14th November 2023, Mumbai: When considering foods associated with type 2 diabetes, the common focus tends to be on sugar, despite unclear evidence.
A recent US study from Tulane University scrutinized data from the UK Biobank study, encompassing around 400,000 adults over almost twelve years. The findings implicated salt, with approximately 13,000 participants developing type 2 diabetes during the study period.
In an official statement, the lead researcher of the study stated that…“taking the saltshaker off the table can help prevent type 2 diabetes”. But is it really as simple as that?
For a start, this type of study, called an observational study, cannot prove that one thing causes another, only that one thing is related to another. (There could be other factors at play.) So it is not appropriate to say removing the saltshaker “can help prevent”.
Dan Green and one of the researcher have previously criticised university press releases such as this as they can lead to misleading news stories. The Tulane study can only suggest an association between salt use and the risk of developing type 2 diabetes – nothing more.
This is before considering the quality of the data itself.
The information utilized to evaluate salt consumption relied on a straightforward query…“Do you add salt to your food?” (It specifically excluded salt added in cooking.)
Participants in the study responded to a question that offered only the following choices: “never/rarely”, “sometimes”, “usually” or “always”. This implies that it’s not feasible to gauge, based on the responses, the extent to which salt might be linked to an elevated risk of developing type 2 diabetes.
‘Dose-Response’ Effect
In countries like the UK, the typical salt intake is approximately 8g or two teaspoons daily, with about three-quarters originating from processed foods. The remaining portion is primarily added during cooking, with minimal additional salt at the table.
The NHS recommends limiting daily salt intake to around 6g. Despite a reduction in salt consumption over the past few decades, there’s still room for improvement. As salt reduction is a public health objective, accurately quantifying intake becomes crucial to assess the potential for a “dose-response” effect.
The provided data, however, doesn’t clarify whether consuming 2g of salt daily at the table increases the risk of developing type 2 diabetes more than, for example, consuming 1g a day.
The researchers employed alternative tests to assess salt intake, including estimating the amount of salt participants excreted in their urine over a 24-hour period – considered the most precise method for measuring sodium or salt intake.
This approach indicated a correlation between higher sodium levels in urine and an elevated risk of developing type 2 diabetes. However, this analysis didn’t take participants’ dietary choices into account, making it unclear if salt can be directly implicated in increasing the risk of type 2 diabetes.
Some evidence suggests that increased salt intake, as measured by urinary sodium levels, may be associated with elevated cortisol, a stress hormone.
This connection has been linked to higher blood pressure and reduced insulin effectiveness. However, this mechanism has only been demonstrated in rats.
Embracing Health: The Benefits of Reducing Salt Intake
What we can assert with more confidence is that individuals with type 2 diabetes, often accompanied by high blood pressure, tend to witness blood pressure improvements with reduced salt consumption.
The key takeaway is clear: incorporating less salt into a balanced diet, known to lower the risk of type 2 diabetes, is advisable.
While this study didn’t specify the extent of necessary salt reduction, it only hinted at a weak association between adding salt to food and the risk of developing type 2 diabetes. Therefore, it’s prudent to focus on established risk reduction measures, such as maintaining a healthy weight, engaging in regular physical activity, and adopting a nutritious diet.
By Vaishnavi Rastogi