Lactotripeptides are small protein fragments from milk, each composed of three amino acids. They are not active in fresh milk but exist within larger milk proteins. To become active, they must be released from these parent proteins, primarily through fermentation. Their main role in the body involves interacting with systems that regulate blood pressure.
Formation and Natural Sources
Lactotripeptides are formed when casein, the main protein in milk, is broken down. While this can happen during digestion, it is most effectively achieved through the fermentation of milk by specific lactic acid bacteria. The enzymes from these bacteria break down casein into smaller fragments, including the two most studied lactotripeptides: Valine-Proline-Proline (VPP) and Isoleucine-Proline-Proline (IPP).
These bioactive peptides are most abundant in fermented dairy products like soured milks, certain yogurts, and some aged cheeses. The concentration of these peptides often increases as cheese ripens. The amount of lactotripeptides in any product depends on the specific bacterial cultures and processing conditions used during fermentation.
Mechanism of Action
Lactotripeptides help regulate blood pressure by interacting with the Renin-Angiotensin System (RAS), a hormonal system that manages vascular constriction. A component of this system is the Angiotensin-Converting Enzyme (ACE). ACE converts angiotensin I into angiotensin II, a molecule that causes blood vessels to narrow.
This narrowing of blood vessels increases resistance to blood flow, which raises blood pressure. VPP and IPP function as natural ACE inhibitors. By binding to the ACE enzyme, these peptides block it from converting angiotensin I to angiotensin II, which reduces the amount of this vessel-constricting molecule in the bloodstream.
With lower angiotensin II levels, blood vessels can relax and widen. This relaxation decreases pressure within the vascular system, which is the primary mechanism behind the effects of lactotripeptides.
Reported Health Effects
The primary health effect of lactotripeptide consumption relates to cardiovascular health, specifically in managing mild hypertension. Clinical studies on VPP and IPP show a modest reduction in blood pressure for individuals with elevated levels. The effect is not dramatic but can support a broader dietary strategy for blood pressure management.
Beyond blood pressure, research suggests lactotripeptides may improve endothelial function. The endothelium is the cellular lining of blood vessels, and its health is needed for regulating blood flow. These peptides may improve function by stimulating nitric oxide, a compound that helps keep blood vessels flexible, and some research has explored their potential anti-inflammatory properties.
Dietary Intake and Supplementation
Lactotripeptides can be incorporated into a diet by consuming the fermented dairy products where they are naturally found. However, the amount of VPP and IPP in these foods can vary. This makes it difficult to ensure a consistent daily intake through diet alone.
For a standardized dose, lactotripeptides are available as dietary supplements, either as a concentrated extract or in functional foods. When choosing a supplement, look for products that specify the exact amounts of VPP and IPP. This ensures a consistent and measurable intake.
Since these products are derived from milk, they are not suitable for individuals with a milk allergy. Before beginning any new supplement, consulting with a healthcare professional is recommended. This is particularly important for those with existing health conditions or who are taking blood pressure medication to ensure it is appropriate for their health needs.