Browse evidence-based analysis of health-related claims and assertions
If you're overweight and have high 'bad' cholesterol, eating fewer carbs for four weeks might help lower your bad cholesterol and improve your overall cholesterol balance better than eating low-fat, high-carb foods.
Correlational
If you're overweight and eat fewer carbs instead of less fat for four weeks, you might lose more body fat—even if you lose the same amount of total weight as someone on a low-fat diet.
If you're overweight and eat fewer carbs instead of less fat for four weeks—without counting calories—you might lose about 8 pounds more than someone on a low-fat diet, and it might be because you're losing more body fat.
Eating more fiber—especially from whole grains—lowers your risk of heart disease and helps you live longer after a heart attack, probably by lowering bad cholesterol and stabilizing blood sugar.
Having one or two drinks a day is linked to a lower risk of heart disease than not drinking at all or drinking a lot, possibly because it helps raise good cholesterol and thin the blood.
People who eat healthy diets like the Mediterranean, DASH, or AHEI style tend to have a 20–30% lower chance of dying from heart problems, because these diets include good foods and avoid bad ones.
If you swap out butter and fatty meats for oils like olive oil or nuts, you might lower your risk of heart disease—but if you swap them for white bread or sugary snacks, it doesn’t help and might even hurt.
Drinking more sugary drinks like soda is linked to a higher chance of heart problems, partly because it makes you gain weight, but also because it directly messes with your blood sugar, insulin, fats in your blood, and blood pressure.
Mechanistic
Eating processed meats like bacon and sausages might raise your risk of heart disease more the more you eat, because these foods contain chemicals that can trigger body inflammation, damage cells, and mess up your gut bacteria.
Eating more fruits, veggies, whole grains, nuts, and beans is linked to a lower chance of heart disease and dying from it—probably because these foods help lower bad cholesterol, reduce blood pressure, and calm inflammation.
Even women who just got basic health info once a month ate fewer calories and less salt and fat by the end of the study.
Causal
In rural women over 40 who are overweight or obese, adding structured exercise classes didn’t make them move more during the day than just giving them basic advice — so those classes alone might not help them get more active.
Descriptive
A program in rural areas that helped women over 40 who are overweight get more active by walking and getting involved in their community led to them reporting they walked more—about 113.5 extra MET-minutes a week—than women who got only basic info, even though actual movement didn’t change when measured with devices.
A program that taught rural women over 40 who are overweight how to eat more vegetables helped them eat about one-third of a cup more veggies each day than women who got only basic info — showing that even in places with limited food options, education can make a real difference.
A program that helped older rural women eat more fruits and veggies led to them eating about half a cup more each day than women who got little help — showing that good education can make a difference even when fresh food isn’t always easy to find.
People who sleep less than 7 hours a night are more likely to develop heart problems like heart attacks or irregular heartbeats than those who sleep 7 to 9 hours.
Getting between 7 and 9 hours of sleep each night seems to be the sweet spot for lowering your risk of heart problems — sleeping less or more than that might raise your risk.
People who sleep more than 9 hours a night don’t seem to have a higher chance of heart problems or dying from heart issues than those who sleep 7 to 9 hours, at least based on how their sleep was tracked with a wrist device.
People who sleep less than 7 hours a night are more likely to develop heart problems or die from them compared to those who sleep 7 to 9 hours, based on wearable device data.
Sleeping more than 9 hours a night doesn’t make your heart healthier—once you’re getting 7 to 8 hours, sleeping longer won’t lower your risk of heart disease.
If you usually sleep less than 6 hours a night and start getting 7 to 8 hours instead, you’re less likely to develop heart disease—so getting enough sleep might help keep your heart healthy.
People who have trouble sleeping—like not being able to fall asleep, stopping breathing at night, or falling asleep at the wrong times—are much more likely to develop heart disease, and it might be because poor sleep messes up the body’s stress, inflammation, and metabolism systems.
People who take a lot of naps during the day might be more likely to develop heart problems, even if they sleep well at night and aren’t overweight—this could mean their sleep isn’t restful or their heart is under extra stress.
People who sleep six hours or less each night are more likely to develop heart disease, and this might be because not enough sleep messes up their metabolism and causes body inflammation.