will ensure complete proteins at a meal.
If you consume only plant-based proteins, you may also want to increase your total protein intake by 10-20% to compensate for the lower digestibility of these plant-based protein.
The Recommended Daily Allowance for protein is 0.8 g per kg of body weight (or 0.36 g per pound). Strict vegetarians may want to aim for a minimum of 1 g per kg (or 0.45 g per pound).
These are these are minimum recommended intakes. Research suggests that there may be benefits to higher protein diets, especially for athletes, the elderly, those recovering from surgery or illness, or during weight loss. If you’re in any of these groups, you might want to aim for something closer to twice the recommended minimum.
In this week’s Nutrition Diva podcast, I debunked the myth that you should avoid certain types of fruit, either because they are higher in sugar or higher in fructose.
All fruit can be part of a healthy diet–especially if you are eating fruit in place of other less healthy choices.
But if you’re curious to see how various types of fruit stack up in terms of total sugar content as well as fructose and glucose content, here’s a chart of some common fruits. You can click on any column to sort by that value.
| Fruit (1 cup serving) | Total Sugars (g) | Fructose (g) | Glucose (g) |
|---|---|---|---|
| Raisins | 108 | 57 | 50 |
| Dates, medjool | 86 | 42 | 44 |
| Figs, dried | 71 | 34 | 37 |
| Apricots, dried | 69 | 16 | 43 |
| Plums, dried (prunes) | 66 | 22 | 44 |
| Bananas | 28 | 11 | 11 |
| Grapes | 23 | 12 | 11 |
| Mangos | 23 | 8 | 3 |
| Tangerines | 21 | 5 | 4 |
| Cherries | 18 | 7 | 9 |
| Plums | 16 | 5 | 8 |
| Pineapple | 16 | 4 | 3 |
| Kiwi | 16 | 8 | 7 |
| Grapefruit | 16 | 4 | 4 |
| Blueberries | 15 | 7 | 7 |
| Apricots, fresh | 14 | 1 | 4 |
| Oranges | 14 | 4 | 3 |
| Cantaloupe | 14 | 3 | 3 |
| Honeydew | 14 | 5 | 5 |
| Pears | 14 | 9 | 4 |
| Peaches | 13 | 2 | 3 |
| Papaya | 11 | 5 | 6 |
| Apples | 11 | 6 | 2 |
| Nectarines | 11 | 2 | 2 |
| Watermelon | 10 | 5 | 2 |
| Strawberries | 7 | 4 | 3 |
| Blackberries | 7 | 3 | 3 |
| Raspberries | 5 | 3 | 2 |
| Cranberries | 5 | 1 | 4 |
| Source: USDA National Nutrient Database for Standard Reference |
The other day, I was browsing nutrition headlines when I came across a summary of some new research on exercise and fat loss, which concluded that “it is not possible to lose more than 1 kilogram of fat per month.” (A kilogram is just over 2 pounds).
Not possible to lose more than 2 pounds of fat per month? Most diets promise that you’ll lose that much every week!
This article is also available as a podcast. Click to listen.
Intrigued, I pulled up the actual study, which was published last month in the British Journal of Clinical Pharmacology, and read the whole thing. Weirdly, however, the study said absolutely nothing about the amount of fat that can be lost per month. The researchers were looking at the amount of fat that can be oxidized during a single exercise session.
So, I tracked down the researcher, Dr. Juan del Coso Garrigós, who lives and works in Madrid, Spain. He explained that his comment about it being impossible to lose more than 1 kilogram of fat per month in fact had nothing to do with his recent study. Apparently, it was taken out of context from a different part of the interview, which was also translated from Spanish. It just goes to show you how easy it is for bad information to get into widespread circulation.
As long as I had him, though, I took the opportunity to ask him more about his research. Dr. del Coso Garrigós explained that, when conditions are just right, well-trained athletes can burn about three-quarters of a gram of fat per minute during moderate intensity exercise. The rest of us seem to max out at about a half a gram of fat per minute or 30 g of fat per hour.
At that rate, it’ll take most of us about 15 hours of moderate intensity exercise to burn a pound of body fat. Exercise for one hour a day, and you can hope to lose about 2 pounds (or about 1 kilogram) of fat per month. Exercise for longer than 60 minutes a day and you could hope to lose more. You can also get your body to oxidize fat by eating less, which forces your body to convert some of its fat stores into energy.
As Dr. del Coso Garrigós confirmed, it is theoretically possible to lose more than a kilogram of fat per month. That said, he and I both agree that losing more than a couple of pounds of body fat per month is both difficult and rare.
Of course, most diets promise that you’ll lose 8-10 pounds a month or more. And if you follow any of those diets faithfully, you probably will. But how much of that weight loss is actually fat loss? Probably no more than 25%. The rest is water and muscle tissue, which is the last thing you want to be losing. In fact, the faster you are losing weight, the smaller the percentage of actual fat loss is likely to be. And the harder it will be to sustain that weight loss over time.
I think the reason that a majority of dieters regain the weight that they’ve lost is that they lose weight too quickly. Instead of trying to lose 1-2 pounds a week, we should aim to lose 1-2 pounds a month. When we lose weight slowly, we preserve more muscle tissue and keep our metabolism from slowing down. We also are more likely to develop long-term habits and behaviors that will support long-term success. We avoid the yo-yo dieting cycle that sabotages both our health and our self-esteem.
Of course, when you’re losing weight very slowly, it’s hard to see the results on the scale, especially because your weight can fluctuate by several pounds from day to day without reflecting actual fat loss or gain. That’s why I recommend tracking your weight using a moving average, as described in my episode on Weight Fluctuation (#199).
So, what would it take to lose 1 to 2 pounds a month? The good news is that it doesn’t require anything nearly as drastic or unpleasant as it takes to lose 2 pounds a week! Small changes in your daily routine will do the trick. You just need to be consistent and patient.
Here are some of my favorite slow weight loss strategies:
You don’t need to do all of these at once. Start with a couple that seem easy and one that seems like a bit more of a challenge. Add more as you get the hang of it.
Don’t think of it as dieting. Think of it as right-sizing. And, please, let me know how it’s going.
This article was originally published at QuickandDirtyTips.com
I’ve gotten several emails from readers asking me to respond to a viral video in which a Harvard (Harvard!) professor asserts that coconut oil is “pure poison.”
It’s hard to imagine how someone with such a prestigious pedigree could make such as silly and sensational statement in public. Presumably she was pushed over the edge by the ridiculous claims that some people have been making about coconut oil lately.
Can we all just calm down about coconut oil?
Coconut oil is not pure poison. On the other hand, it’s also not going to make you smarter, thinner, younger, or fold your laundry for you.
Proponents of coconut oil make a big deal out of the fact that coconut oil is rich in medium chain triglycerides (MCTs). But, as I discussed in my podcast episode on MCTs, claims for these specialty fats tend to be exaggerated or unproven.
Coconut oil haters such as this Harvard (!) professor mostly object to the fact that coconut is is almost 100% saturated fat. But, as I discussed in my recent podcast episode on butter, saturated fat in moderation may even have some heart health benefits.
Despite saturated fat’s rehabilitated reputation, I still think it makes sense to limit saturated fat intake to around 10-15% of calories, if for no other reason than to leave room in the diet for other healthy fats. But if you want to spend your sat fat allowance on coconut oil, I see no reason to call in Poison Control.
When I saw this headline earlier this morning, I clicked through (Mission accomplished, headline writers) and skimmed the article, which seemed to contradict the basic facts that we all learn in nutritional biochemistry. Having not yet had my coffee (yes, I’m making lame excuses), I impulsively posted it on Facebook with a “Shame on you, CNN” comment.
Fortunately, my followers are smarter than I am…and are not afraid to tell me so. So, let me try this again, appropriately humbled.
Had I been one of those-who-should-know-better surveyed by the authors, I too would have fallen into the trap and said that fat is converted into energy (with water and CO2 as byproducts). But this is not quite accurate. Continue reading “Where does fat go when you lose it?”
There’s a lot of buzz about collagen peptide supplements these days. Collagen is a structural protein present in the skin, joints, hair and nails. The gradual loss of collagen as we age can make the skin look less plump. The idea is that collagen supplements can replace some of that lost collagen and improve the look of the skin.
Assessing the effectiveness of skin care products or supplements is notoriously difficult. For one thing, it’s difficult to isolate the effects of any particular cream or pill. The condition of our skin surface can be affected by diet, hydration, sun exposure, temperature and humidity. It’s also really hard to be objective about what we’re seeing in the mirror. So how do we know whether these supplements are actually working? Continue reading “Can collagen supplements make your skin younger?”