Following the NHS advice to eat fish twice a week can make you more susceptible to the deadliest skin cancer, today’s research shows.
The researchers analyzed the diagnosis of melanoma in adults who ate the equivalent of 300 g of any type of fish each week, including batter. They were compared to participants who consumed much less. Some didn’t even eat.
The results show that people who adhere to official advice, according to which a healthy diet includes at least two servings of fish a week, are up to one-fifth more likely to develop cancer.
U.S.A. scientists say it could be due to contaminants causing cancer in fish. But other independent experts say fish is still a key part of a healthy diet and you don’t need to stop eating it.
Meanwhile, a separate study in the United States found that men who consumed more than 430 grams of dairy products a day – the equivalent of two glasses of milk – were 25 percent more likely to suffer from prostate cancer than those who had less than 20 grams.
The British are advised to consume three servings of dairy products a day, one serving is a glass of skim milk, a pot of yogurt or 30 grams of cheese.
Researchers have said that hormones that are naturally present in milk may be to blame.
They encouraged men with a family history of the disease to be “careful” to drink even “moderate” levels of milk until the findings were clear. And they said that in the meantime, they should consider switching to alternatives to soy, oats or cashews.
The NHS recommends that people eat at least two servings of fish a week, including one oily fish, one portion weighing about 140 g. But now U.S. researchers have warned that people who eat this amount may be one-fifth more likely to develop malignant melanoma than those who eat 22 grams a week.
How much fish should we eat?
A healthy, balanced diet should include at least two servings of fish a week, including one oily fish.
Most people don’t eat that much. One serving is about 140 g.
However, for some types of fish, there are recommendations for the maximum amount you should eat.
The British are told to eat at least one serving (about 140 grams when cooked) of oily fish per week.
However, girls, women who are planning to have a child, and pregnant women should not eat more than two servings of oily fish per week.
This is because contaminants in fish can affect the future development of babies in the womb.
The British are also told to avoid eating too much bream, sea bass, turbot, flounder, rock salmon and crabs, as they also contain contaminants.
Source: NHS
For the first study, researchers at Brown University looked at data on 491,367 adults who provided nutritional data in the mid-1990s. They were in their sixties when the study began.
Participants were asked how often they ate fried, uncooked and tuna fish in the previous year, as well as the size of their portions.
The researchers then tracked new cases of melanoma among participants over the age of 15, using data from cancer registries.
The results, published in Cancer Causes & Control, show that 5,034 people developed malignant melanoma during the study period. Almost all cancer patients in the first stage survive, but the percentage drops to only three in 10 for those caught in the fourth stage.
About 3,284 have developed abnormal cells in the outer layer of the skin – known as stage 0 melanoma or in situ melanoma (also sometimes called precancerous).
The team found that people with a typical daily fish intake of 42.8 g – equivalent to about 300 g per week – were 22 percent more likely to develop malignant melanoma than those with a daily intake of just 3.2 g. .
Those who eat more fish also have a 28% increased risk of stage 0 melanoma.
But the results do not apply to eating fried fish, the study showed. The risk is seen only in adults who eat melody or fried fish, which according to the NHS are healthier choices.
Current health advice states that Britons should eat at least two servings of fish a week, including one oily fish.
The study’s author and dermatologist, Dr. Eunyoung Cho, said the team’s findings “identified an association that required further investigation.”
She said: “We speculate that our findings could be due to contaminants in fish, such as polychlorinated biphenyls, dioxins, arsenic and mercury.
“Previous research has found that higher fish intake is associated with higher levels of these pollutants in the body and has found links between these pollutants and a higher risk of skin cancer.
“We note, however, that our study did not examine the concentrations of these contaminants in the participants’ bodies, so further research is needed to confirm this link.”
The researchers took into account factors that could affect the results, such as weight, diet, whether they smoke or drink alcohol and their family history of cancer.
The team also recorded average levels of UV radiation in local areas of volunteers to take into account sun exposure – a known risk factor for skin cancer.
But they do not take into account other key risk factors for melanoma, such as the number of moles, hair color, history of severe sunburn and whether people are sunbathing or wearing sunscreen.
In addition, the average daily intake of fish was calculated at the beginning of the study and may not represent how many people eat in their lifetime.
Dr Michael Jones of the Cancer Research Institute in London did not take part in the study, but said the results were “statistically significant and therefore unlikely by chance”.
But he noted that people who eat more fried fish and adjust may have other lifestyles that increase the risk of melanoma. Further research is needed to confirm the findings, Dr Jones said.
He added: “The overall healthy balanced diet should include fish and the results of this study do not change this recommendation.”
Dr Dwayne Meller, a senior lecturer at Aston Medical School who was not involved in the study, said that if contaminants in fish were to blame for the increased risk of skin cancer, it would also increase the rate of other cancers.
He said the study did not clearly identify how eating fish could increase the risk of melanoma, and eating two servings of fish a week was “part of a healthy diet.”
Experts from Loma Linda University of Health in California warned today that men who consume 430 grams of dairy products a day are more likely to be diagnosed with prostate cancer than those who consume only 20 grams – only half a glass of milk a week
How much dairy should we eat?
Milk and dairy foods provide calcium for healthy bones and teeth.
The best foods that get you calcium are yogurt, milk and cheese.
The British are told to strive for two to three servings each day.
One serving is a small piece of cheese the size of a matchbox (about 30 g), 150 g of a pot of yogurt or a glass of milk.
Milk and dairy products usually provide almost a third of the recommended calcium intake.
But the diet provided by dairy products exceeds only calcium.
A glass of semi-skimmed milk provides protein, potassium and three-quarters of the daily requirement of vitamin B12.
Meanwhile, experts from Loma Linda University of Health in California today also warned that men who consume 430 grams of dairy products a day are more likely to be diagnosed with prostate cancer than those who consume only 20 grams – only half a glass of milk. per week.
Researchers studied the dairy intake of more than 28,000 men in the United States, all of whom were initially cancer-free. Information about their diet was gathered through regular questionnaires and phone calls.
The team then used cancer registries to determine which patients developed prostate cancer eight years later. About 1,254 people were diagnosed.
About 52,000 men in the United Kingdom and 270,000 in the United States are diagnosed with prostate cancer each year. About 80% of men within 10 years after the confirmation of their cancer.
The results, published in the American Journal of Clinical Nutrition, show that those who take 430 g a day are a quarter more at risk than those who take only 20 g a day.
And men who consume 430 grams a day are 62% more likely to develop prostate cancer than those who do not have dairy products in their diet.
However, the consumption of cheese and milk is not associated with prostate cancer, the team said.
The Association of Nutritionists in the United Kingdom advises the British to consume three servings of dairy foods a day, one serving is equal to one cup of semi-skimmed milk, 150 g of a pot of yogurt or 30 g of cheese.
No link has been found between non-dairy sources of calcium – such as nuts, seeds, vegetables, legumes, fruits and fortified cereals – and prostate cancer.
This suggests that substances other than calcium in dairy products are to blame, they said.
And there was a “minimal” variation in the risk of prostate cancer between those who drank whole milk compared to people who chose low-fat or no-fat options.
Researchers have not found a link between increased dairy intake and an equally increased risk of prostate cancer.
Dr Gary Fraser, head of research and an expert on internal medicine and cardiovascular disease at the university, said the risk was no longer increasing among people who already consumed 150 grams of dairy a day – about two-thirds of a glass of milk.
He said, “Almost any biological or biochemical pathway is saturated with about two-thirds of a glass of milk a day.”
Dr Fraser said the results could suggest that dairy foods are “causally linked to the risk of prostate cancer”.
He said this may be due to the content of sex hormones in milk. About three-quarters of milk comes from pregnant cows, and prostate cancer is a “hormone-responsive cancer.”
Earlier studies found that consuming dairy products increased levels of a hormone in the blood called insulin-like growth factor-1, which is thought to increase the risk of developing certain cancers.
Dr. Fraser said he would encourage men with a family history of prostate cancer or those with other risk factors to be “careful” when drinking even “moderate” levels of milk until the findings are clear.
“If you think you are at higher than average risk, …
Add Comment