Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes
U Masharani, P Sherchan, M Schloetter, S Stratford, A Xiao, A Sebastian, M Nolte Kennedy and L Frassetto
Why Frassetto Paleo?
The first thing I do when I see a new paleo diet study is try to find out WHAT the diet actually was. So even before I got the full text, I saw the "group" author and the description of the ramped up diets and knew it was her brand of paleo. Here's a summary from this post, which has links to individual posts I've done on the other various studies.
As you can see, Frassetto stands out because they are high calorie (weight maintaining), and thus relatively high carb. Her version would also qualify as "low fat" and exceeds (as in lower than) current sat fat reductions from the AHA for those with heart disease. I blogged on what appears to be the same diet used in a 10 day 2009 study here. The study: Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. This first diet was done in only 9 healthy sedentary folks. Again, there are details in my post, but to save a trip about the web, and because the diets aren't detailed in this current study, but the ramp up protocol sounds identical, I include the screenshot below.
Synopsis of Current Study in Diabetics
Subjects: n = 24 Obese, Type 2 Diabetics
- The self-identified races were: 15 (62.5%) White and 3 (12.5%) each African American, Asian and Hispanic. No information provided as to the racial distribution between groups.
- Gender: Unspecified ??!! Say what?
There is no information provided as to the distribution of these subjects between groups. Doses were maintained throughout trial, any supplements stopped at recruitment.
- Diabetes: 4 on no medications , 14 on metformin only , 5 on metformin + sulfonylurea , and 1 on sulphonylurea + long acting once daily insulin.
- Other: 9 subjects on a statin, 2 on statins + fibrates, and 11 on various BP lowering drugs
All meals/snacks provided in outpatient setting, some eaten at the center, the rest packaged for take out. Calories were calculated for individual weight maintaining needs and adjusted if weight fluctuated. Macros below.
Also, sodium was very low for paleo vs. ADA (< 70 mg v. ~ 4g), potassium was much higher for paleo vs. ADA (~3300 v. ~300 mg - I'm assuming there's a typo there as these values are reversed but Frassetto paleo *is* high potassium hence the ramp up diets), and calcium is listed as ~900 mg for paleo vs ~1900 for ADA.
This is a high carb diet with roughly 400 grams carb per day. Looking at the menus from the previous study, and the protein differentials, one can presume more honey, fruit, tomato soup, etc. make for the difference.
"Baseline data ... were collected while patients were on their usual diets (days -2 to 0). Then, subjects were randomized either to the Paleo diet or to the ADA diet. There were three ramp-up diets for 7 days, then 14 days of the test diet. All the initial tests were repeated atdays 19 to 21."
"Ramp 1 diet was 1 day, ramp 2 for 3 days and ramp 3 for 3 days and then the Paleo diets were eaten for the remainder of the study. There was no ramp up for the ADA diet."
- The Paleo Diet actually lasted 3 weeks -- One week with 3 ramp up diets, and two weeks intervention.
- ADA Diet was 3 weeks (apparently)
Study Results from Study Abstract
Both groups had improvements in metabolic measures, but the Paleo diet group had greater benefits on glucose control and lipid profiles. Also, on the Paleo diet, the most insulin-resistant subjects had a significant improvement in insulin sensitivity (r=0.40, P=0.02), but no such effect was seen in the most insulin-resistant subjects on the ADA diet (r=0.39, P=0.3).Conclusions:
Even short-term consumption of a Paleolithic-type diet improved glucose control and lipid profiles in people with type 2 diabetes compared with a conventional diet containing moderate salt intake, low-fat dairy, whole grains and legumes.
The Actual Study Results
The table of statistically significant changes between groups is shown below.
OK ... and now for the results
|Adapted from Table 3 to focus on just between group comparison|
Only the change in fructosamine flirts with statistical significance in the between group comparison. This statement -- "the Paleo diet group had greater benefits on glucose control and lipid profiles" -- should never have made it past peer review. Shame on you European Journal of Clinical Nutrition.
This is the full table. The change in IS for the Paleo diet group was not statistically significant (p = 0.09 ... vs. p = 0.1 for ADA) so this correlation seems meaningless to me. Meanwhile, when between group tests showed no differences, the authors resort to the following:
We observed greater effects on metabolic parameters while on the Paleo diet than on the ADA diet just after 3 weeks. The Paleo diet group had improvement in glucose levels—declines in HbA1c of 0.3% (P = 0.04) and fructosamine by 34 μmol/l (P = 0.009). The ADA group had a 0.2% drop in HbA1c (P = 0.04) but no decline in fructosamine. ...
... The Paleo diet group had statistically significant declines in total cholesterol, HDL cholesterol and calculated LDL cholesterol. The triglycerides trended down but did not reach statistical significance. In contrast, the ADA group only had a decline in HDL cholesterol but not in total cholesterol, calculated LDL cholesterol or triglycerides.
Conclusions, For Now:
I'll definitely be publishing up a Part II in a few days at most (it's mostly written, but waiting on one section so I thought to split it up). But some bullet points, some of which are to be expanded upon:
- Three week dietary trials are pretty meaningless unless they are acute interventions for acute conditions.
- As has been mentioned, back in 2009, Frassetto's group conducted a small uncontrolled study on the paleo diet. The results in that (even shorter) trial could not be attributed to the diet alone. So this time they did an RCT ... and then they threw that out, because there was no statistically significant difference in the outcomes between paleo and the ADA diet.
- This paleo diet is unlike even most of the other diets in paleo clinical trials
- The paleo diet in this study differed even from that in the previous trial
- The diet controlled for macro ratios and that's about it, there were too many other factors that were not controlled for or differed (often in unknown ways) that pretty much nullify the results.
But in well controlled diabetics, providing foods so that they actually followed what turned out to be a somewhat hypocaloric diet, over 400 grams of carbohydrate per day for three weeks led to reductions in HbA1c over a three week period. This reduction, within each diet group, was statistically significant.