Browse evidence-based analysis of health-related claims and assertions
Certain receptors on immune cells grab onto antibodies attached to germs, helping the cells swallow them up so they can be broken down and shown to other immune cells.
Descriptive
When tested in animals at high doses, natural and man-made chemicals are about equally likely to show up as cancer-causing.
The 27 plant chemicals that caused cancer in rats at high doses are also found in everyday foods like fruits and vegetables.
Out of the 52 plant-made pesticides tested in animals, 27 caused cancer in rodents when given very high doses.
Quantitative
Scientists have tested 52 plant-made pesticides in very high doses on animals to see if they cause cancer.
Almost all the pesticide-like chemicals we eat in our food come from plants themselves, not from man-made products.
From 2000 to 2006, both 'bad' and 'good' cholesterol levels in heart disease patients admitted to the hospital gradually went down.
Women with heart disease tend to have higher 'bad' cholesterol levels when they’re admitted to the hospital than men do.
Correlational
Very few heart disease patients—just 1 in 70—have both very low 'bad' cholesterol and high 'good' cholesterol at the time they’re admitted to the hospital.
More than half of heart disease patients admitted to the hospital have low levels of 'good' cholesterol, which is linked to higher heart disease risk.
When people with heart disease are admitted to the hospital, their 'bad' cholesterol is usually around 105 mg/dL, which is higher than what doctors now recommend for heart health.
If you’re already strong and trained, you don’t need fancy workout tricks like pyramids or going to failure to get the best results—just do the same total work with any method.
Causal
The researchers made sure everyone did the exact same total amount of work—same number of reps, same weights—so any differences in results could only be because of how they did the workout, not how much they lifted.
By having each person train one leg one way and the other leg another way, the study made sure that differences in people’s bodies didn’t mess up the results—so we can be sure it’s the training method, not the person, that matters.
Going from light to heavy and back to light again in your workouts doesn’t make you stronger or bigger than just doing the same total weight with consistent loads—if you’re already trained.
Even if you push yourself to complete exhaustion with drop sets, you won’t grow bigger or stronger than if you just stick to regular sets—as long as you lift the same total weight.
If you lift the same total weight no matter how you arrange your sets—pyramid, failure, or regular—you’ll get the same results. Fancy methods don’t make you stronger or bigger if you’re already trained.
Your muscle fibers don’t get longer with one training method over another—whether you go to failure, use pyramids, or stick to the basics—as long as you do the same total amount of work.
No matter if you use a pyramid, go to failure, or stick to a normal routine, your muscle fibers don’t change their angle or how they’re packed together any more with one method than another—when you do the same total work.
When people who already train hard do different kinds of leg workouts—pyramid, failure sets, or regular sets—all of them get about the same boost in how much weight they can lift in a leg extension machine, around 17%.
Whether you lift weights using a pyramid, go to failure, or stick to a standard routine, if you do the same total amount of work, your leg strength improves by about the same amount—around 25%—after 12 weeks.
When people who already lift weights train with different methods—like starting light and going heavy, or doing sets to failure—all of them get about the same muscle growth if they do the same total amount of work.
Just because short rests make you feel more tired and your muscles burn more during one workout doesn’t mean they’ll make your muscles bigger over time—you’d need to study people for months to know that.
You can make your workout feel harder and your muscles burn more by resting less between sets—but you can still lift the same total weight without getting weaker.