The Best, Healthiest Foods: Avocado, Salmon and Walnuts

Avocado

A serving of 1/4 of an avocado provides 14 percent of the daily value for fiber, 10 percent of the DV for folate and 13 percent of the DV for vitamin K. People who regularly eat avocados tend to have more nutritious diets in general and have lower body mass indexes and higher levels of high-density lipoprotein, the good cholesterol, according to a study published in "The Nutrition Journal" in January 2013. Avocado may also function as an antioxidant and help lower low-density lipoprotein, the bad cholesterol, according to another study published in "The African Journal of Pharmacy and Pharmacology" in September 2011.

Salmon

Eating a 3-ounce serving of salmon will provide you with 57 percent of the DV for selenium; more than 40 percent of the DV for protein, niacin, vitamin B-6 and vitamin B-12; more than 20 percent of the DV for phosphorus and riboflavin; and about 15 percent of the DV for potassium and thiamine. This serving of salmon also provides 1,877 milligrams of essential omega-3 fatty acids, more than half of the amount you need each week. Eating salmon helps lower your blood pressure, LDL cholesterol and triglycerides while increasing your HDL cholesterol, thus lowering your risk for heart disease, according to a study published in "Atherosclerosis" in July 2007.

Walnuts

Walnuts provide 11 percent of the DV for magnesium, 23 percent of the DV for copper and 48 percent of the DV for manganese in each 1-ounce serving. Among nuts, walnuts are best at lowering LDL levels since they provide the most of an antioxidant that binds cholesterol for removal from your body, according to an article published in "The Royal Society of Chemistry" in 2012. Eating 30 grams, or slightly more than 1 ounce, of walnuts per day may also help reduce belly fat and your risk for metabolic syndrome, according to another study published in "The Journal of Nutrition" in September 2010.

Considerations

While avocado, salmon and walnuts are all nutritious, they are also somewhat high in fat. The majority of this fat is the healthy unsaturated fat, but it still adds a lot of calories to your diet, so eat these foods in moderation. Choose wild salmon over farmed salmon, since farmed salmon is higher in contaminants like dioxin, which can increase cancer risk. Limit farmed salmon consumption to no more than one meal per week. Wild salmon can be consumed more often, since the omega-3 benefits outweigh the risk posed by the smaller amount of contaminants found in this type of salmon, according to an article published in "Environmental Health Perspectives" in February 2009.