How berries help build a better brain

One of the best guides to food variety is colour. And for colour, there’s a group of natural plant chemicals called anthocyanins that are getting a lot of attention for their potential benefits on the brain. Anthocyanins are the pigments that give red, purple, and blue plants their rich colouring – they literally put the ‘blue’ into blueberries. A few years back on this podcast, I took you through the science of anthocyanins and brain health. In this episode, I’m revisiting that story with new research. In this episode, I’ll unpack what this new research review found, how it fits with what we already know about anthocyanins and the brain, and what it all means for your shopping basket and your long-term cognitive health.

Links referred to in the podcast

• Podcast episode 81 on berries and brain health https://thinkingnutrition.buzzsprout.com/808853/episodes/9099255-blue-is-the-new-black-berries-anthocyanins-and-your-brain-health
• Systematic review on anthocyanins and cognitive function 2025 https://pubmed.ncbi.nlm.nih.gov/41351717

Episode transcript
To access the full episode transcript, go to the following link and select the individual podcast episode and then click on the ‘Transcript’ tab https://thinkingnutrition.buzzsprout.com

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Transcript

One of the best guides to food variety is colour. And for colour, there’s a group of natural plant chemicals called anthocyanins that are getting a lot of attention for their potential benefits on the brain. Anthocyanins are the pigments that give red, purple, and blue plants their rich colouring – they literally put the ‘blue’ into blueberries. A few years back on this podcast, I took you through the science of anthocyanins and brain health. Today, I’m revisiting that story with new research. In this episode, I’ll unpack what this new research review found, how it fits with what we already know about anthocyanins and the brain, and what it all means for your shopping basket and your long-term cognitive health.

There is so much to be gained from having plenty of plant-based foods in your diet, and colour is one of the easiest visual cues you can use as a guide for diversity of different plant foods for the beneficial chemicals they contain. One of those groups of chemicals are called anthocyanins which are a subgroup of flavonoids – themselves part of the larger polyphenol family. Anthocyanins are responsible for the red, purple and blue colours in many fruits, vegetables and even some grains. You’ll find them in blueberries, blackberries, blackcurrants, cherries, red grapes, purple cabbage, eggplant, black rice and even purple corn.

Anthocyanins have been getting a lot of attention because of their antioxidant and anti-inflammatory properties, but the story goes beyond a simple antioxidant label. In cell and animal models, anthocyanin-rich foods can alter how neurons communicate, dampen neuroinflammation, modulate signalling pathways involved in cell survival, and even affect adult neurogenesis and synaptic plasticity. There’s also emerging work suggesting metabolites of anthocyanins can cross the blood–brain barrier and may act both directly in the brain and indirectly via the gut–brain axis.

So, mechanistically, there are plausible ways through which anthocyanins could influence how the brain ages and functions. But what really matters is whether these molecules move the needle in actual humans doing real-world tasks.

Observational evidence has pointed directly at anthocyanins helping improve cognition with people with higher habitual anthocyanin intake from whole foods showing less cognitive decline over time, adding another line of support that these colourful compounds might offer a brain protective role. But observational studies can’t prove cause and effect. And that’s why synthesising the randomised trial evidence is so important.

In an earlier episode of my podcast, episode 81 which I’ll link to in the show notes, I first looked at anthocyanins and brain health and profiled a systematic review from back in 2021that pulled together 49 trials and concluded that anthocyanins could improve cognitive performance in specific areas like memory, and in some cases attention, psychomotor speed and executive function, alongside improvements in vascular function and blood pressure. https://thinkingnutrition.buzzsprout.com/808853/episodes/9099255-blue-is-the-new-black-berries-anthocyanins-and-your-brain-health

That set the scene for the latest and most comprehensive synthesis of the evidence to date which set out to answer a very focused question: do anthocyanin-rich interventions improve cognitive function? After screening articles, 59 trials met the inclusion criteria which is a substantial body of randomised controlled trial evidence for a single phytochemical class. And I’ll link to this review in the show notes. https://pubmed.ncbi.nlm.nih.gov/41351717

Looking across the 59 included trials, there was considerable diversity, but some clear themes emerged. Most studies involved older adults aged 55 years and over. 34 trials included healthy individuals, while 22 focused on people with cognitive problems such as mild cognitive impairment or dementia, while a few trials recruited people with other medical conditions like cardiac disease or stroke.

Interventions ranged from whole foods and juices usually based on blueberries, blackcurrants, grapes, cherries and mixed berry drinks. Some studies used extracts of specific anthocyanin-rich sources. Daily anthocyanin doses spanned quite a wide range: from as low as a few milligrams in some grape-based nutraceuticals, up to several hundred milligrams in high-dose blueberry or blackcurrant interventions. To put that in context, around 100 grams of blueberries can provide several hundred milligrams of anthocyanins, so many interventions used anthocyanin doses that within the realm of what you could get from diet alone.

Intervention durations also varied: some trials lasted only a few weeks, many ran for 3 to 6 months, and one extended out to 12 months.

​Let’s get to the headline results. Overall, anthocyanin-rich interventions produced a statistically significant improvement in cognitive performance compared to control conditions. The size of the effect was rated as small-to-moderate which is not a miracle cure, but certainly not trivial either.

When they drilled down into specific domains of cognition, significant benefits emerged in several key areas including visuospatial processing, reasoning and attention, processing and psychomotor speed, verbal speed and fluency, episodic memory and working memory.

Collectively, these findings suggest that anthocyanin supplementation can favourably influence multiple cognitive domains, especially those that we know tend to decline with age, such as episodic memory and processing speed. The effect sizes being in the small-to-moderate range are in line with what you might expect for a single dietary component operating within the complex biology of brain ageing.

Meta-analyses are only as good as the data that goes into them, and the research team spent a fair bit of effort stress-testing their results by doing things like influential-analysis where studies are removed one at a time to see how much they sway the overall result which positively showed that no one single trial dominated the outcomes.

So, should we now all rush out and buy anthocyanin capsules? As always in nutrition, context matters. Anthocyanins don’t exist in isolation in usual diets – they come packaged in whole foods alongside fibre, other polyphenols, vitamins, minerals and, in the case of berries, a lot of water for very few kilojoules. Observational studies that link higher anthocyanin intake to better cognitive outcomes typically reflect people who eat more fruits and vegetables overall and whose diets align more closely with patterns like the Mediterranean or MIND diets.

From a mechanistic perspective, anthocyanins may exert direct neuroprotective effects – via blood–brain barrier penetration, modulation of microglial activation, oxidative stress and mitochondrial function – and indirect effects through improving vascular health and cardiometabolic risk factors that themselves contribute to dementia risk. That’s consistent with the earlier systematic review I discussed previously, which found that anthocyanin-rich interventions improved vascular function and blood pressure alongside cognitive outcomes.

The new meta-analysis strengthens the case that anthocyanins are not just markers of a generally healthy dietary pattern but could be active agents contributing to brain health. However, the real-world application still sits squarely within promoting dietary patterns rich in a variety of colourful plant foods, rather than pushing a single phytochemical as a stand-alone solution.

Translating all of this into something actionable for your brain health, there are a few key takeaways. First, including anthocyanin-rich foods regularly in your diet is a low-risk, potentially high-reward strategy. That means foods like blueberries, blackberries, raspberries, strawberries, blackcurrants as well as cherries and red grapes, purple or red cabbage, eggplant with the skin on, black rice, purple corn and other dark-coloured grains.

Fresh berries are great when in season, but frozen berries are an excellent, often more affordable option. Because they’re typically processed and frozen soon after picking, nutrient losses are small, and freezing doesn’t appear to diminish anthocyanin antioxidant activity over several months; in fact, ice crystal formation can disrupt plant cell structures and may even make anthocyanins more available. That makes a bag of frozen mixed berries in the freezer one of the simplest insurance policies you can keep for both dessert and brain health.

Second, the doses used in many of the successful trials can be achieved with food. As I’ve mentioned, 100 grams of blueberries can provide several hundred milligrams of anthocyanins, which matches or exceeds the anthocyanin content of some of the capsule-based interventions in the meta-analysis. Regularly including a cup of berries or other anthocyanin-rich foods most days of the week is a very plausible target that also supports overall cardiometabolic health.

So, let’s wrap all this up. Anthocyanins should be viewed as part of a broader brain-healthy lifestyle. That includes a dietary pattern high in fruits, vegetables, wholegrains, legumes, nuts and extra virgin olive oil; regular physical activity; adequate sleep; social engagement; and management of vascular risk factors like blood pressure, cholesterol and blood glucose. Anthocyanin-rich foods fit very neatly into that package, and the new meta-analysis gives us stronger evidence that they’re likely doing some specific cognitive heavy lifting along the way.

As for supplements, the evidence suggests they can work, particularly in higher-risk groups like older adults with mild cognitive impairment, but we don’t yet have clear guidance on optimal dose, duration or ‘best’ anthocyanin source. For most people, starting with food will bring multiple benefits without the cost or regulatory uncertainties that come with nutraceuticals.

Given the safety profile of anthocyanin-rich foods and their broader cardiometabolic benefits, aiming for more naturally purple, blue and red foods on your plate is a pragmatic and evidence-based strategy for supporting your brain over the long haul.

So that’s it for today’s show. You can find the show notes either in the app you’re listening to this podcast on, or else head over to my webpage at www.thinkingnutrition.com.au and click on the podcast section to find this episode to read the show notes.

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I’m Tim Crowe and you’ve been listening to Thinking Nutrition.