Quick Studies: A snapshot of the latest research on diet, exercise, and more

Catching Colorectal Cancer Early

Everyone aged 45 or older should get screened for colorectal cancer, says a new recommendation from the U.S. Preventive Services Task Force. (The American Cancer Society has had similar advice since 2018.)

Until now, the task force had recommended screening only for adults aged 50 to 75. (It still leaves doctors to decide whether to screen adults aged 76 to 85.) However, the incidence of colorectal cancer in adults in their 40s has climbed by nearly 15 percent since 2000.

What to do: Get screened at 45 (earlier if you have risk factors like inflammatory bowel disease or adenomatous polyps). Avoiding a colonoscopy? Try a test that detects DNA biomarkers of cancer or hidden blood in your stool.

JAMA 325: 1943, 1965, 1978, 1998, 2021.

Size Matters

Bigger servings lead to bigger snacks. People consumed nearly 300 calories’ worth of popcorn when given a small (3½ oz.) bag—but nearly 400 calories when given a large (7 oz.) bag—to eat while watching TV in a university lab.

The real-world difference may be greater. At home, people ate 300 calories from the small bag and 500 calories from the large bag.

What to do: Trying not to overindulge? Shrink your servings.

Appetite 2021. doi:10.1016/j.appet.2021.105160.

DASH Diets & Inflammation

A DASH (Dietary Approaches to Stop Hypertension) diet may do more than lower your blood pressure.

Roughly 400 people with either elevated or high blood pressure were randomly assigned to a typical U.S. diet or a DASH diet—both provided by researchers. The DASH diet was rich in fruits, vegetables, and low-fat dairy. It included poultry, fish, whole grains, and nuts, and was low in red meat and added sugars.

After four weeks, levels of c-reactive protein (a measure of inflammation) were 13 percent lower and cardiac troponin (a measure of damage to the heart) was 14 percent lower in those eating the DASH diet.

What to do: Eat a DASH-like diet, which may also lower your risk of type 2 diabetes, gout, and memory loss.

J. Am. Coll. Cardiol. 77: 2625, 2021.

Cycle, Run, Walk, Dance, Repeat

Exercise plus a weight-loss drug can help keep pounds off and boost fitness, says a study funded by the drug’s manufacturer.

Researchers randomly assigned 195 people with obesity who had lost roughly 30 pounds on a low-calorie diet to (a) take injections of liraglutide (Saxenda), a drug that lowers blood sugar and inhibits appetite, (b) do 150 minutes of moderate (or, preferably, 75 minutes of vigorous) exercise a week, (c) take liraglutide and exercise, or (d) take a placebo.

After a year, the drug-plus-exercise group had lost another 7 pounds, the drug-alone group had lost another 2 pounds, the exercise-alone group had gained 4 pounds, and the placebo group had gained 13 pounds. Cardiorespiratory fitness improved only in the two exercise groups. Heart palpitations were more common in the drug-only (but not the drug-plus-exercise) group.

Liraglutide causes thyroid tumors in rodents, says the label warning. Whether it causes tumors in humans is unknown.

What to do: Get moving! Even if you take a weight-loss drug, exercise makes you healthier.

N. Engl. J. Med. 384: 1719, 2021.