Diabetes

One big issue for which there is as yet no clear answer, is the question of whether it's the intensity or the amount of exercise which is more important.

One study involving 300 obese adults aimed to test this in a 6-month trial comparing those who maintained their usual activity level, those who did a low amount (around 30 minutes) of low-intensity exercise, those who did a high amount (around an hour) of low-intensity exercise, and those who did around 40 minutes of high-intensity exercise. All had five exercise sessions every week.

After 24 weeks of this, all the exercise groups showed smaller mean waist circumference and greater mean weight loss, compared to the control group, but there was no difference between the exercise groups in these measures. However, only the high-high group had lower 2-hour glucose levels than the controls, and only the two groups who did a higher amount of exercise had better insulin sensitivity.

Ross R et al. Effects of exercise amount and intensity on abdominal obesity and glucose tolerance in obese adults: A randomized trial. Ann Intern Med 2015 Mar 3; 162:325. (http://dx.doi.org/10.7326/M14-1189)

A very small Israeli study, involving eight men and 10 women aged 30-70 with type 2 diabetes, has found that a big breakfast and a small dinner helped control blood sugar levels through the day.

Patients were randomly assigned to follow either a “B diet”, in which breakfast contained 2946 kilojoules, lunch 2523 kj, and dinner 858kj, or a “D diet”, which involved a 858 kj breakfast, 2523 kj lunch, and 2946 kj dinner. In other words, the same total amount of calories, in the same foods, was eaten by both groups, and lunch was the same for both, but the 'breakfast' and 'dinner' meals swapped timing.

After six days on the diet, patients ate their meals on the 7^th day at the lab, where glucose levels were repeatedly tested during the day. After a break of two weeks, each patient was put on the alternate diet, and the same procedure was followed.

It was found that blood glucose levels rose 23% less after the lunch preceded by a large breakfast.

http://www.eurekalert.org/pub_releases/2015-03/afot-abo031615.php

Jakubowicz, D., Wainstein, J., Ahrén, B., Bar-Dayan, Y., Landau, Z., Rabinovitz, H. R., & Froy, O. (2015). High-energy breakfast with low-energy dinner decreases overall daily hyperglycaemia in type 2 diabetic patients: a randomised clinical trial. Diabetologia, 58(5), 912–919. http://doi.org/10.1007/s00125-015-3524-9

Mouse and human immune cells have demonstrated that a compound produced by the body when dieting or fasting (β-hydroxybutyrate — BHB) directly inhibits a protein, NLRP3, which is part of a complex set of proteins that drive the inflammatory response in several disorders, including autoimmune diseases, type 2 diabetes, Alzheimer's disease, atherosclerosis, and autoinflammatory disorders.

BHB is produced in response to fasting, high-intensity exercise, caloric restriction, or consumption of the low-carbohydrate ketogenic diet.

The finding helps explain why calorie restriction reduces inflammation.

http://www.eurekalert.org/pub_releases/2015-02/yu-amo021315.php

Youm, Y.-H., Nguyen, K. Y., Grant, R. W., Goldberg, E. L., Bodogai, M., Kim, D., … Dixit, V. D. (2015). The ketone metabolite β-hydroxybutyrate blocks NLRP3 inflammasome-mediated inflammatory disease. Nature Medicine, 21(3), 263–269. http://doi.org/10.1038/nm.3804

Studies have found that low levels of magnesium increases the chance that you will develop type 2 diabetes, but a large study shows that this association is modified by genetic variations in magnesium-related ion channel genes. So, for example, among Hispanic American women with high magnesium intake, those with one particular variant had a 35% lower risk of developing type 2 diabetes.

The study involved 7,287 black women and 3,285 Hispanic women aged 50-79.

http://www.eurekalert.org/pub_releases/2015-01/bu-t2d010715.php

http://www.futurity.org/diabetes-magnesium-833412/

Chan, K. H. K., Chacko, S. A., Song, Y., Cho, M., Eaton, C. B., Wu, W.-C. H., & Liu, S. (2015). Genetic Variations in Magnesium-Related Ion Channels May Affect Diabetes Risk among African American and Hispanic American Women. The Journal of Nutrition, 145(3), 418–424. http://doi.org/10.3945/jn.114.203489

A trial in which 163 overweight adults with elevated blood pressure were given one of four complete diets that contained all their food for five weeks has found that a low glycemic diet did not improve insulin sensitivity, lipid levels or blood pressure. But it's important to note than all diets were based on a healthful DASH-type diet, varying only in their glycemic index and carbohydrate proportions.

So, the trial found that a healthy diet with low–glycemic index carbohydrate-containing foods didn't improve insulin sensitivity, HDL cholesterol levels, LDL cholesterol levels, or systolic blood pressure any more than the healthy diet with high–glycemic index foods It did reduce plasma triglyceride levels slightly more.

In fact, the low–glycemic index with high-carbohydrate diet was worse than the high–glycemic index, high-carbohydrate diet — decreasing insulin sensitivity and increasing LDL cholesterol and LDL apolipoprotein B levels. This finding was unexpected and inconsistent with other research. However, a meta-analysis of 28 trials found that lowering glycemic index did not affect HDL cholesterol or triglyceride levels and lowered LDL cholesterol level only if fiber content was also increased.

In line with the researchers' previous findings, the DASH diet had slightly better effects when its carbohydrate content was reduced. When the same calories were instead supplied by unsaturated fat and protein, triglycerides and VLDL levels were substantially lowered and diastolic blood pressure slightly lowered.

As in previous trials, all the DASH-type diets lowered blood pressure and LDL cholesterol levels.

Previous research has shown inconsistent results on whether low glycemic index helped people lose weight.

http://www.eurekalert.org/pub_releases/2014-12/bawh-lgd121614.php

Sacks FM, Carey VJ, Anderson CM, et al. Effects of High vs Low Glycemic Index of Dietary Carbohydrate on Cardiovascular Disease Risk Factors and Insulin Sensitivity: The OmniCarb Randomized Clinical Trial. JAMA. 2014;312(23):2531-2541. doi:10.1001/jama.2014.16658.

Goff  LM, Cowland  DE, Hooper  L, Frost  GS.  Low glycaemic index diets and blood lipids: a systematic review and meta-analysis of randomised controlled trials. Nutr Metab Cardiovasc Dis. 2013;23(1):1-10.

Anecdotal and scientific evidence suggests curcumin, a compound found in turmeric, promotes health because it lowers inflammation. However, it is not absorbed well by the body. Most curcumin in food or supplements stays in the gastrointestinal tract, and any portion that's absorbed is metabolized quickly.

A new study thinks they've come up with a better and more effective way to deliver curcumin, and in so doing has demonstrated how it works. Curcumin powder was mixed with castor oil and polyethylene glycol, allowing it to dissolve and be more easily absorbed by the gut to enter the bloodstream and tissues.

When this was given to mice who had been injected with an extract that stimulates an immune reaction, a key protein that triggers an immune response was blocked. The mice given plain curcumin, on the other hand, showed the same protein actively triggering an immune response.

The emulsified curcumin also stopped recruitment of macrophages. Inflammation triggered by overactive macrophages has been linked to cardiovascular disease, disorders that accompany obesity, Crohn's disease, rheumatoid arthritis, inflammatory bowel disease, diabetes and lupus-related nephritis.

http://www.eurekalert.org/pub_releases/2014-11/osu-nra110614.php

A review of studies investigating lifestyle interventions that can delay or prevent the onset of type 2 diabetes in people with prediabetes and focusing specifically on ones that looked at gender differences, found that both men and women benefited equally from the interventions. The review of 12 studies found that those who received lifestyle interventions (including diet and exercise) were 40% less likely to progress to type 2 diabetes after 1 year, and 37% less likely to progress after 3 years.

People involved in lifestyle interventions also experienced greater weight reductions, and greater reductions of fasting plasma glucose.

http://www.eurekalert.org/pub_releases/2014-11/d-bit112614.php

Glechner, A., Harreiter, J., Gartlehner, G., Rohleder, S., Kautzky, A., Tuomilehto, J., … Kautzky-Willer, A. (2014). Sex-specific differences in diabetes prevention: a systematic review and meta-analysis. Diabetologia, 58(2), 242–254. http://doi.org/10.1007/s00125-014-3439-x

A new class of lipids produced in human and mouse fat has been discovered, and these ones seem to be good for you. Following the discovery that diabetes-resistant mice had dramatically higher levels of these “fatty acid hydroxy fatty acids (FAHFAs)”, levels were found to be low in pre-diabetic humans. Moreover, when mice with the equivalent of type 2 diabetes were given this lipid, blood sugar levels dropped and insulin levels rose. FAHFAs also seem to reduce inflammation.

FAHFAS are found in low levels in a wide range of vegetables, fruits and other foods, as well as being (unlike omega-3 fatty acids) produced and broken down inside the body.

http://www.eurekalert.org/pub_releases/2014-10/si-sda100814.php

Yore, M. M., Syed, I., Moraes-Vieira, P. M., Zhang, T., Herman, M. A., Homan, E. A., … Kahn, B. B. (2014). Discovery of a Class of Endogenous Mammalian Lipids with Anti-Diabetic and Anti-inflammatory Effects. Cell, 159(2), 318–332. http://doi.org/10.1016/j.cell.2014.09.035

Data collected from more than 5,300 employed Germans aged 29-66 has revealed that, over 13 years, 291 developed type 2 diabetes. Those who were under a high level of pressure at work and also perceived themselves as having little control over their activities had about a 45% higher risk of developing type 2 diabetes than those subjected to less workplace stress.

http://www.eurekalert.org/pub_releases/2014-08/hzm--wsi080814.php

Huth, C. et al. (2014), Job Strain as a Risk Factor for the Onset of Type 2 Diabetes Mellitus: Findings From the MONICA/KORA Augsburg Cohort Study, Psychosomatic Medicine, 10.1097/PSY.0000000000000084

Using data from about 600 000 adults over 26 years, researchers have concluded that the lifetime risk of developing type 2 diabetes for the average American 20-year-old rose from 20% for men and 27% for women in 1985, to 40% for men and 39% for women in 2000. The largest increases were in Hispanic men and women, and non-Hispanic black women, for whom lifetime risk now exceeds 50%.

http://www.eurekalert.org/pub_releases/2014-08/tl-tld081214.php

Gregg, E. W., Zhuo, X., Cheng, Y. J., Albright, A. L., Narayan, K. M. V., & Thompson, T. J. (2014). Trends in lifetime risk and years of life lost due to diabetes in the USA, 1985–2011: a modelling study. The Lancet Diabetes & Endocrinology, 2(11), 867–874. http://doi.org/10.1016/S2213-8587(14)70161-5