Paleolithic nutrition for kids:

Why hunter-gatherer diets may reduce your child’s risks of obesity, diabetes, and other diseases

© 2009-2010 Gwen Dewar, Ph.D., all rights reserved

Paleolithic people were athletic, fit, and free from the chronic diseases associated with modern, affluent, sedentary lifestyles: obesity, hypertension, heart disease, and diabetes.

Why?

They exercised regularly—-walking an average of 8 miles a day.

And their diets were notably different.

They ate no milk products and consumed very lean meat. They ate fish and shellfish.

As a result, their diets were low in saturated fats. They consumed virtually no trans fats (Eaton et al 2007).

In addition, a relatively high proportion of their fat intake was in the form of healthy omega-3 fatty acids (Sinclair and O’Dea 1993).

These differences were very important--excessive saturated fat and insufficient omega-3 fatty acids are linked with impaired cognitive development, cardiovascular disease, autoimmune diseases, and cancer.

But I’d like to focus on another aspect of the Paleolithic diet--the plant foods.

Studies of contemporary foragers reveal a remarkable breadth of foods--including an average of more than 100 different plant species.

These plant foods accounted for a carbohydrate intake that is similar to that of people living in affluent industrialized countries—-about 45-50% of daily energy (Eaton et al 1999).

But there was an important difference. Modern, affluent diets feature carbohydrates that rapidly raise blood sugar levels. Carbs like refined sugars, highly-processed grains, and starchy potatoes. In addition to raising blood sugar, these foods are also relatively poor sources of fiber, vitamins, and minerals.

By contrast, foragers got their carbs from vitamin-and mineral-rich, high-fiber vegetables and fruits.

Big difference? Oh yes. Nutritionists evaluate a food’s potential for raising blood glucose levels by measuring it’s “glycemic index,” or GI.

Glucose has a glycemic index of 100. Anything under 55 is considered to be low. You can check the GI of various foods by checking the International Table of Glycemic Index and Glycemic Load Values (Foster-Powell et al 2002).

Consider how these agricultural staples score:

• Baked russet potatoes, GI approximately 86.

• Corn tortillas (from a Western supermarket), GI approx. 74.

• Breakfast cereals (like corn flakes), GI over 70.

• Wheat flour breads vary. Coarse wheat breads (with uncracked kernels) have GIs in the 50s. White breads have GIs in the 70s.

• Rice varies. Jasmine rice (my favorite) has a GI of approximately 109. Basmati rice has a GI in the range of 58.

By contrast, many of the starchy roots and tubers eaten by non-Western peoples have GIs less than 50. Most green vegetables have GIs far below 50.

And even sweet fruits sold in Western supermarkets have GIs under 55:

• Apples, GI approximately 38

• Bananas, GI approx. 52

• Oranges, GI approx. 42

• Mangos, GI approx. 51

• Peaches, GI approx. 42

So here’s the point: The “Paleolithic” carbs trigger relatively gradual rises in blood sugar levels. And that’s a good thing, since chronically high blood sugar levels increase the risk of many ailments, including heart disease and stroke, diabetes, and kidney disease.

In addition, the high fiber intake associated with the Paleolithic diet should protect people from obesity, cancer, and diseases of the digestive system.

And people consuming a Paleolithic diet would be at little risk of vitamin and mineral deficiencies.

Vitamins and MineralsAccording to an analysis by S. Boyd Eaton and his colleagues, contemporary foragers consume higher levels of vitamins and minerals than are currently recommended by the US RDA (Eaton et al 1999). For instance, foragers average

• 0.357 mg of folate

• 6.49 mg of riboflavin

• 3.91 mg of thiamin

• 600 mg of vitamin C

• 1950 mg of calcium

• 10,500 mg of potassium

• 43.4 mg of zinc.

These aren’t megadoses, and Eaton’s group doesn’t advocate megadoses. Taking supplements of vitamins and minerals in megadoses can be dangerous—especially for children.

But the Paleolithic example helps put modern agricultural diets in perspective. According to data collected in the 1990s, most Americans aren’t getting the recommended amounts of magnesium, calcium, or zinc. Almost one third of Americans aren’t getting enough folate, riboflavin, or thiamin, and 37% fail to get even 60 grams of daily vitamin C.

Implications: What the hunter-gatherers teach us about nutrition for kids

Is the “food pyramid” wrong?

Other research supports this idea. A new study suggests that the high consumption of fruits and vegetables is one of the key reasons that that the classic Mediterranean diet is so healthful (Trichopoulou et al 2009).

Researchers tracked thousands of Greek men and women for more than 8 years. Then they compared diets and mortality. The results suggested that high intake of vegetables and fruits was a strong predictor of survival. By contrast, the effects of high cereal intake (e.g., bread consumption) were small.

But we needn't avoid all the cereal-based foods. When cereals are less thoroughly refined and processed, they have much lower glycemic indices. According to the International Table of Glycemic Index and Glycemic Load Values, corn tortillas made by the Pima indians have a GI of only 38.

Nor should we assume that the Stone Age menu is ideal, or that any deviations from it are automatically bad.

Evidence that humans have evolved to cope with more “modern” diets

Humans have evolved significant, new adaptations since the rise of agriculture.

For instance, the gene AMY1 is linked with salivary amylase--an enzyme that breaks down dietary starch. The more copies you possess of this gene, the more salivary amylase you can make. And here’s the important point: People who live in populations with high-starch diets carry more copies of the AMY1 gene (Perry et al 2007).Or consider the more familiar case of the gene for lactase, the enzyme that helps the body break down milk sugars. Most human adults don’t produce lactase. Lactase gnee is turned off when childhood ends.

But among certain populations—such as those in the Europe, the Middle East, and North Africa—most people carry genes that permit them to

Should lactose-tolerant people give up milk?

Research suggests that there are both costs and benefits associated with milk consumption.

For instance, studies suggest that milk increases insulin resistance. But milk also enhances growth (Hoppe et al 2006; Rich-Edwards et al 2007). And for some people--including those who are vegetarians by choice or necessity--milk may provide a crucial source of calcium and animal proteins.

So I think we need to avoid sweeping generalizations. When it comes down to it, there isn’t anything magical about Paleolithic nutrition. What’s best for kids may depend on individual differences, including genetics and environmental factors, like the availability of different nutrients.

And in case you were wondering about life spans...

Of course people are less likely to die of heart disease if accidents, warfare, infectious disease, or famine kills them first.

And it would be silly to compare a group of geriatric Americans with a group of young hunter-gatherers!

But that’s not what anthropologists like S. Boyd Eaton do.

Rather, they examine the health status of younger people. They look for the early warning signs of chronic disease--biomarkers like increased platelet aggregatability, clinical hypertension, high cholesterol, and insulin resistance.

When you compare hunter-gatherers with their similarly-aged counterparts in affluent, industrial countries, the hunter-gatherers have much healthier-looking profiles (e.g., Eaton et al 1988; Joffe et al 1971).

Researchers also examine the health status of older hunter-gatherers. About 20% of hunter-gatherers live to age 60 or beyond, and these individuals are remarkably free of symptoms of chronic, degenerative diseases (Eaton et al 2002).

Does this mean that we’d all be better off as hunter-gatherers, or that the Paleolithic was a Garden of Eden? Certainly not. As I’ll argue in a future article, life in the Paleolithic wasn’t just shorter--it was undoubtedly much less pleasant than many sentimentalists realize.

But the point here is that eating lots of high-fiber, nutrient-rich plant foods--and trading saturated fats for the “good” fats--has probably played a key role in lowering the risk of chronic, degenerative disease.

More information about nutrition for kids

Not every claim made about the Paleolithic diet is supported by the evidence. And many diets being marketed as "natural" are of questionable value for kids. In fact, some are dangerous.

For more information, check out this critical look at some popular, "natural" diets and their effects on kids.

References: Paleolithic nutrition for kids

Eaton SB, Cordain L, and Lindeberg S. 2002. Evolutionary health promotion: A consideration of common counterarguments. Preventative Medicine 34:119-123.

Eaton SB, Eaton SB III, and Konner MJ. 1999. Paleolithic nutrition revisited. In W. R. Trevathan, E.O. Smith, and J.J. McKenna (eds), Evolutionary Medicine. New York: Oxford University Press.

Foster-Powell K, Holt SH, and Brand-Miller JC. 2002. International table of glycemic index and glycemic load values. Am J Clin Nutr 76:5–56.

Gibbons A. 2009. Of tools and tubers. Science 324 (5927): 588 - 589.

Hoppe C, Mølgaard C, and Michaelsen KF. 2006. Cow's milk and linear growth in industrialized and developing countries. Annu Rev Nutr. 26:131-73.

Patin E, Quintana-Murci L. 2008. Demeter's legacy: rapid changes to our genome imposed by diet. Trends Ecol Evol. 2:56-9.

Perry GH, Dominy NJ, Claw KG, Lee AS, Fiegler H, Redon R, Werner J, Villanea FA, Mountain JL, Misra R, Carter NP, Lee C, and Stone AC. 2007. Diet and the evolution of human salivary amylase gene copy number. Nat. Genet. 39(10): 1256–1260.

Rich-Edwards JW, Ganmaa D, Pollak MN, Nakamoto EK, Kleinman K, Tserendolgor U, Willett WC, and Frazier AL. 2007. Milk consumption and the prepubertal somatotropic axis.Nutrition Journal 6: 28-35.

Sinclair A and O’Dea K. 1993. The significance of arachidonic acid in hunter-gatherer diets: Implications for the contemporary Western diet. Journal of Food Lipids 1: 143-157.

Trichopoulou A, Bamia C, and Trichopoulos D. 2009. Anatomy of health effects of Mediterranean diet: Greek EPIC prospective cohort study. BMJ. 338:b2337.

Content last modified 8/10