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From: Science-based Medicine (by H.Hall)
Staffan Lindeberg is a Swedish researcher who has been studying the inhabitants of Kitava, one of the Troriand Islands of Papua New Guinea. He claims that there has been no occurrence of sudden cardiac death, stroke, and exertion-related chest pain; attributing to the Kitavans eating a ‘Paleolithic diet‘.
In brief, a ‘paleolithic diet or paleo diet’ is the modern interpretation of the diet that humans (our ancestors) ate during the Paleolithic or “Old Stone Age” era. This period was about 2.5 million years ago and refer to foods obtained by hunting and gathering. Such foods include lean meats, fish, fruits, vegetables, nuts and seeds. A paleo diet limits foods that became common when farming emerged about 10,000 years ago such as dairy products, legumes and grains.
The Island of Kitava has a population of 2,250 people and are traditional farmers. Their staples are tubers (yam, sweet potato and taro), fish, fruits, and coconut. The use of dairy products, alcohol, coffee, or tea are non-existent. Oils, margarine, cereals, and sugar intake are negligible. Their activity levels are high and 80% of the population smoke daily and an unspecified number of them chew betelnut. Western foods make up less than 1% of their diet. The macronutrient composition of the Kitavan diet was estimated as 21% of total calories from fat, 17% from saturated fat, 10% from protein, and 69% from carbohydrates.
Lindeberg’s Kitava study examined a sample of 220 Kitavans aged 14-87 and compared them to healthy Swedish populations. They found substantially lower diastolic blood pressure, body mass index, and triceps skinfold thickness in the Kitavans. Systolic blood pressure was lower in Kitava than in Sweden for men over 20 and women over 60. Total cholesterol, Low-Density Lipoproteins (LDL) cholesterol, and apolipoprotein B (the ‘bad cholesterol’) were lower in men over 40 and in women over 60. Triglycerides (or fat) were higher in Kitavans aged 20-39 than in Swedes of the same age. High-Density Lipoproteins (HDL or the “good” cholesterol) was not significantly different.
In another study, researcher Lindeberg examined how the Kitavans’ risk factors changed with age. In the Kitava study, the ages of subjects were not objectively provable, but estimated from whether or not they remembered significant historical events. The absence of heart disease and stroke was presumed by asking islanders if they had never known anyone who had the symptoms of either condition. This was reinforced by subjective reports from doctors who stated that they didn’t see those diseases in islanders. Electrocardiograms (ECGs) were done on the Kitavans, but a normal ECG does not rule out atherosclerosis or cardiovascular disease. Lindeberg remained doubtful due to insufficiency of concrete data to rule out the presence of cardiovascular disease or other so-called “diseases of civilization” in that population.
Supposing those diseases don’t exist in Kitava, what could we determine from that?
Lindeberg thinks it constitutes evidence to support the Paleolithic diet of meat, fish, vegetables, fruit and nuts that our ancestors ate 2,000,000 to 10,000 years BP. Comparisons of what the Western ancestors ate with what the Kitavans ate, the differences with the type of protein (meat or fish), tubers, fruits and nuts influenced occurrences of diseases in these people. He goes on to state that Western ancestors were hunter-gatherers whilst the Kitavans are farmers (to which history indicates agriculture did not develop until around 10,000 BP.
So, what can we learn and/or conclude from the Kitavans eating lifestyle?
Well, the Kitava study serves as a invalidating example to question the claims made for low-carb diets. That is, Kitavans eat a very high-carb diet, with lots of saturated fat and little protein, and they appear to thrive on it without becoming obese or developing a high incidence of metabolic syndrome as the low-carb theorists would predict.
It is evidence against the hypothesis that low-fat diet recommendations caused the obesity “epidemic” simply because people replaced fat with carbohydrates; and that a diet high in carbohydrates does not necessarily lead to obesity. Especially if they are complex carbohydrates and the total calorie intake is not excessive.
It supports the general consensus of most diet experts that:
- a predominately plant-based diet is healthy;
- it backs up Mom’s scolding to eat our vegetables;
- saturated fat need not be avoided, especially if it is of vegetable rather than animal origin;
- its tendency to confirm the health benefits of weight control and the principle that weight can be controlled simply by limiting calories;
- it tends to support advice to avoid processed foods and refined carbohydrates; and
- it reinforces the concept that humans can thrive on a wide variety of diets.