Eating processed meat such as sausages increases the likelihood of heart disease, while red meat does not seem to be as harmful, a study suggests.

一项研究显示，食用加工过的肉类，诸如香肠，可增加患心脏病的可能性，而且红色肉类似乎并无害处。

Researchers believe it may be the salt, not the fat, that's the problem

A Harvard University team which looked at studies involving over one million people found just 50g of processed meat a day also raised the risk of diabetes¹（糖尿病） .

But there was no such risk from eating even twice as much unprocessed（未加工的） meat, such as beef, lamb（羔羊） or pork.

This was despite the fact the two forms of meat have a similar fat content.

Writing in the journal Circulation, the researchers speculated（推测，思索） that given the similar quantities of cholesterol²（胆固醇） and saturated³ fats（饱和脂肪） , the difference may be explained by the salt and preservatives⁴ added to processed meats.

This is defined as any meat preserved by smoking, curing or salting and includes bacon, sausages, salami（意大利蒜味腊肠） and other luncheon⁵（午宴） meats.

Salt can increase blood pressure in some people, a key risk factor for heart disease.

In animal experiments, nitrate（硝酸盐） preservatives can promote atherosclerosis（动脉硬化） and reduce glucose⁶ tolerance⁷, which can in turn lead to heart problems and diabetes.

Similar lifestyle

The team from Harvard School of Public Health looked at 20 studies involving more than one million participants（参与者） from 10 countries.

On average, each 50g serving of processed meat per day - the equivalent of a sausage or a couple of rashers（薄片） of bacon - was associated with a 42% higher chance of developing coronary heart disease（冠心病） and a 19% higher risk of diabetes.

"Although cause-and-effect（有因果关系的） cannot be proven by these types of long-term observational studies, all of these studies adjusted for other risk factors," said Renata Micha, lead author.

"Also, the lifestyle factors associated with eating unprocessed meats and processed meats were similar, but only processed meats were linked to higher risk."

Victoria Taylor, senior heart health dietician at the British Heart Foundation, said: "If you like red meat, this can still be included as part of a balanced heart-healthy diet.

"Go for lean cuts and aim to cook from scratch using healthier cooking methods like grilling⁸ or baking. If you need to add flavour, then try using fresh and dried herbs（药草，草本植物） , spices and chillies instead of salt."

A spokesman for BPEX, which represents pork producers, insisted processed meats could form part of a balanced diet.

He suggested further research was needed before any dietary（饮食的） recommendations could be made.

"Various studies indicate that high consumption of processed meat can be indicative of an overall poorly balanced diet: therefore it could be other aspects of the diet that are contributing to the increase in risk," he added.