Deadly Harvest: The Intimate Relationship Between Our Heath and Our Food (32 page)

Legumes

Legumes are newcomers to the human diet and there are major drawbacks to consuming them: the body is not equipped to handle their plant poisons (antinutrients) and antigens. Only from time to time should you include a moderate portion of legumes in your diet; the purist will avoid them altogether. Examples of legumes are lentils, beans, peas, and peanuts. Peas are a slightly different case: they contain fewer antinutrients, but on the other hand they are starchy and glycemic. In addition, we single out the soybean for special mention because of its false reputation as a miracle food—avoid soy and all its products (tofu, soy protein burgers, tofu-substitute yogurts, and so on).

Nuts

Nuts are a natural food for humans to be consuming. All tree nuts are generally fine. Examples are walnuts, almonds, Brazil nuts, and filberts. However, chestnuts and coconut do not fit into this tree nut category. Chestnuts are mainly starch and so are included in the starchy vegetable group; coconuts are mainly oil and are included in the fats and oils group. Peanuts are a legume and are included in the previous group.

Nuts should be raw and fresh. Regrettably, food manufacturers usually roast and salt nuts to improve shelf life and taste. However, this destroys useful nutrients and the salt is an unwelcome burden to the diet. Around half the weight of a nut is oil, much of it omega-6 fatty acids. Nuts are therefore calorie-dense and tend to upset the omega-3 to omega-6 balance. For these reasons, nuts should be consumed in moderation. Those classified “Green-Green” have a high omega-3 content. We make special mention of walnuts, which have the exceptional property of being rich in omega-3 oil. However, it is essential that the walnuts be fresh, because their omega-3 oil turns rancid very easily and becomes an oxidized fat particularly harmful to cardiovascular health.

Fats and Oils

In nature, fats and oils do not occur on their own: they are always part of something else. The Bushman could not eat the mongongo oil without eating the nut; he could not eat the animal fat without eating the animal. Fats and oils in their separated state are in a very concentrated form and therefore more potent. That is why they should always be treated with caution.

As a rule of thumb, oils that are solid at room temperature are suspect, as they are almost certainly unhealthy, saturated fats. Examples are butter, lard (including bacon fat), and tallow (beef and sheep fat). Artificial saturated fats are equally unhealthy, such as trans fats and hydrogenated fats. They are present in many processed foods and in margarines and spreads. In other words, all fats should be avoided.

The general injunction is to consume oils sparingly. We should focus on omega-3 oils. A prime example is canola (rapeseed) oil, which is readily available in supermarkets. However, we recommend going for cold-pressed, organic canola oil, if possible. Flaxseed oil has the highest concentrations of omega-3s and is preferred if you can afford it. The oil is fragile and needs to be kept in the refrigerator and consumed within a few weeks. Other options are hempseed oil and walnut oil (make sure it is not made from roasted walnuts).

All these omega-3 oils should only be used cold, for example, in a salad dressing. Omega-3 oils do not resist heat very well and the oil oxidizes and becomes toxic. If you need to heat the oil for cooking, then a monounsaturated (and thus inert) oil is best, such as olive oil.

The human organism also needs a second class of oil, the omega-6s, in a balanced ratio with the omega-3s. The trouble in the modern diet is that omega-6 vegetable oils are in everything and thus overwhelm our omega-3 consumption. We must therefore avoid any unnecessary intake. For this reason, you should strictly avoid knowingly consuming omega-6 oils, such as sunflower oil, safflower oil, peanut oil, and corn oil.

The criteria we have used in our classification are: omega-3 content; omega-6 to omega-3 ratio; and presence of harmful fatty acids, such as palmitic acid and myristic acid. In all cases, they should be consumed with restraint. We have included mayonnaise and spreads, but it makes a big difference which oils they are made from. Check the labels and reject products that are “Amber-Red.” Watch out for hydrogenated fats in spreads and all kinds of processed foods.

Sugars and Sweeteners

Sweet-tasting foods were a rarity in our ancestral diet. Consumption of any of these items should be restrained. The various sweetnesses available to us today fall into three main categories: high-glycemic sugars, low-glycemic sugars, and artificial sweeteners. We have seen how most sugars, the high glycemic ones such as table sugar and most confectionary, are harmful for us. They must be ruthlessly removed from the diet. More surprising for many of you is that the “natural” sugars, honey and maple syrup, are to be equally avoided. Some dried fruits have high sugar content and are highly glycemic; for example, dried figs, dried dates, and sultanas. They should also be avoided.

A second class of sugars is based on fructose, a naturally occurring, low-glycemic sugar. They are not glycemic and are admissible in moderation. Fructose itself is available in powder and liquid form in many supermarkets and in health food stores. It is present to a greater or lesser degree in honey. That is why, depending on which flower the honey comes from, the honey changes classes. The sugar from the agave plant is almost entirely fructose and has a very low glycemic index. In contrast, high-fructose corn syrup is a misnomer: it is as glycemic as table sugar itself. It is easy to overdose even on fructose, so its consumption should be kept moderate.

What about artificial sweeteners? Researcher William Grant estimates that 150,000 American deaths a year can be attributed to sugar consumption. This is a massive figure and it would be even more if the true causes of all heart attacks, cancers, and other illnesses could be identified. Just imagine the outcry if just one death could be attributed to the use of an artificial sweetener. In a world where we sometimes have to choose the lesser of two evils, substituting an artificial sweetener for sugar, as a first step, is a move in the right direction. From a theoretical point of view, Aspartame, saccharine, and other artificial sweeteners never formed part of the Pleistocene diet. Nevertheless, government authorities around the world have exhaustively tested them. If sugar had been obliged to pass the same regulations as artificial sweeteners, the authorities would have banned sugar as a dangerous substance. The purist will wish, understandably, to eliminate all artificial sweeteners from the diet. However, it is our view that they can form a very useful support when weaning from sugar itself.

Chocolate which is made with a high percentage of cocoa solids (and therefore little sugar) is low glycemic and contains many useful micronutrients; it can be consumed in restrained quantities. Most other confectionary items are high glycemic and devoid of useful nutrients; they usually contain bad fats and dairy as well—the dreaded “Red” column for them. Watch out for manufactured foods that claim to have “no sugar added.” Often you are being duped: they are sweetened with apple or grape juice concentrate, which are just as bad.