Nutrition tidbits #14: myth-busting (part 1)
Over the last 12+ years as a dietitian, I’ve gathered a collection of responses to popular nutrition questions and statements that I would categorize as “myths”. We’ll define myths here as Google dictionary defines it: a widely held but false belief or idea. And my gosh, there are many of them, both old and new. I thought I’d share some of the most common myths and my responses to them - here’s hoping that the majority of them finally disappear at some point in my lifetime.
“They say that…”
Who is they? It’s usually vague corners of the internet, great aunt Sally, the grocery store cashier, Dr. Oz, so and so influencer, “I actually don’t know,” etc., all of which are not sound sources for health information and therefore anything “they” said should be deemed null and void (or as Joey Tribbiani would say, a “moo” point).
“Bananas are the bad type of fruit”
I just got this one again the other day, which inspired this post. The myth is that bananas have significantly more sugar than other fruit and are therefore toxic, dangerous pieces of produce (yes, I’m exaggerating). Here’s what I say: one medium banana contains about 14 grams of sugar and 3 grams of fiber. One cup of blueberries contains 10 grams of sugar and 3.5 grams of fiber. The difference here is slight, and what always matters is the context in which you’re eating any food that has sugar. Are you eating it with something that has protein, fat and/or fiber? Great, that’s helpful for blood sugar and satiety. Both of these fruits have fiber themselves, are great as part of a snack or breakfast, and excellent for gut health. That’s that.
“Sugar feeds cancer”
I discussed this daily when I worked in breast cancer, and I know it’s still a widely thought belief. My answer is this: all of our cells need glucose, or sugar, for energy, including cancer cells. There is no way around that. Cancer cells are metabolically different from our other cells in that they prefer glucose to produce energy through a process that is different from normal cells. This causes them to take up glucose more rapidly (called the Warburg Effect); however, eating sugar does not directly cause cancer cells to grow more quickly. And thus, cutting out sugar or fasting will likely not slow cancer growth. When glucose is not around, all cells use other nutrients to produce energy (protein, fat) instead, and cancer cells are not only programmed to use these nutrients, but anything in your body to grow. Restrictive diets during cancer treatment can also contribute to malnutrition, undernourishment and enhance treatment-related side effects.
“Not getting my period means I’m working hard”
Compared to even 10 years ago, there is a lot more collective knowledge now among elite and recreational athletes alike that this statement is untrue. However, I’m going to surmise that the number of female athletes who still don’t get their periods is fairly high, and this is usually due to low energy availability (often a combination of underfueling and over-exercising). The menstrual period should be thought of as the fifth vital sign - if it’s irregular or missing all together, it should be taken seriously and is not normal. In athletes, not having a period (or amenorrhea) often accompanies disordered eating and eating disorders, which if not treated can lead to a plethora of mental and physical health problems, and poor athletic performance. I remember about 15 years ago (so around age 28 or 29, time flies), I was running marathons and my eating habits were sub-par at best. My period had been missing for some time and when I mentioned it to my gynecologist she said, “well, it’s fine but might be a problem if you ever want to get pregnant.” End conversation. Um, what? This was before I was a dietitian or had any idea about really anything, so I didn’t advocate for myself or think it was an issue until much later (and obviously got a new doctor, this one was awful). I say this because even though they should, not all healthcare providers know or care about disordered eating, overexercising and low energy availability, the impact it has on the body and how to address it (and refer out) to help avoid long-term health problems. Always advocate for yourself if you don’t think you’re getting the care you deserve. And back to my original point, know that not getting a period is a red flag that needs to be addressed ASAP.
Stay tuned for part 2!
Take good care,
Kelly