Psychologists tell us that there are four basic stages that human beings pass through when they enter and live in a new culture.

Culture begins with the “honeymoon stage”. This is the period of time when we first arrive in a country where everything about the new culture is strange and exciting. We may be suffering from “jet lag” but we are thrilled to be in the new environment, seeing new sights, hearing new sounds and language, eating new kinds of food.

Unfortunately, after we have settled down into our new life, we can become very tired and begin to miss our homeland and our family, friends, pets. All the little problems in life seem to be much bigger and more disturbing when you face them in a foreign culture.

The third stage comes when you begin to realize that things are not so bad in the host culture. Your sense of humor usually becomes stronger and you realize that you are becoming stronger by learning to take care of yourself in the new place. Things are still difficult, but you are now a survivor.

The fourth stage can be called “at ease at last”. Now you feel quite comfortable in your new surroundings. You can cope with most problems that occur. You may still have problems with the language, but you know you are strong enough to deal with them.

There is a fifth stage of culture shock which many people don’t know about. This is called “reverse culture shock”. Surprisingly, this occurs when you go back to your native culture and find that you have changed and that things there have changed while you have been away. Now you feel a little uncomfortable back home. Life is a struggle!

Prefer your coffee black? Then you probably like dark, bitter chocolate, according to new research identifying a genetic (基因的) basis for those preferences. If that’s you, then congratulations — you are the lucky genetic winner of a feature that may offer you a boost toward good health, according to caffeine researcher Marilyn Cornelis, an associate professor of preventive medicine at Northwestern University Feinberg School of Medicine.

Studies find appropriate amounts of black coffee between 3 and 5 cups daily has been shown to lower the risk of certain diseases, including Parkinson’s, heart diseases, Type 2 diabetes and several types of cancer. But those benefits are likely to be more pronounced if the coffee is free of all of the milk, sugars and other fattening flavorings we tend to add.

“We know there’s growing evidence suggesting there’s a beneficial impact of coffee consumption on health. But reading between the lines, anyone advising someone to consume coffee would typically advise them to consume black coffee due to the difference between consuming black coffee and coffee with milk and sugar,” Cornelis said. “One is naturally calorie free. The second can add possibly hundreds of calories to your coffee, and the health benefits could be quite different.” she added.

In previous research, Cornelis and her team discovered that a genetic variant (变异) may contribute to why some people enjoy many cups of coffee a day, while others do not. “People with the gene metabolize (新陈代谢) caffeine faster, so the stimulating effects wear off faster, and they need to drink more coffee,” she said.

In a new study published in Scientific Reports, Cornelis analyzed more precise types of coffee drinkers, separating black coffee lovers from cream and sugar (or more) lovers. “We found coffee drinkers with the genetic variant that reflects a faster metabolism of caffeine prefer bitter, black coffee,” Cornelis said. “We also found the same genetic variant in people who prefer plain tea over sweetened, and bitter, dark chocolate over the more mellow milk chocolate.”

A healthy amount of sunshine may be the secret to staying young. British scientists have discovered.

Vitamin D is produced naturally by the skin in response to (对…的反应) sunlight and may help to slow the ageing process and protect against heart disease, according to the study.

Researchers from King's College London studied 2,160 women aged between 18 and 79, looking at their telomeres-a biological marker of ageing found in DNA. As people get older, their telomeres get shorter and they become more susceptible (易受伤害的) to certain illnesses.

But the study found women with high levels of vitamin D had comparatively longer telomeres-a sign of being biologically younger and healthier.

The study suggests vitamin D may help to slow down the ageing process of DNA, and therefore the ageing process as a whole.

Lead researcher Dr Brent Richards said, "These results are exciting because they show for the first time that people who have higher levels of vitamin D may age more slowly than people with lower levels of vitamin D." This could help to explain how vitamin D has a protective effect on many ageing related diseases, such as heart disease and cancer."

Professor Tim Spector, a co-author of the report, added, " Although it might sound absurd(荒唐的), it's possible that the same sunshine which may increase our risk of skin cancer may also have a healthy effect on the general ageing process.

Vitamin D made by the action of sunlight on the skin accounts for 90 percent of the body's supply, but lower levels can also be got through food such as fish, eggs and breakfast cereals(粥).

Other studies have suggested the vitamin plays a key role in protecting against cancer and heart disease.