SIMBA project update

I was recently asked to do a small newsletter for the SIMBA project shortly describing the intervention and where we were in the process of getting it started. I thought it would be a good idea to update you as well on the project process.

We have been working hard on getting the ethical approval and on the 16th of September we got the go-ahead. We have just hired Simon, a Ph.D. student, to help out with the practical work on the project. There will be a lot to do with recruitment, running examinations and other practical parts of running a human trial.

The newsletter also contains a short description of the major hypothesis and a bit about the design of the study. Hope you enjoy the news! (continues after the picture)

SIMBA project

SIMBA newsletter

Globally, the incidence of obesity and related metabolic diseases are steeply increasing, and this has major consequences both for individuals as well as the health care system worldwide. This urgently calls for early preventive strategies, but also for treatments targeting the early developing stages of diseases such as metabolic syndrome. The gastrointestinal system and the gut microbiome, in particular, have been proposed as a key target for such interventions. A dysbiotic, or altered, gut microbiome has been associated with increased metabolic and immune disorders in humans, affecting insulin secretion, fat accumulation, energy homeostasis and plasma cholesterol levels and initially manifests as metabolic syndrome, a health condition that places people at a higher risk of cardiovascular diseases, type 2 diabetes and some cancers. Therefore, the gut microbiome may serve as a potential therapeutic target for metabolic syndrome. However, only a few potential candidates for alleviating metabolic syndrome via gut microbiome manipulation have been tested in humans.

This is about to change with the SIMBA project. As part of Work Package 5, a novel, sustainable, fermented plant-based dietary supplement will be tested on humans. The product, developed by our partner FermBiotics, is a fermented canola-seaweed product that is produced via a lactic acid bacteria driven fermentation of canola (rapeseed) and seaweed. The product is rich in glycosinolates and putatively prebiotic oligosaccharides, and it’s projected to have a huge impact on the human gut microbiota, and thereby human health.

The intervention study will be carried out as a double-blinded, placebo-controlled randomized controlled trial using a parallel design, with 100 obese participants consuming 5 grams/day of fermented seaweed and canola, or a rye cereal placebo. The participants will be instructed to maintain their daily routines throughout the six-week study, and thus potential changes would be mediated only by the supplement.

We will study the effects of the fermented canola-seaweed product on glucose handling and related cardiometabolic traits such as dyslipidemia and low-grade systemic inflammation. At each visit, an oral glucose tolerance test will be conducted to investigate insulin sensitivity by measuring 30- and 120-min blood glucose. Moreover, a small number of participants will also be included in a sub-study where they will have blood glucose levels monitored with a 24-hour continuous glucose monitoring for 14 days. We will also measure anthropometry and blood pressure. Finally, we will examine the gut microbiota and the metabolic phenotype of the subjects to explore molecular mechanisms related to the potential improvements.

Recruitment of participants has started in October 2019 and the final participants are expected to finish the trial in March 2020. The study will provide a better understanding of how a sustainable, fermented plant-based dietary supplement could be used as a potential supplement to alleviate obesity-related metabolic disorders in a population at high risk of developing type 2 diabetes and cardiovascular disease. Furthermore, the study will examine whether the product can affect obesity-related metabolic disorders through modulation of the gut microbiota and host metabolome. We expect this study to enhance our insight into useful and valuable interventions for future development of microbiota-based interventions for patients with obesity and related metabolic disorders.

Starting up the Inuit diet intervention study

Grønlandsbilled

Last month I arrived in Nuuk ready to start up our project of examining the Inuit diet.

As you can read in an earlier blog post, we are examining the effect of this diet and how it could potentially be used to prevent the rising type 2 diabetes prevalence among the Greenland Inuit population.

Setting up a trial is always a bit chaotic and stressful since a lot of unknowns needs to come together. We started by sending a bunch of letters to potential participants. This was done manually, so Else, our Greenlandic project employee (it’s hard to find a good name for her position – basically she is essential in all parts of the project from examinations, recruitment to the handling of everyday project related activities) had her work cut out for her.

Next up we went buying foods for the participants. We have a deal with one of the local supermarkets, Brugseni, which has a large selection of both Danish and Inuit foods and who helps us with handing out the foods. Since we did not have enough freezer storage at our examination site this was a huge help leaving one of the logistic unknowns solved. We ended up providing the participants with a wide range of foods. For the traditional Inuit diet, this included a selection of fish (cod, halibut, salmon, trout, etc.), seafood (shrimps) and sea mammals (whale, seal). For the westernized diet we provided a 28-day box with frozen imported meats (incl. beef, lamb, pig, sausages, chicken and cold cuts of meat), various pasta, cereals, and bread (both rye bread and white bread). We went for providing foods for the participants covering around 25% of their daily energy intake and thus the participants need to cover some of the foods themselves. They got a detailed pamphlet on which foods to consume and which foods to avoid when being on the different diets. Luckily the participants were very enthusiastic about the study, especially the traditional Inuit diet.

Indkøb grønland

Mads fisk

One of the traditional ways of living in a hunter-gatherer society is collecting your own food. Fishing is still a big part of society in Greenland and for the period where the participants are encouraged to eat an Inuit diet, they are encouraged to eat locally caught fish. I got to try this out while being on a local boating trip, where our guide asked whether we would like to try to fish. In Denmark, this can be a lengthy process taking hours with very little success. However, our guide assured us that we would, of course, catch something; it would take a maximum of 30 min. I was skeptical, but went along with it, even though I have only tried fishing once or twice. To my amazement, I was able to pick up 8 sizeable codfish and another tourist from the boat trip picked up 9 codfish – all in 30 min. Here you see a picture of me getting it ready for consumption – an amazing dinner – really showing the amazing tastes of the Greenland Inuit cuisine.

Of course, we also need to examine the participants and a special focus for this trial is to test how the diet affects the blood sugar regulation in order to understand whether it can ultimately prevent the participants from developing type 2 diabetes. We do this in multiple ways. First, we examine the participant’s blood sugar when they arrive at the examinations, also called fasting blood sugar. If this is elevated you will have a higher risk of developing type 2 diabetes. Furthermore, we examine their HbA1c or glycated hemoglobin. This is a marker of longer-term average blood glucose levels (8-12 weeks). Hemoglobin is normally what carries oxygen in the blood, however, when hemoglobin is exposed to glucose in the blood, it can also bind glucose and we can measure if the hemoglobin has been exposed to higher levels of glucose over the preceding weeks. To further test how well the participants handle their blood glucose we also do an oral glucose tolerance test. In this test, the participants consume 75 gram of glucose in 150 ml of water within 5 min (yes it’s very sweet!) and then we measure their blood sugar over the next two hours. This tells us something about how well they can handle a large amount of sugar – the better they can do this (with lower blood sugar) the lower the risk of developing type 2 diabetes. One last way we assess their blood sugar regulation in this study is providing the participants with a small glucose monitor, which we place on their upper arm. This can measure their blood sugar continuously for 14 days in a row (!) and provide very detailed data on how their blood sugar is behaving during the two diet periods. Below you can see an example of how it looks when we have measured the blood sugar for 14 days. We hope that this can make us much more knowledgeable about how we can use the diet to regulate blood sugar, something which can be both of importance when preventing but also treating type 2 diabetes. Besides looking into the blood sugar regulation of the participants, we also examine various other markers in their blood such as their cholesterol level and level of inflammation, but that will be a story for another time.

CGM — Here you see the individual glucose measurements (dots) throughout the day with a clear top at breakfast, lunch, and dinner. At the y-axis, you can see glucose concentration and the x-axis shows the time.

For now, the study is up and running and we are looking forward to seeing the first results. However, there is still a lot of work to do and we need to plan for the next two study sites in Qaanaaq (the northwest of Greenland) and in Qasigiannguit in the Disco Bay (west Greenland). Hope you enjoyed the update on the Greenland Inuit diet project and I look forward to writing the next update on the project.

New Project – The Greenland Inuit diet intervention

Nuuk_city_below_Sermitsiaq I’m happy to announce that I’m working on a new project which is centered around a dietary intervention study in Greenland. The overall objective of the study is to investigate a traditional Inuit diet compared to a westernized diet in Greenland Inuit. The reason we are examining this is that the lifestyle of Inuit in Greenland is undergoing a transition from a fisher-hunter society, with a physically active lifestyle and a diet based on the food available from the natural environment, to a westernized society. Parallel to this, a rapid increase in the prevalence of lifestyle diseases such as type 2 diabetes and obesity has been observed[1]. What we are especially interested in is whether switching to a more traditional Inuit diet could improve glycemic control and thus prevent the development of type 2 diabetes.

Studies of Greenland Inuit before the 1980s found a low prevalence of type 2 diabetes compared to Western populations, however, recent population studies in Greenland have found a higher prevalence of pre-diabetes and type 2 diabetes[2,3]. This might in part be explained by the transition in lifestyle, but in addition, a genetic variant increasing the susceptibility to type 2 diabetes have been found to be prevalent in the Greenland Inuit [4], thus further increasing their risk of type 2 diabetes. Therefore, the objective of our study is also to assess whether this gene modifies the effect of following a traditional Inuit diet.

What is a traditional Inuit diet? This is of course hard to examine but multiple studies have tried to assess this in Greenland throughout the last 100 years. They have found that the traditional food of the Greenland Inuit included sea mammals, fish, seafood, and to a lesser degree terrestrial animals and game birds. The sea mammals include walrus, seal meat and blubber, dried whale meat and skin. Fish are local and include halibut, cod, char, salmon and trout, and seafood such as mussels, shrimps, or crab. The terrestrial animals and game birds include lamb, caribou, musk ox, hare, guillemot, eider duck, and eggs from these birds[5–8]. This result is the traditional Inuit diet being higher in fat and protein and lower in carbohydrate compared to a westernized/Danish diet. We have designed the traditional western diet so that it will contain meat from chicken, cow, and pig, as well as having a high amount of cereal products, bread, pasta and rice (carbohydrate).

The study is designed to be a 4-week cross-over intervention study, meaning that each participant has to follow both dietary interventions for 4 weeks in a random order. The study is expected to provide relevant information in relation to whether diet has a role in preventing type 2 diabetes in Greenland and also whether this might be dependent on which genes you have. We have obtained ethical approval for the project and we are currently working on getting all the practical stuff in order so we can begin recruiting participants. The project will start in Nuuk this April, fingers crossed.

The study was initiated by Marit Eika Jørgensen, Lotte Lauritzen and I. The project is a collaboration between researchers at the University of Copenhagen, Steno Diabetes Center Copenhagen, University of Southern Denmark and University of Greenland. It is funded by The Novo Nordisk Foundation who plays no role in the design, methods, data management and analysis or in the decision to publish the results of the study.

References

[1] Hansen JC, Deutch B, Odland JØ. Dietary transition and contaminants in the Arctic: emphasis on Greenland. Int J Circumpolar Health 2008;67:1–98. doi:10.1080/22423982.2007.11864604.

[2] Jørgensen ME, Bjeregaard P, Borch-Johnsen K. Diabetes and impaired glucose tolerance among the inuit population of Greenland. Diabetes Care 2002;25:1766–71.

[3] Jørgensen ME, Borch-Johnsen K, Witte DR, et al. Diabetes in Greenland and its relationship with urbanization. Diabet Med 2012;29:755–60. doi:10.1111/j.1464-5491.2011.03527.x.

[4] Moltke I, Grarup N, Jørgensen ME, et al. A common Greenlandic TBC1D4 variant confers muscle insulin resistance and type 2 diabetes. Nature 2014;512:190–3. doi:10.1038/nature13425.

[5] Bjerregaard P, Jeppesen C. Inuit dietary patterns in modern Greenland. Int J Circumpolar Health 2010;69:13–24.

[6] Deutch B, Dyerberg J, Pedersen HS, et al. Traditional and modern Greenlandic food — Dietary composition, nutrients and contaminants. Sci Total Environ 2007;384:106–19. doi:10.1016/j.scitotenv.2007.05.042.

[7] Bang HO, Dyerberg J, Hjøorne N. The composition of food consumed by Greenland Eskimos. Acta Med Scand 1976;200:69–73.

[8] Jeppesen C, Bjerregaard P, Jørgensen ME. Dietary patterns in Greenland and their relationship with type 2 diabetes mellitus and glucose intolerance. Public Health Nutr 2014;17:462–70. doi:10.1017/S136898001300013X.

Should you take folate supplements to reduce the risk of type 2 diabetes?

diabetes folate folic acid

I recently published an article in the American Journal of Clinical Nutrition[1], which is kind of a big deal for me since this is one of the first articles where I really feel ownership of the idea. One of my main research interests and what I also did my PhD work on is one-carbon metabolism (yes, nerd alert big time). Basically, this is a pathway centered around folate designed to transfer carbon units for all kinds of biological processes, so if things go wrong here it has a major impact on the whole system. This is partly why inhibitors (blockers) of this pathway are widely used as antibiotics and chemotherapeutics[2]. I could (and probably will) write multiple blog posts on this fascinating and complex biological system, but for now, I will tell you a bit more about the new study.

Actually, this study began with me doing the literature review for my PhD thesis where I wanted to cover pretty much all intervention studies with nutrients related to one-carbon metabolism (I soon realized that this was impossible in the timeframe I had, but did a fair job and ended up with 539 references)[3]. I did cover quite a lot of folate studies and thought that it was strange that no one had noticed the marked decreases in insulin resistance (Insulin and HOMA-IR) values, so I asked my supervisor how hard it was to do a meta-analysis of them. “Easy”, she replied; should have known better. All of the work started in spring 2016 and has finally been published in the American Journal of Clinical Nutrition – almost 3 years later. This tells you something about the speed of science sometimes. Of course, I did not do all the work by myself and have to give a big shout out to especially the last author Jane for providing some much-needed structure and a more clinical angle on the discussion.

The findings in the study were quite interesting as we found that folate supplementation lowered fasting insulin and HOMA-IR indicating that subjects taking folate were less insulin resistant (better of) compared to a control (placebo) group. Another funny finding was that changes in homocysteine were linked to clear changes in both fasting glucose and glycated hemoglobin (HbA1c), and also tended to be associated with changes in insulin and HOMA-IR. Homocysteine is a molecule that is linked with detrimental health outcomes (here insulin resistance), and homocysteine is lowered by folic acid supplementation, which is hypothesized to be a benefit for health. So long story short, we found that the more you can lower homocysteine the larger improvements we see on insulin resistance. This would normally mean that we would also lower the risk of type 2 diabetes… However, we did not find many studies examining the effect on type 2 diabetes (only 2) and overall this did not show marked effects on risk – probably due to the limited number of studies and the modest (if any) effect. Disappointing… That would have been a really good story.

So, should you then take an extra vitamin pill with folic acid to prevent type 2 diabetes? Well, no. First of all the improvements in insulin resistance was not translated into a clear reduction in risk of type 2 diabetes. Meaning that we cannot see clear effects on the disease we were hypothesizing to prevent. Furthermore, there are some concerns around potential increased risk of cancer and thus uncritically supplementing with folate cannot at present be recommended[4](https://hawcproject.org/assessment/public/). However, our results are still interesting since there might be some remarkable prospects for people already at high risk of developing type 2 diabetes or have type 2 diabetes, with regards to cardiovascular risk (stroke). One very large study has shown that for people with high plasma glucose values or diabetes have a marked reduction (34%) in stroke risk when receiving folic acid[5]. This link between folic acid, type 2 diabetes, and stroke might explain some of the large differences earlier studies of folic acid supplementation found with regards to CVD risk reduction. Thus, as always, more research is needed. Moreover, folate is just one of the components of one-carbon metabolism and the balance/optimal functioning of this pathway depends upon a number of nutrients including other B-vitamins such as B₁₂[6]. And this is what I spend much of my research time on and untangling this complex link between folate and disease is probably going to keep me busy for a while…

References

[1] Lind MV, Lauritzen L, Kristensen M, et al. Effect of folate supplementation on insulin sensitivity and type 2 diabetes: a meta-analysis of randomized controlled trials. Am J Clin Nutr 2019. doi:10.1093/ajcn/nqy234.

[2] Ducker GS, Rabinowitz JD. One-Carbon Metabolism in Health and Disease. Cell Metab 2017;25:27–42. doi:10.1016/j.cmet.2016.08.009.

[3] Lind MV. The role of diet in one-carbon metabolism and epigenetics, a metabolic syndrome perspective. University of Copenhagen, Faculty of Science, Department of Nutrition, Exercise and Sports, 2016. PhD thesis.

[4] House AA, Eliasziw M, Cattran DC, et al. Effect of B-Vitamin Therapy on Progression of Diabetic Nephropathy. JAMA 2010;303:1603. doi:10.1001/jama.2010.490.

[5] Xu RB, Kong X, Xu BP, et al. Longitudinal association between fasting blood glucose concentrations and first stroke in hypertensive adults in China: effect of folic acid intervention. Am J Clin Nutr 2017;105:564–70. doi:10.3945/ajcn.116.145656.

[6] Paul L, Selhub J. Interaction between excess folate and low vitamin B12 status. Mol Aspects Med 2017;53:43–7. doi:10.1016/j.mam.2016.11.004.

Measuring diet without asking – can we rely on biomarkers as our only source of information?

biomarkers as diet measurement

Recently I was asked if I would do a short article for the magazine BestPractice – general practitioners in Denmark mostly read it. I was going to cover a subject called dietary biomarkers and risk of type 2 diabetes which I found quite remarkable that general practitioners could find interesting. Anyway, I chose to accept the challenge and tried to cover this with an example of our own research where we did an assessment of dietary intake without relying on people to report their diet – How you ask? (Or at least I hope the general practitioners ask that and don’t turn the page thinking that this is anything but interesting!)

Well, this was based on an article I co-authored with my former supervisor and good colleagues at Chalmers University of Technology and University of Gothenburg, Sweden. Otto (the first author) deserves most of the credit for this one since he developed the awesome method used for analysis of the samples, as well as did a lot of statistics work and writing to make this happen. The study was published in American Journal of Clinical Nutrition (2017) and was called “Biomarkers of food intake and nutrient status are associated with glucose tolerance status and development of type 2 diabetes in older Swedish women” (link to the original study)[1].

The idea was that we had a cohort of 64-year-old women who only had blood samples taken, with no dietary assessment. Could we really find out what they ate simply using biomarkers in a blood sample?

What is a biomarker?

Well, it can be almost any type of molecule, which is related to the body that reflects some kind of biological condition or state. For example, anything you can measure in blood, urine, faecal, saliva, hair, adipose tissue, semen, teardrop, nose drip, earwax or other biological fluid or tissue you can get your hands on (and who doesn’t like to get their hands on lots and lots of earwax?)[2]. Sometimes people even use the term on other bodily measurements such as waist circumference, limp length or other more exotic anthropometric measurements as biomarkers [3]. However, most often it is a biological molecule found in body fluid or tissue.

In our case, we measured a wide range of molecules present in a blood sample to try to assess markers related to dietary intake using a really cool method on a very expensive machine[4]. E.g., we tried to assess whether you ate a lot of whole grain, fish, meat or bananas from a blood sample (unfortunately, we were not able to cover the last one otherwise you would have already heard about it in some newspaper or blog stating: “Bananas cure diabetes”).

So, what did we find? Well, if I simplify the findings a bit we found that markers of beef intake (β-alanine) were higher in women with type 2 diabetes and impaired glucose tolerance (on the way to type 2 diabetes) while markers of wholegrain wheat and rye (alkylresorcinols), as well as fatty fish (eicosapentaenoic acid, EPA) and vitamin E status (α-tocopherol), were lower. We also found that a higher fish intake (3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, CMPF) and vitamin E status (α-tocopherol) were associated with a lower risk of developing type 2 diabetes over a 5-year period.

So, can we rely on biomarkers as our only source of information for dietary assessment? Well, in my honest opinion, no, at least not yet. There is great potential in using such advanced methods for gathering complex biomarker information regarding dietary intake [5](shamelessly citing myself), but for now the current methods do not cover enough dietary markers to cover the entire diet sufficiently. Furthermore, there are other limitations and barriers to overcome related to how far back they cover dietary intake or how specific such markers can be… But that will be the topic for another blog post 😉 Thank you for reading along – feel free to leave a comment.

References

[1] Savolainen O, Lind MV, Bergström G, et al. Biomarkers of food intake and nutrient status are associated with glucose tolerance status and development of type 2 diabetes in older Swedish women. Am J Clin Nutr 2017;106. doi:10.3945/ajcn.117.152850.

[2] Biomarkers Definitions Working Group. Biomarkers and surrogate endpoints: Preferred definitions and conceptual framework. Clin Pharmacol Ther 2001;69:89–95. doi:10.1067/mcp.2001.113989.

[3] Gunnell D. Commentary: Can adult anthropometry be used as a ‘biomarker’ for prenatal and childhood exposures? Int J Epidemiol 2002;31:390–4. doi:10.1093/ije/31.2.390.

[4] Savolainen OI, Sandberg A-S, Ross AB. A Simultaneous Metabolic Profiling and Quantitative Multimetabolite Metabolomic Method for Human Plasma Using Gas-Chromatography Tandem Mass Spectrometry. J Proteome Res 2015. doi:10.1021/acs.jproteome.5b00790.

[5] Lind MV, Savolainen OI, Ross AB. The use of mass spectrometry for analysing metabolite biomarkers in epidemiology: methodological and statistical considerations for application to large numbers of biological samples. Eur J Epidemiol 2016;31. doi:10.1007/s10654-016-0166-2.