Normal Aging

Background: Bone marrow is the soft material found inside most large bones of the body. Bone marrow produces red blood cells, white blood cells, and platelets that are released into the blood stream. Inside the marrow, these cells start off as young, immature cells called progenitor cells. Researchers want to study these cells in healthy people. Objective: To understand how progenitor cells change with age. Eligibility: Healthy people ages 18 and older Design: Participants will be screened with a questionnaire, a physical exam, and blood tests. Participants will have a bone marrow aspirate. They will be asked to lie on their stomach or side. A local anesthetic will be injected with a small needle under the skin at the site. A needle will then be placed through the skin and into the hip bone. A small amount of the liquid part of the bone marrow will be taken up into the needle. After the needle is removed, a pressure bandage will be placed on the site. Participants will be asked to become a repeat volunteer and have a bone marrow aspirate sample collected once every other year. They will have a physical exam and blood tests before each collection. The cells from the collection will be used for genetic testing and research. Participants will be in the study for as long as they remain healthy and willing to participate.

his study investigates whether eating lean beef every day can help support brain health and healthy aging in older adults. As people age, protecting memory and cognitive function becomes increasingly important. Lean beef is a rich source of essential nutrients-such as vitamin B12, iron, zinc, and creatine-that are known to support brain function. However, the direct biological effects of a beef-rich diet on brain health markers are not fully understood. In this study, researchers will recruit 20 generally healthy older adults (aged 65 and older) to participate in a dietary feeding trial. Participants will complete two separate 2-week dietary phases. During one phase, participants will consume 5.5 ounces (156 grams) of provided lean beef daily. During the other phase, they will consume an iso-caloric, protein-matched, non-beef control food daily. A two-week "washout" period, where participants return to their normal diets, will separate the two phases to ensure there are no overlapping effects. Researchers will collect blood, urine, stool, and saliva samples at the beginning and end of each 2-week dietary phase. These samples will be analyzed to see if the lean beef diet improves specific biological markers in the blood related to memory, nerve protection, and overall brain aging. Ultimately, the findings from this study will help determine if incorporating lean beef into a regular diet can be a natural, food-based strategy to help preserve neurological health in older adults.