New paper explores the fascinating history of research into the Eskimo diet.
The Eskimo diet and its effect on the heart has been a source of confusion and contention for decades. The observation that Eskimos, who traditionally consumed large amounts of saturated fat and small amounts of carbohydrates, had low rates of heart disease appeared to contradict the orthodox view that saturated fat was a major cause of heart disease. More recently new reports suggested that Eskimos did not have low rates of heart disease, thus confounding a newer emerging view that favors fats, including saturated fats, over carbohydrates.
Now one researcher who has been assiduously working to defend the low carbohydrate hypothesis has gone back and reexamined the Eskimo studies and discovered evidence for a dramatic shift in the Eskimo diet that offers a coherent explanation for the confusing stories.
In a short paper published in Open Heart James DiNicolantonio argues that there has been a large shift away from the traditional Eskimo diet containing high amounts of fatty fish and toward a modern western diet containing far more refined carbohydrates and sugar. This shift, he argues, explains the more recent reports showing higher rates of heart disease than had been earlier reported.
In one study from the late 1940s cited by DiNicolantonio, Eskimos in Greenland had a rate of heart disease that was four times lower than a comparable group in Finland. Other studies showed that carbohydrate consumption increased from a minuscule proportion of 2-8% in the traditional diet to 40% by the 1970s. Several other studies also recorded very large amounts of carbohydrates in the Eskimo population as the more modern diet became prevalent. It is these changes, argues DiNicolantonio, that explains the observed high rate of heart disease in modern Eskimos. “The rise in sugar intake paralleled the rise in heart disease in the Greenland Eskimo,” said DiNicolantonio in an email statement.
Several experts supported the study findings as reasonable but cautioned against giving it too much significance. Andrew Mente (McMaster University) pointed out that even “if we accept that conclusion, it does not necessarily mean that increased carbohydrate intake caused the increase in atherosclerosis rates, since these are time trend data and can only suggest possible links between diet and health outcomes that need to be studied in more rigorous studies with both diet and health outcomes assessed in individuals.”
Mente said it makes sense to believe “that increased carbohydrates are probably the cause of higher atherosclerosis, as it is consistent with other native populations (eg, Pima Indians, Sandy Lake community in Ontario) being prone to diabetes and CVD via high carb intake.”
James Stein (University of Wisconsin) said the study was “fun and interesting” but that it is difficult to “draw any conclusions from these types of observations.” He noted that the Eskimos in Greenland differ from people in the US in a multitude of ways. He cited genetics, air quality, soil quality, levels of activity, coexisting diseases, and diet among others. Further, interpretation of the study is limited by the changes in these and other factors over time. The study has “no real implications for public policy,” he concluded.