Browse evidence-based analysis of health-related claims and assertions
Eating more fruit seems to help more than eating more vegetables when it comes to lowering the risk of dying from cancer.
Correlational
When scientists combined data from 26 big studies with over a million people, they found the same thing: eating five servings of fruits and veggies a day helps people live longer.
Even when researchers accounted for people changing their diet because they were already sick, the link between eating more fruits and veggies and living longer still held up.
Eating more than five servings of fruits and veggies a day doesn’t make you any less likely to die early — five is the sweet spot.
Eating leafy greens, broccoli, oranges, and other colorful fruits and veggies is linked to living longer, likely because they’re packed with good nutrients.
Whether you’re young or old, smoke or don’t, are overweight or not — eating five servings of fruits and veggies a day still helps lower your risk of dying early.
People who eat five servings of fruits and veggies a day are much less likely to die from lung diseases like COPD than those who eat only two servings.
Drinking fruit juice or eating potatoes doesn’t help people live longer — unlike eating whole fruits and vegetables, which do.
Eating starchy veggies like corn and peas doesn’t seem to help people live longer, unlike other fruits and vegetables, which do.
People who eat two pieces of fruit and three servings of vegetables every day have a lower chance of dying from heart disease than those who eat less, but eating more doesn’t help much beyond that.
People who eat about five servings of fruits and veggies a day tend to live longer than those who eat only two, but eating more than five doesn’t make them live any longer.
When shown pictures of their foods, Hadza people picked honey as their favorite and tubers as their least favorite — they really like sweet stuff and don’t care much for roots.
Descriptive
Hadza people don’t really like tubers, but they eat them a lot when berries aren’t around — so tubers are like a backup food when their favorite stuff isn’t available.
When Hadza women eat more tubers, they tend to have less body fat; when they eat more meat, they tend to have more body fat — but this doesn’t mean tubers make you skinny or meat makes you fat, just that the two are linked.
A treatment called IVIg, made from pooled antibodies, helps calm overactive immune systems in autoimmune diseases by turning on a 'brake' receptor called FcγRIIB.
Mechanistic
Inside cells, there’s a sensor (TRIM21) that finds viruses tagged with antibodies, destroys them, and also helps the cell alert killer T cells to attack.
People with two copies of a certain version of a receptor (R131) are more likely to get lupus because that version doesn’t grab onto certain antibodies as well, leading to poor clearance of immune complexes.
A genetic glitch in one inhibitory receptor (FcγRIIB) stops it from working properly, so the immune system can’t calm down — leading to attacks on the body’s own tissues.
When immune cells grab antibody-tagged germs, they turn on signals (like CD86 and CD40) and release alarm chemicals (like IL-6 and TNF-α) that tell T cells to wake up and fight.
A special receptor (FcRn) saves antibodies from being destroyed inside cells and helps shuttle them — along with any germs they’re attached to — to the right place to be shown to immune cells.
One type of receptor (FcγRIIB) can also swallow antibody-tagged germs, but it doesn’t turn on the immune system as strongly — it needs 30 times more germs to get the same effect as the activating receptors.
Quantitative
When antibodies tag a germ, immune cells that show antigens to killer T cells do a much better job of it than if the germ was just floating around without tags.
When antibodies stick to germs and bind to certain receptors on immune cells, the cell swallows the whole thing into a bag that goes to a trash compactor (lysosome) to break it down for display.
One type of receptor (FcγRI) grabs onto single antibodies really tightly, while other receptors only grab well when many antibodies are stuck together on a germ.