Oat and oatmeal studies

Wolever TMS, Jenkins AL, Prudence K, Johnson J, Duss R, Chu Y, Steinert RE. Effect of adding oat bran to instant oatmeal on glycaemic response in humans - a study to establish the minimum effective dose of oat β-glucan. Food Funct. 2018 Mar 1;9(3):1692-1700. doi: 10.1039/c7fo01768e. Epub 2018 Feb 26. PMID: 29480316.

Abstract. Reducing the glycaemic response to carbohydrate-containing foods may have desirable physiological effects for many people. Here, we aimed to determine the minimum amount of oat β-glucan from oat-bran which, when added to instant-oatmeal, would reduce the glycaemic response by 20% compared to a β-glucan-free cereal. Therefore, the glycaemic responses elicited by one serving (27 g) instant-oatmeal plus 247 g 2% milk (IO, 28 g available-carbohydrate, 1.2 g β-glucan) or IO plus 0.2, 0.4, 0.8 or 1.6 g oat β-glucan (OBG) from oat-bran, or an available-carbohydrate matched portion of cream of rice (CR) plus milk were measured over 2 h in n = 40 subjects using a randomized, cross-over design. The primary endpoint was incremental area under the curve (iAUC). The secondary endpoint was glucose peak-rise. The results showed that grams OBG consumed were significantly correlated with mean iAUC (p = 0.009) and with mean glucose peak-rise (p = 0.002). Each gram of OBG reduced iAUC by 7% and peak-rise by 15%. Thus, to achieve a ≥20% reduction in iAUC relative to CR, 1.6 g OBG had to be added to IO (74 ± 7 vs. 93 ± 6 mmol min L-1, p < 0.05), but, to achieve a 20% reduction in peak-rise, only 0.4 g OBG was required (2.00 ± 0.1 vs. 2.40 ± 0.1 mmol, p < 0.05). We conclude that adding OBG to IO flattened postprandial glycaemic responses in a dose-dependent fashion; 1.6 g OBG was required to reduce iAUC by ≥20% versus CR, but a 20% reduction in peak-rise required only 0.4 g. The greater effect of OGB on peak-rise than iAUC presumably reflects the way viscous dietary fibres modulate glucose absorption kinetics.

Kim SH, Kim KJ, Kang HJ, Son YJ, Choi SW, Lee MJ. The Dual Role of Oat Bran Water Extract in Bone Homeostasis Through the Regulation of Osteoclastogenesis and Osteoblast Differentiation. Molecules. 2018 Nov 28;23(12):3119. doi: 10.3390/molecules23123119. 

Abstract. The number of patients with bone metabolic disorders including osteoporosis is increasing worldwide. These disorders often facilitate bone fractures, which seriously impact the patient's quality of life and could lead to further health complications. Bone homeostasis is tightly regulated to balance bone resorption and formation. However, many anti-osteoporotic agents are broadly categorized as either bone forming or anti-resorptive, and their therapeutic use is often limited due to unwanted side effects. Therefore, safe and effective therapeutic agents are needed for osteoporosis. This study aims to clarify the bone protecting effects of oat bran water extract (OBWE) and its mode of action. OBWE inhibited RANKL (receptor activator of nuclear factor-κB ligand)-induced osteoclast differentiation by blocking c-Fos/NFATc1 through the alteration of I-κB. Furthermore, we found that OBWE enhanced BMP-2-stimulated osteoblast differentiation by the induction of Runx2 via Smad signaling molecules. In addition, the anti-osteoporotic activity of OBWE was also evaluated using an in vivo model. OBWE significantly restored ovariectomy-induced bone loss. These in vitro and in vivo results showed that OBWE has the potential to prevent and treat bone metabolic disorders including osteoporosis.

Wu W, Tang Y, Yang J, Idehen E, Sang S. Avenanthramide Aglycones and Glucosides in Oat Bran: Chemical Profile, Levels in Commercial Oat Products, and Cytotoxicity to Human Colon Cancer Cells. J Agric Food Chem. 2018 Aug 1;66(30):8005-8014. doi: 10.1021/acs.jafc.8b02767. 

Abstract. Avenanthramides (AVAs), unique phytochemicals in oat, have attracted an increasing amount of attention due to their outstanding health benefits. However, the chemical profile and the levels of AVAs in commercial oat products as well as their health benefits have not been examined in detail. In the present study, a total of 29 AVA aglycones and AVA glucosides were identified and characterized from oat bran using NMR (1D and 2D NMR) and LC-MS techniques. Among them, 17 novel AVA glucosides were reported in oat bran for the first time. The most abundant AVA glucoside, 2c-3'- O-glc, had a similar growth inhibitory activity with the major AVA, 2c, against HCT-116 and HT-29 human colon cancer cells, indicating glucosylation does not affect the growth inhibitory effects of AVAs. Furthermore, the levels of all individual AVAs in 13 commercial oat products were analyzed using HPLC-MS/MS. The total AVAs contents in various oat products ranged from 9.22 to 61.77 mg/kg (fresh weight).

Ban Y, Qiu J, Ren C, Li Z. Effects of different cooking methods of oatmeal on preventing the diet-induced increase of cholesterol level in hypercholesterolemic rats. Lipids Health Dis. 2015 Oct 24;14:135. doi: 10.1186/s12944-015-0138-7. PMID: 26498197; PMCID: PMC4619352.

Abstract. Background: The aim of present study is to investigate the influences of brewing and boiling on hypocholesterolemic effect of oatmeal in rats fed with a hypercholesterolemic diet.....Conclusion: These results indicated that the capability of boiled oatmeal in improving cholesterol metabolism is better than that of brewed oatmeal, which is mainly attributed to its higher soluble β-glucan content and apparent viscosity.

Leão LSCS, Aquino LA, Dias JF, Koifman RJ. Addition of oat bran reduces HDL-C and does not potentialize effect of a low-calorie diet on remission of metabolic syndrome: A pragmatic, randomized, controlled, open-label nutritional trial. Nutrition. 2019 Sep;65:126-130. doi: 10.1016/j.nut.2019.03.007. Epub 2019 Mar 23. PMID: 31082790.

Chakraborty P, Witt T, Harris D, Ashton J, Stokes JR, Smyth HE. Texture and mouthfeel perceptions of a model beverage system containing soluble and insoluble oat bran fibres. Food Res Int. 2019 Jun;120:62-72. doi: 10.1016/j.foodres.2019.01.070.

Esfandi R, Willmore WG, Tsopmo A. Peptidomic analysis of hydrolyzed oat bran proteins, and their in vitro antioxidant and metal chelating properties. Food Chem. 2019 May 1;279:49-57. doi: 10.1016/j.foodchem.2018.11.110. 

Jane M, McKay J, Pal S. Effects of daily consumption of psyllium, oat bran and polyGlycopleX on obesity-related disease risk factors: A critical review. Nutrition. 2019 Jan;57:84-91. doi: 10.1016/j.nut.2018.05.036.

Oatmeal is obtained by grinding the plant Avena sativa belonging to the Poaceae family. It is a refined flour so it retains some of the plant's nutritional properties.

Oatmeal typically refers to the product made from oats that have been ground, steel-cut, or rolled. It can be used to make a hot cereal, added to baked goods, or used in various culinary applications.

Oatmeal is made by grinding whole oat grains into a meal. The texture can vary from fine to coarse and is celebrated for its rich content of soluble fiber, protein, and a variety of essential vitamins and minerals. It is a popular breakfast ingredient, especially in the form of porridge, but also used in baking products like cookies and bread.

Nutritional Profile (per 100 grams):

• Calories Approximately 389 kcal.
• Protein About 16.9 grams, making it a significant source of plant-based protein.
• Fat About 6.9 grams, predominantly unsaturated fatty acids.
• Carbohydrates About 66.3 grams, a large part of which is fiber.
• Fiber About 10.6 grams, which helps improve digestion and can help regulate blood cholesterol levels.
• Vitamins and Minerals Contains B vitamins, magnesium, iron, phosphorus, zinc, and selenium.

Considerations

Oatmeal is particularly valued for its cardiovascular health benefits, mainly due to the presence of beta-glucan, a soluble fiber that helps reduce LDL cholesterol. It is also a popular choice for those looking to manage weight or diabetes due to its ability to provide slow-release energy.

Culinary Use Oatmeal can be cooked to create porridge, added to smoothies to increase fiber intake, or used in baked goods as a fiber-rich ingredient.

Health Benefits Supports digestive health, helps regulate blood sugar, and contributes to cardiovascular health.

Storage Store in an airtight container in a cool, dry place to preserve freshness and nutritional properties.

Industrial Production Process

• Selection. The production of oat flour begins with the selection and harvesting of high-quality oats, ensuring that the grains are mature and free from impurities.
• Cleaning. The harvested oats are cleaned to remove any impurities, such as dirt, stones, and other plant residues, ensuring that only clean grains proceed to the next stage.
• Hulling. The oats undergo hulling to remove the outer shell. This process leaves the hulled oat kernels, known as groats, which contain the full nutritional value of the grain.
• Stabilization. The groats are then stabilized through a light heating process. This step deactivates enzymes that can cause rancidity, improving shelf life and preserving flavor.
• Milling. The stabilized groats are milled into a fine flour. Milling is carefully performed to keep the temperature controlled, avoiding overheating that could degrade nutrients.
• Sifting. The oat flour is sifted to ensure a uniform consistency, removing any larger pieces not fully milled.

 Oatmeal is high in fiber, especially beta-glucan, which is beneficial for heart health and blood sugar control. It also contains a good amount of protein, vitamins, and minerals, including manganese, phosphorus, magnesium, and iron.

It also contains a good amount of potassium and vitamin B and is one of the cereals that have a particularly low glycemic index.

Heart Health: Consuming oatmeal regularly can help lower cholesterol levels and reduce the risk of heart disease (1) due to its soluble fiber content.

Blood Sugar Control: The beta-glucan in oatmeal helps slow the absorption of carbohydrates into the bloodstream, aiding in blood sugar control (2) and making it a good dietary choice for people with diabetes.

Digestive Health: The fiber in oatmeal supports digestive health, helping to prevent constipation, promote regular bowel movements and has an effect on gut microbial functions (3).

Versatile Ingredient: Oatmeal can be used in various culinary applications, from breakfast cereals to baking. It can be made into porridge, added to baked goods like cookies and bread, or used as a thickener in soups and stews.

Weight Management: The high fiber content in oatmeal can help you feel fuller longer, potentially aiding in weight management by reducing overall calorie intake.

Skin Health: Colloidal oatmeal (finely ground oatmeal) has properties that can soothe skin irritation and itching, making it a beneficial ingredient in skincare products for conditions like eczema and rashes (4).

More recent studies have shown the antioxidant (5) capacity of this cereal .  

Oatmeal studies

References________________________________________________________________________

(1) Kwok CS, Gulati M, Michos ED, Potts J, Wu P, Watson L, Loke YK, Mallen C, Mamas MA. Dietary components and risk of cardiovascular disease and all-cause mortality: a review of evidence from meta-analyses. Eur J Prev Cardiol. 2019 Sep;26(13):1415-1429. doi: 10.1177/2047487319843667. Epub 2019 Apr 11. PMID: 30971126.

Abstract. Aims: The optimal diet for cardiovascular health is controversial. The aim of this review is to summarize the highest level of evidence and rank the risk associated with each individual component of diet within its food group. Methods and results: A systematic search of PudMed was performed to identify the highest level of evidence available from systematic reviews or meta-analyses that evaluated different dietary components and their associated risk of all-cause mortality and cardiovascular disease. A total of 16 reviews were included for dietary food item and all-cause mortality and 17 reviews for cardiovascular disease. Carbohydrates were associated with a reduced risk of all-cause mortality (whole grain bread: relative risk (RR) 0.85, 95% confidence interval (CI) 0.82-0.89; breakfast cereal: RR 0.88, 95% CI 0.83-0.92; oats/oatmeal: RR 0.88, 95% CI 0.83-0.92). Fish consumption was associated with a small benefit (RR 0.98, 95% CI 0.97-1.00) and processed meat appeared to be harmful (RR 1.25, 95% CI 1.07-1.45). Root vegetables (RR 0.76, 95% CI 0.66-0.88), green leafy vegetables/salad (RR 0.78, 95% CI 0.71-0.86), cooked vegetables (RR 0.89, 95% CI 0.80-0.99) and cruciferous vegetables (RR 0.90, 95% CI 0.85-0.95) were associated with reductions in all-cause mortality. Increased mortality was associated with the consumption of tinned fruit (RR 1.14, 95% CI 1.07-1.21). Nuts were associated with a reduced risk of mortality in a dose-response relationship (all nuts: RR 0.78, 95% CI 0.72-0.84; tree nuts: RR 0.82, 95% CI 0.75-0.90; and peanuts: RR 0.77, 95% CI 0.69-0.86). For cardiovascular disease, similar associations for benefit were observed for carbohydrates, nuts and fish, but red meat and processed meat were associated with harm. Conclusions: Many dietary components appear to be beneficial for cardiovascular disease and mortality, including grains, fish, nuts and vegetables, but processed meat and tinned fruit appear to be harmful.

(2) Missimer A, DiMarco DM, Andersen CJ, Murillo AG, Vergara-Jimenez M, Fernandez ML. Consuming Two Eggs per Day, as Compared to an Oatmeal Breakfast, Decreases Plasma Ghrelin while Maintaining the LDL/HDL Ratio. Nutrients. 2017 Jan 29;9(2):89. doi: 10.3390/nu9020089. 

Abstract. Eggs contain high quality protein, vitamins, minerals and antioxidants, yet regular consumption is still met with uncertainty. Therefore, the purpose of this study was to compare the effects of consuming two eggs per day or a heart-healthy oatmeal breakfast on biomarkers of cardiovascular disease (CVD) risk and satiety measures in a young, healthy population. Fifty subjects participated in a randomized crossover clinical intervention; subjects were randomly allocated to consume either two eggs or one packet of oatmeal per day for breakfast for four weeks. After a three-week washout period, participants were allocated to the alternative breakfast. Fasting blood samples were collected at the end of each intervention period to assess plasma lipids and plasma ghrelin. Subjects completed visual analog scales (VAS) concurrent to dietary records to assess satiety and hunger. Along with an increase in cholesterol intake, there were significant increases in both low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol following the egg consumption period (p < 0.01). However, there was no difference in the LDL/HDL ratio, a recognized biomarker of CVD risk, nor in the plasma glucose, triglycerides or liver enzymes, between diet periods. Several self-reported satiety measures were increased following the consumption of eggs, which were associated with lower plasma ghrelin concentrations (p < 0.05). These results demonstrate that compared to an oatmeal breakfast, two eggs per day do not adversely affect the biomarkers associated with CVD risk, but increase satiety throughout the day in a young healthy population.

(3) Valeur J, Puaschitz NG, Midtvedt T, Berstad A. Oatmeal porridge: impact on microflora-associated characteristics in healthy subjects. Br J Nutr. 2016 Jan 14;115(1):62-7. doi: 10.1017/S0007114515004213.

Abstract. Oatmeal porridge has been consumed for centuries and has several health benefits. We aimed to investigate the effect of oatmeal porridge on gut microflora functions. A total of ten healthy subjects ingested 60 g oatmeal porridge daily for 1 week. The following microflora-associated characteristics were assessed before and after the intervention: intestinal gas production following lactulose ingestion, faecal excretion of SCFA and faecal levels of urease and β-galactosidase. In addition, rectal levels of PGE2 were measured. Microbial fermentation as evaluated by intestinal gas production and excretion of SCFA did not change significantly following the dietary intervention. However, faecal levels of β-galactosidase and urease decreased after eating oatmeal porridge (P=0·049 and 0·031, respectively). Host inflammatory state, as measured by rectal levels of PGE2, also decreased, but the change was not significant (P=0·168). The results suggest that oatmeal porridge has an effect on gut microbial functions and may possess potential prebiotic properties that deserve to be investigated further.

(4) Capone K, Kirchner F, Klein SL, Tierney NK. Effects of Colloidal Oatmeal Topical Atopic Dermatitis Cream on Skin Microbiome and Skin Barrier Properties. J Drugs Dermatol. 2020 May 1;19(5):524-531. 

Abstract. Atopic dermatitis is characterized by dry, itchy, inflamed skin with a dysbiotic microbiome. In this clinical study (NCT03673059), we compared the effects of an eczema cream containing 1% colloidal oat and a standard moisturizer on the skin microbiome and skin barrier function of patients with mild to moderate eczema. Patients were randomly assigned to treatment with 1% colloidal oat eczema cream or a standard, non-fragranced daily moisturizer. Treatment lasted 14 days, followed by a 7-day regression period. Of 61 patients who completed the study, 30 received the 1% colloidal oat eczema cream and 31 received the standard moisturizer. At 14 days, the 1% colloidal oat eczema cream reduced mean Eczema Area Severity Index and Atopic Dermatitis Severity Index scores by 51% and 54%, respectively. Unlike treatment with the standard moisturizer, treatment with the 1% colloidal oat eczema cream was associated with trends towards lower prevalence of Staphylococcus species and higher microbiome diversity at lesion sites. The 1% colloidal oat eczema cream significantly improved skin pH, skin barrier function, and skin hydration from baseline to day 14, whereas the standard moisturizer improved hydration. Overall, the results demonstrate that topical products can have differing effects on the skin barrier properties and the microbiome. Importantly, we show that the use of a 1% colloidal oat eczema cream improves microbiome composition and significantly repairs skin barrier defects. J Drugs Dermatol. 2020;19(5):   doi:10.36849/JDD.2020.4924.

(5) Esfandi R, Willmore WG, Tsopmo A. Antioxidant and Anti-Apoptotic Properties of Oat Bran Protein Hydrolysates in Stressed Hepatic Cells.   Foods. 2019 May 11;8(5). pii: E160. doi: 10.3390/foods8050160.

Abstract. The objective of this work was to find out how the method to extract proteins and subsequent enzymatic hydrolysis affect the ability of hepatic cells to resist oxidative stress. Proteins were isolated from oat brans in the presence of Cellulase (CPI) or Viscozyme (VPI). Four protein hydrolysates were produced from CPI and four others from VPI when they treated with Alcalase, Flavourzyme, Papain, or Protamex. Apart from CPI-Papain that reduced the viability of cell by 20%, no other hydrolysate was cytotoxic in the hepatic HepG2 cells. In the cytoprotection test, VPI-Papain and VPI-Flavourzyme fully prevented the damage due to peroxyl radical while CPI-Papain and CPI-Alcalase enhanced the cellular damage. Cells treated with VPI-hydrolysates reduced intracellular reactive oxygen species (ROS) by 20-40% and, also increased the intracellular concentration of glutathione, compared to CPI-hydrolysates. In antioxidant enzyme assays, although all hydrolysates enhanced the activity of both superoxide dismutase and catalase by up to 2- and 3.4-fold, respectively relative the control cells, the largest increase was due to VPI-Papain and VPI-Flavourzyme hydrolysates. In caspase-3 assays, hydrolysates with reduced ROS or enhanced antioxidant enzyme activities were able to reduce the activity of the pro-apoptotic enzyme, caspase-3 indicating that they prevented oxidative stress-induced cell death.