Category: Fact or Fiction?

The straight dope on nutrition myths, trends, and fads

Does drinking milk increase your IGF levels?

by Monica Reinagel, MS, LDN

milk in glass bottlesSteve writes:

“I have been seeing a lot of information about milk and dairy raising levels of IGF1 in our bodies. The claim is that will increase the growth of cancer cells, particularly in hormonal based cancers like prostate and breast cancer. Apparently, high levels of IGF1 are good if you are growing but less important once you have matured.  Can you put our minds at ease, please? ”

Drinking a lot of milk might raise your IGF-1 levels, but it’s not because of the hormones in the milk itself. Any IGF-1 that may be present in foods such as dairy products is broken down during digestion and doesn’t have any biological effect in humans.  The amount of protein you take in, on the other hand, has a more direct effect on IGF-1 levels.

Dairy contains protein, of course, but so does meat, fish, beans, legumes, and so on. Continue reading “Does drinking milk increase your IGF levels?” >

Are avocado pits nutritious?

by Monica Reinagel, MS, LDN

Avocados for Healthy Weight GainAmanda writes:

“I’m seeing a lot of  claims about health benefits of eating avocado pits, but I’m having a terrible time finding solid nutritional information for them. Have you got any data?”

Amanda’s note was the first I’d heard about eating avocado pits. (My first thought was: How on earth do you eat one?) But a quick Google search reveals that adding avocado pits to smoothies is indeed a trending topic among the nutritionally ambitious.

None of the the standard nutritional databases I rely on include nutrition information on avocado pits, which are traditionally regarded as “inedible refuse.” However, I was able to dig up a couple of obscure papers on the nutritional value of avocado pits. (Thanks to my friends at the Hass Avocado Board for the assist.)

A lot of the excitement has to do with the fact that the antioxidant activity  of the pit is much higher than the antioxidant capacity of the part you usually eat. More antioxidants = more better, right? Actually not so much. Continue reading “Are avocado pits nutritious?” >

Maple syrup and diabetes: a reality check

by Monica Reinagel, MS, LDN

maple syrupMark writes:”There are a lot of articles on the internet about how real maple syrup contains has phytochemicals that help prevent diabetes. As a type 2 diabetic but also someone who considers myself well able to discount the latest  “miracle cures,”  I’m wondering whether there’s any research to back this up. Is there any benefit for people who are already diabetic?”

The buzz about maple syrup and diabetes does in fact have some published research to back it up. There are a series of studies, all done by the same researcher (and funded in part by the Quebec Maple Syrup Producers), which have identified a variety of antioxidants and polyphenols in maple syrup that have a variety of potential effects on human health. Continue reading “Maple syrup and diabetes: a reality check” >

Could cutting back on salt lead to thyroid problems?

by Monica Reinagel, MS, LDN

salt-shakerIodized salt was introduced in the 1920s as a way to prevent iodine deficiency. It worked! But now, some experts worry that if people really start cutting back on salt, thyroid problems and birth defects could be an unintended consequence.

Your body needs iodine in order to produce thyroid hormone. Iodine deficiency is especially dangerous (and especially common) during pregnancy, when it can cause problems with the infant’s neural development and lead to mental retardation. Some researchers are investigating whether low iodine levels during pregnancy might increase the risk of ADHD.

Sodium is intake up but iodine intake is down

Iodized salt is the primary source of iodine in the American diet. But even though average salt consumption is twice the recommended level, iodine intake has actually declined about 50% over the last 30 years.  How can that be?  Well, we used to cook at home, using iodized salt. Today, most of the salt we consume comes from packaged and processed foods–which are not necessarily made with iodized salt.

As long as we’re bossing around the food industry and requiring them to reduce the sodium in their products, perhaps we ought to require them to use iodized salt.

Alternate sources of iodine

In the meantime, if you don’t use iodized salt at home (or you don’t cook much), be sure you have an alternate source of iodine.  Seafood and edible seaweeds, such as wakame, are particularly rich in iodine.  You also get some iodine from vegetables, depending on the iodine content of the soil in which it is grown.  According to the Linus Pauling Institute, iodine is added to feed for dairy cows in the U.S., which makes dairy products a fairly good source of iodine.

Even though iodine intake has declined, most people are still getting the recommended amount. But if you are pregnant (or planning on it) a multivitamin with the daily recommended amount of iodine (150 mcg) would be a good back-up.

Don’t cancel that gym membership just yet

by Monica Reinagel, MS, LDN

A glass of red wine equals an hour at the gym, according to researchers from the University of Alberta. News outlets obediently picked up the story and repeated the claim:  “Resveratrol was seen to improve physical performance, heart function and muscle strength in the same way as they’re improved after a gym session.”

Lead researcher Jason Dyck says he is especially excited about the potential benefits for those who are unable to exercise. Just pour them a glass of zinfandel and it’s as if they spent an hour working out.

And now for the fine print: Continue reading “Don’t cancel that gym membership just yet” >

Is a Varied Diet Over-rated?

by Monica Reinagel, MS, LDN

Over the past ten or twenty years, scientists have spent a lot of energy investigating the world’s healthiest and longest-lived populations, trying to figure out what they are doing right. Why do they live so much longer and have vastly lower rates of cancer, heart disease, diabetes, and other diseases than Western countries?  We’ve picked apart and analyzed the traditional diets and lifestyles of Okinawans, Cretans, Icelanders, Cameroons, Pima Indians, and so forth, in an attempt to codify, once and for all, the healthiest diet.

The problem is that health and longevity are about the only things that these cultures have in common. Continue reading “Is a Varied Diet Over-rated?” >

Everything in Moderation is Bad Diet Advice?

by Monica Reinagel, MS, LDN

Aaron writes:

“I just saw this article on the How Stuff Works Blog. I know you’ve talked about “eating in moderation” on the podcast, so I thought you might have an opinion.”

howstuffworks

My initial take was that the blogger seemed to be confused about what the study was about. But when I looked at the study itself, it looks like the confusion comes from the researchers. Continue reading “Everything in Moderation is Bad Diet Advice?” >

Is weight gain now beyond our control?

by Monica Reinagel, MS, LDN

portionsA new analysis of diet and exercise data from thousands of people across several decades has come to a shocking conclusion.

“The study concluded that a person in 2006 who consumed the same number of calories and exercised the same amount as someone in 1988, would have a BMI that was 2.3 points higher.” (quote is from CNN’s coverage)

What’s going on here? The researchers present several possible explanations. We’re more stressed and stress chemicals promote fat storage. We get less sleep, which elevates stress hormones, which promotes fat storage. We’re exposed to more chemicals and pollutants that could affect our metabolism. Continue reading “Is weight gain now beyond our control?” >