Kidney beans can:

1. Detoxify sulfites. Kidney beans are an excellent source of the trace mineral, molybdenum, an integral component of the enzyme sulfite oxidase, which is responsible for detoxifying sulfites. Sulfites are a type of preservative commonly added to prepared foods like delicatessen salads and salad bars. People who are sensitive to sulfites may experience rapid heartbeat, headache, or disorientation if they consume sulfites. If you have ever reacted to sulfites, it may be because your molybdenum stores are insufficient to detoxify them.
2. Promote cardiovascular health. The folate in kidney beans helps lower levels of homocysteine, an amino acid that is an intermediate product in an important metabolic cycle. Elevated blood levels of homocysteine are a risk factor for heart attack, stroke, or peripheral vascular disease. The soluble fiber lowers your cholesterol levels by binding with bile, which contains cholesterol, and carrying it out of your body. Phosphorus in kidney beans helps maintain a steady heartbeat. Thiamine also supports proper heart function. The magnesium in kidney beans acts as a calcium channel blocker, which relaxes veins and arteries, reducing blood pressure and improving the flow of blood, oxygen and nutrients throughout your body. The potassium is essential for maintaining normal blood pressure and heart function. Saponins in kidney beans lower blood cholesterol and decrease risk of cardiovascular disease. Kaempferol seems to prevent arteriosclerosis by inhibiting the oxidation of low density lipoprotein and the formation of platelets in the blood.
3. Give you energy while stabilizing your blood sugar. Kidney beans provide steady, slow-burning energy, and their high fiber content prevents blood sugar levels from rising too rapidly after a meal. Phosphorus helps you efficiently use carbohydrates and fats. Thiamine in kidney beans maintains your energy supplies and coordinates the activity of nerves and muscles. Magnesium helps maintain normal muscle and nerve function, helps regulate blood sugar levels, and is involved in energy metabolism and protein synthesis. The iron in kidney beans is an integral component of hemoglobin, which transports oxygen from your lungs to all body cells, and is also part of key enzyme systems for energy production and metabolism. The vitamin B6 supports a wide range of activities in your nervous system and promotes proper breakdown of sugars and starches. Hemoglobin synthesis relies on the copper in kidney beans; without it, your red blood cells cannot properly use iron. Saponins in kidney beans lower blood glucose responses, and kaempferol has antidiabetic activities.
4. Promote digestive health. The insoluble fiber in kidney beans not only helps to increase stool bulk and prevent constipation, but also helps prevent digestive disorders like irritable bowel syndrome and diverticulosis.
5. Fight free radicals. Kidney beans are an excellent source of manganese and a very good source of copper, two trace minerals that are essential cofactors of a key antioxidant enzyme called superoxide dismutase, which disarms free radicals produced within your mitochondria (the energy production factories within your cells). Saponins in kidney beans prevent cancer cells from growing and mutating, neutralize free radicals to prevent disease. Kaempferol is a strong antioxidant that helps to prevent oxidative damage of your cells, lipids, and DNA, and acts as a chemopreventive agent, which means that it inhibits the formation of cancer cells.
6. Build strong, flexible bodies. A cup of kidney beans provides 31% of the Daily Value for protein. Phosphorus in kidney beans helps in the formation of bones and teeth, synthesis of protein, and muscle contraction. Magnesium helps maintain normal muscle and nerve function and keeps bones strong. Copper is also necessary for the activity of lysyl oxidase, an enzyme involved in cross-linking collagen and elastin, both of which provide strength and flexibility in blood vessels, bones, and joints. Saponins in kidney beans stimulate your immune system by increasing the production of antibodies, fight bacterial and fungal infections, reduce inflammation, prevent dental cavities, protect against bone loss, and increase the effectiveness of certain vaccines. Kaempferol has anti-inflammatory, antimicrobial, neuroprotective, anti-osteoporotic, antiestrogenic, anxiolytic, analgesic, and antiallergic activities.
7. Maintain your brain function. The thiamine in kidney beans is critical for brain cell and cognitive function. This is because thiamine is needed for the synthesis of acetyl choline, the important neurotransmitter essential for memory and whose lack has been found to be a significant contributing factor in age-related impairment in mental function (senility) and Alzheimer's disease.