While most vegans聽eat enough protein, it seems聽many fall short on essential amino acids such as lysine and leucine, according to a new study.聽The finding suggests vegans聽may need to be more careful about the kind聽of protein in their diet, not just the quantity they consume.
at the Riddet Institute in Palmerston North, New Zealand, and her colleagues analysed the diets of 193 adults living in New Zealand who had been vegan for at least two years prior to the study.
Participants recorded all of their food, beverage and supplement intake over a four-day period. The researchers then quantified participants鈥� protein intake using the , which provides information on various nutrients in New Zealand food products. After accounting for body weight and sex, the researchers found that nearly 79 per cent of men and 73 per cent of women in the study met their daily protein requirement.
Advertisement
However, further analysis suggests a more complex picture. Proteins are made of amino acids, nine of which are considered essential, meaning the human body cannot produce them on its own. Plant-based foods are less likely than animal products to provide all essential amino acids , and so the researchers calculated participants鈥� amino acid intake. The information to do so wasn鈥檛 in the New Zealand database, so they used a food database from the US Department of Agriculture instead, then adjusted it based on how well the body absorbs amino acids from different foods.
While most participants seemed to consume enough essential amino acids, that changed after accounting for differences in absorption. This revealed that only about half of them met the daily requirements for lysine and leucine 鈥� two amino acids crucial for muscle, bone and metabolic health.
鈥淥ur body does not have a long-term storage of amino acids, so they must be consumed in our diet consistently throughout the day,鈥� says Soh. Over time, deficiencies in these nutrients may lead to muscle loss, especially in people already prone to muscle wasting, such as elderly people, she says.
However, the short-term nature of this study doesn鈥檛 make clear whether vegans actually experience these health consequences, says at the University of New England, who spoke to New 杏吧原创 in an independent capacity and not as a representative of her institution.聽鈥淭he ultimate litmus test of how nutrition quality affects health is whether humans have positive or negative health outcomes when following specific dietary patterns,鈥� she says. 鈥淎nd it has long been established that individuals who eat a totally plant-based diet have lower rates of chronic disease.鈥�
It also isn鈥檛 clear whether inadequate lysine and leucine intake is exclusive to vegans, as the study didn鈥檛 look at people following other diets. Still, previous research has shown blood levels of these amino acids are lower in vegans than in omnivores, says Soh.
Vegans can up their intake of essential amino acids by incorporating legumes, pulses and other high-protein, plant-based foods into their daily meals and adding one or two protein-dense snacks, she says.
PLoS One
