May 17, 2021

EXTRA CHEESE: Shape-Shifting Pasta and Deadly Fava Beans

Sarah tells Becca about a new shape-shifting pasta that may help make the food system more sustainable. Plus, we hear a harrowing listener story about favism (glucose-6-phosphate dehydrogenase deficiency) and discuss the science behind it.

WE WANT TO HEAR FROM YOU! Do you have an interesting food-related story? Maybe a quirky food habit or unique sensitivity? Email us at 

For a full list of references, visit our website.

This is an independently produced podcast and your support means a lot to us. Please rate, review, and subscribe wherever you listen!

Follow @itsthedadpod on Twitter or @dieteticsafterdark on Instagram to stay in the loop on all things podcast-related.

Follow Sarah & Becca on Instagram @sarahdoesnutrition and @thenutritionjunky for recipes and all things dietetics. 

This podcast was produced by Geoff Devine at Earworm Radio. Follow Geoff @ewradio on Instagram or visit

Special thanks to @ken.dietitian for the listener story this week. 



Carnegie Mellon University (2021). Flat Pasta Developed That Morphs Into Shape When Cooked. 

Ewbank, A. (2018). Why beans were an ancient emblem of death. 

Fox, A. (2021). Mighty Morphing ‘Flat-Pack’ Pasta Changes Shape in Boiling Water. 

Kuipers, M. T., van Zwieten, R., Heijmans, J., Rutten, C. E., de Heer, K., Kater, A. P., & Nur, E. (2020). Glucose-6-phosphate dehydrogenase deficiency-associated hemolysis and methemoglobinemia in a COVID-19 patient treated with chloroquine. American Journal of Hematology, 95(8), E194-E196. 

Luzzatto, L., & Arese, P. (2018). Favism and glucose-6-phosphate dehydrogenase deficiency. The New England Journal of Medicine, 378(1), 60-71.



Hi, I’m Sarah. 

& I’m Becca, and you’re listening to extra cheese! 

I have a quick but super cool story for you today, followed by a listener story that will blow your mind and then I’ll tell you the fascinating medical explanation behind it. But first, I need to know: Do you have a favourite pasta shape?

Mine are Macaroni or Orecchiette or Orzo or baby shells - all the little tiny ones. 

One of the best things about pasta is that it comes in a wide variety of shapes, and I think it’s actually science - objective science - that some shapes taste better than others. They can all be 100% durum semolina wheat, some pasta shapes just hit different. But some pasta shapes take up more space. Think fusilli, rotini, cavatappi - those twisty shapes require more air space and therefore more packaging, but maybe not for long! 

A research team out of Carnegie Mellon University has developed a completely flat pasta that transforms into tubes, spirals, twists, and waves when cooked. 

The pasta looks, feels, and tastes like traditional pasta, but offers new possibilities for packaging, storage, and transportation. The researchers were inspired by flat-packed furniture (think IKEA) and so they pressed tiny grooves into the pasta that help create a new shape as the pasta absorbs water. The pattern of the grooves increases the time it takes for water to cook that area of the pasta (so small, tight grooves will cook at a different rate then large grooves or a flat surface), and so by placing the patterns in a certain way, the researchers can control the form that the pasta takes on when cooked. 

The researchers goal is to create more effective food packaging that can help create a more sustainable food system. The team estimates their flat-pack shapes could reduce packaging requirements for the popular food by 59 to 86 percent. They’re also aiming to reduce GHG emissions from the cooking process itself. In Italy, apparently 1% of GHG emissions come from cooking pasta (which I LOVE), and the flat-packed pasta actually cooks faster than traditional pre-shaped pasta, which could potentially reduce emissions. 

The lead author of this study tested the flat-packed pasta on a camping trip and reported that the pasta took up less room in her bag, did not break while hiking, and cooked successfully on her portable stove. Some interesting applications for the pasta could be astronaut food or even food deliveries to disaster areas, much like the K-ration in our starvation episode! 

Alright, so now we have our listener story for the week from Ken, who you can find on instagram @ken.dietitian. This one is pretty wild. 

Play Ken’s Audio

Wow, Ken - thank you so much for sending us that harrowing story! And please, don’t touch another fava bean ever again! You are probably correct, the most likely explanation for this experience is glucose-6-phosphate dehydrogenase deficiency. So what exactly is it? Glucose-6-phosphate dehydrogenase deficiency is a genetic condition, and globally it is actually the most common enzyme defect. It is found in about 400 million people worldwide and is more common in African, Middle Eastern, Mediterranean and South Asian populations. Typically, biological males are more likely to be affected because the gene that encodes G6PD resides on the X chromosome, but biological female carriers may have symptoms. This is because males only have one X chromosome, whereas females have two. If this one chromosome has a mutation, they will have the G6PD deficiency. However, it can occur in biological females as well. This inherited trait was discovered in 1956, and is responsible for 3 diseases that were previously thought to be unrelated: drug-induced hemolytic anemia, severe neonatal jaundice, and favism. Today we’re going to be talking about the link between G6PD deficiency and favism. 

While the G6PD deficiency was only discovered in 1956, people have been fearful of fava beans since the 5th century B.C. In fact, the famed Greek mathematician and philosopher, Pythagoras, known for his work on the Pythagorean Theorem, was a vocal opponent of the fava bean. Him and his followers considered fava beans symbols of death and believed that their flesh-like nature meant they contained the souls of the dead. Throughout ancient texts this historical aversion to fava beans persisted in many civilizations and could actually be rooted in favism. 

So what exactly is favism? Well, within 5-24 hours of ingesting fava beans, someone with G6PD deficiency will begin to experience a very severe, life-threatening reaction called acute hemolytic anemia. This reaction is triggered by two glucosides that are present in higher concentrations in fava beans, called divicine and convicine. Acute hemolytic anemia quite literally means that red bloods are destroyed faster than they can be made, which, in serious cases, can be fatal. Some of the signs and symptoms include paleness, yellowing of the skin and whites of the eyes (jaundice), dark urine, fatigue, shortness of breath, confusion, dizziness, weakness, fever, enlargement of the spleen and liver (so maybe that’s where the pain was coming from), and a rapid or altered heart rate - we’re not doctors and this is not a retrospective diagnosis, but this sounds a lot like what Ken described. If an individual is breastfeeding an infant with G6PD deficiency and they consume fava beans, it can cause a favism attack in the baby. There is a rumour that people with G6PD dehydrogenase deficiency can also experience a “favism attack” by inhaling the pollen of a fava bean plant, but this is now thought to be a myth. 

Most people with this enzyme deficiency, however, never experience any signs or symptoms and are unaware that they have the condition. They can live a happy, safe, asymptomatic life as long as they avoid eating fava beans. So Ken, I know we probably don’t have to tell you this, but please stay away from fava beans or maybe get tested for G6PD deficiency just to be sure. In case anyone listening is now wondering if they should cut out fava beans just in case, the vast majority of us can eat fava beans safely and shouldn’t be too concerned. 

That’s it for today! I hope you enjoyed today’s episode of Extra Cheese and we’ll see you next week. 

Extra Information

Glucoside: a compound that yields glucose.

Glucose-6-phosphate dehydrogenase: This enzyme helps protect red blood cells from damage and premature destruction. Glucose-6-phosphate dehydrogenase is responsible for the first step in the pentose phosphate pathway, a series of chemical reactions that convert glucose (a type of sugar found in most carbohydrates) to another sugar, ribose-5-phosphate.

The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt) is a metabolic pathway parallel to glycolysis. ... While the pentose phosphate pathway does involve oxidation of glucose, its primary role is anabolic rather than catabolic.