Scientific Update
By Reed Mangels, PhD, RD
Dietary Factors Associated with Type 2 Diabetes
Diabetes is reported to cause one in eight deaths globally and it is becoming increasingly common. More than 500 million adults worldwide have diabetes; about 90% of cases are type 2 diabetes. A recent analysis, using computer modeling, estimated the impact of 11 dietary factors on new cases of type 2 diabetes throughout the world. Dietary factors were estimated to account for 70% of new cases of type 2 diabetes, either directly or by their effect on obesity, a risk factor for type 2 diabetes. Excess intakes of refined grains, processed meat, red meat, sugar-sweetened beverages, potatoes, and fruit juice explained about 60% of the new cases of type 2 diabetes linked to diet.
About 40% of new diet-related cases were attributed to insufficient intakes of whole grains, yogurt, fruit, non-starchy vegetables, and nuts and seeds. The dietary factors that were most associated with type 2 diabetes were insufficient whole grains, excess refined rice and wheat, excess processed meat, and excess red meat. In central and eastern Europe and central Asia, excess consumption of processed meats was estimated to be associated with more than half of new cases of type 2 diabetes.
O'Hearn M, Lara-Castor L, Cudhea F, et al. Incident type 2 diabetes attributable to suboptimal diet in 184 countries. Nat Med. 2023;29(4):982-995.
New Guide for Vegetarian Athletes
A group of Italian scientists recently published the VegPlate for Sports: A Plant-Based Guide for Athletes. This guide was designed to be a practical tool for nutrition professionals who work with vegetarian, including vegan, athletes. A variety of plant foods are included in the guide; dairy products and eggs are considered to be optional. It includes good sources of omega-3 fatty acids, reliable sources of calcium, and recommendations for vitamin B12 and vitamin D. Foods are divided into six food groups (grains, protein-rich foods, vegetables, fruits, nuts and seeds, and fats), and the number of servings from each group is specified.
Along with the main VegPlate, which can be used to plan the main meals of the day, there are two "small plates." One is for the meal or snack prior to a workout, and is high in slow-release carbohydrate, and provides some protein. The other "small plate" is for the meal or snack after a workout. It supplies mostly simple, rapidly absorbed carbohydrate to replenish muscle glycogen stores, along with some protein. The authors hope that this teaching tool will allow nutrition professionals to better respond to the nutritional needs of their vegetarian athlete clients. Once clients have learned the system, they can use it to choose a variety of health-promoting foods.
The article describing the VegPlate for Sports can be found at mdpi.com/2072-6643/15/7/1746. If you're a vegan/vegetarian athlete, consider sharing it with the nutrition professional that you work with.
Baroni L, Pelosi E, Giampieri F, Battino M. The VegPlate for Sports: A plant-based food guide for athletes. Nutrients. 2023;15:1746.
Phytoestrogens Are Associated with Lower Mortality
Estrogen is a hormone produced by the human body. Substances with weak estrogen-like activity that are found in plant foods are called phytoestrogens. Phytoestrogens are present in a variety of foods and beverages, including soy products, flaxseeds, tea, and whole grains. Higher intakes of phytoestrogens have been associated with lower risk of developing heart disease and breast cancer. A recent study examined the effect of phytoestrogen intake on total mortality and on mortality from specific diseases.
Researchers studied more than 75,000 U.S. women and more than 40,000 U.S. men for 34 years. A higher intake of phytoestrogens was associated with a lower risk of dying overall and a lower risk of dying from cardiovascular disease. A higher intake of isoflavones, a type of phytoestrogen found mainly in soy products, was also associated with a lower risk of dying overall and a lower risk of dying from cardiovascular disease. When the researchers examined specific foods, higher intakes of tofu, soymilk, whole grains, tea, flaxseeds, and flaxseed oil were all associated with a lower risk of death. Higher intakes of tofu were associated with a lower risk of death from heart disease, and higher intakes of whole grains and tea were associated with a lower risk of death from heart disease and cancer.
Chen Z, Qian F, Hu Y, et al. Dietary phytoestrogens and total and cause-specific mortality: results from 2 prospective cohort studies. Am J Clin Nutr. 2023;117:130-140.
More Adults in the United States Are Eating Chickpeas
Think about hummus, curried chickpeas, falafel, pasta e ceci, or no-tuna salad. It's clear that chickpeas, a main ingredient in all these dishes, are a versatile product. Chickpeas are a good source of protein, fiber, iron, zinc, and other nutrients. Although the percentage of U.S. adults consuming chickpeas doubled between 2003 and 2018, the percentage of U.S. adults eating chickpeas remains quite low. Only 4.5% of adults participating in the National Health and Nutrition Examination Survey (NHANES) in 2015-2018 reported consuming chickpeas in any form on the two days that diet records were kept. NHANES results from 2003-2006 indicate that fewer than half as many U.S. adults (1.9%) reported consuming chickpeas in the two days that were studied. The trend towards increased chickpea consumption was consistent across different age groups, income levels, and all racial/ethnic groups identified. There was a larger increase in adults consuming hummus than in consumers of other forms of chickpeas.
Those consuming chickpeas had higher intakes of whole grains, fruit, and nuts and seeds and lower intakes of red meat compared with those consuming other legumes or those not consuming legumes at all. Chickpea consumers had higher intakes of fiber and magnesium and lower intakes of sodium, as well as an overall healthier diet. They were more likely to be physically active and to be in excellent or very good health. The increased usage of chickpeas may be due to more people eating Mediterranean-style diets and plant-based diets.
Rehm CD, Goltz SR, Katcher JA, Guarneiri LL, Dicklin MR, Maki KC. Trends and patterns of chickpea consumption among United States adults: Analyses of National Health and Nutrition Examination Survey Data. J Nutr. 2023;153:1567-1576.
Calcium Supplements and Risk of Cardiovascular Disease
Calcium supplements are recommended for people whose diets are low in calcium. They are commonly used by middle-aged or older people as a way to reduce their risk of bone fractures due to osteoporosis. Some Studies have raised concerns about the safety of calcium supplements due to findings such as a higher risk of cardiovascular disease or heart attack. Other studies have not found an increased risk of health problems in calcium supplements users.
A recent study used a statistical technique, meta-analysis, to combine results from a number of smaller studies of the effects of calcium supplementation. Results from 11 smaller studies were used to examine the effect of calcium supplements on cardiovascular disease. The researchers first looked at studies in which an average dose of 1 gram of calcium per day was given without vitamin D. There was no increase in risk of having a heart attack or a stroke or of dying from heart disease in those using calcium supplements, compared to those not using calcium supplements. The results when calcium was given along with vitamin D were similar to those when calcium was given without vitamin D. Most (80%) of the study participants were older women, and so results may not be generalizable to men or younger people.
Huo X, Clarke R, Halsey J, et al. Calcium supplements and risk of CVD: A meta-analysis of randomized trials. Curr Dev Nutr. 2023;7:100046.
