Pteridophytes, also known as ferns or fern allies, may sound exotic to people in the USA, but in Africa they are a crucial source of food. Many rural communities in sub–Saharan Africa depend on these wild edible plants not only during times of food shortage, but also as a pivotal component of their normal diets. There are at least 24 different species of pteridophytes eaten, with Pteridium aquilinum being the most widely consumed. These ferns also pack a punch when it comes to nutrition, with higher levels of minerals, carbohydrate, and protein than other common vegetables. There remains much to learn regarding the role of ferns in the sub–Saharan African diet and culture.
Journal of Ethnobiology and Ethnomedicine. 2014 Dec; 10: doi: 10.1186/1746–4269–10–78. (Maroyi A.)
The benefits of oats on blood sugar and cholesterol are well known, but new research suggests that the gut might also be involved. In a small study in Utah, 24 mice were fed a diet of either whole grain oat flour or refined (low bran) oat flour for eight weeks. The whole grain group had vastly different gut microbiota (the friendly bacteria in the gut) than the refined oat group, including twice as many beneficial Lactobacillacea. Those fed the whole grain oats also had significantly improved insulin sensitivity (a measure of how well a body is able to regulate its own blood sugar), 9.9% lower total cholesterol and 11% lower non-HDL (a combination of LDL and VLDL or “bad cholesterol”). The researchers speculate that the changes in gut microbiota could be a mechanism for improved insulin sensitivity and cholesterol, and conclude that these findings “further confirm the beneficial effect of whole grain oats.”
Journal of Nutrition. 2014 Dec 10. (Zhou A et al.)
Microbes are important for our digestive health, and researchers still have much to learn about how different foods impact our gut microbiome. In this study, researchers cooked 3 days worth of food from 3 different diets (a typical American diet with lots of convenience foods; a USDA recommended healthy diet with whole grains, fruits, vegetables, dairy, and lean meats; and a vegan diet consisting only of plant foods) and then analyzed the microbes present in the foods. The USDA recommended healthy diet was shown to have the highest total microorganisms. However, it was also the only meal plan that included yogurt, a non-heat-treated fermented food well known for its probiotic content.
PeerJ. 2014 Dec 9;(2):e659. doi:10.7717/peerj.659 (Lang JM et al.)
We know that healthy microbes are present in yogurt and other fermented foods, but research is showing that these friendly bacteria are actually present all throughout healthy diets. Researchers at the University of California, Davis measured the microbes in meals from three common diets: the standard American diet (consisting of fast food and convenience foods, and no whole grains), a vegan diet (which included oatmeal and peanut butter, a vegetable and tofu soup with soba noodles, and a Portobello burger on a whole wheat bun), and a healthy diet based on the USDA dietary guidelines (which included whole grain cereal with fruit and yogurt, a turkey sandwich on whole wheat bread, and a quinoa, chicken, and vegetable dinner). Researchers found that the microbe level in both whole grain diets outnumbered that of the standard American diet lacking in whole grains. The USDA diet had 1.3 billion microbes per day, the vegan diet had 6 million microbes per day, and the standard American diet had only 1.4 million microbes per day. While it’s unclear whether the benefit can be traced directly to whole grains or to a combination of interacting factors, this study points to the overall benefits of a healthy diet including whole grains.
PeerJ. 2014 Dec 9. (Lang J M et al.)
In a study of 63 overweight and obese adults instructed on various diets, South Carolina researchers examined the differences in nutrient intake and Dietary Inflammatory Index (DII). After two months, those assigned to vegan, vegetarian, and pescatarian diets had significantly lower DII scores and greater improvements in fiber, carbohydrate, fat, saturated fat, and cholesterol. However, after six months, no differences were seen among the diets. Due to these short-term benefits, the researchers concluded that greater consideration should be given to “finding ways to provide support for adoption and maintenance of plant-based dietary approaches.”
Nutrition Research. 2014 Dec 3. Pii:S0271-5317(14)00267-X. (Turner-McGrievy GM et al.)
Telomeres, DNA sequences at the end of chromosomes, can tell us a lot about aging and longevity, as shorter telomeres are associated with many age related diseases, such as heart disease and cancer. To determine the relationship between DNA and diet, Harvard researchers analyzed food intake and telomere length from over 4,600 healthy nurses using data from the Nurses’ Health Study. Researchers found that people with the greatest adherence to the Mediterranean Diet (lots of vegetables, fruits, grains (mostly unrefined), fish, legumes, and nuts, and less meat) had the longest telomeres, a good indicator of healthy aging. Additionally, the scientists pointed out that no one specific food was pinpointed as the best, reinforcing the importance of a well-rounded, healthy diet.
British Medical Journal. 2014 Dec 2;349. (Crous-Bou M et al.)
Chronic inflammation (the body’s response to stress) is linked with a number of diseases. To see how diet may play a role, Spanish researchers reviewed data on the Mediterranean diet and inflammatory disease, and found that following a Mediterranean diet is linked with both short and long term benefits for inflammatory diseases. In the short term, Mediterranean diets can help reduce risk factors associated with cardiovascular disease, like blood pressure and cholesterol. But the benefits of following a Med diet persist over time. In the long term, following this eating pattern has an intense, systemic, anti−inflammatory effect. This suggests that adherence to a Mediterranean diet may help protect against diseases like atherosclerosis, cancer, and neurodegenerative diseases, such as Alzheimers disease.
Endocrine, Metabolic & Immune Disorders−Drug Targets. 2014 Nov;14:245−254. (Casas R et al.)
To see how vegetable intake relates to adolescent metabolic health, researchers analyzed the eating patterns and health outcomes of 175 overweight Latino youth (average age = 15) in California over 5 years. Teens who ate 2.5 servings of vegetables per day (excluding fried vegetables) had 39% less fat in the liver (measured by HFF) compared with those who hardly ate any (0.1 servings per day), with even stronger results for non-starchy vegetables, especially dark green and orange vegetables. Those who ate the most non-starchy vegetables (1.7 servings per day) also had significantly better insulin resistance, and 54% less prevalence of non-alcoholic fatty liver disease than those who ate the least (0.1 servings per day). The difference in dark green and orange vegetable consumption between the highest and lowest groups was just ½ serving (or ¼ cup), meaning that a small scoop of carrots or broccoli could potentially go a long way towards health.
Journal of the Academy of Nutrition and Dietetics. 2014 Nov;114(11):1776-83. (Cook LT et al.)
Amaranth is a tiny grain that is often eaten popped, like popcorn, and is thought to have cholesterol lowering properties. To study this cholesterol lowering process, researchers in New Zealand fed 27 rabbits a high cholesterol diet or standard diet, and then gave some of the rabbits in the high cholesterol group popped amaranth. The scientists found that eating amaranth restored endothelial function (blood vessel health) to “nearly normal” during the 21-day recovery, and also substantially lowered total cholesterol and LDL (“bad”) cholesterol.
Food & Function. 2014 Nov 19;5(12):3281-6. (Caselato-Sousa V M et al.).
Our kidneys have many important functions; besides filtering waste, they help control blood pressure, help make red blood cells, and more. The eGFR (estimated glomular filtration rate) is a blood lab that is used to assess kidney function, as low eGFR levels can indicate kidney damage or even kidney failure. In a 15 year study following 900 adults (free of stroke and coronary artery disease), researchers analyzed diet and eGFR status. The researchers found that people most closely following the Mediterranean Diet were least likely to have a low eGFR, and least likely to have a high rate of eGFR decline (which would have indicated a worsening of kidney function).
Clinical Journal of the American Society of Nephrology. 2014 Nov 7;9(11). (Khatri M et al.)
Low bone mineral density causes bones to become weaker, increasing the chance of fractures and osteoporosis. To determine the relationship between diet and bone health, researchers analyzed the food intakes and bone mineral density of over 1800 Korean adults. Four different dietary patterns emerged from this data (rice and kimchi; eggs, meat, and flour; fruit, milk, and whole grains; and fast food and soda). The ‘fruit, milk and whole grains’ pattern was associated with higher bone mineral density at multiple sites for both men and women, while ‘rice and kimchi’ pattern was only associated with higher bone mineral density in the arms. The other food patterns were not linked with bone health.
European Journal of Clinical Nutrition. 2014 Nov 5. [Epub ahead of print] (Shin S et al.)
