Study under review: Type and amount of dietary protein in the treatment of metabolic syndrome: a randomized controlled trial
Metabolic syndrome is a cluster of risk factors that greatly increases the risk of dying from any cause (1.5-fold) and especially cardiovascular disease (CVD) specific causes (2.4-fold). This condition is diagnosed as either having or being on medications to treat at least three of the five following criteria:
Abdominal obesity (waist circumference greater than 40 inches (men) or 35 inches (women)),
Elevated fasting blood glucose (more than 110 mg/dL),
Elevated fasting triglycerides (more than 150 mg/dL),
Low HDL-c (less than 40 (men) or 50 (women) mg/dL), and
Hypertension (systolic blood pressure higher than 130 mmHg and/or diastolic blood pressure higher than 85 mmHg).
Reducing these risk factors for CVD is the primary goal of managing metabolic syndrome, which is often done through lifestyle modification. Notably, changes to diet and exercise that facilitate a 5-10% weight loss can address and significantly improve each risk factor. While a variety of dietary approaches can result in weight loss in overweight and obese adults, as explored in Study Deep Dives Issue #6 (April, 2015), some dietary approaches may benefit people with metabolic syndrome more than other approaches.
One currently accepted dietary pattern to reduce CVD risk factors is the Dietary Approaches to Stop Hypertension (DASH) diet, which is high in vegetables, fruit, low-fat dairy products, whole grains, poultry, fish, and nuts. The diet is low in sweets, sugar-sweetened beverages, and red meats. The DASH diet is designed to be low in saturated fat, total fat, and cholesterol, and rich in fiber, potassium, magnesium, and calcium.
In the OmniHeart (Optimal Macronutrient Intake Trial for Heart Health) trial, two variations of the DASH dietary pattern were compared with DASH. One variation replaced 10% of total daily energy from carbohydrate with protein, and the other replaced the same amount of carbohydrate with unsaturated fat. Both variations led to greater reductions of estimated CVD risk than the standard DASH diet. Notably, all three tested diets had a roughly even split between animal- and plant-based protein.
This study sought to expand upon the findings of the OmniHeart trial by comparing the effects of three variations of the DASH diet, which differed in protein type (plant vs. animal) and amount (18% vs. 27%), on metabolic syndrome criteria.
Metabolic syndrome is a cluster of risk factors that greatly increases the risk of cardiovascular diseases, the treatment of which includes diet and exercise to facilitate weight loss. The DASH diet is considered a prudent dietary pattern to address these risk factors, but other research has shown variations of the diet to be more efficient. The study under review was designed to determine how protein type (plant vs. animal) and amount (18% vs. 27%) affected metabolic syndrome criteria.
Other Articles in Issue #12 (October 2015)
Eat less, live more
Animal trials suggest that calorie restriction may extend lifespan. This is the longest human trial conducted thus far on the topic, and serves to inform calorie restriction’s health impacts and feasability.
Am I less hungry after I eats me spinach?
The gut is a hot weight loss topic, even aside from the microbiome – some pharmaceutical drugs attempt to manipulate hormones or fat digestion in order to spur weight loss. What if an extract of spinach could also impact these factors?
Sugar Wars, Episode 2: “Fructose Strikes Back”
Few food components have been demonized as much as fructose in the past decade. With fructose being presumed guilty in metabolic syndrome and heart disease, this systematic review sheds light on it’s actual impact on blood lipids.
The case of the misleading yohimbe labels
What’s actually in a supplement bottle can be a mystery. These intrepid researchers investigated the actual contents of yohimbe bottles in order to see if this popular but possibly sometimes quasi-legal supplement is more (or less) than meets the eye.
- Interview: Robert Krikorian Ph.D.
Paying attention to omega-3s for ADHD
With more and more people being diagnosed with ADHD, there’s a continuing hunt for helpful treatments. Researchers tested an omega-3 supplement on young males, and also explored a potential dopamine-related mechanism.
- Interview: Trevor Kashey, Ph.D.
From jelly to muscle: collagen and body composition
Collagen has long been equated to junk protein, at least if you’re looking to gain muscle. Could it be underrated for this purpose? A trial of older men tested collagen protein to see if it could boost muscle gain and fat loss.
Can omega-3s modulate the mind-muscle connection?
While strength gains are usually associated with protein and muscle-related ergogenics, the nervous system isn’t targeted as often. This study explored a different type of omega-3 source (seal oil) for neuromuscular exercise effects.