Whole grains

In a meta analysis, Harvard scientists analyzed the whole grain intake and rates of death for 786,076 adults across 14 studies. Compared to people who ate the least whole grains, people who ate the most whole grains had a 16% lower risk of death from all causes, an 18% lower risk of death from heart disease, and a 12% lower risk of death from cancer. However, the significantly lower risk of cancer death was only seen in people who ate at least 30g whole grains per day (the amount in about ½ cup cooked brown rice, or 2 slices of 100% whole grain bread). The researchers also observed a dose response relationship, meaning the more whole grains someone ate, the less likely they were to die during the study period. According to the scientists, these results “strongly supported the current Dietary Guidelines for Americans,” which encourage at least 3 servings of whole grains per day (totaling at least 48g whole grains).
Circulation. 2016 Jun 14;133(24):2370-80. (Zong G et al.)

Researchers in Europe and the US analyzed 45 studies (ranging from 245,012 to 705,253 participants each) in a meta analysis to understand the relationship between whole grains and health. Compared to people who ate the least whole grains, people who ate the most whole grains had a 16-21% lower risk of heart disease, an 11% lower risk of cancer, and an 18% lower risk of death from all causes, as well as a 19% lower risk of death from respiratory disease, a 36% lower risk of death from diabetes, a 20% lower risk of death from infectious disease, and a 21% lower risk of death from all non-cardiovascular, non-cancer causes. The researchers also found that a 90g increase in whole grain foods per day (about 3 servings) was linked with a 19-22% lower risk of heart disease, a 15% lower risk of cancer, and a 17% lower risk of death from all causes, and that “even moderate increases in whole grain intake could reduce the risk of premature mortality.” Whole grain bread, whole grain cereals, total grains, total cereals, total bread, pasta, and bran, were also singled out for their relationship with lower rates of various diseases and/or early death. The researchers conclude that their findings “strongly support existing dietary recommendations to increase whole grain consumption in the general population.”
British Medical Journal. 2016 June 14;353. (Aune D et al.)

Plant-based diets are linked with numerous health benefits, but you must take care to choose healthier plant foods close to nature, that haven’t been refined or include lots of added sugars. To investigate the importance of this point, Harvard researchers analyzed the eating habits of 195,727  adults across three large cohorts, and tracked their health records for decades. Eating a healthy plant based diet (with whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea, and coffee) was linked with a 34% lower risk of type 2 diabetes, while eating a less healthy plant based diet (with fruit juice, sugary drinks, refined grains, potatoes, and desserts) was linked with a 16% higher risk of diabetes.
PLoS Medicine. 2016 Jun 14;13(6):e1002039. (Satija A et al.)

While there is still much to learn about the gut microbiome, what we do know is that certain microbes appear to be more beneficial than others, and that a large diversity of different microbes seems to be protective. To figure out what constitutes a “normal” gut microbiome, European researchers combined microbiome data from nearly 4,000 people across the US and Western Europe. The researchers found that even within this large sample size, they have not yet uncovered the total richness of gut diversity. The scientists also analyzed a number of lifestyle and health factors to see if they might affect microbiome composition. After medication use and stool consistency, dietary factors (preference for whole grain bread, high fiber intake, and high fruit intake) were pinpointed as probable contributors of healthy gut diversity. 
Science. 2016 Apr 29;352(6285):560-4. (Falony G et al.)

Researchers analyzed the diet of nearly 55,000 Danish adults and then tracked their health outcomes for over 13 years. Those consuming the most whole grains per day had a 25-27% lower risk of having a heart attack than those eating the least amount of whole grains per day. In fact, increasing whole grain intake by 25g per day was linked with a 12-13% lower risk of a heart attack. Among the different types of whole grains, rye and oats appeared to be especially protective.
American Journal of Clinical Nutrition. 2016 Feb 17. Pii:acjn124271. (Helnæs A et al.)

Since there is no known cure for cognitive decline, prevention and deceleration of this condition are an important area of research. Most people’s diets change from time to time, so researchers wanted to study how these changes affect cognition. In a study of over 2000 Swedish older adults at least 60 years old, eating a “Western diet” (lots of refined or processed foods, red meats, high fat dairy products, saturated/trans fats, and sugar) was associated with more cognitive decline, whereas eating a more “prudent” diet (a healthy diet with lots of fruits, vegetables, whole grains, rice/pasta, legumes, nuts, fish, and low-fat dairy products) was associated with a deceleration of cognitive decline. However, the most fascinating finding is that every little bit helps. More frequent intake of foods from the “prudent” diet might weaken the negative cognitive effects associated with the Western diet, even if you’re unable to change all your habits.
Alzheimers and Dementia. 2016 Feb;12(2):100-9. (Shakersain B, et al.)

Dietary fiber is an important nutrient found in plant foods (mostly in whole grains, fruits, vegetables, and pulses). To study the link between fiber intake and breast cancer risk, Harvard scientists analyzed the adolescent and early adulthood diets of over 90,000 women, and noted any diagnosis of breast cancer. The researchers found that every 10g of fiber in adolescence and young adulthood was linked with a 14% and 13% lower risk of breast cancer, respectively. In fact, those eating the most fiber in adolescence and young adulthood (25g per day) were 25% less likely to get breast cancer than those eating the least fiber (12g per day).
Pediatrics. 2016 Feb 1. pii: peds.2015-1226. (Farvid MS et al).

A “grain brain” seems to be a healthy defense against inflammation and accelerated cognitive decline. In a British study, researchers analyzed the diets, inflammation markers, and cognitive health of over 5,000 middle aged adults over six years. The scientists found that those eating diets high in red and processed meat, peas, legumes (mostly baked beans) and fried food, and lower in whole grains, were more likely to have higher levels of inflammation and accelerated cognitive decline. In fact, whole grains had the strongest link to anti-inflammatory markers among all 37 food groups studied.
Clinical Nutrition. 2016 Jan 29. Pii: S0261-5614(16)00035-2. (Ozawa M et al.)

We know that healthy whole grains are growing in popularity, but new data quantify this trend. Minnesota researchers analyzed the whole grain intake and BMI, waist circumference, and obesity of nearly 45,000 children and adults from 2001 to 2012. The scientists found that while less than 1% of kids and 8% of adults met whole grain recommendations (about 3 oz equivalents per day), whole grain consumption has improved in both groups (adults from 0.72 oz equivalents in 2001 to 0.97 in 2012, kids from 0.56 oz equivalents in 2001 to 0.74 in 2012). The biggest source of whole grains for both kids and adults alike were yeast breads and ready to eat cereals. Those eating the most whole grains had a lower BMI and waist circumference, and were less likely to be overweight or obese. The researchers conclude that “greater whole grain consumption is associated with better intakes of nutrients and healthier body weight in children and adults,” and that “Continued efforts to promote increased intake of whole grain foods are warranted.”
Nutrition Journal. 2016 Jan 22;15(1):8. (Albertson AM et al.)

Healthy food choices can be an important way to help prevent gestational diabetes, a type of diabetes that occurs during pregnancy. To learn more about types of foods that might be helpful or harmful, Harvard researchers analyzed the diets and health outcomes of over 15,000 women. They found that replacing two servings per week of potatoes with whole grains lowered the risk of gestational diabetes by 12% (compared to 10% for replacing potatoes with legumes, and 9% for replacing potatoes with other vegetables).
British Medical Journal. 2016 Jan 12;h6898. (Bao W et al.)