Study challenges government call to shift to plant-based protein

A recent study from Purdue University is challenging government dietary guidelines after finding that ounce-equivalent (oz-eq) protein from animals offers more essential amino acid (EEA) bioavailability than plant-based protein. EEA bioavailability refers to how well the body absorbs and processes essential amino acids.

Researchers conducted a randomized controlled crossover and investigator-blind study of 30 young adults and 25 older adults. Each participant took part in four 300-minute trials, two of which consisted of two oz-eq of unprocessed lean pork loin and scrambled whole eggs. The other two trials consisted of two oz-eq of black beans and raw sliced almonds.

Based on blood samples taken throughout each trial, the researchers found higher EEA bioavailability for the animal protein group in both young and older adults.

“Consistent with our hypotheses, consuming a meal with two oz-eq of unprocessed lean pork or whole eggs resulted in greater postprandial EAA bioavailability compared to a meal with two oz-eq of black beans or raw sliced almonds,” wrote the study’s authors.

This finding led the researchers to question why the federal government’s most recent Dietary Guidelines for Americans (DGAs) call for a shift to plant-based protein.

Shifts are needed within the protein foods group to add variety to subgroup intakes," says the US Department of Agriculture (USDA) in the 2020-2025 DGAs. “Selecting from the seafood subgroup or the beans, peas, and lentils subgroup more often could help meet recommendations while still ensuring adequate protein consumption.” 

The study’s findings are consistent with similar research on cow’s milk versus plant-based milk.

Researchers looked at 233 brands of oat, soy, rice, pea, cashew and hazelnut milk made by 23 companies and found that nine out of ten were lacking the nutrients found in real milk. 

According to the US Department of Agriculture (USDA), cow’s milk contains about eight grams of protein per 8.1 fl oz, 306 mg of calcium and nearly three mcg of vitamin D per serving.

The overwhelming majority of fake milk products, on the other hand, miss the mark on each. Only 28 fake milk products were found to have at least as much of each nutrient as whole milk, and only 38 carried as much protein.

Cow’s milk consumers would need to drink 1.5 liters — or about six glasses — of real milk to follow the FDA’s recommendation of 50 daily grams of protein. Plant-based milk drinkers, however, would need to consume 6.2 liters, or about 25 glasses.

“Our results provide evidence that many plant-based milk alternatives are not nutritionally equivalent to cow’s milk,” said epidemiologist Dr. Abigail Johnson, the study’s lead researcher. Dr. Johnson added that those who consume fake milk should supplement the missing nutrients from other products.