DIETS HIGH IN RED/PROCESSED MEAT AND LOW IN GRAIN FIBER LINKED WITH COLORECTAL CANCER
In a recent study, researchers enrolled over 400,000 participants and followed them for 5 years, analyzing their diet and health outcomes. The researchers found that the participants who ate the most red or processed meat had the highest risk of developing colorectal cancer. There was also an increased risk of colorectal cancer in participants who drank the most alcohol. Interestingly, the group that ate the most red and/or processed meat also tended to have a higher intake of alcohol, a lower intake of fruits and vegetables, and were more likely to smoke tobacco. The group with the highest intake of ﬁber from grains had the lowest risk of colorectal cancer. This study indicates that diets high in red or processed meats and lower in whole grains may be associated with an increased risk of colorectal cancer.
International Journal of Epidemiology. 2019 Apr 17. pii: dyz064. doi: 10.1093/ije/dyz064. (Bradbury KE, et al)
WHOLE GRAINS LINKED WITH 37% LOWER RISK OF LIVER CANCER
Hepatocellular carcinoma, a common type of liver cancer, has been on the rise in the US, and researchers wonder if eating habits might play a role. In a study of 125,455 adults followed for 24 years, those eating the most whole grains (33g per day, or about 2 servings) were 37% less likely to develop hepatocellular carcinoma than those eating the least whole grains (7g per day, or less than half a serving). When looking at the isolated relationship of ﬁber, bran, and germ, the results were not statistically signiﬁcant, indicating that whole grains are greater than the sum of their parts.
JAMA Oncology. 2019 Feb 21. doi: 10.1001/jamaoncol.2018.7159. [Epub ahead of print] (Yang W et al.)
WHOLE GRAINS AND FIBER LINKED WITH LOWER RISK OF MANY DISEASES
Whole grains are one of the most popular food sources of ﬁber, and both whole grains and ﬁber are important for overall health. In this study, researchers analyzed data from more than 200 studies encompassing 4,635 participants to better understand ﬁber and whole grains’ relationship with disease prevention. Fiber was linked with a 15-30% lower risk of heart disease, stroke, type 2 diabetes, colorectal cancer, and death, with similar ﬁndings for whole grains. The researchers noted a dose-response relationship for both whole grains and ﬁber, indicating that those who eat the most may confer an even greater beneﬁt.
The Lancet. 2019 Feb 02;393(10170):434-445. doi: 10.1016/S0140-6736(18)31809-9 (Reynolds A et al.)
EAT-LANCET COMMISSION OUTLINES A HEALTHY, SUSTAINABLE DIET
Diet is intimately linked both to human and environmental health. In this article, a commission of distinguished scientists from diﬀerent ﬁelds set out to examine the components of a healthy diet and the link between diet and environmental health. Through an extensive review of literature, the researchers found that an ideal diet that meets basic nutritional needs and can be sustainably produced is mostly plant-based. Speciﬁcally, this diet is based around about 11 ounces vegetables, 9 ounces of dairy foods (a little over a cup of milk) 8 ounces of whole grains (about 8 servings, such as a slice of bread or a ½ cup cooked grains), 7 ounces of fruit, 3 ounces of legumes, 2 ounces of nuts, and an optional 2 ounces of other animal foods (like eggs, poultry, or meat) per day. The authors suggest that a global shift towards these dietary principles can prevent approximately 11 million deaths per year, and can sustainably produce enough food for the growing population without further damage to the environment.
Lancet. 2019 Feb 2;393(10170):447-492. doi: 10.1016/S0140-6736(18)31788-4. (Willett W et al)
SPROUTED TRITICALE MAY BENEFIT BLOOD SUGAR MANAGEMENT
Whole grains contain ﬁber, vitamins, minerals, and antioxidants, and sprouting grains may make these compounds more available. In this study, researchers fed volunteers a meal of sprouted whole wheat, sprouted whole grain triticale, or sugar and compared how these foods aﬀected the volunteers blood sugar and insulin levels. People who ate the sprouted triticale had lower levels of blood sugar and insulin than those who ate sugar; the volunteers who ate sprouted wheat had lower blood sugar than those who had just sugar, but there was no diﬀerence in insulin response. Both grains were associated with improved blood sugar control, however this eﬀect was strongest in the sprouted triticale group. This study indicates that whole grain triticale may be especially beneﬁcial to blood sugar management.
Journal of Nutrition and Metabolism. 2019 Jan 10;2019:6594896. doi: 10.1155/2019/6594896. (Meija et al.)
REPLACING WHITE RICE WITH WHOLE GRAIN BREAD MAY LOWER DIABETES RISK.
White rice has displaced many traditional whole grains across Asia, so researchers wonder how white rice might relate to diabetes risk. In a study of 45,411 Chinese adults followed for 11 years, researchers found that replacing white rice with white bread and whole grain bread can reduce type 2 diabetes risk by 10% and 18% respectively, and that replacing white rice with noodles, red meat, or poultry might actually increase diabetes risk. Rice intake itself was not associated with higher type 2 diabetes. The authors conclude that “recommendations to reduce high white rice consumption in Asian populations for the prevention of [type 2 diabetes] may only be eﬀective if substitute foods are considered carefully.”
European Journal of Nutrition. 2018 Dec 10. doi: 10.1007/s00394-018-1879-7. [Epub ahead of print] (Seah JYH et al.)
SWITCH TO WHOLE WHEAT FOR BETTER LIVER HEALTH
The liver is important for metabolism, so researchers wonder how substituting whole grains might impact liver health. To assess this relationship, 50 overweight middle-aged adults were randomly assigned to a diet with 5 servings of whole wheat foods per day or 5 servings of reﬁned wheat foods per day for 12 weeks, and compliance was conﬁrmed by measuring biomarkers of whole wheat intake (alkylresorcinol). The reﬁned wheat diet signiﬁcantly increased liver fat, indicating that it may contribute to the development of nonalcoholic fatty liver disease. On the other hand, the whole wheat diet prevented an increase in liver fat, and better maintained liver health.
American Journal of Clinical Nutrition. 2018 Dec 1;108(6):1264-1274. doi: 10.1093/ajcn/nqy204. (Schutte S et al.)
QUALITY TRUMPS QUANTITY WHEN CHOOSING CARBS AND FATS
For decades, experts have debated the merits of a low-fat versus a low-carb diet. In this review, nutrition scientists of widely varying perspectives detailed evidence supporting both low-fat and low-carb diets, as well as points of consensus they could agree on. The experts agreed that carbohydrate quality (whole grains and low Glycemic Index foods over reﬁned grains and sugars) and fat quality (unsaturated fats over trans fats and saturated fats) are much more important than the amount of carbohydrates or fat in the diet.
Science. 2018 Nov 16;362(6416):764-770. doi: 10.1126/science.aau2096. (Ludwig DS et al.)
WHOLE GRAINS LINKED WITH BETTER BLOOD SUGAR MANAGEMENT
Metabolic syndrome is a cluster of conditions (high blood pressure, high blood sugar, high cholesterol, and excess fat around the waist) that can increase your risk of heart disease, stroke, and diabetes if they occur together. In this study, researchers randomly assigned more than 100 adults with metabolic syndrome from Finland and Italy to a diet with whole grains or a control diet without whole grains for 12 weeks. The whole grain group had better blood sugar control after meals. Researchers hypothesize that this may be because eating whole grains may help stimulate the production of certain chemical compounds (betaine compounds, such as pipecolic acid betaine) which are linked with improved insulin resistance and insulin secretion.
American Journal of Clinical Nutrition. Am J Clin Nutr. 2018 Sep 25. doi: 10.1093/ajcn/nqy169. [Epub ahead of print]. (Kärkkäinen O et al.)
WHOLE GRAINS LINKED WITH LOWER CHOLESTEROL
To better understand whole grains’ relationship with heart health, New Zealand’s Heart Foundation analyzed 19 meta analyses encompassing thousands of participants, for their September 2018 report entitled “Whole Grains and the Heart.” The authors conclude that “observational research suggests three [servings] of whole grains per day are associated with heart health beneﬁts, and there are likely to be additional beneﬁts with higher intakes. Intervention studies on risk factors are less compelling but show most consistent evidence of beneﬁts for a small reduction in total and LDL cholesterol, especially in relation to oats and barley, and possibly improved [glycemic] control.”
Heart Foundation. 2018 Sept. (Gorton D et al.)
WHOLE GRAINS ASSOCIATED WITH LOWER RISK OF DIABETES
Whole grains are healthy carbohydrate foods that may be especially protective against type 2 diabetes. In this study, researchers analyzed the eating habits and health status of 55,465 middle-aged adults in Denmark. Those eating more whole grains were 11% and 7% less likely to develop type 2 diabetes (for men and women, respectively) over the 15-year study period. Rye bread, whole-grain bread, oatmeal, and muesli were all signiﬁcantly associated with a lower risk of type 2 diabetes for both men and women, indicating a beneﬁt for whole grains in general, rather than just one speciﬁc type of whole grain food.
The Journal of Nutrition. 2018 Sep 1;148(9):1434-1444. doi: 10.1093/jn/nxy112. (Kyrø C et al.)