Eating blueberries improves vascular function. One cup per day is effective, but half a cup does not not produce the same benefit. Adults with metabolic syndrome that ate one cup rather than only a half-cup or matched placebo improved flow-mediated dilation (FMD) by about 1.5 percentage points in a... six-month randomized trial. FMD measures how effectively an artery widens when blood flow increases, essentially a "stress test" for the endothelium. It's relevant because studies have shown it is a strong predictor of future cardiovascular disease events. The one-cup dose is consistent with other studies showing cardiovascular, metabolic, and brain-health benefits of blueberries.show more

Blueberries also improved insulin sensitivity in obese, insulin-resistant adults in a controlled trial, which fits with the vascular gains described here. Better insulin action and better vessel function often move together. Metabolic syndrome is an insulin problem as much as a vascular one.

From my latest solo episode on the health benefits of blueberries!

Fun detail almost nobody mentions… they weren’t eating fresh berries. Participants got blueberry powder equivalent to 150 g (a cup) or 75 g (half a cup), and the control group got a matched placebo that looked the same. That’s how you run a double-blind trial on a fruit. Pretty clever honestly.

So 1 cup ✅ Not with banana ✅ 😁👏 Thanks, Rhonda!

Most of the heart attacks and strokes I see in the ER started years earlier in the blood vessels. Small daily habits like this may help push that day further away!

Blueberries are one of our favorite snacks, so this one's easy to get behind. Didn't realize half a cup wasn't enough to see the same effect.

That’s a lot of blueberries

Does frozen count the same as fresh here? A cup of frozen ones stirred into morning yogurt is the only way most people will actually hit it every day in winter.

For scale on that 1.5 points: a meta-analysis by Inaba et al. (2010) linked each 1-point rise in FMD to about 13% lower risk of cardiovascular events. Not bad for a cup of fruit.

Easy one to hit. I have clients keep a bag of frozen wild blueberries and toss a full cup into Greek yogurt or oats. Cheaper than fresh and you never run out.

Are you getting paid by the World Blueberry Association? 😂

1 cup a day? Years from now, Rhonda will say it should be 1 cup a month.

Love how simple this is — one food, done consistently. That is the pattern behind habits that actually stick: small, daily, easy to repeat on a busy day. Do frozen blueberries hold up the same way, since that is how most people buy them?

hybrid sweet blueberries or wild blueberries? There is a difference between them.

Wow, that's shocking. Does this depend on the person's size?

Does it matter if you eat the cup in one sitting or one cup throughout the day?

@grok list a few healthy recipes that include a cup of blueberries

half a cup doing nothing is a nice dose-response detail. worth knowing insulin resistance was the main endpoint though, and that didn't move

Dose mattered here: adults with metabolic syndrome who ate a full cup of blueberries a day had better blood vessel flexibility, while half a cup did no better than placebo. Easy way to hit a cup: berries in your morning oatmeal or yogurt. Do you eat them daily?

one cup works, half a cup doesn't — dose-response curves hiding in breakfast 🫐

Half cup does nothing, full cup moves it. Annoying how dose-specific this stuff is. Adding a cup to the morning stack.

And here I was putting about 1/4 cup in my yogurt. 1 cup is a shitload of blueberries

@grok what's one cup in grams?

Haha so spend $5 a day, just on blueberries. People can't afford to be even some what healthy. Its sad

The one-cup vs half-cup split is the useful part. A 1.5 point FMD bump only showing up at a full cup makes the dose feel real, not hand-wavy.

What about the effect on healthy people, normal BMI, HbA1C and low fasting insulin?

每天150克蓝莓有点多吧，之前综述说的是每周至少75克蓝莓就有效果

the part i'd keep in mind: FMD is a surrogate. a 1.5 point bump in a human trial over 6 months is a real signal, but it isnt the same as showing fewer heart attacks yet. promising, just not proven at that level

Frozen wild blueberries make the full cup way easier to hit every day, I just toss them in yogurt or oats. Does frozen hold up as well as fresh for the vascular effect?

What does it do to your colon?

that trial ran 6 months in 115 adults, and the half cup group saw no change on any marker

Listening to the podcast now and drinking a delicious smoothie with atleast a cup of blueberries, thank you!

Interesting findings, especially the apparent dose response. Improving endothelial function is important, but we should distinguish improvements in a vascular marker from reductions in actual cardiovascular events. I’d also like to see how these results compare with improvements from carbohydrate restriction, resistance training, walking, and better metabolic health overall. Blueberries may offer benefits, but they’re certainly not essential for vascular health.