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

Get Your Insulin Going

Once your cells become insensitive to insulin, your risk of type 2 diabetes climbs. Can exercise help?

Danish researchers randomly assigned 188 sedentary overweight or obese people to:

BIKE: start biking to work,

MOD: do aerobic exercise (walking, running, rowing, cycling, or cross-training) at a moderate pace,

VIG: do the same aerobic exercise at a vigorous pace, or

CON: continue their sedentary lifestyle.

Each exercise group aimed to burn 320 calories a day (women) or 420 calories a day (men) on five days each week for six months.

Compared to the CON group, insulin sensitivity improved 26 percent in the VIG and 20 percent in the BIKE group but only 17 percent in the MOD group, which fell below the 20 percent target. Bonus: All exercise groups lost belly fat.

What to do: Don’t like to bike? Walk, run, row, spin, swim, whatever.

Br. J. Sports Med. 2019. doi:10.1136/bjsports-2018-100036.

No Breakfast? No Problem.

Does skipping breakfast make you pack on pounds because you overeat at lunch?

Scientists looked at 13 trials that randomly assigned adults to either eat or skip breakfast for one day to 16 weeks. The results: breakfast skippers ate 260 fewer calories per day.

What to do: Don’t worry that skipping breakfast leads to weight gain.

BMJ 2019. doi:10.1136/bmj.l42.

Vitamin D & Cancer

Many people with GI cancers are low in vitamin D. Could taking more help?

In the AMATERASU trial, scientists randomly assigned 417 patients with mostly colorectal, stomach, or esophageal cancer to take vitamin D (2,000 IU a day) or a placebo. Over five years, it took no longer for the vitamin D takers than the placebo takers to relapse or die.

In the SUNSHINE trial, scientists randomly assigned 139 people being treated with chemotherapy for advanced or metastatic colorectal cancer to take a high dose of vitamin D (8,000 IU a day for two weeks, then 4,000 IU a day) or a standard dose (400 IU a day). The high-dose group fared no better than the standard-dose group.

After the researchers adjusted for age, sex, race, weight, metastatic sites, and other factors that could affect cancer progression, the high-dose group did better, but that result needs to be confirmed in a larger trial.

What to do: Take vitamin D if your levels are low, but don’t rely on it to help treat GI cancer.

JAMA 321: 1354, 1361, 1370, 2019.

Scared of Omega-6s?

“Avoid vegetable oils high in omega-6,” says healthline.com. (That includes soybean, corn, and some safflower oils.)


Researchers pooled results from 30 studies that tracked roughly 69,000 people for 3 to 32 years. Those with the highest blood levels of linoleic acid, a key omega-6 fat, had a 23 percent lower risk of dying of cardiovascular disease than those with the lowest levels. Blood levels of arachidonic acid—an omega-6 fat that is often vilified—weren’t linked to a higher risk of cardiovascular disease.

What to do: Don’t fear omega-6 fats. This study (partly funded by mayo and margarine maker Unilever) isn’t definitive, but other evidence backs up advice to replace saturated fats with polyunsaturated fats rich in either omega-3s or omega-6s.

Circulation 2019. doi:10.1161/CIRCULATIONAHA.118.038908.

Photos (top to bottom): stock.adobe.com: nd3000, blvdone, maonakub, seventyfour.