Valentine's Day is the one day of the year totally devoted to love and romance when a box of chocolates and a bouquet of roses are always appreciated. Many couples head to their favorite restaurant for a special meal, but others opt for a quiet, intimate meal at home. But you can turn any day into Valentine's day by choosing foods that will fan the flames of romance:

Have Brazil nuts and blueberries as a pre-dinner snack. Brazil nuts are high in both magnesium and selenium. Magnesium helps raise testosterone levels, and selenium helps keep the prostate healthy. A Turkish study found that athletes given about 750 mg of magnesium daily for four weeks increased their free testosterone by 26 percent, and an Italian study found that older men who had low levels of magnesium also had lower levels of testosterone when compared to men who had the highest magnesium levels. Researchers at Stanford with high blood levels of selenium were associated with a four to fivefold decrease in the risk of developing prostate cancer.

Blueberries are often called "nature's little blue pill" because they, like other berries, contain natural compounds that raise the levels of nitric acid in the body. This allows blood vessels to relax and sustain blood flow in a manner similar to Viagra.

Enjoy oysters as an appetizer. Believed for thousands of years to be an aphrodisiac, oysters contain zinc, which in addition to increasing libido by boosting the production of testosterone, increases muscle growth, physical endurance, and sperm production. Experts estimate that up to 45 percent of older adults lack an adequate intake of zinc, and one study found that even short-term zinc deficiency can lower testosterone. Oysters may also protect against prostate cancer. They are nature’s single best source of zinc, providing almost 100 mg per gram.

Eat fish as your main course. Cold-water fish, such as salmon and tuna, contain the amino acid L-arginine that boosts levels of nitric acid, which are essential for erections. In addition, the omega-3 oils that protect your heart may raise the levels of the neurotransmitter which helps get you in the mood for a bedroom romp.

Choose broccoli for a vegetable. Cruciferous vegetables, which include broccoli, cabbage and cauliflower, rids the body of excess estrogen, thus increasing testosterone. A study found that diets high in indole-3-carbinol, a component of cruciferous vegetables, increase the excretion of estradiol (one of the most important estrogen hormones) in men by up to 50 percent.

Have a glass of wine. Quercetin, a powerful flavonoid found in red wine, helps keep levels of testosterone elevated in the blood, according to a study published in Nutrition Journal. Scientists at Seattle's Fred Hutchinson Cancer Research Center found that men who drink four to seven glasses of red wine every week cut their risk of developing prostate cancer by 52 percent when compared to men who didn't drink red wine.

Eat a decadent chocolate dessert. Chocolate has been linked with romance for decades, and one reason could be that it contains phenethylamine (PEA). PEA is a chemical known as the "love drug," and your body creates it when you fall in love. PEA activates the brain's pleasure center and triggers the release of "feel good" endorphins. Chocolate also reduces stress due to the compound anadamide, which stimulates the same receptors in the brain as marijuana.

Have coffee with dessert. A study published in PLOS ONE found that men who drink two or three cups of coffee every day are less likely to suffer from erectile dysfunction (ED) than men who don't. Men who consumed 85 to 170 milligrams of caffeine a day — the amount found in two to three cups of coffee — were 42 percent less likely to have ED than men who consumed zero to 7 milligrams a day.

Finish the evening with a session of lovemaking. According to research from the U.K.'s Royal Edinburgh Hospital, people between the ages of 40 and 50 who looked younger than their chronological age said they enjoyed sex 50 percent more often — three times a week versus twice a week — than was average for their age group. According to researchers, sex boosts circulation, releases human growth hormone and painkiller endorphins, burns fat, and reduces stress, allowing you to look younger longer.

Enjoying sex now will help preserve your sexual ability. A Finnish study of men between the ages of 55 and 75 found that those who had sex less than once a week were twice as likely to develop erectile dysfunction as those who had sex at least once a week. Very sexually active men — those who had sex three or more times a week — lowered their risk by 400 percent. Another study found that older women who had sex every week had estrogen levels twice as high as women who abstained, meaning they were less likely to suffer from vaginal atrophy, which causes sex to be uncomfortable.

Regular sex will also give your immune system a boost. Researchers at Pennsylvania's Wilkes University found that people who have regular sex (once or twice a week) have higher levels of the antibody immunoglobulin A (IgA), which fights off bacteria and viruses. People who made love more than once a week had a 30 percent increase in IgA levels.