Tag Archives: diet

A junk food diet in early years slightly decreases IQ

This has been all over the news this week.

Are dietary patterns in childhood associated with IQ at 8 years of age? A population-based cohort study

Background Little is known about the effects of overall diet in childhood and intelligence later in life.

Methods The current study, based on the Avon Longitudinal Study of Parents and Children, uses data on children’s diet reported by parents in food-frequency questionnaires at 3, 4, 7 and 8.5 years of age. Dietary patterns were identified using principal-components analysis and scores computed at each age. IQ was assessed using the Wechsler Intelligence Scale for Children at 8.5 years. Data on a number of confounders were collected, and complete data were available for 3966 children.

Results After adjustment, the ‘processed’ (high fat and sugar content) pattern of diet at 3 years of age was negatively associated with IQ assessed at 8.5 years of age—a 1 SD increase in dietary pattern score was associated with a 1.67 point decrease in IQ (95% CI −2.34 to −1.00; p<0.0001). The ‘health-conscious’ (salad, rice, pasta, fish, fruit) pattern at 8.5 years was positively associated with IQ: a 1 SD increase in pattern score led to a 1.20 point increase in IQ (95% CI 0.52 to 1.88; p=0.001).

Conclusion There is evidence that a poor diet associated with high fat, sugar and processed food content in early childhood may be associated with small reductions in IQ in later childhood, while a healthy diet, associated with high intakes of nutrient rich foods described at about the time of IQ assessment may be associated with small increases in IQ.

I suspect the issue isn’t the fat, or even the sugar, but low levels of nutrients like omega three oils, vitamins and minerals. This whole study has a slight ‘duh’ quality to it, although I was surprised it made as little difference to the final IQ as it did. I’m glad now that I got my kids to eat all that homemeade fish pie.

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Humans evolved to be meat eaters… fighting vegetarian/vegan disinformation.

Still arguing with the vegan idiot, who is insisting humans evolved to be vegetarian.. So, I dug out a few  papers that directly contradict him

The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic

OBJECTIVE: Field studies of twentieth century hunter-gathers (HG) showed them to be generally free of the signs and symptoms of cardiovascular disease (CVD). Consequently, the characterization of HG diets may have important implications in designing therapeutic diets that reduce the risk for CVD in Westernized societies. Based upon limited ethnographic data (n=58 HG societies) and a single quantitative dietary study, it has been commonly inferred that gathered plant foods provided the dominant energy source in HG diets.

METHOD AND RESULTS: In this review we have analyzed the 13 known quantitative dietary studies of HG and demonstrate that animal food actually provided the dominant (65%) energy source, while gathered plant foods comprised the remainder (35%). This data is consistent with a more recent, comprehensive review of the entire ethnographic data (n=229 HG societies) that showed the mean subsistence dependence upon gathered plant foods was 32%, whereas it was 68% for animal foods. Other evidence, including isotopic analyses of Paleolithic hominid collagen tissue, reductions in hominid gut size, low activity levels of certain enzymes, and optimal foraging data all point toward a long history of meat-based diets in our species. Because increasing meat consumption in Western diets is frequently associated with increased risk for CVD mortality, it is seemingly paradoxical that HG societies, who consume the majority of their energy from animal food, have been shown to be relatively free of the signs and symptoms of CVD.

CONCLUSION: The high reliance upon animal-based foods would not have necessarily elicited unfavorable blood lipid profiles because of the hypolipidemic effects of high dietary protein (19-35% energy) and the relatively low level of dietary carbohydrate (22-40% energy). Although fat intake (28-58% energy) would have been similar to or higher than that found in Western diets, it is likely that important qualitative differences in fat intake, including relatively high levels of MUFA and PUFA and a lower omega-6/omega-3 fatty acid ratio, would have served to inhibit the development of CVD. Other dietary characteristics including high intakes of antioxidants, fiber, vitamins and phytochemicals along with a low salt intake may have operated synergistically with lifestyle characteristics (more exercise, less stress and no smoking) to further deter the development of CVD.

This paper actually addresses the common vegetarian belief that hunter gatherers eat a mainly plant based diet, discussing how this came about from a misunderstanding of someones earlier work.

Lee’s (1968) analysis was widely misinterpreted over the next 32 y to mean that gathered plant foods typically provided the major food energy (65%) in worldwide huntergatherer diets, while hunted animal foods made up the balance (35%; Beckerman, 2000; Dahlberg, 1981; Eaton & Konner, 1985; Milton, 2000; Nestle, 1999; Zihlman, 1981). As we have previously pointed out (Cordain et al, 2000a, b), this general perception is incorrect because fished animal foods must be summed with hunted animal foods in the analysis of the ethnographic data to more correctly evaluate dietary plant to animal subsistence ratios (ie the percentage of energy contributed by plants vs animal foods). Our analysis (Figure 1) of the Ethnographic Atlas data (Gray, 1999) showed that the dominant foods in the majority of huntergatherer diets were derived from animal food sources. Most (73%) of the world’s hunter-gatherers obtained >50% of their subsistence from hunted and fished animal foods, whereas only 14% of worldwide hunter-gatherers obtained >50% of their subsistence from gathered plant foods. For all 229 hunter-gatherer societies, the median subsistence dependence upon animal foods was 66 – 75%.

The subsistence dependence upon hunted and fished animal foods was 66 –75% (median value), whereas the median value for gathered plant foods was 26 – 35%

I’d like to comment, after doing a survival course it became remarkably obvious that anything involving bulk carbs was extremely uncommon, and that vegetable protein sources just don’t usually exist in a non agricultural setting.

Meat in the human diet: an anthropological perspective.

Contrary to views that humans evolved largely as a herbivorous animal in a ‘garden of Eden’ type of environment, historical evidence indicates a very different reality, at least in the last four to five million years of evolutionary adaptation. It was in this time frame that the ancestral hominid hominid emerged from the receding forests to become bipedal, open grassland dwellers. This was likely accompanied by dietary changes and subsequent physiological and metabolic adaptations. The evolutionary pressure for some primates to undergo this habitat and subsequent diet change involving open grassland, foraging/scavenging, related directly to massive changes in global climatic conditions, primarily drier conditions followed by worldwide expansion of the biomass of temperate climate (C4) grasses at the expense of wetland forests, (2) accompanied by a worldwide faunal change, (3) including the spread of large grazing animals. Thus, the foods available to human ancestors in an open grassland environment were very different from those of the jungle/forest habitats that were home for many millions of years

These results alone would indicate that even very early hominids consumed a considerable proportion of meat in their diet.
Another line of investigation which is useful in ascertaining the dietary preferences and suitability of a species to certain food types is to study the structural features of the gastrointestinal tract. Both pure herbivores (folivores and frugivores) and pure carnivores (such as felids have physiological and metabolic adaptations suited to their diet. (14,15) Humans fit neither category, but are truly omnivores, falling between the largely frugivorous fruit-eating  make-up of such anthropoid  relatives as the chimpanzee and the adaptations of the true carnivores. Carnivores tend to have a well-developed acid stomach and long small intestine small intestine The human gut with its simple stomach, relatively elongated slender.  small intestine and reduced caecum and colon, does not fit any one group but lies between the frugivore  and faunivore groups, suggestive of suggestive of reliance on a high-quality diet in which meat is a predominant component.
The increased contribution of carbohydrate from grains to the human diet following the agricultural revolution has effectively diluted the protein content of the human diet. Whether current protein intakes are below the ideal is a question now being asked, especially in regard to effects on satiety and rates of obesity.

Digging through anthropology papers turned up that there are butchered animal bones in  Africa dating back 3.4 million years, and seeing as chimps hunt and eat meat, it’s not unreasonable to assume some level flesh consumption prior to the human/chimp split about seven million years ago. So much for eating meat being unnatural and something humans aren’t evolved to do.

This also does beg the question, how can something we spent millions of years evolving to do (eating meat) cause CVD and osteoporosis, as is claimed? Well, being familiar with the studies for protein and osteoporosis, I can tell you that most studies show better bone density with increased animal protein, not a loss, and that once refined bulk carbs are cut out of the diet, saturated animal fats lose their association with high blood pressure and bad blood lipids, which suggests that it’s the wacky blood sugar that’s the base cause of CVD in the west (which is probably why the most vulnerable to CVD are diabetics and insulin resistant metabolisms).

Anyone who has studied the bones of ancient humans can tell you they were as solid as rock (thicker than modern peoples; they had to be as hunters take some heavy duty impacts). The idea that a high animal protein causes weak bones not only defies the bulk of studies done, but also evolutionary logic.

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