The New Optimum Nutrition Bible
Page 10
The graph above shows how blood sugar levels and insulin rise and fall after eating spaghetti. As the blood glucose level rises, the body produces insulin, and down it comes again.
In the graph on the next page, you can see what happens after eating bread. Now this particular bread and this spaghetti were made from the same flour, using the same amount of flour.13 So, in this case, the only difference is in the way it has been processed—in letting the dough rise and cooking it—and what it’s mixed with. Bread is made to rise by feeding yeast sugar, which makes bubbles, hence producing a lighter loaf. The bread is then cooked. Pasta is essentially wheat and some egg. It isn’t made to rise and isn’t cooked so long. Both contain the same amount of wheat, but this small difference in preparation makes a big difference in blood sugar response.
Notice that the blood sugar level not only peaks twice as high for bread as for pasta, but also dips twice as low. It’s the peaks that damage your arteries, making them less responsive to insulin, and the troughs that leave you tired, sleepy, and craving carbohydrates or stimulants. Again, you can see a massive increase in insulin release. In fact, almost four times as much insulin has been produced in the first two hours after eating! What this means is that bread will make you put on weight much more than pasta. It might sound hard to believe, but that is the truth.
Glycemic response: bread. Within forty minutes of eating bread, blood sugar levels are almost double those seen with spaghetti. The body produces more than three times as much insulin to bring blood glucose levels under control. The body overreacts and blood glucose goes to low, leading to strong cravings for something sweet or a stimulant such as caffeine, peaking three hours later.
Neither fat nor protein has any appreciable effect on blood sugar. Fat and protein can be converted into sugar, but not in the blood; hence their effect on your blood sugar level is negligible. In fact, I recommend you eat some fat and protein with your carbohydrate because this will further lessen the GL score of the carbohydrate you eat.
GL—beyond the glycemic index
It was the discovery that even quite similar foods could have very different effects on blood sugar that led to classifying foods as slow-releasing or fast-releasing carbohydrates. The fast-releasing foods are like rocket fuel, releasing their glucose in a sudden burst. They give a quick burst of energy with a rapid burnout.
But how do you know what is fast or slow releasing? The very measure of a food’s fast- or slow-releasing effect is linked to the degree to which it raises your blood sugar; this can be worked out on the aforementioned scale called the glycemic index (or GI for short). It involves measuring the level to which a food raises your blood glucose in relation to the effect glucose has.
If a food raises blood sugar level significantly, and for some time, the area under the curve made by glucose is great (as for bread, see figure on this page). Conversely, if a food hardly raises blood glucose levels at all, and only for a short time, the area under the curve is smaller (as for pasta, see figure on this page). The amount of food tested obviously affects how high the blood sugar level will go. The GI of a food is calculated by feeding a person however much of the food is needed to give 50 grams of carbohydrate. Below, you can see the glycemic index for a variety of foods. Generally, the high-GI foods are the ones to avoid, while the low-GI foods are the ones to eat. Some examples are given below. Here, apples and oats are slow releasing, while raisins and cornflakes are fast.
THE GLYCEMIC INDEX (GI) OF COMMON FOODS
The GI score of a food is very useful, but there’s one problem. Compare carrots with chocolate. Why do they have nearly the same scores? Wouldn’t you think intuitively that carrots would be good for you? You’d be dead right. The answer is that there is comparatively little carbohydrate in a carrot or a slice of watermelon. In fact, you’d have to eat seven carrots to get the same amount of carbohydrate, and the same effect on your weight, as 125 grams (4.4 oz) of chocolate would give you. This inconsistency is why the GI score of foods can be misleading.
Forget the GI—it’s the GL that counts
The GL score of a food—its glycemic load—solves this inconsistency. It’s a calculation based on the amount of carbohydrate in the food and its glycemic index. It takes both the quantity of carbohydrate in the food and the quality of the carbohydrate into account. This tells you exactly what a given serving of a food does to your blood sugar. See the chart in part 9 (this page–this page) to find out which foods have the lowest GLs.
You’ll see that oats are way better than any other cereal, whole-grain rye bread is much better than the others, brown basmati rice is much better than white rice, and whole wheat pasta is better than refined. Boiled potatoes are better than baked, while all peas, beans, and lentils have very low GLs. The best fruits are berries, plums, apples, and pears, while the worst are dates, raisins, and bananas.
When you eat carbohydrate foods with a low GL with protein foods, you stabilize your blood sugar level even more. Examples would be chicken with brown basmati rice, or salmon with whole wheat pasta, or a scrambled egg on whole rye toast. The fiber content of a food also lowers its GL, so I recommend high-fiber foods, from beans to brown rice. Lastly, when you eat is very important. It is better to graze, eating little and often, rather than gorge, as far as your blood sugar is concerned.
Breaking the habit
The taste for concentrated sweetness is often acquired in childhood. If sweet things are used as a reward or to cheer someone up, they become emotional comforters. The best way to break the habit is to avoid concentrated sweetness in the form of sugar, sweets, sweet desserts, dried fruit, and pure fruit juice. Instead, dilute fruit juice and get used to eating fruit instead of having a dessert. Sweeten breakfast cereals with fruit and have fruit instead of sweet snacks. If you gradually reduce the sweetness in your food, you will get used to the taste. Remember, we are designed to eat food that you can pick off a tree or pull out of the ground. Take a look at your average supermarket cart. Ever seen that stuff grow on trees?
Sugar alternatives
Alternatives to sugar, such as honey or maple syrup, are only marginally better. They both contain more minerals than refined sugar; however, most commercial honey is heated to make it more liquid so it can be cleaned up and put into jars. The heat turns honey’s natural sugar, levulose, into another, fast-releasing sugar more like glucose. If you like to eat honey, buy the untreated kind from local suppliers. Artificial sweeteners are not so great either. Some (admittedly in large quantities) have been shown to have harmful effects on health, and all perpetuate a sweet tooth. One of the best sugar alternatives is xylitol, a vegetable sugar that has a very low GL. It tastes much the same as regular sugar but has little effect on raising blood sugar—half that of fructose. Plums are rich in xylitol, which is part of the reason why they have a very low GL score.
Fiber
Not all types of carbohydrate can be digested and broken down into glucose. Indigestible carbohydrate is called fiber. This is a natural constituent of a healthy diet high in fruit, vegetables, lentils, beans, and whole grains, and, by eating a high-fiber diet containing these foods, you will be at less risk of bowel cancer, diabetes, and diverticular disease and unlikely to suffer from constipation.
Contrary to the popular image of fiber as “roughage,” it can absorb water. As it does so it makes fecal matter bulkier, less dense, and easier to pass along the digestive tract. This decreases the amount of time that food waste spends inside the body and reduces the risk of infection or cell changes due to carcinogens that are produced when some foods, particularly meat, degrade. A frequent meat eater with a low-fiber diet can increase the gut-transit time of food from twenty-four to seventy-two hours, giving time for some putrefaction to occur. So if you like meat, make sure you also eat high-fiber foods.
There are many different types of fiber, some of which are proteins and not carbohydrates. Some kinds, such as that found in oats, are called soluble fiber and combine with sugar m
olecules to slow down the absorption of carbohydrates. In this way, they help keep blood sugar levels balanced. Some fibers are much more water-absorbent than others. While wheat fiber swells to ten times its original volume in water, glucomannan fiber, from the Japanese konjac plant, swells to one hundred times its volume in water. By bulking up foods and releasing sugars slowly, highly absorbent types of fiber can help control appetite and play a part in weight maintenance.
An ideal intake of fiber is not less than 35 grams a day. Provided the right foods are eaten, this level can easily be achieved without adding extra fiber. Professor of nutrition John Dickerson from the University of Surrey (England) has stressed the danger of adding wheat bran to a nutrient-poor diet. The reason is that wheat bran contains high levels of phytate, an antinutrient that reduces the absorption of essential minerals, including zinc. Overall, it is probably best to get fiber from a mixture of sources such as oats, lentils, beans, seeds, fruit, and raw or lightly cooked vegetables. Much of the fiber in vegetables is destroyed by cooking, so they are best eaten crunchy.
To get enough of the right kinds of carbohydrates
Eat whole foods—whole grains, lentils, beans, nuts, seeds, fresh fruit, and vegetables—and avoid refined, and overcooked foods.
Eat five servings a day of dark green, leafy, and root vegetables, such as watercress, carrots, sweet potatoes, broccoli, Brussels sprouts, spinach, green beans, and peppers, either raw or lightly cooked.
Eat three or more servings a day of fresh fruit, preferably apples, pears, or berries.
Eat four or more servings a day of legumes or whole grains such as rice, rye, oats, wheat, corn, quinoa whole-grain as cereal, or breads, or pasta.
Avoid any form of sugar, added sugar, and refined foods.
Dilute fruit juices and eat dried fruit only infrequently and in small quantities, preferably soaked.
11
Stimulants—Are You Addicted?
Sugar is only one side of the coin, as far as blood sugar problems are concerned. Stimulants and stress are the other. As you can see from the figure on the next page, if your blood sugar level dips there are two ways to raise it. One is to eat more glucose, and the other is to increase your level of the stress hormones adrenaline and Cortisol. There are two ways in which you can raise adrenaline and Cortisol: consume a stimulant—tea, coffee, chocolate, or cigarettes—or react stressfully, causing an increase in your own production of adrenaline.
Knowing this, you can see how easy it is to get caught up in the vicious cycle of stress, sugar, and stimulants. It will leave you feeling tired, depressed, and stressed much of the time.
Here’s how it works. Through excess sugar, stress, and stimulants you lose your blood sugar control and wake up each morning with low blood sugar levels and not enough adrenaline to kick-start your day So you adopt one of two strategies:
Either you reluctantly crawl out of bed on remote control and head for the kettle, make yourself a strong cup of tea or coffee, light up a cigarette, or have some fast-releasing sugar in the form of toast, with some sugar on it called “jam.” Up go your blood sugar and adrenaline levels and you start to feel normal.
Or you lie in bed and start to think about all the things that have gone wrong, could go wrong, will go wrong. You start to worry about everything you’ve got to do, haven’t done, and should have done. About ten minutes of this gets enough adrenaline pumping to get you out of bed.
The sugar cycle. Eating sugar increases blood glucose levels. The body releases insulin into the blood to help escort glucose out of and into body cells to make energy or convert into fat. The result is low blood glucose. Either “real” stress, causing an increase in adrenaline, or stress induced by consuming a stimulant such as caffeine, which raises adrenal hormones, causes breakdown of stores of sugar in the liver and muscles, called glycogen, which raises blood sugar levels. Low blood glucose causes stress or cravings for either something sweet or a stimulant.
If this sounds like you, you’re caught in that vicious circle, with all its negative effects on your mind and mood.
Caffeine makes you tired
Here’s the irony. The reason that people get hooked on drinking coffee, particularly in the morning, is because it makes them feel better, more energized, and alert. But, wondered Dr. Peter Rogers, a psychologist at Bristol University in England, does coffee actually increase your energy and mental performance or just relieve the symptoms of withdrawal? When he researched this, he found that after that sacred cup of coffee, coffee drinkers don’t feel any better than people who never drink coffee. Coffee drinkers just feel better than they did when they woke up.14 In other words, drinking coffee relieves the symptoms of withdrawal from coffee. It’s addictive.
Not only is coffee addictive, but also it worsens mental performance. A study published in the American Journal of Psychiatry looked at 1,500 psychology students and divided them into four categories depending on their coffee intake: abstainers, low consumers (one cup or equivalent a day), moderate (one to five cups a day), and high (five or more cups a day). The moderate and high consumers were found to have higher levels of anxiety and depression than the abstainers, and the high consumers had the greatest incidence of stress-related medical problems, as well as lower academic performance.15 A number of studies have shown that the ability to remember lists of words is reduced by caffeine. According to one researcher, “Caffeine may have a deleterious effect on the rapid processing of ambiguous or confusing stimuli.” That sounds like a description of modern living!
Caffeine blocks the receptors for a brain chemical called adenosine, whose function is to stop the release of the motivating neurotransmitters dopamine and adrenaline. With less adenosine activity, levels of dopamine and adrenaline increase, as does alertness and motivation. Peak concentration occurs thirty to sixty minutes after consumption.
CAFFEINE BUZZOMETER
Here are caffeine levels in a number of popular products:
Product
Caffeine content
Coca-Cola Classic 350 ml (12 fl. oz.)
46 mg
Diet Coke 350 ml (12 fl. oz.)
46 mg
Red Bull
80 mg
Hot cocoa 150 ml (5 fl. oz.)
10 mg
Coffee, instant 150 ml (5 fl. oz.)
40–105 mg
Coffee, filter 150 ml (5 fl. oz.)
110–150 mg
Coffee, Starbucks (grande)
500 mg
Decaffeinated coffee 150 ml (5 fl. oz.)
0.3 mg
Tea 150 ml (5 fl. oz.)
20–100 mg
Green tea (5 fl. oz.)
20–30 mg
Chocolate cake (1 slice)
20–30 mg
Dark (cooking) chocolate 28 g (1 oz.)
5–35 mg
Caffeine pills (per pill)
50–200 mg
The more caffeine you consume, the more your body and brain become insensitive to its own natural stimulants, dopamine and adrenaline. You then need more stimulants to feel normal and keep pushing the body to produce more dopamine and adrenaline. The net result is adrenal exhaustion—an inability to produce these important chemicals of motivation and communication. Apathy, depression, exhaustion, and an inability to cope set in.
Coffee isn’t the only source of caffeine. There’s as much in a cup of strong tea as in a cup of regular coffee. Caffeine is also the active ingredient in most cola and other energy drinks such as Red Bull, which sold over 100 million cans last year. Chocolate and green tea also contain caffeine, but much less than these drinks.
Kicking the habit
If you want to be in tip-top mental health, stay away from stimulants. This is doubly important for those with mental health problems because too much caffeine can, in some, produce symptoms that lead to a diagnosis of schizophrenia or mania. This may happen because high caffeine consumers can become both allergic to coffee and unable to detoxify caffeine. The net effect is se
rious disruption of both mind and mood.16
Here’s how you can give up these stimulants.
Coffee contains three stimulants: caffeine, theobromine, and theophylline. Although caffeine is the strongest, theophylline is known to disturb normal sleep patterns, and theobromine has a similar effect to caffeine, although it is present in much smaller amounts in coffee. So decaffeinated coffee isn’t exactly stimulant free. As a nutritionist, I have seen many people cleared of minor health problems such as tiredness and headaches just from cutting out their two or three coffees a day. The best way to find out what effect it has on you is to quit for a trial period of two weeks. You may get withdrawal symptoms for up to three days. These reflect how addicted you’ve become. After this, if you begin to feel perky and your health improves, that’s a good indication that you’re better off without coffee. The most popular alternatives are Teeccino, Caro Extra, or Bambu (made with roasted chicory and malted barley) or herb teas.
Tea is the great British addiction. A cup of strong tea contains as much caffeine as a cup of regular coffee and is certainly addictive. Tea also contains tannin, which interferes with the absorption of essential minerals such as iron and zinc. Particularly addictive is Earl Grey tea containing bergamot, itself a stimulant. If you’re addicted to tea and can’t get going without a cup, it may be time to stop for two weeks and see how you feel. The best-tasting alternatives are Rooibos tea (red bush tea) with milk and herbal or fruit teas. Drinking very weak tea from time to time is unlikely to be a problem.