The Colour Purple

Alzheimer’s and Dementia are diseases close to me. Mum is not the Mum I knew most of my life. My wife and I spent years caring for her Mum before she passed. Her long term GP wrote “cause of death – dementia” on the last document relating to her life. It’s difficult to care for those you love when they change into people who are so different from what you’ve always known; Alzheimer’s and Dementia are terrible diseases.

Of the age related chronic diseases Alzheimer’s and Dementia stand out relative to the others. More material is published offering advice for carers, than is published about Alzheimer’s or how to cure it.  We can take steps to prevent Alzheimer’s. I became aware of one such step when watching a documentary about the traditional Okinawan population.

The Okinawan’s

Okinawa is the southern most large island of Japan.  Okinawan’s following their traditional lifestyle have an exceptional life expectancy; this is well known.  It is also well known that as we age, our brain shrinks. It is also a fact that as we live longer the risk of Alzheimer’s increases.  Traditional Okinawan’s, (while living to very old ages) have virtually no incidence of Alzheimer’s disease. According to the documentary, this was helped by the fact that their staple food was a purple sweet potato. The purple colour was a chemical called Anthocyanin, and this chemical prevented, or slowed the onset of Alzheimer’s.  Never having heard the word before I went to Wikipedia to get the spelling right, there it was Anthocyanin, a flavonoid that causes the purple and blue colours in plants.


I searched the NIH Pubmed database for “Anthocyanin & Alzheimer’s” and found numerous articles on the subject, most dealing with experimentation on genetically modified mice designed to express Alzheimer like brain abnormalities. These experiments demonstrated that supplementation with Anthocyanin did indeed slow the progress of the disease, and also partially reversed established disease; WOW!

Next step was to go back to archived NIH daily Alzheimer tweets where I found articles published by the RUSH UNIVERSITY MEDICAL CENTER  about the MIND diet, I do not suggest that this is the most healthy diet. The MIND diet excludes fruit (I agree with eating fruit sparingly) with the exception of coloured berries.  It went on to say “Blueberries are one of the more potent foods in terms of protecting the brain“.


Any change in what we consume via food medicine or supplements to improve our wellbeing must first pass the “do no harm test”. When treating established disease with medicine, the benefits must outweigh any harmful side effects.  One of the issues with mouse model medical experiments is that measurements are taken to test effectiveness, but it is more difficult to measure any unintended consequences. Every tissue in the mice specimen would have to be tested for long term adverse effects. This is an issue with all medical research, sometimes the adverse effects are only discovered decades after the public has been exposed to a chemical concoction we call food, supplements or medicine.

In this case the food has been tested on humans who have eaten it every day for centuries; the Okinawan’s.  That’s good enough for me and now I make an effort to eat some purple food everyday.


In many cases the purple is only skin deep (eat the skin of most foods if you can). For the best results we want food where the purple runs through the food; not just the skin.  Purple running through the food occurs mostly in fruit (eg red plums), berries (eg Blue Berries) and vegetables (purple carrots, potatoes, cauliflower, cabbage etc). Blueberries are mentioned above as brain super food, but they also contain as much sugar as regular Coca Cola, and 50% of that sugar is the bad sugar Fructose (as is the case with regular Coke). So our recommendation is to choose purple vegetables as the best source of purple, after all that’s what the Okinawan’s eat.

The Okinawan’s eat a really purple spud relative to the white or red we normally consume. The purple potato tastes like, and has the texture of, white potato; they just look different.  The purple spud’s skin is a bit thicker and more chewy, I like it more.

How much purple potato did the Okinawan’s eat?  The below shows what Okinawans  ate in 1949 (ie the traditional Okinawan diet)


Reference: Calorie Restriction, The Traditional Okinawan Diet, and Healthy Ageing

The traditional Okinawan diet was 67% purple sweet potato.  As far as veggies go there are purple, white, and brown onions. There are purple or orange carrots. White or Purple Cauliflower, Purple or Green Cabbage. Remember to choose some purple every day.


Ok, below is a slap dash meal I prepared for myself recently.  Baked veggies, carrots (orange), purple potato, red onions, and some purple cauliflower.  Boiled peas, sliced snow peas, and broccoli. Plus some stir fried Hoisin basted chicken pieces (purchased some shashliks and removed the sticks). Threw it on the plate, sprinkled sea salt, a drizzle of olive oil, and a squeeze of lemon; Yum!

This meal was easy to cook. Bake some extra baked veggies, cover with cling rap and put them in the fridge. They keep well, and can be microwaved days later when needed.  To cook the rest of the meal up only takes a few minutes. It’s healthy fast food!


Purple spuds and cauliflower are freely available, carrots are apparently a little harder to come by.  So your Green Grocer can buy them, but most don’t.  The only reason the purple variety is not in store is because the public doesn’t buy them. Funny that; the reason we don’t buy them is not taste, it’s just that it is hard to change habits.  See the Boomers Health “Rewire Your Brain” article to change habits. To make the future what we want it to be, we need to rewire our brains, before we begin to suffer the symptoms of dementia, because then it will be too late.

If you have some purple cooking ideas (or issues) you would like to share with us, email them to

Glenn Sargent

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