Swedish investigators at Karolinska Institutet found diminished weight, body mass index, blood pressure, and waist circumference in 14 healthy medical students eating a paleo diet for three weeks.
Published in 2008, this seems to be one of the seminal scientific studies of the paleo diet in modern Europeans.
Their version of the paleo diet:
- Allowed ad lib: All fresh or frozen fruits, berries and vegetables except legumes, canned tomatoes w/o additives, fresh or frozen unsalted fish and seafood, fresh or frozen unsalted lean meats and minced meat, unsalted nuts (except peanuts – a legume), fresh squeezed lemon or lime juice (as dressing), flaxseed or rapeseed oil (as dressing), coffee and tea (w/o sugar, milk, honey, or cream), all salt-free spices.
- Allowed but with major restrictions: dried fruit, salted seafood, fat meat, potatoes (two medium-sized per day), honey, cured meats
- Prohibited: all milk and dairy products, all grain products (including corn and rice), all legumes, canned food except tomatoes, candy, ice cream, soft drinks, juices, syrups, alcohol, sugar, and salt
What Did They Find After Three Weeks?
- Average weight dropped from 65.2 kg (144 lb) to 62.9 (139 lb)
- Average body mass index fell from 22.2 to 21.4
- Average waist circumference decreased from 74.3 cm (29.25″) to 72.6 cm (28.58″)
- Average systolic blood pressure fell from 110 to 104 mmHg
- plasminogen activator inhibitor-1 decreased from 5.0 kIE/l to 2.8 kIE/l
- All of these changes were statistically significant
The researchers looked at a number of other blood tests and didn’t find any significant differences.
Five men and three women completed the study. Of the 20 who originally signed up, one could not fulfill the diet, three became ill (no details), two failed to show up.
That’s a remarkable weight loss over just three weeks for slender people eating ad lib.
The study authors concluded that these paleo diet-induced changes could reduce risk for cardiovascular disease. They called for a larger study with a control group. (If it’s been done, I haven’t found it yet.)
It’s too soon to say whether the paleo diet is just a fad. It will depend somewhat on short- and long-term health effects of paleo-style eating, which may take years to clarify. On the other hand, it’s hard to imagine large swaths of the population giving up grains, legumes, and dairy products, even if it’s a healthier way of eating.
PS: You’d think they would have said more about the three participants who got sick, rather than leave us wondering if the diet made them ill.
PPS: I’m considering whether the paleo diet is healthy for people with diabetes. Follow my progress at PaleoDiabetic.com.
Reference: Österdahl, M; Kocturk, T; Koochek, A; Wändell, PE. Effects of a short-term intervention with a paleolithic diet in healthy volunteers. European Journal of Clinical Nutrition, 62 (2008): 682-685.