Featured article in the Summer 2015 Issue of Nutrition Close-Up; written by Tia Rains, PhD
One of the latest buzzwords in nutrition seems to be “plant-based diets.” A Google search of that and similar terms produces more than 600,000 listings, with nearly the same number of descriptions as to what constitutes a plant-based diet. In some cases, the term plant-based is used interchangeably with vegetarian or vegan. But I’m sure we all know self-described “vegetarians” that get through the day on a diet of processed carbohydrates that are a far cry from the native plants from which they were derived.
Other definitions of “plant-based diets” include animal foods, typically favoring dairy, eggs, poultry, and fish over other sources of protein. Where there is agreement across different interpretations of a plant-based diet is the emphasis on minimally processed foods, including vegetables, fruits, beans, peas, lentils, seeds, nuts, and whole grains.
Numerous studies have linked diets rich in plant foods with health outcomes ranging from optimal body weight to chronic disease risk reduction (i.e., cardiovascular disease, type 2 diabetes, cancer). Plant foods have also been linked to bone health and cognitive function, although the data is still emerging in these areas. Recent recommendations from the American Heart Association/ American College of Cardiology and the Dietary Guidelines Advisory Committee reflect this evidence, encouraging dietary patterns such as the Mediterranean-Style Diet and others that are based on unprocessed or minimally processed sources of fruits, vegetables, whole grains, etc.
In fact, there has definitely been a shift in nutrition guidance in recent years. Dietary patterns are in, single nutrients are out. And it’s about time! Nutrition professionals have long been professing that people eat food, not nutrients. However, until recently, most dietary guidance was centered around a list of limits with very little emphasis on the specific types of foods that are the foundation of a healthy diet.
But there is also ample evidence that dietary protein, and specifically high-quality protein, serves a critical role throughout the lifespan. In fact, a recent supplement in The American Journal of Clinical Nutrition comprehensively reviewed the evidence on dietary protein and concluded that intakes of 0.8 to 1.6 g/kg/day (but staying within the Acceptable Macronutrient Distribution Range of 10-35% of calories) can contribute to reaching nutrient targets, and may be especially important for select populations, such as middle-aged and older adults as well as those on calorie-restricted diets. Additionally, spreading protein intake evenly throughout the day with an emphasis on ~20 to 30 g at breakfast, the meal most likely to be far lower in protein, may optimize protein’s benefits.
Independent of the benefits of protein, certain proteincontaining foods may also augment other aspects of the diet. For example, research from the laboratory of Dr. Wayne Campbell at Purdue University showed greater absorption of carotenoids when eggs were co-consumed with a vegetable-based salad. The increase was a function of the fat present in eggs (avocado and fat-based salad dressings have shown similar effects on increasing absorption of fat-soluble antioxidants), but also the presence of lutein and zeaxanthin within the egg yolk. While this was an acute study, it is reasonable to hypothesize that sustaining a dietary pattern that pairs plant foods with sources of healthy fats at the same meal could lead to greater concentrations of circulating antioxidants.
Other articles in this issue of Close-Up also focus on whole foods, meals, and overall dietary patterns. And for the first time, a suggested wine pairing for eggs! Also in this issue, we are excited to share our latest educational tool, Protein & Plant Pairings (on page 7). Being it’s the heat of the summer with access to fresh fruits and vegetables across the country, it feels like the perfect time to enjoy as many plants as possible, and we hope this infographic inspires some new and unique combinations.