Nutrition Archive

In the journals

Spinach is one of the best sources for the antioxidant lutein, which may promote eye health and reduce the risk of macular degeneration. A new study in the March 30, 2019, issue of Food Chemistry suggests that eating uncooked chopped spinach can ensure you get the highest amounts compared with traditional cooking methods.

The researchers measured the lutein content of baby spinach after it was fried, boiled, and steamed. They found that lutein levels dropped by 40% after only four minutes of boiling, and by 90% after 90 minutes, while levels decreased by more than 60% after just two minutes of frying. Spinach lost about 50% of its lutein after four minutes of steaming.

In the journals

People who have had a heart attack or a stroke are routinely prescribed a statin to reduce the risk of a repeat event. But by also following a Mediterranean-style diet, they can improve their chance of living longer, suggests a study in the Feb. 1, 2019, issue of the International Journal of Cardiology.

The study looked at 1,180 people, average age 68, who had at least one previous heart attack or stroke, and recorded their statin use and diet intake at the study's beginning. The researchers identified the people who faithfully followed a Mediterranean-style diet. A Mediterranean-style diet involves consuming medium to high amounts of whole fruits and vegetables, whole grains, legumes and nuts, olive oil, and poultry and fish, with limited amounts of red meat, alcohol, and dairy.

Ask the doctors

Q. I recently had diverticulitis. I'd like to avoid a recurrence. Is there anything I can do to prevent this painful condition in the future?

A. As people age, small pouches often form in the wall of the large intestine, a condition called diverticulosis. If food or bacteria become trapped in these pouches, they can become inflamed or infected, which is known as diverticulitis.

The answer to that question is becoming clearer, thanks to new research.

Some 10% of American adults regularly take an omega-3 supplement, despite uncertainty about whether these products truly live up to their health claims. But two new studies published in November 2018 shed some light on who might benefit from omega-3 supplements — and who probably won't.

VITAL

The first study was the Vitamin D and Omega-3 Trial (VITAL), a large multiyear study with 25,871 healthy adults with no history of cardiovascular (heart or blood vessel–related) disease and at "usual risk" for it. The group was racially diverse and chosen to be representative of the general population, says the study's lead author Dr. JoAnn E. Manson, professor of medicine and the Michael and Lee Bell Professor of Women's Health at Harvard Medical School.

Research we're watching

Want to reduce your risk of cardiovascular disease, diabetes, and colorectal cancer? Eat more fiber, says a meta-analysis published online January 10 by The Lancet.

Authors reviewed data from 185 prospective studies and 58 clinical trials and found that people who ate the most fiber had a 15% to 30% lower risk of dying from cardiovascular disease or developing diabetes or colon cancer, compared with people in the study who ate the least. People appeared to get the biggest benefit when they ate between 25g and 29 g of fiber a day.

Pay attention to healthy ingredients, inspection documents, and online reviews.

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Food trucks — once the catering staples of construction sites — are no longer just about convenience. These rolling kitchens bring innovative gourmet food to busy streets and crowded parking lots, with diverse menus that attract hordes of hungry customers and discerning foodies.

But as popular as food trucks are — nationally, a billion-dollar industry that defines the landscape in places like Los Angeles; Miami; Austin, Tex.; and Portland, Ore. — they still serve restaurant fare, which is typically loaded with saturated fat, salt, refined carbo-hydrates, sugar, and calories.

Olive oil is just one of many plant-based oils rich in unsaturated fats, the more healthful type of fat.

When you're cooking or baking, choose a fat that's liquid instead of solid at room temperature. That advice, from the federal Dietary Guidelines for Americans, is based on a large body of evidence showing that replacing solid fat (mainly saturated fat) with liquid fat (mostly unsaturated fat) is linked to a lower risk of heart attack and death from heart disease.

To be clear, all fat — whether it comes from seeds, nuts, meat, milk, olives, or avocados — contains a mixture of different fatty acids, the basic building blocks of fats. However, butter, lard, coconut oil, and palm oil contain mostly saturated fatty acids. Most plant-based oils, on the other hand, consist predominantly of unsaturated fatty acids, which include both monounsaturated and polyunsaturated fatty acids (see "The fats of life: Healthy oils").

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All beans are rich in fiber, but the top-ranking variety is the navy bean, allegedly named for its popularity in the U.S. Navy in the early 20th century. These pea-sized, cream-colored beans provide 10 grams of fiber per half-cup serving. Most Americans are woefully deficient in dietary fiber, which helps lower harmful LDL cholesterol and is linked to a lower risk of heart disease.

Navy beans are just one of many varieties of white beans, which include cannellini, great northern, and white kidney beans. Cook's Illustrated magazine describes cannellini beans as having a "meaty, lush texture with a buttery, subtle mushroomlike flavor" whereas great northerns are "slightly chalky and mealy, with strong mineral notes." Lima and baby lima beans (also known as butter beans) are also considered white beans.