“Fruit has been part of the human diet for longer than we’ve been human. We cannot demonise such a nutritious food group, as with most things, it is the quality, quantity and condition of the host that makes the difference”

The law of individuality

Although people tend to generalise all fruits into one category, there is a vast difference between tropical fruits, citrus fruits, stone fruits, berry fruits, super fruits and dried Fruits (nature’s candy).  There are also different Glycaemic components, FODMAP, Fibre and Fructose Quantities, along with being grown organically or genetically modified to consider that can make the metabolic response and tolerance level to fruit very different.

Just like no two fruits are the same; there are no two humans that are the same. Each human has different genes, gene expression, stress loads, gut microbiome, food intolerances, digestive capabilities, health status, preferences, availability, environments, activity levels, and goals.  These differences can influence how we process both macronutrients (protein, carbohydrates, and fat) and micronutrients (vitamins, minerals, and trace minerals).

Hungry for Nutrition

There is no single optimal diet for everyone because everyone is unique but there are some core nutrition principles that do apply to everyone.

There are two types of nutrients in food: macronutrients and micronutrients. The human body requires macronutrients and micronutrients for normal metabolic function.  Maximising nutrient density should be the primary goal of our diet because deficiencies of any of these essential nutrients can contribute to the development of chronic disease.

Some important nutrients that are important for health include Vitamins, Minerals, Carotenoids, Polyphenols, Flavonoids, Lignans, Fibre, Plant sterols, Isothiocyanates, Dithiolethiones, Diallyl sulphide and Prebiotic fibers (soluble and insoluble).

Many of these nutrients are found in fruits and vegetables.

Everything in nature in connected

For years, nutritionists have categorized foods into groups of Macronutrients (Carbohydrates, proteins, fats) but there is another way of thinking about and categorizing the foods we eat, a way that can offer more meaning and value than our traditional distinctions: What if we thought about foods in terms of whether or not they are alive? Whether they have been denatured or not? Or whether they are dead processed non-foods.

We are all divinely connected in nature’s intricate web of life, an interdependent eco-system.

Flowers produce sugar (nectar), scents and pollen that attract pollinators  (bees, microbes and insects) looking for food.  They are nourished by sunlight and water and the pollen is scattered by winds and insects.  Because the bodies of insects are largely composed of nitrogen, upon their death this important ingredient is then returned to the soil.

To humans, bees are the most important pollinator. Without bees, many of the plants we rely on wouldn’t be able to reproduce—and produce many of the fruits we eat, such as apples and blueberries.

The humble earthworm turns the soil creating drainage tunnels and assists by decomposing organic wastes, feeding on plant debris and adding nutrient rich compounds to the soil through its feces.  Bacteria are the final decomposers and fertilisers.

By using the energy of sunlight, plants can convert carbon dioxide and water into carbohydrates and oxygen in a process called photosynthesis.  We then inhale this byproduct of oxygen and share the breath of life!

Living foods (fruits included) are foods that are consumed fresh, raw and/or in a condition as close as possible to their original, vibrant, living state, grown in naturally fertilised soils and loaded with nutrients and universal life force.

Personalising the Glycaemic Load of fruit

Different fruits affect blood sugar differently, and these effects are often quantified by measures known as the Glycaemic Index and the Glycaemic Load.

What are Glycaemic Index (GI) and Glycaemic Load (GL)?

The Glycaemic Index (GI) assigns a numeric score (0-100) to a carbohydrate based on how drastically it expects your blood sugar to rise. Unfortunately, Glycaemic Index (GI) alone doesn’t give us the full picture and can at times be MISLEADING. A more detailed scale is the Glycaemic Load (GL) because it helps us to understand how quickly it makes glucose enter the bloodstream and how much glucose it can deliver dependant on the total grams of carbohydrates provided in the food.

The Glycaemic Load (GL) is determined by multiplying the grams of a carbohydrate in a serving by the Glycaemic Index, then dividing by 100. A Glycaemic Load of 10 or below is considered low; 10-20 is moderate, and 20 or above is considered high.

Glycaemic Load (GL) fruits (Reference Harvard Medical School article: Measuring Carbohydrate effects can help Glucose management) include: Limes (GL-1), Strawberry (GL-1), Kiwi – (GL-2), Grapefruit (GL-3), Watermelon (GL-4), Blueberry – (GL-5), Peach – (GL-5), Apple – (GL-5), Oranges – (GL-5), Mango – (GL-8), Prune – (GL-10), Grapes – (GL-11), Banana – (GL-11)

A better way to check your blood sugar response

Although Glycaemic Load can be a useful marker for general guidelines, everyone is unique and the best way to check your individual blood sugar spike caused by any particular fruit is to purchase a simple glucometer and measure your blood sugar levels after eating.

A glucometer is a very affordable device that measures blood sugar.  You simply prick your finger with a sterilized lancet, and then you apply the drop of blood to a “test strip” that has been inserted into the glucometer, and it measures your blood sugar.

Testing Blood Sugar

Test your fasting blood sugar first thing in the morning after fasting for at least 12 hours. Retest again one, two and three hours after eating a meal.  Keep a food diary and note down blood sugar results in addition to energy levels and mood.

An optimal target would be to get fasting blood glucose < 86mg/dL and to find compatible fruits that keep blood sugar levels < 140mg/dL after one hour, < 120mg/dL after 2 hours and optimally back to baseline after three hours. (Reference: Dr Chris Kresser – Functional Medicine Pioneer)

*To convert mmol/L to mg/dL simply multiply by 18.0182.

This is a personalised approach which will allow you to identify what trigger fruits are not currently compatible with you.  Over time with a commitment to healthy eating, as your body becomes more insulin sensitive, you may notice a higher tolerance level to certain fruits even if they have a higher glycaemic load.

*** Choosing whole fruits (not juiced) that are highest in fibre or combining fruits with an additional fibre supplement (e.g. freshly ground flax, Glucommanan, Psyllium and chia seeds) or healthy fats such as coconut oil or nuts alongside the fruit can bind up excess sugars, slow down the absorption and further decrease any raise in blood sugar levels.

Fruit contains Fructose

When you consume fruit, you are usually consuming a combination of naturally occurring Glucose and Fructose.  The body can absorb fructose when there is a sufficient amount of glucose that’s eaten with it. Different fruits contain different amounts of glucose and fructose but most fruits also contain lots of fiber, which drastically helps to slow down the absorption.  While Glucose is processed into energy and stored as glycogen in the muscles and liver, high levels of Fructose is metabolised by the liver.

Currently, it is estimated that Americans eat 156 pounds of fructose-based sweeteners per year, mainly consumed in the form of High Fructose Corn Syrup (HFCS).  High Fructose Corn Syrup is fructose that is extracted from its natural occurring source (often genetically modified corn) and is added to food and drinks by food companies, cooks or consumers.  High fructose corn syrup is anywhere from 55 to 75% or more fructose, and it’s free fructose, meaning it’s not bound to the glucose so it gets rapidly absorbed.  This cheap inflammatory liquid poison is added to almost all of the low fibre, low nutrient, and hyper-processed and packaged foods and to sweet drinks and sodas.

Unfortunately, there’s still a large contingent of health professionals and social media writers and bloggers who don’t distinguish between sugar in its natural state (e.g. starchy vegetables and whole fruits) versus sugar that’s been chemically altered, processed and de-natured.

This high consumption of excess inflammatory Fructose (lacking in fibre) is what has been linked to non-alcoholic fatty liver, obesity, metabolic syndrome, gout and type II diabetes and is the primary cause for the fear of fructose that has unfairly condemned fruit.

Fruit Juices

Think of a store brought fruit juice in the same way as a sugary soda as many cartons of fruit juice have high fructose corn syrup added to them.  If you are juicing your own juices, focus of plant based vegetables and only use a small amount of low or moderate glycaemic fruit for flavour or add chia seeds or additional fibre and a dash of coconut oil to the juice.  People could easily drink a glass of orange juice that contains five oranges but would certainly struggle to eat five whole oranges in one sitting so always choose whole fruits over juicing.

Low Carbohydrate Diets

While there is no strict definition of a low-carb diet, anything under 100–150 grams per day is generally considered low-carb in comparison to a standard westernised diet but ketogenic diets can even fall as low as 20-50 grams per day. A more accurate definition is to calculate total daily carb intake by using a percentage of total daily calories.  Very low carb would be <10%, Low carb would be 10-15%, Moderate Carb 15-30%, High Carb >30%

Low carbohydrate diets have shown amazing benefits for treating blood sugar issues, some cancers, mental health and neurological disorders, PCOS, GERD and small intestinal Bacterial overgrowth (SIBO) when unprocessed nutritious real foods are included.

Even on a very low carbohydrate diet, you may still choose to include some high fibre, low glycaemic nutrient dense fruits, berries or citrus into the daily intake of carbohydrates. When calculating grams of carbs, subtract grams of dietary fibre to obtain the net amount of carbs as fibre is a type of carbohydrate that your body can’t digest.

When long-term low carbohydrate diets fail

I find most people initially get great results when low carbing but proceed to making the mistake of either dropping their intake too low for too long, not including enough variety of real foods or not increasing other macronutrients enough which can have detrimental consequences, especially for the diversity of the gut microbiome.

Everyone is different in his or her ability to thrive on a low carbohydrate diet and whether or not their health will improve on such a plan is dependent upon many factors.

Very Low carbohydrate diets may fail when:

You have thyroid problems: The amount of carbs you eat each day has a significant effect on thyroid function. A very low carbohydrate diet can cause chronically low levels of insulin, which is needed for the conversion of Inactive T4 into a metabolically active form of T3 so that the thyroid can function optimally

You have HPA Dysregulation (Adrenal Issues): The majority of people suffering with HPA Dysregulation also have problems with blood sugar regulation such as reactive hypoglycaemia. Cortisol abnormalities are also a common problem for people with HPA axis dysregulation, and low-carb diets may exacerbate the problem. An extremely high or low carbohydrate diet is often a poor choice as it can escalate symptoms that are typical with this condition and further harm the function of the HPA axis leading to changes in the output of hormones and neurotransmitters such as; Cortisol, DHEA, Melatonin and Epinephrine

You suffer with Hypoglycaemia: A diet too low in healthy carbohydrates can cause a hypoglycaemic state that can induce a sympathetic stress response.

You are pregnant: Carbohydrates are essential during pregnancy to ensure adequate fetal brain development and growth, which is why The Institute of Medicine recommends a minimum of 175 grams of healthy carbohydrates per day during pregnancy.

You are an athlete: Usually a peak performance athlete will need to cycle carbohydrate intake or will eventually burn out on a long-term carbohydrate diet if the intake is too low. This can result in poor performance, plateaus, weight gain, increased recovery time, fatigue, and eventual burnout. Studies show some endurance athletes can still thrive using ketones but activities such as cross fit or martial arts that involve explosive movements are highly glycolytic and usually require a higher carbohydrate intake.

You have Candida Overgrowth or SIFO (small intestinal fungal overgrowth): Eliminating high sugar, sweeteners, alcohol, yeast and refined carbohydrates is undoubtedly the best approach for Candida overgrowth but low carb doesn’t mean no carbohydrates. Although fantastic at starving bacteria or viral infections, unfortunately there are some Protozoa and fungi pathogens that have mitochondria that are able to metabolise either ketones or glucose for energy.

Although initial relief of symptoms can be experienced, if the right strategic botanicals are not used then in search of sugar, starved candida can migrate upwards through the intestines projecting invasive filaments into the intestinal wall allowing it to pass into the bloodstream, and – if not quickly destroyed by white blood cells – become systemic resulting in a rebound of escalated and now non-specific symptoms.

You have compromised gut health: Long term low carbohydrate dieting has been linked to dysbiosis, constipation and a reduction in the diversity of the gut flora due to a reduced intake of important prebiotics (i.e. food for your gut flora) like soluble fibre and resistant starch.

These essential prebiotics are important for promoting the growth of beneficial gut flora. It is a good idea to be mindful about incorporating adequate fibre, prebiotics, probiotics or supplementation during a low carb diet to support optimal gut health.

A causal link between the Gut Microbiota and weight

The first piece of evidence that connected gut bacteria and weight gain was published in 2005.  Scientists found that the microbiota composition of obese mice was not the same as healthy lean mice (the obese mice showed an increased amount of bacteria from the phylum Firmicutes and the overall microbial diversity was lower)

To further investigate, the study took the gut bacteria from human twins in which one was lean and one was obese and introduced it into germ-free mice.  The results showed that the mice given bacteria from the obese twin quickly gained weight but the mice given bacteria from the lean twin remained lean despite the same diet, exercise and environment.  This shows a clear causal link between weight gain and the gut microbiota.

A human fecal transplant study with obese individuals was also done.  In this case feces from a lean individual was transplanted into an obese individual and the result showed an improved metabolic response in addition to weight loss.

Soluble and Insoluble Prebiotic fibres, nutrient dense real foods, fermented foods and probiotics support a healthy microbiome. Diets that are excessively low in carbohydrates, especially when lacking is prebiotic fibres can have a detrimental effect on beneficial bacteria in the gut leading to a dysbiotic state.

For short-term interventions, I believe that a low carbohydrate diet can offer miraculous benefits, especially when shifting from a standard Westernized diet but it is not for everyone and the program needs to be adapted, structured and supported extremely carefully for participants with certain health complications and to ensure adequate nutrition and continued support for a healthy microbiome.

Fruits (Unripe Banana and stewed Apples) for Gut Healing

 Resistant starch is a type of starch that resists digestion, reaching the colon intact and working as a powerful prebiotic for the beneficial bacteria. Thus, we do not see the same spikes in either blood glucose or insulin after eating Resistant Starch.

One simple way to add more resistant starch to your diet is to peel and freeze chopped green chalky unripe bananas and add them to your daily smoothies.  Studies indicate that resistant starch can be beneficial for the good bacteria in the gut, when consumed in quantities around 15 to 30 grams daily (always start slowly and build up gradually)

Good old stewed apples have potential for healing leaky gut and feeding the good bacteria.  Simply chop 6 apples with the skin intact (the content of phenolic compounds, dietary fibre, and minerals are higher in apple peel), removing the core.  Fill a pot with filtered water about 1/3 of the height of the apples.  Throw in some cinnamon and bring it to a boil and then simmer for about 8-13 mins. You will know when it’s done when the skin of the apples gets a little shine/shimmer.

By cooking the apples, the pectin from the cooked apples is easily accessible to the beneficial bacteria and the lining of your gut. Try to consume a teaspoon of the apple stew twice a day for a week. Then maybe once every few days afterwards for at least a month.

Final Thoughts

Fruit has been part of the human diet for longer than we’ve been human. We cannot demonise such a nutritious food group, as with most things, it is the quality, quantity and condition of the host that makes the difference.

The biggest concern is that fruit has not been available in the mass quantities that we now have access to and conventionally grown genetically modified fruits are sprayed with toxic chemicals, pesticides, fertilizers and growth enhancers to produce larger fruits and higher yields.

Make sure you are choosing living organic and locally grown fruits whenever possible.  If you are not sure if the fruit is naturally grown, then I recommend washing your produce thoroughly.  You can make your own produce wash by combining one tablespoon of lemon juice, two tablespoons of apple cider vinegar and one cup of water in a spray bottle.

Unfortunately, due to the popularity of low carbohydrate diets and the poor portrayal of Glycaemic Index (GI), many people started to completely avoid fruits fearing the high sugar content. However, in the majority of modern day diets, it is refined carbohydrates, processed foods, alcohol, commercial fruit juices and added Sugars that are the real enemies (if people gave up refined carbohydrtaes and replaced them with organic fruits and vegetables, I believe the improvement in national health would be phenomenal).

It is important to remember that whole fruit contains vitamins, minerals, antioxidants, phytonutrients, enzymes, fibre, water and life force and the first thought regarding food should be it’s nutritional profile.  Most fruits also have a high water content (often 80–95 %), which will also help with hydration.

Even some fruits that are not the lowest in sugar can have some powerful cleansing properties, e.g. Lychee is loaded with Vitamin C, Pineapple contains a powerful blood cleansing enzyme called Bromelain, Rambutan is a powerhouse of antioxidants, Dates are very high in fibre and can prevent constipation, Cranberries contain high levels of proanthocyanidins which helps to stop certain bacteria from adhering to the urinary tract walls, Raisons are a good source of Iron, Papaya is loaded with digestive enzymes, Plums contain Vitamin K that can be beneficial to the heart and Grapes contain Resveratrol that has been well-studied in terms of cancer prevention and treatment.

For most people, fruit is a luxury that can be consumed sensibly as part of a healthy diet if the rest of the diet is healthy and focused around real foods. The healthy recommendation for an average person would be 1-2 pieces of fruit per day (not in addition to processed foods, alcohol, refined carbohydrates).

It is also best to think of dried fruits and very high glycaemic fruits as natures candy, which do need to be limited and consumed in small portions but would still make a better choice as a natural fibre dense sweetener than most of the processed sweeteners available on the market (e.g. one date has a massive 8 grams of fibre and is packed with nutrients).

If you are not getting the results you desire or feel worse after consumption of low glycaemic fruits, try eliminating high FODMAP fruits, checking for food intolerances by doing an elimination diet, tracking your blood sugar response using a glucometer or working with a nutritionist to help to customise your food choices.

References:

• Kresser, C. (2019). What Is the Optimal Human Diet? | Chris Kresser. [online] Chris Kresser. Available at: https://chriskresser.com/what-is-the-optimal-human-diet/ [Accessed 11 Feb. 2019].
• Cleveland Clinic. (2019). Everything Sugar (and How to Eliminate it from Your Diet) with Dr. Mark Hyman. [online] Available at: https://my.clevelandclinic.org/podcasts/health-essentials/everything-sugar-and-how-to-eliminate-it-from-your-diet-with-dr-mark-hyman [Accessed 18 Feb. 2019].
• Ash, M. (2019). Is this a Perfect Functional Meal for Mucosal Tolerance? | Clinical Education. [online] Clinicaleducation.org. Available at: https://www.clinicaleducation.org/resources/reviews/is-this-a-perfect-functional-meal-for-mucosal-tolerance/ [Accessed 15 Feb. 2019].
• WUR. (2019). Fibebiotics. [online] Available at: https://www.wur.nl/en/project/Fibebiotics-3.htm [Accessed 18 Feb. 2019].
• Bulletproof. (2019). Mark Hyman: The Dangers of Fructose – #144. [online] Available at: https://blog.bulletproof.com/mark-hyman-on-the-dangers-of-fructose-podcast-144/ [Accessed 15 Feb. 2019].
• Themedicalbiochemistrypage.org. (2019). Fructose Metabolism: Relation to Food Intake & Metabolic Dysfunction. [online] Available at: https://themedicalbiochemistrypage.org/fructose.php [Accessed 15 Feb. 2019].
• Mark Hyman, M. (2019). The 13 Pillars of the Pegan Diet. [online] Experience Life. Available at: https://experiencelife.com/article/mark-hyman-peganism/ [Accessed 18 Feb. 2019].
• Kresser, C. (2019). RHR: Top 4 Mistakes People Make When Treating Candida Overgrowth. [online] Chris Kresser. Available at: https://chriskresser.com/top-4-mistakes-people-make-when-treating-candida-overgrowth/ [Accessed 15 Feb. 2019].
• Harvard Medical School. (2019). [online] Available at: http://www.mv5.ca/EWF/docs/glycemic%20index.pdf [Accessed 18 Feb. 2019].
• Saragottfriedmd.com. (2019). Is Fungal Overgrowth Causing your Symptoms? | Sara Gottfried MD. [online] Available at: https://www.saragottfriedmd.com/is-fungal-overgrowth-causing-your-symptoms/ [Accessed 15 Feb. 2019].
• Publishing, H. (2019). The lowdown on glycaemic index and glycaemic load – Harvard Health. [online] Harvard Health. Available at: https://www.health.harvard.edu/diseases-and-conditions/the-lowdown-on-glycemic-index-and-glycemic-load [Accessed 18 Feb. 2019].
• Kresser, C. (2019). Answers to your burning questions about digestion | Chris Kresser. [online] Chris Kresser. Available at: https://chriskresser.com/answers-to-your-burning-questions-about-digestion/ [Accessed 15 Feb. 2019].