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Extend your life by eating lots of fibre

Clive Blazey explains why processed and fast foods are making us sick

Avoid processed food due to low fibre content

As we learn more about the internal workings of our body it is only recently that the importance of understanding the causes of obesity, asthma, type 2 diabetes and autism has led to the vital role gut bacteria play.

There are millions of bacteria in our digestive tract which can either aid in food processing or become destructive, upsetting our immune system.

Dietary fibre plays a special role because it is food that our good bacteria feed on and ferment this fibre which improves our immunity to disease; so dietary fibre is food for bacteria rather than food for ourselves.

This principle echoes a basic tenet of organic gardening that instead of directly feeding plants as modern agriculture does, in organics we feed the soil not the plant so that it is the soil that then feeds the plants.

All ecological systems need a biodiverse balance of species which creates a healthy balanced equilibrium and our gut is no different.

The ‘Catalyst’ story on gut bacteria

The recent TV programmes on Catalyst by the ABC are continuing the story of the impacts on our health and longevity from our poorly regulated food supply.

The pedlars of fast food and multinational food companies continue to replace the vital ingredients of dietary fibre in our processed food with sugar and fat, leading to obesity and increases in type 2 diabetes. Processed food promotes bad bacteria and we become sick and obese as a consequence.

When we compare the diets of hunter gatherers before the rise of agriculture their consumption of fibre was up to 200 grams per day, more than 10-15 times the level of Australians today. The National Health and Medical Research Council recommend 25-30 grams per day.

Prevent disease by changing your diet

Those that eat the highest fibre diet live the longest.  This is demonstrated by the Okinowans in Japan but modern medicine's overuse of antibiotics has had the unexpected effect of destroying good bugs in our intestines; almost like dropping a nuclear bomb on Hiroshima.

Our best sources of roughage

Seeds that we eat have the highest contents of fibre with nuts, legumes and wholemeal breads being excellent sources. In the processing of food for sale almost invariably fibre is processed out and sugar and fat are added to increase taste appeal.

Roughage is plant material that cannot be digested, which aids the passage of food and waste product through the gut. Insoluble fibres do not dissolve in water but add bulk and pass through quickly and intact. Most people think of celery as roughage but it is mostly water — a good appetite filler, but contains only 1.6% fibre.

However, gardeners who grow their own food and prepare it in the kitchen without adulterating it, are accessing the most nutritious sources of food that have led to longer lives.

See table below for  some of the highest fibre foods that are common in our diet.

Juicing loses 90% of fibre

Of course those who have fallen for the juicing fad are excluding 90% of the benefit of food fibre as all the ‘pith’ that you discard is actually where the good stuff is.

When you juice an orange the fibre content drops from 2.2% to just 0.2% and it’s the same for apples and lemons.

The skin of apples and potatoes is the best source of fibre and antioxidants. Those who peel it off are destroying most of its value. For those wanting to explore this issue further look up “American Gut Project, Boulder Colorado”. They analyse faeces for gut bacteria from as far away as Australia

High fibre diets from Sweet Potatoes

The purple Sweet Potato, cultivated by Okinawans, has very high levels of antioxidants (up to 2.5 times the anthocyanin levels of blueberries!) and is also high in flavonoids, vitamin C, carotenoids and slow-burning carbohydrates.

Also known as Hawaiian Sunshine, it is high in flavonoids, vitamin C, carotenoids and slow-burning carbohydrates with six times the dietary fibre of pumpkin and 50% more than potatoes. Combined with the high levels of antioxidants (up to 2.5 times the anthocyanin levels of blueberries!) Purple Sweet Potato is the tastiest elixir for long life you can get.

Michael Pollan, the Californian food ethicist, succinctly articulates many mantras for a healthy human diet in his book The Omnivore’s Dilemma and Food Rules: An Eater’s Manual .

Some of these include “Don’t eat anything your grandmother wouldn’t recognise as food”, “Eat food, not too much, mostly plants” and “Always leave the table a little hungry”.

The last two, in particular, resonate with the story of the world’s longest-lived people from the tropical Japanese island of Okinawa.

The notion of eating less than your appetite demands is echoed in the Confucian proverb “Hara Hachi bu”, an adage often spoken by fit and healthy centenarians translating as “stop eating when you’re 80 per cent full”.

Why are Okinawans so long lived?

The food traditions of these long-lived Okinawans goes back to a time before the modern western diet, a time when the current generation of 80+ year old people were learning their cuisine, a time when meat was expensive and less common.

The most striking thing about the diet of the old-timers is the huge volumes of Imo, a purple-fleshed Sweet Potato, that comprised almost 70% of their pre-war diet.

This startling revelation was documented by Canadian Professor Craig Wilcox, an internationally recognised expert in health and aging, as part of his work with the Okinawa Centenarian Study (see the pie chart below).

The study matches data from the Okinawan Prefecture 5 yearly census that goes back to 1870 with lifestyle influences including genetics, levels of physical activity and diet.

The study has included over 900 Okinawan centenarians and has found, amongst other things, that they have very low levels of free radicals in their blood.

Free radicals are unstable molecules that damage tissues and this damage accumulates over time, thus speeding up the aging process.

Antioxidants are a recognized free radical scavenger that help reduce the levels of these damaging molecules in the body.



Autumn Vegie Gardening

Bernadette Brady chooses the vegetables to plant when temperatures are falling

Be Your Own Kitchen Gardener

Robyn Fox explains the secrets behind growing heirlooms for Heronswood's restaurant

Can we trust others to grow our food?

Clive Blazey talks about the destruction of our food quality

Caring for Fruit Trees

Caring for Fruit Trees

Chillies: Some like them hot, some don’t!

Gail Thomas explains how to grow and cook with these tender perennials

Community Food Gardening

Bernadette Brady explains how community food gardening overcomes social alienation

Creating an Edible Landscape

Bill Bampton talks about the challenges of combining beauty and functionality in the garden

Diggers 2021 heirloom trials update

Why first-hand trialling and testing our vegetable and flower seed varieties is an important part of the Diggers practice.

Edible hedges

Marcelle Swanson recommends planting edible hedges for privacy and productivity


Winter is the perfect time to get into the garden and tend to your fruit trees to achieve the best possible crops over the warmer months!

Good Health Begins In the Gut

Heather McKern asks whether we can trust others to grow our food

Grow Your Own Garlic

Garlic expert Penny Woodward explains why it can be so tricky to grow

Grow Your Own Greens

Bernadette Brady shows us the fibre foods to plant in autumn and grow through winter

Grow Your Own Herbs

Bill Bampton's top ten points for herb growing

Growing Grapes

Growing Olives

Growing Olives

Growing Your Own in the Edible City

Indira Naido relates her adventures in gardening on her inner city balcony

Healing herbs for health and wellbeing

Heather McKern has a confession to make … she loves herbs.

Heirloom Fruit

Marcus Ryan explains why fruit doesn't taste as good as it used to

Heirloom Silverbeet and Beetroot

Clive Blazey explains how almost all the vegetables we eat today were available before 1900!

Herb Garden

Growing herbs is both joyous and rewarding with kitchen garden crops making the perfect addition to any meal.

Herbs - more than a kitchen garden

Herbs - more than a kitchen garden


Jac Semmler tells you why spring is the time to get excited about growing heirloom tomatoes

Making a beautiful garden edible

Bill Bampton explains how to create a food border by combining the ornamental potential of edibles with the edible potential of ornamentals

Plant Based Fibre

Arabella Forge explains why you should eat more fruit and vegetables

Preserving your harvest

Summer offers an abundance of fruit, vegetables and herbs suitable to preserve and use throughout the rest of the year. Join Marcelle as she discusses some exciting items for preserving!

Pruning Fruit Trees in Winter

Pumpkins Better Than Butternut

Evette Jungwirth ponders on producing the perfect pumpkin

Q&A - Cane Fruit

Cane fruit guru Phil Rowe answers your questions about berries

Q&A - Citrus

Citrus expert Ian Tolley answers your questions about citrus trees and fruit

Q&A - Fruit Trees

Julian Blackhirst answers your questions about summer pruning and general care of fruit trees

Q&A - Tomato Growing

Our experts Julie, Tim and Evette answer your questions about growing tomatoes


Rhubarb would have to be one of the most productive and easy-to-grow perennial food plants.

Start Your First Food Garden

Bernadette Brady encourages you to start your own vegie garden

Starting a vegie patch

Growing your own nutritious vegetables is cost effective and highly rewarding.



The Diggers Mini-Plot

Don't go to the supermarket, grow your own vegies at home!

The urban herbalist

Bill Bampton's top ten herbs to grow in containers

Unusual edibles

Arno King introduces southern gardeners to some northern vegetable staples that succeed down south

Vegie Patch Basics

Vegie Patch Basics

What’s wrong with the food forest concept?

Organic gardener Julian Blackhirst questions the ‘bare foot, lazy gardener’ idea

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Clive Blazey

Clive is the founder of The Diggers Club, a pioneer in the rescue of heirloom vegetable and fruit varieties and author of seven books on flower, vegetable and fruit gardening.

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