Lab Talk: The Whey to Sleep
Like many adults in today's busy world, I often encounter restless nights or awakenings at odd hours due to little ones' nightmares. Sometimes worries and workloads contribute to insomnia. (And sometimes that insomnia leads to blockbuster headlines and article introductions like this.)
Get this. A recent study conducted at the University of Maastricht in the Netherlands shows that evening intake of alpha-lactalbumin increases plasma tryptophan availability, in turn leading to increased alertness and brain activity in the morning.
How do these findings impact the dairy industry? Certain whey ingredients are notable sources of alpha-lactalbumin.
"Whey truly is a remarkable dairy component," says Jim Page, CEO, American Dairy Products Institute, Elmhurst, Ill. "Researchers continue to find out the most amazing properties and functions of this value-added ingredient that for years was viewed as a by-product of cheesemaking."
How zzz's come to beThe study I am referring to was published in the May 2005 issue of the American Journal of Clinical Nutrition (81:1026-33). The researchers explain that brain serotonin function is thought to promote sleep regulation and cognitive processes, where as sleep abnormalities and subsequent behavioral decline are often attributed to deficient brain serotonin activity. Brain uptake of the serotonin precursor tryptophan is dependent on nutrients that influence the availability of tryptophan via a change in the ratio of plasma tryptophan to the sum of the other large neutral amino acids (Trp:LNAA).
Most Americans know all about the effects of tryptophan from a certain very large meal consumed on the last Thursday of November. That's right. Tryptophan is what Thanksgiving turkey eaters attribute their comatose feeling to. The fact is, many other proteins are much more concentrated sources of tryptophan. For example, turkey and beef both contain 1.1g tryptophan per 100g of protein. That's the same concentration in soy protein isolate and acid casein. Greater sources are whole egg and wheat (1.3g/100g), egg white (1.5g/100g), human milk (1.9g/100g) and whey protein concentrate 80% (2.1g/100g). (Most nursing moms think it's the tender moment that soothes baby to sleep when it very likely is the tryptophan!)
The Dutch researchers tested whether evening consumption of alpha-lactalbumin protein with an enriched tryptophan content of 4.8g/100g protein increases plasma Trp:LNAA and improves alertness and performance on the morning after sleep, particularly in subjects with sleep complaints. The double-blind, placebo-controlled study evaluated 28 healthy subjects, 14 with and 14 without mild sleep complaints. The subjects slept at the laboratory for two separate nights so that morning performance could be evaluated after an evening diet containing either tryptophan-rich alpha-lactalbumin or tryptophan-low placebo protein. The tryptophan-rich alpha-lactalbumin was BioPURE-Alphalactalbumin™, which was provided by Davisco Foods International Inc., Eden Prairie, Minn.
Here's what they found. Evening alpha-lactalbumin intake caused a 130% increase in Trp:LNAA before bedtime and modestly, but significantly reduced sleepiness and improved brain-sustained attention processes the following morning. Only in poor sleepers was this accompanied by improved behavioral performance. The researchers concluded that evening dietary increases in plasma tryptophan availability for uptake into the brain enhance sustained alertness early in the morning after an overnight sleep, most likely because of improved sleep.
This research gets even better. Guess what the carrier was for the tryptophan-enriched alpha-lactalbumin protein? It was a strawberry milkshake. Other beverages and bars could also be delivery vehicles.
"Our phone has been buzzing with consumers who want to buy the ingredient," says Polly Olson, v.p. of business development at Davisco. "Unfortunately we are not consumer packaged, so we have had entire families who cannot sleep buying 50-lb bags of powder. An Oregon family told us that they have not slept that well for years. They are each consuming 20g in a milkshake before bed."
Whey proteins are quite easy to work with, so formulating ready-to-consume foods and beverages that tout tryptophan content is rather straight forward. Is it just a matter of time before we see a "sleeping drink" in the marketplace?