Salt is well-known as a contributing factor to high blood pressure and heart disease, but new research has highlighted its effects on obesity.
Obesity has turned in a worldwide epidemic responsible for many health conditions. In 2014, the World Health Organisation reported that 1.9 billion adults aged 18 years and older were overweight, and of these adults, over 600 million were obese.
A high-salt diet is one that includes more than the recommended daily intake of salt. Current recommended levels are no more than 6g a day for adults, but it is thought most people regularly consume more than that.
Salt is often listed as sodium on packaging; this is tricky because sodium levels are recorded in a different way. To understand the correct salt level it's important to times the sodium level by 2.5.
Maximum recommended salt levels are:
Research shows that people regularly consume more salt than is recommended, often despite not adding any to their meals from a saltshaker.
Foods that contain high levels of salt include bacon, anchovies, cheese, gravy granules, ham, soy sauce, stock cubes and yeast. Perhaps surprisingly, other foods such as soups, bread, crumpets, pasta sauce and breakfast cereals can also be high in salt.
Too much salt is dangerous as it can lead to the following serious conditions:
Salt increases blood pressure. This can become dangerous when blood pressure is constantly higher than the recommended levels. A high reading may be picked up during a doctor's exam, but it's not something that has symptoms. If it's not treated, high blood pressure can put extra strain on the heart and arteries, and may lead to heart failure. Blood pressure is one of the world's leading causes of death because it causes strokes and heart attacks. It's thought that 1 in 3 UK adults have high blood pressure.
Kidneys remove waste products and fluid by filtering the blood. To do this they require sodium and potassium. A diet high in salt upsets this delicate balance and reduces kidney function; meaning kidneys may remove less excess water. Excess fluid leads to dangerous high blood pressure.
Salt also increases urine protein that is a risk for kidney decline. This process puts a strain on the kidneys leading to kidney disease.
A high-salt diet may also lead to kidney stones. Urinary calcium creates renal stones and this is increased by excess salt. Kidney stones are painful, they cause vomiting, fever and sometimes complications.
Some research indicates that a high intake of salt increases the risk of stomach cancer.
Countries with higher rates of stomach cancer often have a high national intake of salty food. Salt also boosts helicobacter pylori - a stomach infection that has been linked to stomach cancer.
Osteoporosis is when the bones become thinner. Postmenopausal women are particularly at risk due to decreasing levels of oestrogen, but high levels of salt can also lead to demineralisation.
High levels of salt can exacerbate existing illnesses such as diabetes. Those with heart disease, diabetes and other risk factors need to be particularly careful and follow a low salt diet.
New evidence is pointing towards salt as a risk factor for obesity. A study entitled 'High salt intake: independent risk factor for obesity?', published in the journal Hypertension, found a 1g increase in salt per day correlated to a more than 25% increase in the risk of obesity in both children and adults.
Salt has previously been linked to obesity, in that eating a lot of salt leads to an increase in thirst, which may trigger a greater intake of high-sugar drinks. It is also likely that eating a lot of salt correlates with simply eating too many processed foods high in sodium and calories instead of home cooking, resulting in obesity.
More investigation is needed, but the new research suggests that high salt intake may also be related to fat metabolism. This is significant because the study names salt as an independent cause of obesity for the first time, without the added intake of sweet drinks. Therefore a reduction in salt may lead to a direct cut in obesity rates, making it an important factor for good health.
Obesity is a worldwide issue and the root cause of many health problems, including:
Manufacturers are starting to reduce salt levels in processed foods, but the levels can still be too high for good health. Therefore one of the best ways to reduce intake is to limit the amount of processed foods eaten.
Learn about nutrition labels - Compare brands and meals for salt and sodium content. Many people eat the same food each day, such as breakfast cereal, so choosing one low in salt will help reduce intake.
Cut down on food like bacon, salted nuts, cheese and ham - Cured meats and fish often have high levels of salt and should be eaten sparingly. Tinned vegetables may have high salt levels too. Check the label and buy the salt-free version.
Sauces, such as pasta sauce, curry sauce or Chinese sauce may have high levels of salt - Choose the reduced-salt version or make your own at home. Tomato-based sauces are usually lower in salt.
Reducing levels of salt is a good step towards improving health, particularly if diabetes or heart disease is a factor.
More research is required into the link between obesity and salt, but the current research is enough to prompt health-conscious individuals to take a closer look at their diets and ways to eliminate excess salt.