“I’ve given up carbs!” my client announced proudly as he settled into my clinic office for his consult.
“Carbs?” I asked, looking a little puzzled.
“Yep! Not eating any of them.” I could see he wanted a high five but I was still confused, and a bit worried.
“So… you’re not consuming anything that comes from a plant? No fruits and vegetables at all?”
He looked at me as though I’d taken leave of my senses.
“No carbs…” he stressed, thinking perhaps I was hard of hearing. “You know, lollies and cakes and bread and pastry and soft drinks and stuff.”
I breathed a sigh of relief and happily gave him the high five he’d been waiting for. Then I took some time to make sure he understood the difference between healthy and unhealthy “carb” sources.
This conversation took place many years ago and it’s happened many times since. Some people gloat with saintly pride when they conquer those devilish carbs. Others declare shame-filled defeat at having been corrupted by evil incarnate. This irrational fear of carbohydrates is described in the Urban Dictionary as a current “source of great hysteria. Carbophobia has reached such levels it’s become its own religion.”
From where I’m standing, carbophobia seems like an ever-expanding nutritional black hole that is sucking people in and making valuable nutrients disappear into thin air. When I ask people to define what they mean when they say “carbs”, the definition is different every time and it’s making less and less sense as each year rolls by.
If you’re wondering why I’m a bit dumb, when it comes to the vernacular use of words like “carbs”, it’s probably because of my nutritional and biochemistry training. In my defense, I’m not the only nutrition-trained professional feeling a little exasperated by the use of this word; a facebook meme created by the fabulous Plant-Based Nutritionist Julieanna Hever, points out that that you can’t give up “carbs”, because carbs are not a food group. “They are one of three macronutrients present in all whole plant foods. The healthiest foods – veggies, fruits, whole grains, and legumes – are loaded with carbs. Fibre, one of the most crucial nutrients for health, is found in foods high in carbs.” That’s because fibre is a “carb”!
As the Australian Governments National Health and Medical Research Council points out, “many epidemiological and dietary intervention studies refer to ‘high carbohydrate’ or ‘low carbohydrate’ diets with little or no description of the nature of the carbohydrate.” Carbohydrates are found in a wide array of both healthy and unhealthy foods, ranging from soft drink and cake all the way through to lettuce and avocados.
Harvard has a very sensible take on the carbohydrate issue: rather than follow a “strict diet limiting or counting the number of grams of carbohydrates consumed”, they advise simply eating “carbohydrates from healthy foods.” The amount of carbohydrate in your diet matters less than the type of carbohydrates in your diet, or where you are sourcing them from. In much the same way that the word “carbs” was originally “carbohydrates” before it had most of its letters removed, unhealthy “carbs” sources were once nutritious whole foods before they had most of their nutrients removed. Fruits, vegetables, legumes, nuts, seeds and whole grains like brown rice are extremely healthy carb choices. White rice, white flour products (eg pastry, pasta, cakes, donuts, white bread), lollies, sweeteners and soft drinks are unhealthy carb sources.
WHAT ARE CARBS?
Carbs are carbohydrates, a macronutrient vital for health, found in whole plant foods. As a plant is photosynthesizing, it takes carbon out of the atmosphere (from carbon dioxide) and combines it with oxygen and hydrogen (from water) to create basic sugar molecules (Cn(H20)n) called saccharides. These little packages of solar power provide all the energy a plant needs to support growth and metabolism. Plants bind single sugar molecules together to form larger carbohydrates for various purposes, such as energy storage and building cell walls.
Simple carbohydrates, commonly referred to as simple sugars, are found in fruits, vegetables and breast milk. Unrefined whole foods containing simple carbohydrates are healthy sources of simple carbohydrates. When sugars are extracted from whole foods for use as sweeteners, both the sweeteners and the foods they are added to are unhealthy sources of simple carbohydrates, especially when consumed regularly.
The smallest, simplest carbohydrates with the least number of atoms are called monosaccharides. “Mono” means one, so these are one-sugar molecules. One-sugar molecules, such as glucose, fructose and galactose, provide a fast source of energy that can be absorbed directly into the bloodstream rather than needing to be further broken down in the intestinal tract. This is vital, because we need “fast” sources of energy to quickly fuel our brain, blood cells and cellular respiration.
Plants use glucose as a basic building block to create thousands of other compounds, including vitamin C and other kinds of carbohydrates. The small amounts of glucose found naturally occurring in plant foods are vital for human life. In the human body, glucose becomes blood sugar, functioning as the primary fuel source for the brain, blood cells, and for cellular energy production. And just like plants, human bodies use glucose as the starting point for biosynthesizing countless of other compounds, including fibre.
The second most common monosaccharide after glucose, is fructose, also known as fruit sugar. Fructose is found in fruit, honey, and agave nectar. Fructose and galactose are both converted by the liver into glucose for immediate energy. If we don’t need energy immediately, the liver converts glucose into a short-term storage carbohydrate called glycogen. When we run out of storage space for glycogen, excess glucose is converted into fatty acids for long-term storage as fat.
One-sugar molecules can bond together to create two-sugar molecules called disaccharides. “Di” means two. Two-sugar molecules include sucrose, made from one unit of glucose bonded to one unit of fructose; lactose, made from one unit of galactose bonded to one unit glucose; and maltose, made from two units of glucose. The bond between the two sugars has to be broken down when we digest disaccharides, in order for the individual sugars to be absorbed and used for energy. The enzyme sucrase breaks sucrose bonds, while maltase takes care of maltose and lactase breaks lactose bonds. Sucrose is the main ingredient in cane sugar and maple syrup, but it’s also found in the sap of all green plants, where it transports energy throughout the plant’s body.
REFINED SOURCES OF SIMPLE CARBOHYDRATES (Added Sugars)
Food manufacturers extract simple sugars from whole plant-foods and concentrate them to create sweeteners that can be added to processed foods or sold directly to consumers who add them to their foods and beverages. Good examples of these added sugars include common table sugar made from sucrose that has been isolated from cane sugar, and high-fructose corn syrup (HFCS), commonly used in sweet sugary drinks and processed foods.
Added sugars are “empty calories” or “empty carbs” because they are extremely calorie-dense while providing few (if any) other nutrients. If you took a can of soft drink and then piled up alongside it all the whole plant foods you would need to eat to consume the equivalent quantity of naturally occurring sugar, you would be astonished by the mound of food before you. Unfortunately, when calories are consumed in a liquid form, the body’s appetite-control center struggles to register them. The average 180ml serving of soft drink or fruit drink provides about 150 calories from sugar, close to 10 teaspoons (50ml) of sugar per serving. One serving of soft drink added to the daily diet can cause a weight gain of about 6.8kg per year.
In small doses, added sugars add fun and variety to our diet, but they are addictive and it’s very easy to overdose on refined simple carbohydrates. While small quantities added to nutritious prepared foods don’t pose a health risk, the average Australian’s added sugar consumption exceeds the recommended upper limit, which the World Health Organisation (WHO) sets at 10% of calories. Happily, our consumption as a nation appears to be decreasing. When comparing current trends with those 30 years prior, children especially, are consuming fewer soft drinks, cordial, energy/electrolyte drinks and fruit juices/drinks.
This decline has been inspired by a growing public awareness of the negative health consequences of added sugars, especially when it comes to high-fructose corn syrup (HFCS). Excess calories from added sugars such as HFCS have been implicated in the development of type II diabetes, insulin resistance, metabolic syndrome (abdominal obesity, high blood pressure, high blood sugar, high serum triglycerides and low high-density lipoprotein (HDL) levels), and tooth decay.
There is some evidence to suggest excess HFCS consumption may be slightly more damaging than that of excess sucrose consumption. In sucrose, the bond between glucose and fructose is still intact. By comparison, HFCS contains the free, unbonded monosaccharide forms, and this faster absorption seems to result in slightly higher blood levels of fructose. Mind you, the differences between these popular sweeteners are relatively small, with sucrose being 50% glucose and 50% fructose, while HFCS ranges from 42 to 55% fructose and 42 to 53% glucose. You might also be interested to know that when compared with popular sweeteners such as agave syrup, HFCS isn’t especially high in fructose; it’s just higher than regular corn syrup, which is mostly glucose.
There are many other names for added sugar besides cane sugar, sucrose and HFCS. I’m often surprised how confused the general public are, when it comes to this. Many cafes advertise dishes as “sugar free”. I doubt they mean the dish contains no carbohydrates, and are instead referring to added sugar, but I invariably discover they’ve used at least one added sugar. When it comes to monitoring your added sugars intake, especially from processed foods, it helps to know all the different terms used to describe added sugars so you can recognize them when you see them:
ADDED SUGARS (both vegan and non-vegan)
Barley malt syrup
Brown rice syrup
Dried cane juice
Evaporated cane juice
Fruit juice concentrate
High-fructose corn syrup
UNREFINED SOURCES OF SIMPLE CARBOHYDRATES (Natural sugars)
People not only get confused about what constitutes an added sugar, they also make the mistake of thinking that whole foods rich in simple sugars (such as fruit) should be avoided because they will cause the same health problems caused by excess added sugars. This isn’t true, because simple sugars are one of many ingredients in whole foods, rather than being the only ingredient.
Fruits and vegetables are full to over-flowing with hundreds, if not thousands, of nutrients. This includes many different kinds of carbohydrates and amino acids (proteins building blocks), healthy fats, vitamins, minerals, antioxidants and phytonutrients (natural compounds produced by plants, such as anthocyanins). Some of these ingredients help us properly process simple sugars. Fermentable fibre, for example, is a vital food source for helpful bacteria living in our colon, and this bacteria improves our metabolism of sugar. Many ingredients in whole plant foods have medicinal properties that protect us from the very same diseases that are caused by excessive consumption of added sugars. The human body, having evolved alongside whole plants in their original, unprocessed forms, can easily and expertly recognize and make use of these complex nutritional blends.
While it’s all too easy to overdose on simple sugars in the form of added sugar, it’s almost impossible to do this when consuming unprocessed whole foods, because we feel satisfied and stop eating long before we come anywhere close to consuming excess. This is mostly due to the presence of fibre. Researchers have found that you can cut your calorie intake by 10% just by adding an extra 14 grams of fibre each day! High-fibre foods require more chewing, which can slow the rate of eating, giving us more time to register the feeling of fulness before over-eating. Meanwhile, water-absorbing viscous fibres in wholefoods swell to many times their original size, pressing on the walls of the stomach to activate sensors that register fullness. These viscous fibres also help delay stomach emptying, making us feel full for longer. Whole foods rich in fibre reduce food cravings and overeating by slowing digestion, helping us feel full, and keeping our blood sugar steady.
Most Australians only eat about half the recommended quantity of fruit, which is unfortunate because fruit intake is associated with a reduced risk of chronic diseases such as cancer, heart disease, obesity, high blood pressure and dementia. A large Australian cohort study found that increased fruit and vegetable consumption is associated with a significant reduction in all causes of death.
Complex carbohydrates are found in all plant foods, in every part of the plant. Unrefined whole foods are healthy sources of complex carbohydrates, with some of the richest sources including legumes; raw vegetables; fruits such as avocado, berries, coconut flesh and paw paw; potatoes; whole grains; nuts; and seeds. When the complex carbohydrates in these plant foods are completely or partially removed, or the food is processed in a way that breaks the fibre down, these ‘refined’ foods can become unhealthy carbohydrate sources, especially when consumed regularly.
Short chained complex carbohydrates containing three to nine sugar molecules are called oligosaccharides. The word “Oligo” is a Greek word meaning “few” or ”scanty”.
Oligosaccharides include inulins, which are short strings of fructose units. These are also referred to as fructans. Short inulins are called fructooligosaccharides (FOS). Humans don’t have the enzymes needed to break the beta-glycosidic bonds between fructose units so we can’t digest inulins ourselves, but our gut flora can! These prebiotic carbohydrates are a food source for beneficial intestinal microflora, primarily the bifidobacterial strains. When our good bacteria feeds on inulins, several byproducts are produced, such as short-chain fatty acids (SCFA), including butyrate, which reduces triclyceride synthesis in the liver. These byproducts nourish cells in the colon and help maintain a healthy pH, hence discouraging the growth of bacterial and fungal pathogens (disease-causing microbes).
Rich inulin sources include foods such as onions, leeks, garlic, asparagus, artichoke, and some of my favourite medicinal herbs such as the roots of dandelion, chicory, elecampane and burdock.
Poly is the Greek word for “many”, reflecting the fact that polysaccharides are long chained complex carbohydrates containing anywhere from 10 to thousands of glucose molecules. At a very basic level, polysaccharides are loosely categorized as either starch or non-starch polysaccharides (NSP), but it’s worth keeping in mind that words such as fibre and starch are often used interchangeably. Polysaccharide-naming and classifying can be quite complicated!
Plants can store energy for later use, by stringing multiple glucose molecules together as starches that are mostly stored in seeds and roots. When plants need to access this stored energy for growth and metabolism, they convert stored starches back into simple sugars. This conversion process also occurs during ripening, which add sweetness to fruits and vegetables. When we chop, blend, grate, juice or cook plant foods, plant cells are broken down and this activates starch-digesting enzymes within the plants. Our digestive system uses digestive enzymes to break the bonds stringing the glucose molecules together, giving us a ready source of vital energy.
Non-starch Polysaccharides (NSP)
Also known as fibre, these polysaccharides are made by plants for structural purposes, such as building cell walls, and they can’t be broken down by our digestive enzymes. Surviving small intestinal enzymatic digestion intact, these plant fibres travel on into the colon where they either function as “prebiotic” (food) for healthy gut microbes in the large bowel, or they add to the bulk of the stool. NSP’s are classified as more- or less- fermentable fibre, depending on how easily our gut flora can break them down.
More-fermentable NSP’s, such as beta-glucans, pectins, guar gum, and hemicellulose, nourish our gut bacteria in the same way that nondigestible oligosaccharides do, as well as contributing to stool softening and bulk. With every 100g of fermentable fibre we consume, a whopping 30g of extra bacteria is produced and added to our stool. Less-fermentable NSP’s include cellulose and resistant starch, function as ‘nature’s laxative’, helping to lower the risk of constipation and diverticulitis.
Australians are eating less fibre, especially resistant starch, which may in part be why we are experiencing more gut problems, particularly pain, bloating and bowel disturbances. People most at risk of this reduced intake are those following the paleo/atkins movement, people avoiding potatoes because they are concerned about high GI, and people on gluten free or low FODMAP diets. An expert panel on diet and bowel health conferred in Australia in 2011 and produced a report recommending an intake of 20g of resistant starch per day which is four times the current SAD (standard Australian diet) intake. A whole foods plant-based diet provides two to three times as much total dietary fibre as this, and as long as you are including whole grains, legumes and potatoes, a significant amount of this intake will be resistant starch.
Another way to classify NSP’s is to say they are viscous (gel-like when mixed with water) or non-viscous. Viscosity accounts for some of fibre’s most impressive health benefits, such as delaying stomach emptying, increasing fullness after eating, stabilizing blood glucose levels, and reducing cholesterol. This kind of fibre delays the absorption of fats and carbohydrates from the small intestine, effectively stablising blood sugar and curbing appetite, which can reduce over-eating and weight-gain. Good examples of viscous fibre include gums and mucilages, often found in seeds.
REFINED SOURCES OF COMPLEX CARBOHYDRATES
When plant foods are refined or processed, their fibre content is reduced or broken down. This has a significantly negative impact on the nutritional value of our foods, because the discarded fibre is tangled up with many other nutrients that are lost along with it.
White rice (being the refined, processed version of brown rice) contains less than ¼ of the original fibre content. By taking the fibre out of brown rice, we also lose 67% of the vitamin B3 content, 80% of vitamin B1, 90% of vitamin B6, half the manganese, half the phosphorus, 60% of the iron, all of the essential fatty acids and an untold number of valuable phytonutrients (plant nutrients). Grains often have their fibre removed. Other examples of fibre removal include peeling and discarding the skins of fruits and vegetables. Most of the complex carbohydrates in fruits and vegetables are concentrated in, or just under, the skin.
When whole wheat berries are turned into white flour, we lose approximately 80% of the vitamin, mineral and fibre content, along with a 200- to 300- fold loss of phytochemicals. The loss of these naturally-occurring plant chemicals is tragic, because many of them have potent medicinal properties, such as being anti-inflammatory and anti-carcinogenic. We then use this nutrient-stripped flour to create a myriad of processed foods rich in added sugars, refined oil, and salt (eg cakes, donuts, biscuits, pastry) Either that, or they are bland and boring (eg pasta, bread) and only taste interesting if you add refined oil, salt and sugar.
Sadly, the metabolic processes in the body that transform starches and sugars into usable energy require many of the nutrients lost in the refining process, and if we don’t have the full nutrient spectrum to metabolise sugar properly, we end up with the very same range of health problems experienced by those who consume excessive added sugars (refined simple sugars), namely, diabetes, heart disease, obesity, metabolic syndrome etc.
The mistake that people sometimes make though, is in thinking that ALL foods rich in carbohydrates are damaging to health. Promotors of low-carb diets don’t take the time to properly distinguish between, or explain the difference between, refined vs unrefined whole foods.
UNREFINED SOURCES OF COMPLEX CARBOHYRDATES
Plant foods, in their original forms as produced by nature (or as close to this as we can get) are unrefined sources of healthy complex carbohydrates. In this form, carbohydrate-rich foods fight disease, rather than creating it, but in 2014/15, only 7% of Australians reported meeting the guidelines for daily vegetable intake.
Australia is deep in the midst of a terrible “healthy carbs” deficiency epidemic. I wrote about The Fibre Deficiency Epidemic in the last edition of this magazine, where I quoted a research paper published in the May edition of Nutrition, written by Nutrition Research Australia and the Department of Statistics. The researchers found that only 42.3% of children and 28.2% of adults met the Adequate Intake (AI) for fibre, and “less than 20% of adults met the Suggested Dietary Target (SDT) to reduce the risk of chronic disease.” Viscous fibre, for example, is famous for its ability to bind bile acids in the gut, leading to lower serum cholesterol and LDL levels, and a reduced risk of coronary artery disease. A person’s cholesterol profile can take a dramatic turn for the better after only 2 weeks on a fibre-rich wholefoods diet.
The reductionist argument about which macronutrients are bad or good, or worse or better for your health is one that has always puzzled me. Carbohydrates, fats and proteins are all important in their own unique ways, and they are all good for us, so long as we source them from whole plant foods.
Consider Blue Zones, the five places around the world where a large portion of the population live healthy and active lives well into their 90’s, with some living even longer. All five zones base their diets on whole, unrefined plants. They don’t eat much, if any, processed fast foods or packaged convenience foods. One of these groups doesn’t consume meat at all and the others save it for special occasions. As Blue Zone researcher Dan Buettner says “Beans, wholegrains, and garden vegetables are the cornerstone of all these longevity diets.”
People on low-carb diets generally consume 20-70grams of carbohydrate per day, which is far below the recommended daily intake. Many studies have shown that low carb diets are associated with an increase in all-cause mortality. A classic example is a Harvard study that tracked 130,000 participants, where low-carb diets were linked with a 12% increase in all-cause mortality. Those consuming animal-rich, carbohydrate-poor diets had a 23% higher all-cause mortality, a 14% higher mortality from heart disease, and a 28% higher cancer mortality. Those consuming low-carbohydrate diets rich in whole plant foods (ie less refined carbohydrates but plenty of unrefined carbohydrates), had a 20% lower all-cause mortality and a 23% lower mortality from heart disease.
The emphasis on macronutrients, and the correct ratios between them, detracts from more important conversations about the wholistic value of wholefoods rich in macronutrients, micronutrients (vitamins and minerals) and phytonutrients, working together in dynamic ways to support health. Whole foods are more than the sum of their individual parts, with individual nutrients collaborating to accomplish what they cannot do alone. This is called synergy. If, for example, the potency of one anti-inflammatory phytonutrient has a power of 5 and the potency of another has a power of 3, the synergistic interaction of these two nutrients working as a team, can result in an anti-inflammatory effect that has a power of 30, because they are potentizing (enhancing) one another. Synergy is the reason why whole foods don’t have the damaging effects on health that refined foods have.
Speaking at the Unite to Cure Forth International Vatican Conference, Professor David Jenkins, who is credited with developing the glycemic index (a way of measuring how carbohydrates affect blood sugar), said that the benefits of vegetarianism have been ‘undersold’. Dr Jenkin’s team have been studying the diets of lowland gorillas who eat stems, leaves, vines and fruits rather than a caveman or Paleo-type diet. They then tested this diet on humans. After 63 servings of fruit and vegetables a day for two weeks, they found a 35% fall in cholesterol, which is on par with the effect of statins, without the side-effects. At the same conference, Dr Willett, professor of epidemiology and nutrition at Harvard Medical School, agreed, saying that the benefits of a plant-based diet had been vastly underestimated and could prevent one-third of early deaths.
When people avoid whole plant foods such as fruit, vegetables and grains because they think of them as “carbs” which should be reduced, they are starving themselves of hundreds, if not thousands, of medicinal nutrients that are only found in whole plant foods. By all means, avoid processed, refined carbohydrates, but please, for the sake of your health, don’t stop eating healthy, unrefined, whole plant foods!
Originally written for and published in The Australian Vegan Magazine