Why Men Don’t Iron: The New Reality of Gender Differences. Anne Moir
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it one in 20 we might take note.’
High quality proteins are, in order of merit: meat, fish, eggs and milk. Meat is by far the most efficient provider of protein, containing five times more than milk. Egg protein used to be the reference point for human needs; its amino acid balance is now found to be perfect for a chicken but not for a human, for whom lean meat or fresh fish is closer to the ideal.24 We need protein, men need it more than women, and meat is the ideal source.
Brain neurotransmitters are affected by diet
Neurotransmitters are chemicals released from nerve endings. They transmit impulses – pass messages – from one nerve cell (neuron) to another. Mostly they work within the brain, but some are manufactured elsewhere in the body. In later chapters we shall see that there are differences in the levels of neurotransmitters used by men and women, but for now it is enough to note a few salient facts that are related to men’s and women’s dietary needs.
Serotonin is a brain chemical that is much involved with mood control. It promotes sleep and helps govern impulsive behaviour. Low levels, much more common in males, are related to aggressive behaviour. Serotonin, like the female hormone oestrogen, also acts as an appetite suppressant, which is why weight-reducing drugs are designed to raise serotonin levels in the brain. Women, on average, have slightly more serotonin than men, and many more men than women have the lower levels. (See Chapter six for more details about serotonin.)
Neurotransmitters affect far more than appetite. A high carbohydrate meal (starch or sugars, say) will raise the level of tryptophan.25 Tryptophan is a chemical forerunner of serotonin, and an increase in its level acts as a sedative.26 A high protein meal like red meat, on the other hand, lowers tryptophan and serotonin levels, thus increasing mental alertness. Men facing a challenging task can sharpen their edge by eating steak for breakfast and by drinking coffee. Caffeine increases our ability to concentrate.27 What you eat changes how you think.28
Why men need iron
The body needs a host of micronutrients to function properly. Iron, for instance, is intimately related to the manufacture of blood: deny your body its fix of iron and haemoglobin levels drop, leading to lethargy. It was briefly thought that too much iron in the diet could lead to coronary heart disease,29 but a study of more than 12,000 men and women found no relationship between iron stores in the body and death by heart disease in men. The results for women were more ambiguous.30
Research is showing that we have too few micronutrients – zinc and iron in particular – in our officially recommended diets, and a serious lack of either harms the body’s immune system. Low intake of iron, especially for infants, can lead to irreversible brain damage. A weaning infant has no iron stores and must rely entirely on dietary iron. ‘It is possible to meet these high requirements,’ reads a leading textbook on nutrition, ‘if the diet consistently has a high content of meat and ascorbic-acid [Vitamin C] rich foods.’31 Vitamin C, just like red meat, is an anti-phytic agent. Phytic acid (phytates are found in brown flour: more of that later) impairs the absorption of some nutrients, including iron. Anti-phytic agents oppose the effect of phytic acid and so improve absorption of trace minerals. Too little iron in an adult can mean impaired memory and learning ability, though the effects are reversible.32
Tests on male vegetarians in New Zealand showed them to have little more than a third (35%) of the iron in their blood compared with the majority of the male population. Yet the vegetarians had a significantly higher iron intake. They were eating more iron, but absorbing less, and the researchers concluded: ‘Recommended intakes of iron may need to be higher for vegetarians, particularly men.’33
‘Popeye would have been able to absorb less than 2 per cent of the iron in his spinach,’ Bill notes, ‘whereas Dracula would have absorbed 20 per cent of the iron in his high protein snacks.’34
‘Not quite,’ said Anne. ‘For some unknown reason, iron in blood that is not taken with meat is little more than 2 per cent absorbed.35 Dracula should take a bite along with his blood.’
Lack of beef is directly and significantly correlated with the male lack of zinc and some vitamins
In 1995 three Arkansas nutrition scientists published an analysis of 43 menus that were to be used in a diet manual – a manual that conscientiously met the US Government’s 1990 Dietary Guidelines for Americans.36 To these health-conscious menus they added 11 more from various Arkansas hospitals and discovered that only one in nine of the 54 menus met the 1989 Recommended Dietary Allowance (RDAs) of zinc for men (set by the Food and Nutrition Board of the National Research Council). Four times more men than women were a fifth or more below their daily recommended zinc allowance. Low levels of zinc lead to a decline in the ability to taste and smell one’s food.37 Loss of taste can mean food is not enjoyed and so less is eaten and so the deficiency increases. Night sight deteriorates. New tissue growth slows. Mild zinc deficiencies have been shown to stunt the growth of Canadian38 and American39 infants and preschool children.
The Arkansas authors point out that the continued shift to fish, chicken and legumes ‘may lead to zinc levels even lower than those previously found in the American diet’.40 They conclude that the many dietary calls for the public to cut back on saturated fats may be having a negative impact on mineral utilization. ‘Foods rich in zinc and iron may be further limited when people lower the fat content of their diet.’41 In this they are supported by other research.42 The Arkansas researchers discovered that the single main reason why there still seemed enough iron in most of the diets was because of the inclusion of breakfast cereals in the menus, and such cereals typically contain artificial supplements. Such a dependence on manufactured supplements seems at odds with the dietary grail of holistic, all-natural, ‘organic’ ingredients.
Half of the Arkansas menus failed to meet male needs for Vitamin B6. One in seven men – no women – were a third below the recommended intake. Vitamin B6 is involved in the brain’s synthesis of neurotransmitters, and abnormalities can occur within two weeks of a B6-free diet.43 The lack of vitamin B6 indicates a protein shortage, but instead of recommending more eggs or meat on the menu, the nutritionists urged an increase in the consumption of legumes: pulses, mung beans, lentils, chick peas, soya beans or tofu. The nutritionists recognized that there is a distaste for these foods, much more marked among men than in women,44 but that was not thought to be a barrier. ‘Legumes are not acceptable food items to many patients,’ the nutritionists noted, ‘this is clearly an area that could be addressed by nutrition education.’45 Here is heard the clear voice of the female-dominated nutrition industry: men show symptoms of protein deficiency, meat will cure the deficiency, but legumes, though far less efficient providers of protein, are deemed to be ‘healthier’. He needs red meat? Let him eat tofu.
There are deeply worrying aspects of the officially sanctioned American diet. Nutrition scientists aim to manipulate the average diet to make it ever more healthy, and some of them even accept that it must also be tasty.46 So far so good. Yet when the diet fails to deliver the goods – when the needed nutrients are unavailable in the approved food – the nutritionists still refuse to increase the amount of meat in the diet, despite their own evidence that it was the reduction of meat which created the problem in the first place. Rather than rethink the diet in the light of current research, their advice is to increase the legumes and whole grains on the menu.47
What is not mentioned by the three Arkansas nutritionists is that the USA’s recommended dietary allowance of zinc for men is a fifth higher than the Canadian recommendation and a third higher than the British. Canadian and British RDAs for zinc intake are based on a mixed diet of animal protein supplemented by unrefined cereals. The American RDA for 1989 was based on a diet containing foods with a moderate to low availability of zinc, which implies a near-vegetarian diet.48
Suggested daily vitamin and mineral allowances are set on the high side and are subject to constant