Tuesday, March 2, 2010

A low GI (glycemic index) and high MUFA Mediterranean diet performed better (for HDL and glycemia) than traditional Med or ADA diet

This post does not have much in the way of personal genetics but is not completely unrelated. If personal genetics is going to work then it will have to involve lifestyle changes especially diet, not just for weight loss but for health. As far as obesity is concerned there have been plenty of GWAS and many genes associated, hopefully the results will be be useful for understanding mechanisms because a gene panel for predicting obesity does not seem to be terribly useful right now, it’s one of the phenotypic traits that most people are aware of without any genetic testing. One much sought after goal though is to use genetics to predict what sort of weight loss diet will be most effective – there are some tantalising studies and there is one company, Interleukin Genetics, that recently introduced a weight loss panel. They claim to be able to select the best diet but until they actually publish their work that they refer to we cannot judge. For now the only weight loss use of nutrigenetics that has been published is a small study from our group (open access in Nutrition Journal) – here the genetics was used to “optimise” the diet rather than actually choose which type. Maybe this is where nutrigenetics can help, as a sort of “meta-diet”, whatever you are trying to do to lose weight, you are probably eating fewer calories so it’s important that those calories contain all the nutrients that you need.

Anyway, back to the subject of this post – an interesting paper comparing 3 types of diet: a traditional Mediterranean diet (MED), what they call low carb med diet (LCM) which I think is better described as a low GI/high MUFA diet, and the ADA diet (American Dietetic Association). The study involved 259 patients over 12 months

The diets:


Carbs
Fats
Protein
Fibre
ADA
50-55 %
30 %
20 %
15 g
MED
50-55 %  (Low GI)
30 %
(high level MUFA)
15-20 %
30 g
LCM
35 %
(Low GI)

45 %
(high level MUFA)
15-20 %
30 g

The best results for weight loss we with the LCM:
LCM = 10.1 kg
MED = 7.4 kg
ADA = 7.7 kg

Reduction of HbA1C (a measure of glucose control) was greater in LCM:
LCM = - 2,0 %
MED = -1.8 %
ADA = -1.6 %

Serum TG reduction:
LCM = -1.52 mmol/l
TM =  -1.46
ADA =  -0.88

Finally HDL was raised only on the LCM diet (from 1.08 to 1.21 mmol/l)


In general the Mediterranean diet results were better and in particular the med diet with low GI and high MUFA was the best – it’s important to note the levels of MUFA, it’s not simply a “low-carb” Med diet, but the carbs were replaced mainly with one type of fat, MUFA (as in olive oil) and probably a better term (less catchy of course) would be the High MUFA Mediterranean diet:


MUFA
PUFA
Grassi saturi
ADA
10 % di grassi
12 % di grassi
7 %
MED
10 % di grassi
12% di grassi
7 %
LCM
23 % di grassi
15 % di grassi
7 %



Diabetes Obes Metab. 2010 Mar;12(3):204-9
A low carbohydrate Mediterranean diet improves cardiovascular risk factors and diabetes control among overweight patients with type 2 diabetes mellitus. A one-year prospective randomized intervention study
A. Elhayany 1,2 , A. Lustman 2,3 , R. Abel 2 , J. Attal-Singer 4,5 , S. Vinker 2,3
1 Meir Hospital, Kfar Saba, Israel 44821 2 Department of Family Medicine, Central District Clalit Health Services, Rishon Le Zion, Israel 3 Department of Family Medicine, Tel Aviv University, Tel Aviv, Israel 45 The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel Endocrinology Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva Israel

KEYWORDS Diabetes mellitus • cardiovascular risk • Mediterranean diet • dietary intervention

ABSTRACT

Background: The appropriate dietary intervention for overweight persons with type 2 diabetes mellitus (DM2) is unclear. Trials comparing the effectiveness of diets are frequently limited by short follow-up times and high dropout rates.

Aim: We compared the effects of a low carbohydrate Mediterranean (LCM), a traditional Mediterranean (TM), and the 2003 American Diabetic Association (ADA) diet, on health parameters during a twelve-month period.

Methods: In this twelve-month trial, we randomly assigned 259 overweight diabetic patients (mean age 55 years, mean body mass index 31.4 kg/m2) to one of the three diets. The primary end-points were reduction of fasting plasma glucose, HbA1c, and triglyceride levels.

Results: 194/259 patients (74.9%) completed follow-up. After 12 months, the mean weight loss for all patients was 8.3kg: 7.7 kg for ADA, 7.4 kg for TM and 10.1 kg for LCM diets. The reduction in HbA1c was significantly greater in the LCM than in the ADA diet (-2.0%, and -1.6%, respectively p<0.022). HDL cholesterol increased (0.1 mmol/l±0.02) only on the LCM (p<0.002). The reduction in serum triglyceride was greater in the LCM (-1.3 mmol/l) and TM (-1.5 mmol/l) than in the ADA (-0.7 mmol/l), p = 0.001.

Conclusions: An intensive 12-month dietary intervention, in a community-based setting was effective in improving most modifiable cardiovascular risk factors in all the dietary groups. Only the LCM improved HDL levels and was superior to both the ADA and TM in improving glycemic control.

1 comment:

  1. I'm glad to hear about this new article in Diabetes, Obesity, and Metabolism.

    I'm trying to devise a low-carb Mediterranean diet for my patients with diabetes. One that doesn't require a comprehensive food diary, calculator, and computer analysis.

    Thus far, I have a 5% carbohydrate Mediterranean diet (Ketogenic Mediterranean Diet). I'll probably expand it to 10-20% energy as carbs, for diabetics who can tolerate that many.

    I look forward to seeing how these researchers did it.

    -Steve

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