有规律的性表情 ... ...增强免疫细胞，减少身体和情绪压力，帮助我们对抗疾病

Experts agree, it's important to maintain our bodies in order to have a healthy sex-drive.

Want to have more and better sex? If you eat well and stay in shape, you could be doing it well into your 70s and 80s, say the experts.

Just as a car needs an oil and lube to keep it running, we need to look after our body parts to keep our sex drive running hot. What we put into our bodies, and how we take care of ourselves, go a long way to taking care of business in the bedroom.

Naturopath Cushla Reid says a healthy diet helps the production of phenethylamine – a "love chemical" which helps create feelings of excitement.

"Phenylethylamine is known as the 'love drug'. It is a chemical that mimics the brain chemistry of a person in love and is believed to be the body's natural version of amphetamine," she says.

To maintain production of this love drug we need to eat well and stay hydrated, she says.

"Hydration is so important. Sex is like a game of tennis – it can go on for quite some time and be pretty hot and sweaty, so if you're dehydrated you'll tire easily and it'll be game over all too soon."

Avoid a diet high in saturated fats, such as junk foods and too much red meat, she says. These will clog you and slow you. Instead, make sure you get plenty of foods rich in vitamin A, such as apricots, avocados, carrots, dark green and deep yellow vegetables, and vitamin E, such as fish oils, vegetable and flaxseed oils, and nuts.

Vitamin B, found in such foods as dark leafy greens, grains and cereals, is also good for feeling frisky.

Food with zinc, such as oysters, liver, ginger root and eggs, are especially good for men, she says.

Low zinc levels in men can lead to impotence, low sperm count and a loss of interest in sex. The right zinc levels (up to 100 milligrams daily) will increase male fertility and sex drive. But don't overdo it, she warns, as too much zinc can reduce immune function.

Reid also recommends food high in vitamin B3 for a healthy sex life – red chilli peppers, liver, kidney, sesame seeds, pine nuts, and even coffee.

"Vitamin B3 causes the veins to dilate and help the blood flow, which is especially good for men."

Robyn Salisbury, clinical psychologist and director of Sex Therapy New Zealand, says we could be enjoying a happy and active sex life well into our 70s and 80s if we look after our bodies.

"The better you treat your body, the better it will treat you. When we are younger, we can get away with having a horrific diet and still having a good sex life.

"But when we are older, we need to look after our health and wellbeing if we want good and frequent sex," she says.

"By the time people are in their 50s, if you are a smoker and have a poor diet, particularly a high-cholesterol and high-fat diet, as well too much alcohol, it is going to impact on your sexual function.

"If your veins and arteries are blocked because of a poor diet, blood flow will not be as effective, which means men will find it more difficult to get an erection and women will find it more difficult to become aroused.

"If you are unfit, overweight or unwell, you are not going to be so interested in having sex. You just won't want to be bothered."

Body image is crucial to having a good roll in the hay, according to the Journal of Sex Research published in Dr Jackie Mills' book, Fighting Globesity. It found that the more a woman sees herself as unattractive, the more likely she is to report a decline in sexual desire.

The research found that women involved in weight-loss programmes experienced a boost in sexual desire and feelings of being attractive.

Sex is important, not only because we love it, but because it is good for us, according to Australian sexologist and author of Spicy Sex, Dr Gabrielle Morrissey.

"Physically, sex is good for your heart – literally. Lovemaking is good aerobic exercise, and the sexual response keeps your circulatory system toned and healthy.

"Sexually active people suffer fewer heart attacks. And it can also be good for your wasteline as foreplay and intercourse can burn anywhere between 150 to 550 calories."

Sex also has a positive effect on our emotional and mental states, she says.

"Sex provides a plethora of neurochemicals released at orgasm, which help make us feel good, and the sensation of touch can alleviate depression [mild, not clinical – if you suffer from depression, do not stop taking medication].

"Hormones released during the sexual arousal response act as disinhibitors, ease fears and anxieties, and increase a sense of calm and wellbeing."

Sex is a good antidote to stress, she says.

"Regular sexual expression... boosts immune cells, reduces physical and emotional stress, and helps us fight illness."有规律的性表情 ... ...增强免疫细胞，减少身体和情绪压力，帮助我们对抗疾病

So look after yourself and aim for a lifetime of loving right into your eighth decade and beyond.