Over 60? Dietitians reveal the “rainbow on a plate” rule that supports ageing brains

It often creeps up on a Tuesday. You walk into a room and pause, just a second longer than you used to. A name takes an extra beat to land. You stand in the supermarket aisle, staring at the veg, and think, “I should probably eat better for my brain,” then reach for the same old carrots and peas anyway.

Most of us picture “brain food” as something complicated: expensive supplements, exotic powders, or a list of rules you’ll forget by Friday. Yet when you ask dietitians who work with people in their 60s, 70s and beyond, a surprisingly simple phrase keeps resurfacing: “rainbow on a plate.” Not a miracle cure. Not a strict diet. Just a quiet, visual rule that nudges your fork towards the foods your ageing brain quietly asks for.

The afternoon my mum’s shopping trolley changed

The first time I really understood the rainbow rule, I was trailing my mum round a supermarket in Leeds. She’d just turned 68. Her memory was fine, but she was tired of feeling “woolly” in the afternoon, the way you feel when you’ve read the same line of a book three times.

Normally, her trolley was beige: white bread, potatoes, a few apples, a pack of biscuits “for the tin”. That day, after a chat with a dietitian at her GP surgery, she was on a mission. “She told me my brain likes colours,” Mum said, standing in front of the produce. It sounded silly. Then she started picking on purpose: deep green spinach, dark blueberries, an orange butternut squash, red peppers, a bag of frozen mixed berries “for porridge if I remember”.

It wasn’t an overnight transformation. She still bought the biscuits. She still forgot a few things. But over the next few months, those colours showed up on more plates. A spoon of red cabbage next to a cottage pie. A handful of spinach stirred into scrambled eggs. She’d send me photos and say, with that half-joking pride, “Look, I’ve done my rainbow today.” The rule had done something no lecture on omega-3s ever had: it stuck.

Why “eating the rainbow” matters more after 60

Dietitians like the rainbow idea not because it’s cute, but because it’s a shorthand for something your brain quietly craves: variety of plant pigments and fibres. Those colours aren’t decoration. They’re chemical signals.

• Reds and purples often mean anthocyanins – found in berries, red cabbage, beetroot – which have been linked to healthier blood vessels and slower cognitive decline in some studies.
• Deep greens tend to carry folate, vitamin K and lutein, all involved in brain ageing, vision and blood clotting.
• Oranges and yellows – carrots, squash, peppers – are rich in carotenoids that help combat oxidative stress, the slow wear-and-tear that builds up in brain cells over decades.

Past 60, your brain is dealing with older blood vessels, more inflammation, and years of exposure to stress, illness and the occasional very late night. It’s not about “boosting” the brain in a week. It’s about giving it a steadier supply of the raw materials that help nerve cells communicate and recover. The rainbow rule is a low-effort way to keep score.

“The colours are like a visual checklist,” one dietitian in Birmingham told me. “If your plate looks mostly beige, your brain’s probably missing a trick.”

Turn your plate into a gentle checklist, not a test

The rainbow on a plate rule isn’t about ticking every colour at every meal. Most dietitians frame it more like this: aim for three different colours on your plate at most meals, and five to seven across the whole day. Not perfect. Just deliberate.

Think of it as a sliding scale:

• Beige plate: potatoes, chicken, white bread, maybe a banana later.
• Two-colour plate: add green peas or broccoli, a sliced tomato.
• Three-plus colours: that same meal with a side salad (greens, grated carrot, sweetcorn), or some beetroot, or a small bowl of berries afterwards.

The aim isn’t restaurant-level presentation. It’s tiny upgrades your future self will barely notice in the doing, but feel in the long run. A stew can be brown, but you can scatter chopped parsley on top and serve red cabbage on the side. Porridge can be pale, but a few frozen berries and a spoon of seeds suddenly give it a spectrum.

We’ve all had that moment in the evening where you realise the only vegetable you’ve eaten all day was the sad tomato slice in a sandwich. The rainbow rule is a polite nudge before you get to that point.

What dietitians actually mean by “rainbow”

Underneath the nice image, there’s a fairly practical template many dietitians use. It doesn’t require huge changes, just a different way of looking at what’s already in your kitchen.

1. Anchor every meal with a plant

Instead of starting with the meat or the carbs, they suggest you pick one colourful fruit or vegetable as the anchor, then build the rest around it.

• Breakfast: oats anchored by blueberries (purple) or grated apple (green peel), plus a sprinkle of nuts.
• Lunch: soup anchored by tomatoes (red) or butternut squash (orange), plus a side of green salad.
• Tea: main anchored by something green (broccoli, green beans, peas) or orange (carrots, sweet potato), with other colours drifting in around it.

That anchor becomes a small promise: at least one strong colour, no matter how tired you are.

2. Use colour clusters to make it easy

Most of us buy the same things on repeat. Dietitians often talk about colour clusters – small families of foods in the same colour that you know you like and can grab without thinking. For example:

• Red / purple: strawberries, raspberries, red grapes, beetroot, red cabbage.
• Green: spinach, kale, frozen mixed veg, peas, kiwis.
• Orange / yellow: carrots, sweet potato, peppers, satsumas.

Once you’ve picked two or three favourites in each cluster, you don’t need a new recipe every week. You just rotate. The trick is to keep at least one option from each colour family in the house, especially in the freezer or cupboard where it doesn’t go off the minute you look away.

3. Don’t forget the “invisible” brain foods

The rainbow rule is about visible colour, but dietitians quietly wrap in two almost-colours your brain also loves:

• Brown from wholegrains (oats, wholemeal bread, barley) – steadier energy and more fibre for the gut, which in turn chats constantly to the brain.
• Gold from healthy fats (olive oil, rapeseed oil, nuts, seeds, oily fish) – the stuff brain cell membranes are built from.

They may not be vivid on the plate, but they matter. A bowl of mixed veg on top of a white bread cheese toastie is a rainbow, technically. Add wholegrain bread and a drizzle of olive oil, and the brain gets a much kinder deal.

How to try the rainbow rule without overhauling your life

The biggest complaint dietitians hear from people over 60 isn’t “I don’t care about my brain.” It’s “I’m already tired. Please don’t give me homework.” The rainbow rule survives real life because it can be layered onto what you already do.

Start with just one meal a day. Often breakfast or your main meal is easiest.

• Look at the plate and count the colours, honestly.
• If it’s one or two, ask: “What’s the easiest extra colour I could add?”
  • A handful of frozen peas into any pasta or rice.
  • A piece of fruit after lunch.
  • A carrot grated into a stew.
  • A spoonful of pickled red cabbage or beetroot from a jar.

If shopping is a chore, set a tiny rule for yourself: one new colour in the trolley each week. Not a new item, just a colour you didn’t buy last week. Maybe that’s a bag of frozen berries, or a tin of sweetcorn, or a punnet of cherry tomatoes. The habit is the point, not the specific vegetable.

And be realistic: nobody eats perfectly every day. There will be beige days. Let them pass. Notice, and gently tilt the next day back towards colour.

Memory, mood and the subtle wins

If you’re hoping that eating more colourful food will give you the memory of a 25-year-old, any honest dietitian will disappoint you. Nutrition is one piece in a much larger puzzle that includes sleep, movement, medication, social contact and genes you never chose.

But they also see small, stubborn improvements: people who feel less “foggy” at 3 p.m.; who notice steadier mood over the week; who find it slightly easier to concentrate on a book or a crossword. Part of that is blood sugar and energy. Part is anti-inflammatory compounds humming away in the background. Part is simply paying attention to what you eat, which tends to spill into other gentle upgrades: more walks, better hydration, a bit more sleep discipline.

There’s an emotional side, too. Putting vivid colours on a plate can make meals feel less like “managing” and more like pleasure again. A bright bowl of vegetable soup on a grey day doesn’t fix everything, but it doesn’t hurt either.

One 74-year-old in a community nutrition group summed it up neatly: “I can’t control my age, but I can change my plate. The colours make me feel like I’m doing something for myself.”

A quick cheat sheet for your kitchen

You don’t need a wall chart, but a tiny mental map helps. Dietitians often reduce it to three simple moves:

• Freeze the rainbow: mixed veg, peas, spinach, berries, stir-fry mixes. They sit there, patient, for the nights you can’t face chopping.
• Jar and tin insurance: tinned tomatoes, sweetcorn, beans, jars of passata, roasted peppers, beetroot. Shelf-stable colour you can open in seconds.
• Colour on the side: a small salad, a bowl of fruit, sliced peppers or carrots, a spoon of slaw. Even if the main dish is plain, the side can work harder.

If chopping is difficult for your hands or energy, pre-cut veg, bagged salads and frozen options are not cheating. They’re tools. Use them.

Key points at a glance

What to do	How it looks	Why your brain cares
Aim for 3 colours per main meal	Green veg + orange root veg + red fruit	More varied antioxidants and vitamins
Keep colour clusters stocked	2–3 favourites in each colour family	Makes healthy choices almost automatic
Add brown and gold	Wholegrains + nuts, seeds, olive oil, oily fish	Supports blood flow and brain cell structure

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FAQ:

• Do I really need every colour every day? No. Aim for three colours per main meal and five to seven across the day. Think in weeks, not single plates. Variety over time is what counts.
• Is fruit juice enough for the “rainbow”? Not really. Whole fruit and veg bring fibre and a slower sugar release, both kinder to ageing brains and blood vessels. A small glass of juice can fit, but it shouldn’t replace the real thing.
• What if I dislike most vegetables? Start with what you do tolerate and change the form: soups, smoothies, roasting with herbs, or grating veg into sauces. Even two or three “safe” colourful options, used often, are better than none.
• Can supplements replace eating the rainbow? Supplements can fill specific gaps but don’t replicate the full mix of fibres and plant compounds in whole foods. Dietitians usually suggest food first, supplements only for diagnosed deficiencies or under medical advice.
• Is it too late to make a difference in my 70s or 80s? No. Studies on older adults show benefits from improving diet even later in life – from better energy and mood to slower decline in some thinking skills. Every extra serving of colour is a nudge in the right direction, not a wasted effort.