Sweet potatoes are related to the morning glory family, while yams belong to the lily family.iStockPhoto / Getty Images
Many of us read nutrition labels to find the best foods for you. By doing this, it is easier to choose the highest fiber sliced bread, the granola that has the least sugar, and the yogurt that has the most calcium per serving.
But when you decide between two healthy foods at the grocery store, you can’t always tell which one offers the most nutrition benefit for your money. This is true for foods that do not show nutritional data.
Take a few minutes to test your nutritional intelligence. Which of the following foods offers the best overall nutritional value?
Sweet potatoes versus yams: The names of these two tubers are often used interchangeably, but they are two very different vegetables, botanically and nutritionally.
Sweet potatoes are related to the morning glory family. The most common variety found in grocery stores has coppery or reddish skin, an orange pulp, and a sweet taste.
Yams, which belong to the lily family, may have light pink or brown skin and ivory flesh, pale yellow or purple. Yams are not very sweet and are more starchy than sweet potatoes.
In terms of nutrition, both are excellent sources of potassium that regulate blood pressure and provide a decent amount of fiber and vitamin C. However, when it comes to the antioxidant beta-carotene, sweet potatoes outperform yams.
For half a cup of cooked sweet potatoes, serve 15.5 mg of beta-carotene; the same portion of yams has less than one. A daily intake of 3 to 6 mg of beta-carotene from fruits and vegetables is believed to help prevent chronic disease.
Almond butter versus peanut butter: Both nuts serve protein (7 g per two tablespoons) and are rich in heart-healthy monounsaturated fats. And each provides potassium and B vitamins.
Almond butter, however, has the nutritional advantage over peanut butter, providing seven times more calcium and 40 percent more magnesium. For two tablespoons, almond butter contains 110 mg of calcium and 90 mg of magnesium.
In addition, almond butter is an exceptional source of vitamin E that supports the immune system, providing 7.7 mg (the half-day value) per serving of two tablespoons.
White tuna versus light tuna: Whether it is white (turbid) or clear (bolin, yellowfin, tongol), canned tuna is an excellent source of protein, niacin, vitamin B12 and selenium, a mineral that plays a critical role in healthy thyroid function.
But if you’re also looking for anti-inflammatory omega-3 fats, bluefin tuna is the best choice. Three ounces provide 860 mg of combined eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), three times more than light tuna.
There is no official recommended daily intake for DHA and EPA, but many international health authorities and scientific organizations advise that adults consume 250 to 500 milligrams a day to maintain heart health.
A disadvantage of bluefin tuna: depending on where it is, it may have a high content of methylmercury, a compound that can damage the development of the nervous system of the unborn baby and the young child.
For this reason, Health Canada advises women of childbearing age and pregnant and lactating women to limit their intake of canned white tuna to 300 g (10 ounces) per week, a value of about two cans. . Children ages 5 to 11 should not eat more than 150 grams (about a can) a week; younger children should not eat more than 75 grams (about half a can) a week.
However, yellowfin tuna caught in the waters of the Pacific Northwest are low in mercury. When buying canned white tuna, look for “Canadian product” on the label. Canned light tuna is relatively low in mercury.
Kale versus spinach: These two green leafy vegetables offer a good amount of fiber, calcium and magnesium and deserve a place on your regular menu.
When it comes to antioxidants, however, spinach greatly overshadows kale. Per serving, leaf green provides five times more beta-carotene (11.3 mg per cup cooked), seven times more brain-friendly lutein (20.3 mg per cup cooked) and twice as much vitamin E.
Compared to kale, a cup of cooked spinach is a good source of iron (6.4 mg) and an excellent source of both potassium (839 mg) and folate (263 mcg). Spinach is also one of the best dietary sources of betaine, a phytochemical that acts as an antioxidant and helps fight inflammation in the body.
Leslie Beck, a Toronto-based private practitioner, is Medcan’s director of nutrition and nutrition. Follow her on Twitter @LeslieBeckRD
Sign up for the weekly Health and Wellness newsletter to receive the latest news and tips.