How does sun cream help prevent skin cancer?

Sunblock blocks sun. Sun damage causes damage to the skin which leads to skin cancer. Sun block and sun proof clothing prevent the damaging portion of light from damaging the skin's dna. It also prevents the premature aging of skin which occurs with sun damage.
Sunscreen.. Sunscreen helps reduce the amount of ultraviolet radiation absorbed by the skin. It is this radiation that causes normal cells to transform into cancerous cells.
Prevents sunburns. Sun screen prevents the uv radiation from the skin from damaging the skin cells. When you get a sun burn the dna in your skin is damaged, and these mutations are what is thought to cause melanoma.
Block UV Radiation. Sunscreens work by blocking ultraviolet radiation from sunlight. Ultraviolet radiation is one of the primary causes of all 3 major types of skin cancer--basal cell cancer, squamous cell cancer, and melanoma.

Related Questions

Going to hot country. Should I use less than factor 30 sun cream to get benefit of sun for osteoporosis or would this risk skin cancer. Please advise.

Protect skin. And take vitamin d3. The d3 is the activated vitamin that does not require sun exposure to work.
SPF. Look for spf 30 to provide adequate sun protection. Even with the sunscreen, some uvr (ultraviolet radiation) will still penetrate the skin. Only minutes without sunscreen are needed to generate vitamin d.

Does broad spectrum sunscreen help prevent skin cancer or does it just prevent sunburn and do nothing to prevent skin cancers?

UVB blockage. If the 'broad spectrum' sun screen blocks uvb, it will help in prevening skin cancer.
Sunscreen. Yes. We have good evidence that sunscreen prevents melanoma and other skin cancers.

What else other than wearing sunscreen can I do to prevent skin cancer?

Nutrition. Eat foods that rank high in antioxidants. Proper food is a potential source of “beauty from within” and may help to manipulate or delay skin aging. Eat lots of red and orange foods like tomatoes and orange peppers that contain the antioxidants lycopene and beta-carotene, respectfully. These substances offer protection from the sun and may help repair cells after sun damage.
Suggestions. You can stay out of the sun-particularly during the midday when the uv rays are strongest. Try using hats and clothing that offers uv protection.
Limit UV radiation. Limiting your exposure to uv radiation. Never use a tanning bed. And see your friendly dermatologist for routine complete skin examinations.

Do even lipsticks contain sunscreen with SPF 30? are lip balms really effective in preventing tanning or skin cancer? Some good medicinal brands?

Some do, some don't. Some make-ups contain SPF's, but many don't. You have to read each individual ones list of ingredients to see if that one has SPF in it and if so, how much. Most that do advertise this prominently, because it is such a good and important feature of the item.

A sun shade or sun visor is any good at preventing skin cancer?

All shade helps. The more shade you give your skin, the better. Sunscreens help up to a point but keeping the sun off your skin is the best.
A good start. Exposure to ultraviolet radiation from the sun is the greatest risk factor for developing skin cancers. Any way you reduce your exposure will reduce your risks of developing skin cancers. This includes protective clothing and sun screen on exposed skin.

Can people die of skin cancer before sun creams were invented?

Yes, they did. The most dangerous skin cancer is melanoma. Even with sun blocks one has to be vigilant though and have regular check ups.

What is most likely the lowest SPF sun tanning lotion one can use to prevent skin cancer and still obtain a tan for people with light colored skin?

Be cautious. The most common forms of skin cancer are related to sun exposure and the resultant cellular damage from uv light which has long term effects on the skin. Therefore, any exposure especially in people with a more fair complexion can be harmful. To reduce your chances, you should limit exposure time and high intensity (midday), use a good physical sunblock at least 15-30spf and reapply it often.
Spray tan. If you really feel the need for a tan, use a spray tan and don't skimp on protecting your skin from UV radiation. If you have light skin, you likely burn easily and are at a higher risk as is.

Can moisturisers without SPF, but claim to protect you from free radicals, prevent skin cancer if put on after going in sun?

Need sunscreen. SPF free moisturisers do not protect against skin cancer. UVA and UVB light exposure increase the risk of skin cancer. Choose a moisturiser that has SPF or a sunscreen if going out in the sun.

Hi! What causes skin cancer uvb or uva? If uvb how could we get vitD from sun exposure if we prevent uvb rays cz they only make our skin produce vitD?

Excellent question. You are right! We were designed to live under the sun and that is exactly how we make vitamin D in the body. Judicious exposure to sunlight is the answer. When you develop a tan, it protects you.