Eating a healthy diet can help protect our health from a number of conditions and complications, so researchers wonder how diet might relate to cancer risk. In this study, researchers used models and dietary data to analyze the cancer cases from 2015. They found that 5.2% of all new cancer cases in 2015 could be attributed to poor diet, with 1.8% attributable to low whole grain consumption, 1.2% attributable to low dairy consumption, and 1% attributable to processed meats. The link with colorectal cancer shows the strongest relationship with diet, as poor diet is linked with 38.3% of all new colorectal cancer cases.
JNCI Cancer Spectrum. 2019 May 22;3(2):pkz034. doi: 10.1093/jncics/pkz034. (Zhang FF et al.)

The Mediterranean diet has been associated with longevity since its discovery, so researchers wanted to see if newly-published studies find the same association. In this review, researchers analyzed 29 prospective studies following more than 1.6 million people over several years, and they found that each 2-point increase in Mediterranean Diet adherence was linked with a 10% lower risk of death over the study period, and that this relationship was even stronger in people who lived in the Mediterranean.
Advances in Nutrition. 2019 May 21. pii: nmz041. doi: 10.1093/advances/nmz041. (Soltani S et al.)

Good food is one of life’s greatest pleasures, and emerging research suggests that certain food choices might ward off depression as well. Researchers analyzed the diets and mental health of 154 older adults in Greece, to see how a Mediterranean diet might relate to depression. Eating a Mediterranean diet was not linked with a change in risk of depressive symptoms. However, those most closely following a Mediterranean diet were significantly less likely to be diagnosed with depression. When looking at individual foods, eating more vegetables, more poultry, and less alcohol was also linked with a lower risk of depression. (Note that findings presented at meetings are considered preliminary until published in a peer-reviewed journal.)
Presentation at American Psychiatric Association Annual Meeting. San Francisco, CA. May 19, 2019

Pregnant mothers have a special opportunity to impact not only their own health, but the health of their babies as well, and researchers wonder what some of the short-term and long-term impacts of maternal diet might be. In this article, researchers analyzed 22 studies of pregnant mothers following a Mediterranean diet. They found that, compared with children of mothers who aren’t following a Mediterranean diet, children of mothers who follow a Mediterranean diet during pregnancy are significantly less likely to have depressive behaviors or aggression, and are significantly less likely to have birth defects (such as dangerous heart defects). Allergic disorders (including eczema and asthma) are less likely in children when mothers follow a Mediterranean diet during pregnancy, and an even stronger association is found when children continue with a Mediterranean diet. The researchers also found benefits for the mothers themselves, as those following a Mediterranean diet during pregnancy were less likely to develop diabetes during pregnancy.
Nutrients. 2019 May 17;11(5). pii: E1098. doi: 10.3390/nu11051098. (Amati F et al.)

Many ultra-processed convenience foods are designed to keep us coming back for more. In this study, researchers randomly assigned 20 adults to a diet of ultra-processed foods (packaged pastries, chicken nuggets, American cheese, deli meats, flavored fruit drinks, etc.) or unprocessed foods (spinach, nuts, fruit, chicken breast, plain Greek yogurt, avocado, sweet potato, bulgur, farro, etc.) for 2 weeks, immediately followed by the other diet for the next 2 weeks. The meals on both diets had the same number of calories, carbohydrates, fat, protein, sugar, sodium, and fiber, but participants could choose to eat as much or as little of the food that they wanted. People tended to eat 500 more calories on the ultra-processed diet, and gained about 2 pounds, while people tended to lose 2 pounds on the unprocessed diet. The categorization of ultra-processed vs unprocessed/minimally-processed is based on the NOVA system of food classification. While there are some concerns about the classifications used in the NOVA system (such as white rice and white flour being included in the “minimally processed” category alongside intact whole grains), helping direct consumers towards more wholesome, minimally-processed foods may be one strategy to address overeating and associated weight gain.
Cell Metabolism. 2019 May 16. pii: S1550-4131(19)30248-7. doi: 10.1016/j.cmet.2019.05.008. (Hall KD et al.)

Around the world, transitioning from a traditional diet with daily movement to a sedentary Western diet is linked with rising rates of chronic disease. In this study, researchers investigated the lifestyle factors that are associated with heart disease risk in South Asian adults. They found that moving from a traditional diet and lifestyle to one low in fruits and vegetables, low in physical activity, and high in alcohol and smoking is linked with a 2 to 3-fold higher risk of incident heart disease. “There’s a high recidivism in subjects who are placed on an eating plan different from their usual dietary patterns,” said Dr. Sikand, emphasizing the importance of culturally tailored diets. (Note that findings presented at meetings are considered preliminary until published in a peer-reviewed journal.)
Presentation at National Lipid Association Scientific Sessions. Miami, FL. May 16, 2019. (Sikand G)

African Americans are disproportionately affected by heart disease and other health conditions. In this 9-month long pilot study, researchers teamed up with pastors and church leaders of several predominantly Black churches in the Chicago area to design an intervention to improve the diets of the congregations. The interventions included Bible study, small group sessions led by church leaders, and church-wide activities, all of which focused on increasing the vegetable intake of the participants. These interventions were designed to motivate healthier eating by linking healthy eating patterns to the congregant’s spiritual beliefs. At the end of the 9-month intervention, participants had increased their vegetable intake by an average of one serving per day and their overall diet quality increased. Researchers also found significant decreases in participants’ weight and blood pressure. This study highlights the importance of community and social support in promoting healthy eating patterns. The promising results of this pilot study indicate that faith-based nutrition interventions may be an effective method to improve the diets and health of underserved populations.
Progress in Community Health Partnerships.  2019;13(1):19-30. doi: 10.1353/cpr.2019.0005 (Lynch, E. et al)

Nuts and seeds contain healthy fats, fiber, vitamins, minerals, and antioxidants. In this longitudinal study conducted over a 10-year period, researches evaluated the overall diet, nut intake, and brain function of over 4,000 Chinese people aged 55+. The participants with the highest intake of nuts had a significantly higher cognitive function than those who ate a moderate amount of nuts, or no nuts at all. Lifestyle, socioeconomic status, and overall health status did not change this association. This study indicates that a long-term diet rich in nuts may have a protective effect against age-related cognitive decline.
Journal of Nutrition, Health, and Aging.  2019;23(2):211-216. doi: 10.1007/s12603-018-1122-5. (Li, M. and Shi, Z.)

Although it is still widely feared that high fat diets could lead to weight gain, high fat Mediterranean style diets are actually a helpful tool for weight loss. Using data from the republished PREDIMED study (where adults at risk of heart disease were randomly assigned to a low fat diet, a Mediterranean diet with nuts, or a Mediterranean diet with olive oil for nearly 5 years), scientists analyzed the waist circumference and weight of the participants at baseline and again at the end of the study. While all 3,985 participants with follow up data increased their waist size slightly with aging – even as they lost weight – the Mediterranean diet groups had significantly smaller increases in their waistline compared to the low fat control group. Similarly, the Mediterranean diet with olive oil group lost significantly more weight than the low fat group, at nearly 1 pound more, but the greater weight loss seen in the nut group was not statistically significant. The scientists conclude that “the fear of weight gain from high-fat foods need no longer be an obstacle to adherence to a dietary pattern such as the Mediterranean diet,” and that these results “lend support to not restricting intake of healthy fats in advice for bodyweight maintenance and overall cardiometabolic health.”
The Lancet Diabetes and Endocrinology. 2019 May. [Epub ahead of print] (Estruch R et al.)

Crohn’s Disease is a chronic inflammatory bowel disease that causes stomach pain and severe diarrhea. Diet is a major factor in the management of Crohn’s disease, however there are no international guidelines on diet for the management of this disease. In this study, researchers evaluated the diet, quality of life, disease severity, and inflammation of 86 patients with Chron’s disease. They found that the patients whose Crohn’s disease was in remission had the highest quality of life, and that those patients had a higher adherence to the Mediterranean diet. This may be due in part to the high concentration of antioxidants and other nutrients in the Mediterranean diet, which may reduce inflammation and improve the symptoms of Crohn’s disease. This study shows that the Mediterranean diet may play an important role in managing the symptoms and improving the quality of life of patients with Crohn’s disease.
European Journal of Nutrition.  2019 Apr 20. doi: 10.1007/s00394-019-01972-z. (Papada E, et al)

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)

Insulin is a hormone that helps your body manage your blood sugar, by keeping it from getting too high or too low. In this study, 13 adults with “pre-diabetes” were given a diet with either whole grains or refined grains for 8 weeks, then given a glucose test to assess how well their blood sugar was being managed. They then had a washout period of their normal diet for 8-10 weeks, before switching to the other diet for 8 weeks and taking the glucose test again, thus serving as their own controls. The whole grain diet improved the function of beta cells (the cells that secrete insulin) compared with the refined grain diet, and this effect was found to be independent of gut hormones (such as grehlin, the “hunger hormone”).
Molecular Nutrition and Food Research. 2019 Apr;63(7):e1800967. doi: 10.1002/mnfr.201800967. (Malin SK et al.)