By Roger French

Fresh, ripe fruits are essentially cocktails of minerals, vitamins, other antioxidants, fibre, natural sugar and thousands of phytochemicals, all in a high content of ‘pure’ water. The water content ranges from 75% in bananas to 93% in watermelon.

The Natural Health guideline is to consume approximately 350 to 700 gram daily – as part of a total of fruits and vegetables per day of around 1000 to 1250 gm. Have some fruit each day. High-sugar fruits, such as grapes, should be limited in quantity. Fruits are the most suitable energy foods in hot weather, except that winter fruits are fine for cold weather.

All fresh, ripe fruits are highly alkali-forming, due to their very high content of potassium and modest levels of magnesium and calcium. The acid fruits, although containing significant levels of organic acids, are also ultimately alkali-forming.

This article describes only the common, everyday fruits, and does not include the numerous exotic varieties.                                                                                     


These fruits contain high-ish levels of weak organic acids, such as citric acid, tartaric acid and malic acid. 

Citrus Fruits     

In season in winter, except lemons are available almost all year.

Lemons and Limes

Very high in citric acid at 5 – 6% and should not be eaten neat. A drop splashed into the eye or a wound is sharp evidence of their acidity. Unlike other citrus, sugar content is insignificant.

Lemon or lime is an ideal fruit to start the day, as it is cleansing on the palate, stimulates the liver and is very alkali-forming. It must be always well diluted with water – half an average lemon in a glass of water is about right. At other times of the day, still well diluted, lemons and limes are marvellous cleansing fruits, tending to relieve colds, sore throats and congestion. For the digestive system, these fruits are antiseptic and detoxifying. They reduce uric acid in gout and gallstones.


An excellent fruit for taste and energy. A limitation is that it is easy to over-eat oranges and take in too much sugar. Also, there is a phytochemical in oranges that can upset the liver, producing a headache.

Oranges are high in vitamin C at around 50 mg for an average fruit. Also abundant are the bioflavonoids, rutin, quercitrin, hesperidin and naringin which enhance the efficiency of vitamin C and are essential for strong blood capillaries and prevention of varicose veins. Both C and bioflavonoids are essential for healthy skin and hair, which is why vitamin C deficiency results in scurvy.

Oranges are richer than most fruits in calcium and also folate which helps prevent heart disease and spina bifida.


Similar to oranges and also contain a particularly rich supply of bioflavonoids. They don’t upset the liver the way oranges can. Their easily peeled skin makes them an ideal take-away fruit.


Contain much less sugar than oranges and are a liver tonic and diuretic. Can be white, pink or ruby red, the pink/red colour being due to the carotenoid, lycopene, which is anti-cancer and antioxidant. The bitter flavour is due to liminoids, richest in pink and red grapefruit, which inhibit tumour formation. Also present in grapefruit is salicylic acid, which tends to dissolve calcium out of spurs and arthritic joints.

Low GI makes grapefruit suitable of people with diabetes. Because grapefruit can interfere with certain medications, including statins and calcium channel blockers, keep consumption low if on these medications.


A delicious and nutritious fruit when ripe, but often difficult to find ripe. It is the richest fruit in the enzyme, bromelain, which promotes protein digestion and so assists weak digestion, and is anti-inflammatory, so is helpful for gout and rheumatoid arthritis. Pineapple is a blood thinner and can reduce the risk of clots. It is a good promoter of healing, particularly for the respiratory system. Its high manganese content is good for the brain and nerves and helps protect against free radicals.

Available all year.

Sour berries

Berries are mostly sub-acid, but if unripe, they then rate as acid fruits. They are described in the ‘Sub-Acid Fruits’ section below.                                    


These fruits contain low to medium levels of weak organic acids, such as malic and tartaric acids. 


The apple could well be the king of fruits due to their high levels of antioxidant flavonoids and the soluble fibre, pectin.

Apples are the richest fruit in the flavonoid, quercetin, which provides powerful antioxidant effects that include reducing the risk of heart disease, stroke and cancer, particularly of the lungs and bowel. Red apples contain the extremely powerful antioxidants, anthocyanins, which magnify these benefits. In people who smoke, apples has been found to partially protect against pulmonary and bladder damage.

The excellent supply of pectin, concentrated in the peel, stimulates and cleanses the digestive system and slows the absorption of sugars, making the apple low GI (36) and very suitable with diabetes.

One or two apples a day – when in season, which is autumn and winter – could do wonders for wellness and wellbeing.


In the same genus as apples, pears are another great all-round fruit. This fruit rarely causes allergic reactions, so is suitable for elimination diets and ideal for weaning infants.

Pears contain plenty of soluble fibre and are very gentle on the digestive system in contrast to harsh wheat bran. This fibre binds with toxins in the colon and removes them from the body, and tends to mitigate constipation or diarrhoea. The fibre makes us feel full and keeps hunger away.

For mucous conditions and coughs, pears have a useful role. They are suitable for diabetes because of a low GI (38), similar to apples. Their high copper content gives pears an antioxidant role.        

Pears are in season autumn and winter. They continue to ripen after being picked.

Stone fruit 

The popular stone fruits – distinguished by their large seeds – are peaches, nectarines, apricots, cherries and plums, all members of the genus Prunus. Stone fruits are in-season late spring and summer.


That bright yellow-orange colour is due to a high content of antioxidant carotenoids (particularly beta-carotene, beta-cryptoxanthin, lutein and zeaxanthin), which are anti-heart disease, anti-cancer, etc, and very good for eye health. A high potassium content helps reduce high blood pressure and maintain correct acid-alkaline balance.

A good level of soluble fibre is gentle on an upset stomach. Healthy skin is promoted by a good sulphur content, which also helps prevent gastritis and bronchitis.


The nectarine originated from a mutation of a peach. They are extremely similar, except for the skin, and have the same abundance of carotenoids.


Similar to peaches in many ways, except richer in carotenoids and potassium. In fact, apricots are equal with bananas in being the richest of all fruits in potassium, at 335 mg per 100 grams of fruit. Hence, they are excellent at balancing excess acidity, lowering high blood pressure and relieving depression associated with potassium deficiency. Their carotenoids provide the benefits mentioned for peaches, including being very beneficial for night vision.

Apricots are helpful for asthma and similar lung conditions, and their high copper content can help overcome anaemia. Being low-ish in calories, they are beneficial for weight reduction.

Dried apricots are super-nutrition, as all the benefits are concentrated. But avoid sulphured dried fruits and go for the dark-coloured sun-dried versions. Dried apricots help smokers soften the blow when quitting by having something low-calorie to chew.

Apricot kernels are extremely rich in vitamin B17 (amygdalin), which releases cyanide to cancer cells and kills them. But Australian apricots may be too high in cyanide, so no recommendation can be given here.


This wonderful dark-red to black fruit contains anthocyanins, which are strongly anti-cancer and anti-mutagenic (mutagenic = damages genes). Some of their flavonoids even destroy cancer cells. Their carotenoids and potassium (220 mg per 100 gm fruit) are at high levels and they contain the hormone, melatonin, which lulls us off to sleep.

Anti-inflammatory phytochemicals in cherries can benefit headaches, gout and arthritis.

Very low GI makes cherries very suitable for diabetes sufferers and hyperactive children.

A very short summer season make this ‘lolly look-alike’ rather special among the fresh fruits.

Plums (and Prunes)

Packed with antioxidants and good levels of carotenoids, potassium and fibre, these are excellent fruits. Prunes, which are dried plums, are well known for their laxative power, which is due to their fibre, sorbitol and a substance that stimulates the bowel wall to contract.

High levels of anthocyanins give plums and prunes high antioxidant activity, measured as Oxygen Radical Absorbance Capacity (ORAC). Prunes, being concentrated, have the highest ORAC of all fruits. Plums and prunes have good levels of the same carotenoids as peaches and are low GI.

Non-stone fruit   


Vast quantities of grapes are grown for wine, but as fresh fruit they are excellent nutrition. They are cleansing, high in antioxidants and good for high blood pressure. Their sweetness reflects a high sugar content – mainly glucose (‘grape sugar’) – of around 15% of the whole fruit.

Grapes have a very purifying effect on the bloodstream, are helpful for high blood pressure, rheumatism and arthritis, and their tartaric acid stimulates the intestines.

Dark red and black grapes and their seeds are rich in anthocyanins and proanthocyanidins, which are very powerful antioxidants, protecting against cancers, heart disease and nerve degenerative diseases. Another phytochemical, resveratrol, adds to these protective effects. Many years ago, their powerful healing and anti-cancer properties were touted in a book, The Grape Cure, by Joanna Brandt.

Which brings us to wine. Because the skins of red-black grapes contain these antioxidants, red wine contains them too, making it far superior to other forms of alcohol. This is not a recommendation for alcohol – it is simply that red wine antioxidants can slightly offset the harm of the alcohol to the liver and brain.

Grapes are in season in summer.


A fruit ‘to die for’ to some of us! Mangoes are highly nutritious, supplying good amounts of carotenoids, vitamin C, potassium, magnesium, fibre and easily-digested sugar.

The yellow colour of the delicious flesh is due to beta-carotene and other carotenoids, with a large mango supplying one day’s needs. The combination of nutrients purifies the bloodstream and provides good antioxidant protection. GI is medium.

The mango season is late spring to late summer.

Some people are sensitive to contact with the mango skin, although they can usually still eat the flesh.

To cut up a mango, stand it on its thick side and slice the flesh off each side. Then sit this flat-ish half in the palm of one hand, and scoop out the squares with a spoon.

Ripe berries

These small fruits that are red, blue or black are bursting with the powerful antioxidants, anthocyanins and lycopene, which protect against cancer, skin damage, heart disease, etc. They include blueberries, bilberries, blackberries, blackcurrants, raspberries, cranberries, strawberries, mulberries and loganberries.

Their antioxidant power is among the highest of all foods. The ORAC rating for blueberries is 2400 units per 100 gm of fruit, for blackberries 2036 and raspberries 1220. Blueberries protect the brain from oxidative stress and oppose the development of dementia, cataract and glaucoma. Most berries contain good levels of iron.

For urinary tract infections, cranberry and raspberry juices provide remarkable protection. Mulberries are believed to slow the greying of hair. Strawberries prevent nitrosamines from forming in the stomach, reducing the risk of stomach cancer. Raspberries are well known for their healing powers; they also contain ellagic acid, which neutralises cancer-causing chemicals. Berries in general preserve collagen and help prevent varicose veins.

Most berries are low in calories, so are suitable for people trying to lose weight.

Berries are mostly summer fruits. Strawberries are in season winter to summer.


Outstanding for their vitamin C content – after guava they are the richest fruit at 73 mg per 100 gm of fruit. Potassium is also very high. Water and energy content is average.

Available all year.


These fruits contain no significant levels of organic acids, so are neutral in the acid-alkali status of their flesh.

Pawpaw and Papaya

These are among the best foods to promote healing and are super gentle on the digestive system. They have high levels of antioxidants and a unique content of papain, a protein digesting enzyme. This and their soft flesh makes them ideal for people with weak digestions, for elderly people and young children and for sufferers of colitis, ulcerative colitis and Crohn’s disease.

A high level of vitamin C (60 mg per 100 gm fruit) and carotenoids (similar to those in peaches) provide an antioxidant power that aids vision problems, improves male infertility and slows ageing. With good potassium levels as well, these fruits are particularly good for arthritis. Papaya flesh or ointment can be an effective dressing for wound healing.

In season most of the year, except for poor supply in winter. Papaya, even when their skin is mostly green, can still be sweet and succulent.

Ripe bananas

Another wonderful fruit and one of the oldest cultivated plants in the world. When green, they are starchy and difficult to digest; when ripe they are around 18% sugar and 2% starch and highly digestible. The common banana, Cavendish, is nearly always ripened in gas chambers in ethylene gas, and this compromises their taste and nutrition because gassing enables them to be picked too green. This gas is given off by bananas as they ripen.

The valuable alkaline mineral, potassium, is richer than in any other fruit at around 350 mg per 100 gm. Consequently, bananas strongly counter excess acidity in the body, counteract the sodium in common salt to lower high blood pressure, and support the integrity of muscles.

Their useful pectin content and soft flesh make bananas gentle to poor digestive systems or intestinal diseases. They have medium GI.

Bananas are perfectly packaged. The test for ripeness is that the fruit is fully formed, the skin all yellow with not a trace of green and peels off with ease. A ripe banana is an excellent energy snack (at 90 – 100 calories per 100 gm) and excellent nutrition.

Available all year.

Fresh figs

An ancient fruit, figs are well known for their laxative effects (due to mucin) and have been used for centuries to treat constipation.

Figs are the richest fruit in calcium (38 mg per 100 gm), a good source of potassium (180 mg) and one of the most alkali-forming of all fruits. Vitamin C is low. Their fibre level is quite high. In spite of their pleasant sweetness, sugar content is a modest 8%, and GI is medium.

More popular are dried figs, which are very sweet and concentrate all the above nutrients. 


With a history that can be traced back to 7,000 BC, this intriguing fruit conjures up one thought – fat. Yes, its fat content, typically 20 – 22%, is very high compared to other fruits which are mostly 0.1 or 0.2%, but compared to butter at 80%, the avocado is low. What matters is that it is good fat, mostly unsaturated – 15% is saturated, 70% is monounsaturated (mostly oleic acid), 12% polyunsaturated and a trace of omega-3. A good supply of lecithin provides ‘detergent’ for this fat and a good content of vitamin E protects it from rancidity.

At around 200 calories per 100 gm (due to the fat), avocado provides much more energy than any other fruit, and even twice that of bananas. However, with extremely low GI and safe with diabetes, their fat can be burned for energy directly and need not cause obesity. They are easily digested, but quantity must be moderate.

Avocadoes are very high in potassium at 500 – 600 mg per 100gm, and high in magnesium, chlorine and sulphur which cleanse the system. With all these nutrients, avocadoes are good for heart health, for male infertility, for Parkinson’s disease and so on.

Overall, avocadoes eaten in moderation are a marvellous fruit and an ideal spread on bread. They are in season March to November.


Melons are characterised by very high water contents – 90% or more – subtle sweetness and being great for detoxing. Due to their lightness and ease of digestion, melons, eaten alone, make great breakfasts in summer.

Watermelon (and Sugar Melon)

For some of us, these largest-of-all fruits are ‘king’. Their 93% water is the highest of all fruits, while their 5% sugar is the lowest of the common fruits apart from the lemon. Yet this sugar gives a delicious sweetness when eaten alone – which all melons should be due to their water content. Although the GI of watermelons is high, their energy supply is only 23 calories per 100 gm, so they have a low ‘glycaemic load’.

Minerals and vitamins in watermelon are low-ish, except for carotenoids including lycopene, which is nearly twice that of tomatoes. Lycopene is powerfully antioxidant and anti-cancer, especially anti-prostate cancer. The redder the flesh, the more lycopene.

A super supply of bromine is good for prevention of depression and menopausal problems.

Watermelon is a strictly summer fruit and does not ‘fit’ our metabolism in the cool/cold seasons. On a hot day, a chilled slice of watermelon is pure bliss!


Rockmelon is surprisingly similar to watermelon, with water content 92%, sugar 5% and fibre content average for a fruit. Calorie supply is only 28 per 100 gm.

Reflecting their distinctive orange colour, rockmelons are an excellent source of beta-carotene and other carotenoids and also rich in vitamin C, potassium and bromine.

Ripeness is indicated by yellow-ish skin and sweet aroma.


More subtle in flavour than the watermelon, honeydew nutrition is very similar. Water content is 90%, sugar 7% and energy 32 calories per 100 gm. Calcium level is high as fruits go, while vitamin C and potassium are mediocre. Unlike the other melons, carotenoids are low.

Nevertheless, honeydew can be a very pleasant fruit in warm weather.