Carbohydrates

Carbohydrates are part of a balanced diet, but not all carbohydrates are created equal. In this review, researchers analyzed different labeling strategies that help consumers identify healthy carbohydrate foods when shopping. They identified quality carbohydrates are identified as those that are high in fiber, have high levels of whole grains, or have a low glycemic index or glycemic response. The Whole Grain Stamp was one of many voluntary labeling programs highlighted by the authors as a way to help consumers find quality carbohydrate foods. The authors conclude that it is important for governments to enable these types of 3rd party labeling systems to help steer consumers towards healthier carbohydrate choices.
Nutrients. 2020 Jun 9;12(6):1725. doi:10.3390/nu12061725 (Marinangeli, CPF et al.)

There are countless different diets out there, from low carb to high carb to everything in between. But which eating pattern is linked with longer lives? Scientists are on a mission to find out. Researchers analyzed the eating habits and health outcomes of 15,428 adults in the US, following them for 25 years. The “sweet spot” for the lowest risk of mortality was diets that had 50-55% of their calories from carbohydrates, especially those with lots of plant foods, like whole grain bread, nuts, vegetables, and peanut butter. This amount aligns with traditional diets (such as the Mediterranean diet), as well as the US Dietary Guidelines for Americans. On the other hand, low-carb diets that had lots of meat were linked with higher mortality.
The Lancet Public Health. 2018 Aug 16. pii: S2468-2667(18)30135-X. [Epub ahead of print.] (Seidelmann SB et al.)

Many parents buy gluten-free foods for their kids because they think that those foods are healthier. But unless you have a medically-diagnosed reason to avoid gluten (such as celiac disease), evidence suggests otherwise. Researchers in Canada went to 2 major supermarket chains and purchased all foods marketed to kids (with the exception of candy, soda, and a few other “junk foods”) – 374 products total. They then analyzed the nutrition labels of the foods, to see how products marketed as gluten free stacked up to those not marketed as gluten free. For a more direct comparison, they then identified 43 gluten-free foods marketed to kids that had a non-gluten-free counterpart, and compared nutrition between the matched products. Overall, nutrition was poor among all kids’ products, gluten-free or not, and there were few significant differences. Specifically, products marketed as gluten-free had slightly lower levels of sodium, but slightly higher levels of added sugar. Additionally, a higher proportion of gluten-free products had high levels of trans fat. The researchers concluded that “[gluten-free] supermarket foods that are targeted at children are not nutritionally superior to regular child targeted foods and may be of greater potential concern because of their sugar content,” adding that “parents who substitute [gluten-free] products for their product equivalents (assuming [gluten-free] products to be healthier) are mistaken.”
Pediatrics. 2018 Aug;142(2). pii: e20180525. (Elliott C et al.)

Though many Paleo dieters believe that bread is a relatively “new” foodstuff, archeological evidence paints a different picture of what ancient diets were like for our hunting and gathering ancestors. Archeologists analyzed the remains of ancient fireplaces in what is today Jordan, and found the oldest empirical evidence of bread-like products from 14,400 years ago. These ancient flatbreads existed 4,000 years before Neolithic agriculture, and challenge previous assumptions about grains’ role (or lack thereof) in ancient, Epipaleolithic diets.
Proceedings of the National Academy of Sciences. 2018 Jul 31;115(31):7925-7930. (Arranz-Otaegui A et al.)

Not all carbohydrates are created equal. After all, everything from quinoa and blueberries to candy bars and soda have carbohydrates. In this review, researchers examined the links between different types of carbohydrates and health. They concluded that whole grains are linked with numerous health benefits, including lower cholesterol, body fat, and healthier blood sugar management, as well as lower risks of type 2 diabetes, heart disease, many cancers, and death from all causes. Given that much of the research on whole grains is done using more processed whole grain products (like breakfast cereals and breads), the authors note that more research is needed to determine if intact whole grains without as much added sugar may have even greater health benefits.
BMJ. 2018 June 13. (Ludwig DS et al.) [Epub ahead of print.]

Carbohydrates are the building blocks of a balanced diet, but not all carbs are created equal. To see how diet might relate to bladder cancer risk, researchers analyzed the diets of 578 adults with bladder cancer and 608 controls without bladder cancer. Those regularly eating high glycemic index and glycemic load foods (foods that are more rapidly absorbed into the bloodstream, thus spiking your blood sugar) were more likely to have bladder cancer, as were those who regularly ate refined grains like bread and pasta. However, these results were not as strong in people who regularly eat vegetables. People who regularly eat whole grains and/or legumes tended to be less likely to have bladder cancer, but the results were not statistically significant.
British Journal of Nutrition. 2017 Nov;118(9):722-729. (Augustin LSA et al.)

Very low carbohydrate “keto” diets can increase oxygen uptake (VO2 peak). However, this doesn’t necessarily translate to an improvement in athletic performance, and may be detrimental. In this study of 21 race walkers, researchers assigned them to a very low carb “keto” diet, or 2 different types of high carb diets. In the keto diet, the participants experienced reduced economy, meaning their bodies required more oxygen at a given speed, despite their increased VO2 peak. This translated to no improvement in the keto diet group speed, with 5.3-6.6% improvements in speed for the high carb diet groups.
The Journal of Physiology. 2017 May 1;595(9):2785-2807. doi:10.1113/JP273230. (Burke LM et al.)

Grains have been at the core of traditional diets for millennia, but some misguided celebrities and fad diets have moved away from this tradition. Using national health survey data from 9,341 adults in Australia, researchers found that those avoiding core grain foods were significantly more likely to be overweight or obese than those who eat grains, despite consuming fewer calories, fruits, vegetables and less fiber than grain eaters. After adjusting for age, sex, and calorie intake, avoiding grains was also linked with a higher BMI and waist size.
Nutrients. 2017 Feb 18;9(2). pii: E157. (Fayet-Moore F et al.)

Researchers analyzed 10 years of extensive health and nutrition data in a study of more than 1,600 Australian adults, to see how carbohydrate nutrition (Glycemic Index, Glycemic Load, total carbs, sugars, and fiber) relates to successful aging. The researchers defined successful aging as absence of disability, depression, cognitive problems, respiratory problems, or chronic disease (like heart disease or cancer). Adults eating the most total fiber were significantly more likely to age successfully. Additionally, those eating the most cereal fiber (the type of fiber in whole grains) were 78% more likely to age successfully than those eating the least, and those eating the most fruit fiber were 64-81% more likely to age successfully. Those eating a higher Glycemic Index at the beginning of the study were more likely to die throughout the study, but neither Glycemic Index, Glycemic Load, total carbohydrate, nor sugar intake were significantly associated with successful aging. 
The Journals of Gerontology: Series A, Biological Sciences and Medical Sciences. 2016 Jun 1. pii: glw091. [Epub ahead of print] (Gopinath B et al.)