If your goal is optimal nutrition, which orange root vegetable would you choose, carrots or sweet potatoes? 100 calories from carrots vs. 100 calories from sweet potatoes, let’s have a look!
First, to get 100 calories you can eat almost double the amount of carrots, 245g compared with 111g of a baked sweet potato. Protein and carbohydrate are about the same, whereas there is marginally more fat in carrots. However, for the same amount of calories, carrots have almost double the fiber! Fiber feed gut bacteria, which may be involved in lifespan (https://michaellustgarten.wordpress.com/2014/07/16/are-the-bacteria-in-our-intestines-involved-in-mechanisms-underlying-health-and-lifespan/), so I’m all for that!
What about vitamin content? For the 17 Vitamins below, carrots have higher values for 10 of them, whereas sweet potatoes have higher values for only 3 vitamins. It’s important to note that for the same amount of calories, carrots have almost double the Vitamin A and beta-carotene, 17+ fold more alpha-carotene, and contain lutein+xeaxanthin (whereas sweet potatoes don’t have any!).
What about mineral content? For the 10 minerals shown in the below, raw carrots are better than sweet potato for 5 minerals, whereas sweet potato leads for 4 mineral categories. However, sweet potato is barely better for some, like magnesium, iron and copper, by 1 milligram, 0.1 and 0.1 milligrams, respectively.
Carrots also contain flavanoids, including flavones (luteolin) and flavanols (kaempferol, myricetin, quercetin), whereas these metabolites are absent in sweet potatoes . An increased flavanoid intake in older adults is associated with reduced all-cause mortality risk (Ivey et al. 2015):
So, based on energy and nutrient density (you can eat more carrots, and carrots have far more nutrition than sweet potatoes, for the same amount of calories), I would choose carrots over sweet potatoes. However, as an argument against this, Okinawans, who have one of the highest life expectancies in the world (shown below) consume more than half of the their calories from sweet potatoes (Wilcox and Wilcox 2014). Maybe carrots being better than sweet potatoes doesn’t matter? Or maybe the Okinawans would have slightly better health if they got a similar amount of calories from carrots instead?
Interestingly, vegetables and fruits comprise the base of the Okinawan food pyramid (shown below; Wilcox et al. 2009), which I’ve suggested is both evolutionary accurate (https://michaellustgarten.wordpress.com/2015/07/17/on-a-paleo-diet-not-if-you-fiber-intake-is-less-than/) and is optimal for maximizing nutrient density (https://michaellustgarten.wordpress.com/2015/06/03/in-search-of-optimal-nutrient-density-veggies-or-whole-grains/).
So the take home here is that while carrots are better, it looks like you can’t go wrong eating either carrots or sweet potatoes!
Nutrition info (including flavanoid content) via ndb.nal.usda.gov
Ivey KL, Hodgson JM, Croft KD, Lewis JR, Prince RL. Flavonoid intake and all-cause mortality. Am J Clin Nutr. 2015 May;101(5):1012-20.
Murphy MM, Douglass JS, Birkett A. Resistant starch intakes in the United States. J Am Diet Assoc. 2008 Jan;108(1):67-78. Erratum in: J Am Diet Assoc. 2008 May;108(5):890.
Willcox DC, Willcox BJ, Todoriki H, Suzuki M. The Okinawan diet: health implications of a low-calorie, nutrient-dense, antioxidant-rich dietary pattern low in glycemic load. J Am Coll Nutr. 2009 Aug;28 Suppl:500S-516S.
Willcox BJ, Willcox DC. Caloric restriction, caloric restriction mimetics, and healthy aging in Okinawa: controversies and clinical implications. Curr Opin Clin Nutr Metab Care. 2014 Jan;17(1):51-8.