The vastly popular flavour enhancer salt is known for its detrimental health effects. However, it seems to be even worse than we imagined. Not only does it contribute to heart-related health issues, but Japanese researcher throw light on a less-explored aspect—its impact on our cognitive health. High salt intake is linked to cognitive disorders and Dementia.
Try to reduce the use of salt in your food - (Image Credit: Africa Studio via Shutterstock / HDR tune by Universal-Sci)
With an ageing population and the absence of a cure for Dementia, it's imperative that we look towards prevention. It turns out that one of the primary preventive measures could be as simple as reducing our salt intake.
The study conducted by scientists from Fujita Health University establishes a connection between cognitive decline and excessive salt consumption. While it has long been recognized that high salt intake can lead to hypertension and cardiovascular disease, this new research hints at the possible cognitive repercussions.
What is the difference between Alzheimer's disease and dementia? (Universal-Sci)
How much salt should I eat per day?
According to the FDA, Americans consume approximately 3,400 mg of sodium per day on average. However, the American Heart Association recommends no more than 2,300 milligrams (mg) a day. The ideal daily limit is no more than 1,500 mg for most adults.
The words "salt" and "sodium" are frequently used as synonyms, but they are not the same thing. Table salt, scientifically known as sodium chloride, is a compound with a crystal-like structure prevalent in nature. Sodium, on the other hand, is a mineral and constitutes one of the chemical elements present in table salt. For some perspective, 100 mg of table salt contains about 39 mg of sodium.
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The Study
The research team in Japan investigated the role of the hormone angiotensin II, important for blood pressure regulation and fluid balance, and its receptor AT1. They also examined the protein molecule prostaglandin E2 and its receptor EP1, known to be involved in hypertension and neurotoxicity.
The goal was to understand the extent to which these mechanisms contribute to both high blood pressure and cognitive decline stemming from excessive salt intake.
Their findings confirmed that the interaction of angiotensin II-AT1 and prostaglandin E2-EP1 in the context of salt-induced high blood pressure can indeed cause emotional and cognitive issues.
Assistant professor at Fujita Health University and one of the authors of the study, Hisayoshi Kubota, explained that while high consumption of salt is recognized as a potential trigger for hypertension, cognitive impairment, and Dementia, however studies focusing on the interaction between the peripheral and central nervous system have not sufficiently investigated this link.
Remarkably, the research shows that the primary culprit of these cognitive issues is the excessive addition of phosphates to the protein tau, which is notably involved in the development of Alzheimer's disease.
To arrive at these conclusions, lab mice were fed a saline solution of 2% salt in drinking water for twelve weeks. Researchers monitored their blood pressure and the effects of salt intake on their emotional and cognitive functions. They also examined the protein tau phosphorylation in two critical areas of the mouse brain: the prefrontal cortex and the hippocampus.
Interesting and promising results
The results showed several biochemical changes in the brains of the mice. Researchers observed a decrease in phosphate groups linked to a crucial enzyme, CaMKII, which plays a role in brain signaling, and changes in the levels of PSD95, a protein critical to the organization and function of brain synapses.
These above-mentioned changes, however, could be reversed by administering an antihypertensive drug (losartan). A similar reversion was noticed following the deactivation of the EP1 gene.
These findings may pave the way for new treatment methods for high blood pressure-induced dementia by targeting the angiotensin II-AT1 and prostaglandin E2-EP1 systems.
Recommendations for reducing your salt intake
One immediate and direct way to influence these systems is by reducing salt intake. So be careful not to eat too much of it.
Some helpful tips for reducing your salt intake:
Cook Your Own Meals: When possible, opt to prepare meals yourself so that you can control the amount of sodium yourself.
Try Adding Flavour to Your Food Without Salt: think of herbs and spices.
Choose Your Vegetables Wisely: Purchase fresh, frozen (without sauce or seasoning), or low-sodium or no-salt-added canned vegetables.
Opt for Fresh Produce: Where possible, choose fresh meat, poultry, and seafood over processed versions. Ensure to check if salt water or saline has been added to fresh meat and poultry.
Analyze the Nutrition Facts Label: To ensure you get less than 100% DV (less than 2,300 mg) of sodium each day, always read and compare the labels on different food products.
Rinse Canned Foods: Rinse canned foods that contain sodium, like beans, tuna, and vegetables, before consuming to remove some of the sodium.
Mind Your Condiments: The sodium content in condiments can accumulate quickly. Choose light or reduced-sodium condiments, use oil and vinegar for salads instead of bottled dressings, and use a small portion of seasoning from flavouring packets.
The social and economic implications of this research are far-reaching. With the rising costs of dementia treatment each year, this study emphasizes the importance of developing preventive measures against Dementia, and the first step might just be saying no to that extra dash of salt.
If you are interested in more details about the study, be sure to check out the paper published in the peer-reviewed science journal British Journal of Pharmacology, listed below.
Sources and further reading:
High salt induces cognitive impairment via the interaction of the angiotensin II-AT1 and prostaglandin E2-EP1 systems (British Journal of Pharmacology)
Can Taking Vitamin D Help Reduce the Risk of Dementia? (Universal-Sci)
Scientists may be able to predict types of dementia more accurately based on walking patterns (Universal-Sci)
What is the difference between Alzheimer's disease and dementia? (Universal-Sci)
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