Search Health Studies

Full Fat Dairy Doesn’t Appear to Impact Cholesterol in People with Metabolic Syndrome

U.S. dietary guidelines tend to recommend low- and no-fat dairy options, yet research suggests that the saturated fat in dairy may not pose as many health risks as originally thought. In this study, 66 people with metabolic syndrome (a risky combination of high blood pressure, high blood sugar, high cholesterol, and/or excess fat around the waist) were assigned to either 3.3 servings of low-fat dairy (milk, yogurt, cheese) per day, 3.3 servings of full-fat dairy (milk, yogurt, cheese) per day, or a limited dairy diet of 3 or fewer servings of nonfat milk. After 12 weeks of eating full-fat dairy, there was no effect on cholesterol, triglycerides, or blood pressure. However, the 3.3 servings of low-fat dairy group did trend towards a slight improvement in systolic blood pressure.
American Journal of Clinical Nutrition. 2021 Sep 1;114(3):882-892. doi: 10.1093/ajcn/nqab131. (Schmidt KA et al.)

Peanuts and Peanut Butter Linked with Improved Anxiety and Memory in Young Adults

Nuts like peanuts are part of a brain healthy diet and researchers are starting to understand why. In a randomized controlled trial of 63 healthy young adults in the Mediterranean, people were randomly assigned to a diet with about 3 tablespoons (25g) of peanuts, 2 tablespoons (32g) of peanut butter, or 32 grams of a control spread made from peanut oil (but without the fiber or phenolic compounds). Those eating the peanuts and peanut butter daily over the six-month study were significantly more likely to have improved anxiety and improved immediate memory than those in the control group. The researchers suspect that these improvements may be linked with the peanut polyphenols or the increase in short chain fatty acids (an indicator of a healthy gut microbiome).
Clinical Nutrition. 2021 Sept 20. doi:10.1016/j.clnu.2021.09.020. (Parilli-Moser I et al.)

Eating Traditional Mexican Foods Linked with More Sleep, Less Snoring

As people abandon traditional diets for sugary, fatty Western diets, health can suffer, so researchers wonder if traditional eating might be related to sleep health as well. In a study of 100 Mexican American adults in Arizona, those who reported eating traditional Mexican foods more often were more likely to get 1.41 more hours of sleep per night and were less likely to report snoring than those who don’t eat traditional Mexican foods as often. However, eating traditional Mexican foods was not related to sleep quality, insomnia, or sleepiness.
BMC Nutrition. 2021 Aug 23;7(1):53. doi: 10.1186/s40795-021-00452-0. Ghani SB et al.)

Mediterranean Diet Can Slow Progression of Atherosclerosis

Atherosclerosis, the build up of fatty plaque in arteries, can be a risk factor for heart disease down the road. In a randomized controlled trial of more than 900 people with heart disease, those assigned to a Mediterranean diet improved their atherosclerosis (as measured by reduced thickness of both carotid arteries) over 5 years and maintained their baseline artery thickness at 7 years. Those assigned to a low-fat diet did not have any significant improvements in atherosclerosis.
Stroke. 2021 Aug 10;STROKEAHA120033214. doi: 10.1161/STROKEAHA.120.033214. (Jimenez-Torres J et al.)

Whole Grains Linked with Better Maintenance of Waist Size, Blood Pressure, Blood Sugar

Larger waist sizes (as measured by waist circumference), high blood pressure, and high triglycerides are all signs of potential heart disease down the road, so researchers wonder how whole grains might play a role in these risk factors. In a study of 3,121 adults (average age 55), researchers analyzed the types of grain foods they ate and their health markers to see how different types of grains might relate to cardiometabolic risk. While all study participants got larger around the waist over the 18-year study period, eating the most whole grains (at least 48 grams whole grain per day, or at least 3 full servings) was linked with significantly smaller increases in waist size compared with eating the least whole grains (less than 8 grams whole grain per day, or less than a half serving). Additionally, eating more whole grains was also linked with significantly smaller increases in fasting blood sugar and systolic blood pressure, while eating more refined grains (4+ servings per day) was linked with greater increases in waist size and a smaller decline in triglycerides (a type of fat in the blood).
Journal of Nutrition. 2021 Jul 13;nxab177. doi: 10.1093/jn/nxab177. (Sawicki CM et al.)

Whole Grain Intake in Latin America Falls Short of Recommendations

Dietary guidelines around the world recommend making more of our grains whole, and researchers wonder if people in different countries are meeting these goals. In a study of 9,128 people across eight Latin American countries, the average person was eating less than one full serving (only 14.7 grams) of whole grain foods per day. Women and older adults were more likely to eat more whole grains, while people with lower incomes were less likely to eat more whole grains. The most commonly eaten whole grains in the survey were oatmeal, masa harina, whole wheat bread, corn chips, and wheat crackers.
European Journal of Nutrition. 2021 Jul 7. doi: 10.1007/s00394-021-02635-8.

Plant-Based Diets Linked with Lower Risk of Severe Symptoms in COVID-19

While mask wearing, social distancing, and approved vaccines are thus far the only proven strategies to reduce the risk of contracting COVID-19, research suggests that people with diet-related chronic diseases tend to be at higher risk of having more serious complications if and when they do get COVID-19. In this study of healthcare workers from 7 countries on the front lines of the COVID-19 pandemic (conducted in the summer of 2020, before vaccines became available), those who contracted COVID-19 and reported following a “plant-based diet” or a “plant-based or pescatarian diet” had a 73% and 59% lower risk of moderate-to-severe COVID-19 versus people who did not follow these diets. However, there was no relationship between diet and likelihood of contracting COVID-19.
BMJ Nutrition, Prevention, & Health. 2021 Jun 7;4(1):257-266. doi: 10.1136/bmjnph-2021-000272. eCollection 2021. (Kim H et al.)

Meeting Australian Whole Grain Recommendations in Australia Could Save Over 1.4 billion AUD

Currently, Australian adults are only eating about 21 grams of whole grain per day. In this study, researchers quantified the savings in healthcare and reduction of lost productivity costs associated with a reduction in type 2 diabetes and heart disease through meeting the 48 grams per day whole grain recommendation. If 100% of the Australian adult population were to meet this whole grain goal, researchers estimate a savings of up to 750.7 million Australian dollars (AUD) in healthcare and lost productivity costs for type 2 diabetes, and an additional 717.4 million AUD in healthcare and lost productivity costs for heart disease, totaling more than a 1.4 billion AUD savings. On the low end, even if only 5% or 15% of Australian adults meet the 48 grams per day whole grain goal, there would still be an estimated savings total of 73.4 million AUD to 220.2 million AUD, respectively in healthcare and lost productivity costs related to both conditions.
Nutrients. 2021 May 29;13(6):1855. doi: 10.3390/nu13061855. (Abdullah MMH et al.)

Mediterranean Inspired MIND Diet Linked with Healthier Brain Markers in MS

The Mediterranean diet is well-known for its brain benefits, so scientists wonder how Mediterranean-inspired eating might relate to multiple sclerosis (MS), a brain and spinal cord autoimmune disease. Researchers analyzed the eating habits and brain structures of 180 adults who have had a diagnosis of MS for less than 5 years to see how closely they adhered to a version of the Mediterranean diet called the MIND diet. The MIND diet is a hybrid Mediterranean-DASH diet that emphasizes foods associated with brain health, including whole grains, green leafy vegetables, berries, nuts, olive oil, and fish. In this study, people most closely following the MIND diet had significantly greater thalamic volumes. (The wasting away of the thalamus is a marker of MS disease progression and neurodegeneration, so greater thalamic volume is a good sign that MS might be advancing slower.) Additionally, when looking at specific foods and nutrients, those eating the most full-fat dairy had fewer brain lesions (as measured by lower volumes of T2 lesions) and those eating the most omega-3’s from fish had better microstructural integrity of their normal appearing white matter.
Multiple Sclerosis and Related Disorders. 2021 May 19;53:103031. doi: 10.1016/j.msard.2021.103031. (Katz Sand IB et al.)

Mediterranean Diet Linked with Lower Risk of Memory Decline in Elderly

The Mediterranean diet has long been studied for its link with brain health, and now researchers are starting to understand the mechanisms behind this protective relationship. In a study of 512 older adults (average age 69) who were a mixture of people both with and without a family history of Alzheimer’s, researchers found that more closely following a Mediterranean diet was linked with significantly better memory, larger gray matter volume in the area of the brain related to memory (mediotemporal), and less pTau181 (a predictor of Alzheimer’s progression) and amyloid pathology (misfolded proteins in the brain which are associated with Alzheimer’s progression).
Neurology. 2021 May 5;10.1212/WNL.0000000000012067. doi: 10.1212/WNL.0000000000012067.(Ballarini T et al.)

Diet Quality of Food from Schools and Grocery Stores Improves from 2003-2018, Partly Due to Increasing Whole Grains

Researchers studied the healthfulness of foods from different sources (schools, grocery stores, restaurants) in a group of 20,905 children and 39,757 adults in the period from 2003-2004 to 2017-2018. During this time, the proportion of children eating food of poor diet quality from schools decreased by more than half, from 56% to 24%. Most of these improvements occurred after 2010, in line with the Healthy Hunger Free Kids Act (which updated school nutrition standards) and were associated with kids eating more whole grains and less saturated fat, sugary drinks, and salt at schools. Additionally, the proportion of people eating food of poor diet quality from grocery stores decreased from 53% to 45% in kids and from 40% to 33% in adults, largely due to eating more whole grains and fewer sugary drinks. Food from restaurants tended to be less healthy, with very small improvements in diet quality over the study period. The researchers also found that school food improvements after 2010 were the most equitable improvements, as nutrition improved more evenly across racial and sociodemographic lines. On the other hand, most of the improvements in nutrition from grocery store or restaurant foods tended to be concentrated in high-income households.
JAMA Network Open. 2021 Apr 1;4(4):e215262. doi: 10.1001/jamanetworkopen.2021.5262. (Liu J et al.)

Maternal Mediterranean Diet May Relate to Children’s Weight Later in Life

Childhood obesity is a rising public health concern and a strong predictor of obesity later in life. Previous studies have discovered that mothers’ diets during pregnancy can potentially impact children’s weight and their risks of developing obesity. This study evaluated how mothers’ dietary patterns during pregnancy affect their children’s BMI (body mass index). A total of 1,459 women participated in the study and completed a questionnaire about the food they ate during pregnancy. Their children were followed up for 15 years to measure their weight and height change. The findings showed that children whose mothers had closely followed the Mediterranean diet during pregnancy are more likely to grow faster and have lower BMI than their peers during childhood. However, the researchers cautioned that differences in breastfeeding might partly explain the BMI differences across the groups. Thus, more studies are needed.
American Journal of Clinical Nutrition. 2021 Mar 15;nqaa398. doi: 10.1093/ajcn/nqaa398. (Monthé-Drèze C et al.)

Pages