Salt: Dangerously Addictive
HYPERTENSION
by Kenneth Lyen
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CRAVING FOR IRVINS
Irvins salted eggs is one of the most recent food fads in Singapore (1), presented in the form of potato chips, fish skin or cassava chips, Recently they have introduced a new Spicy Hot Bomb addition to their original trio, in effect doubling one’s choice of chips. Irvins boasts that they are all dangerously addictive. This is a form of reverse psychology where you warn people that your products are both addictive and dangerous, and instead of avoiding them, the public embraces and buys them in droves. At the height of the fad, there were long queues that snaked around the shopping malls, and each customer was restricted to buying only five packs (later relaxed) at a rather high price of Singapore $8 (US $5.90) per pack of 105g.
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BROTHERS THREE
Irvin who? Thirty plus year old Irvin Gunawan is the second of three Indonesian brothers who stumbled upon salted egg potato chips, and began the manufacture and sales of Irvins in Singapore (video 1). They were quite startled by the unexpected sudden craving for their chips. They opened their first outlet in February 2016, and in two years they have seven outlets in Singapore, one in Hong Kong, and one in Manila. The chips are also available in Kuala Lumpur and Jakarta. Their meteoric rise in popularity was due almost entirely to word-of-mouth and to the social media, because they had not paid for any marketing at all.
ADDICTION OR CRAVING?
Why is Irvins so popular? The answer lies in their tag line stamped on every pack: “dangerously addictive”. And what is the major ingredient of this addiction? Most likely It is their relatively high salt content. Each packet contains between 250 to 310 mg of sodium (2).
“But,” you may query, “does salt addiction exist?” Well, there is some evidence that yes, salt addiction actually does exist (3).
“Or do you really mean salt craving?” I do not wish to enter the debate as to whether we are addicted to salt, or whether it is just a craving. The difference is not merely a matter of semantics. There is a real difference between addiction and craving. While addiction does involve a strong desire or craving, the reverse need not occur. In other words you can crave for something, but you can forgo that want if it is not available. However, I will cede to the neuropsychiatrists, and adopt the term “craving” (4).
WHY AM I CRAVING SALT?
The neurobiological answer comes from studies in rats, eating salt stimulates the opioid system in the central amygdala region of the brain: the region where pleasurable sensations are processed (5,6).
WHAT HARM DOES SALT INFLICT?
The earliest record of the connection between excessive salt intake and the cardiovascular system was made nearly 5000 years ago in the Huang Ti Nei Ching Su Wen (the Yellow Emperor's classic on internal medicine 2698–2598 BC), and it states: “if too much salt is used for food, the pulse will harden”(7). However, it was not until 1960 when Lewis Dahl demonstrated a positive relation between excess salt intake and hypertension (8).
The evidence that excessive salt intake causes hypertension is overwhelming. The contention that salt does not lead to high blood pressure is based on a few flawed studies (9), and should be ignored.
WHAT IS THE MECHANISM BEHIND SALT AND HYPERTENSION?
One of the major factors controlling our blood pressure is the cardiac output. If there is more fluid in our body, the heart will pump out more blood and this will increase the blood pressure. Excess salt intake leads to excess fluid in our body and hence causes hypertension (10,11, Video 2, Video 3).
DOES LOWERING DIETARY SALT INTAKE REDUCE BLOOD PRESSURE?
The overwhelming research data conclude that salt reduction lowers blood pressure (12,13,14). But recently there has been a bit of controversy.
A few well-publicized research publications did not show the benefits of dietary salt reduction. However, these are exceptions The vast majority of studies showed significant favorable results of dietary salt reduction (15,16,17).
I suspect the problem is that there are many factors affecting blood pressure. Long-term clinical studies are notoriously difficult to control all the confounding variables including maintaining a constant salt intake, the consumption of other cations like potassium, ensuring that foods that elevate blood cholesterol are evenly distributed between the groups studied. The amount of physical exercise undertaken, emotional stress, and cigarette and alcohol consumption, can all affect blood pressure and they also need to be comparable in the groups being compared. All these factors can complicate the study and render the results rather ambiguous.
I would suggest that until this issue is resolved, perhaps one might pursue a middle-of-the-road balanced approach. As there is considerable and incontrovertible evidence that high salt diet can increase blood pressure, it would be sensible to avoid consuming too much salt. Although the evidence that lowering salt intake may not necessarily reduce blood pressure is somewhat controversial, maybe it would still be advisable to err on the side of caution, and to try to reduce salt intake for the time being, until this issue is better resolved.
DIURETICS
An important method of lowering blood pressure is through the use of passing out salt in the urine using diuretics so as to reduce total body sodium. This strongly argues for the efficacy of salt reduction in decreasing hypertension (18). What seems ironic is that many critics of dietary salt reduction advocate the use of salt-reducing diuretics!
WHAT IS THE OFFICIAL RECOMMENDATIONS FOR DIETARY SALT RESTRICTION?
A diet containing more than 2,400 milligrams of sodium (about one teaspoon of salt) each day is associated with high blood pressure. Hypertension affects about 25% of adults worldwide, and is associated with heart attacks, kidney disease and strokes. While there are several other factors, such as age, family history and race, that can influence one’s risk of hypertension, lowering dietary sodium intake can significantly reduce one’s risk.
The American Heart Association recommends that adults should consume less than 2300 mg sodium per day, but the ideal should be around 1500 mg sodium. If a person has hypertension, then the daily dietary sodium should be 1500 sodium (19). The American Heart Association notes that if Americans cut their sodium intake to 1,500 milligrams per day, cases of high blood pressure would decrease by 26 percent.
The USDA recommends that healthy adults limit their sodium intake to less than 2,400 milligrams of sodium per day. High-risk individuals, such as African Americans, those with high blood pressure, existing heart disease, diabetes or kidney disease or those over the age of 51 should limit their sodium intake even further to 1,500 milligrams per day (20).
Other American agencies like the Food and Drug Administration (FDA) and the Communicable Diseases Centre (CDC) also advise a dietary intake of less than 2300 mg per day (21,22).
Most countries follow the American guidelines.
HOW MUCH SALT DO SINGAPOREANS TAKE EACH DAY
According to the World Health Organization, Singaporeans are ingesting an average of 3320 mg sodium each day which exceeds the US guideline of 2300 mg (23).
Singapore’s Health Promotion Board recommends reducing the salt intake to less than 2000 mg sodium (5 gm of salt) per day (24).
WHAT IS THE PREVALENCE OF HYPERTENSION IN SINGAPORE?
According to the Singapore’s Ministry of Health: “The high blood pressure (hypertension) level of adults declined from 24.9% in 2004 to 23.5% in 2010. A higher proportion of men were hypertensive (26.4%) compared to women (20.7%). Among the ethnic groups, the hypertension level was highest in the Malays (28.0%), followed by Chinese (23.4%) and Indians (19.3.7%). Prevalence of hypertension increased markedly from age 40 onwards. More than half (53.4%) of the elderly aged 60 to 69 years had hypertension. Among those found to have hypertension, the proportion of previously-undiagnosed hypertensives declined from 39.7% in 2004 to 26.3% in 2010” (25).
HOW TO LOWER DIETARY SALT INTAKE?
This is easier said than done. Do not add salt or soy sauce to one’s food. Try to eat more fresh fruits and vegetables. Asian foods in general are high in sodium, especially the soup-based ones. See the appendix for the list of Asian foods and their sodium content. Please see the references listed below that give you advice on how to lower dietary sodium (26,27,28,29,30).
FINAL VERDICT
I am afraid that Irvins slogan “dangerously addictive” might contain a grain of truth. Hence, you should all refrain from Irvins. But perhaps you should take what I say with a pinch of salt :) I suspect that if I asked you to cut down on your salt intake, it might have the opposite effect, that is, more of you will rush out to buy Irvins! (video 4, video 5) Okay, enjoy now, but suffer later!
REFERENCES
1 Salted but not sated https://www.businesstimes.com.sg/lifestyle/food-drink/salted-but-not-sated
2 Calories (and sodium) in Irvins Salted Egg Fish Skin https://www.myfitnesspal.com/food/calories/irvins-salted-egg-fish-skin-664690443
3 Does salt addiction exist? Scientific evidence suggests that it certainly does.
http://www.scielo.org.mx/pdf/sm/v39n3/0185-3325-sm-39-03-00175.pdf
4 Food addiction or food craving?
https://www.eufic.org/en/food-today/article/food-addiction-or-food-craving
5 Scientists reveal why salt is so addictive
https://www.smh.com.au/technology/scientists-reveal-why-salt-is-so-addictive-20161111-gsnhx6.html
6 Why am I craving salt https://www.healthline.com/health/craving-salt#reducing-salt-intake
7 Commentary: Salt intake, hypertension and risk of cardiovascular disease: an important public health challenge https://academic.oup.com/ije/article/31/2/327/617699
8 Lewis K Dahl: Results of chronic excess salt feeding.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2137450/pdf/231.pdf
9 Salt and hypertension: why is there still a debate?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4089608/
10 Dietary Salt intake and Hypertension https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4105387/
11 Why is too much salt bad for you? https://www.livescience.com/36256-salt-bad-health.html
12 Reducing salt seems to lower blood pressure as well as or better than many drugs. USA
13 Should we eat less salt? France
https://www.sciencedirect.com/science/article/pii/S1875213613000302
14 The case for salt reduction . Australia
https://www.vichealth.vic.gov.au/media-and-resources/publications/state-of-salt
15 Low Sodium Intakes are Not Associated with Lower Blood Pressure Levels
https://app.core-apps.com/eb2017/abstract/536903b6b3303af8e0989e14822abae7
16 Do you really need to eat less salt? http://time.com/4758175/high-blood-pressure-sodium/
17 The salt myth https://www.healthline.com/nutrition/how-much-sodium-per-day
18 Diuretics for Hypertension: A Review and Update
19 American Heart Association recommendations: 2300 mg sodium, 1500 mg sodium preferred
20 USDA Guidelines for Sodium Intake: 2400 mg sodium, 1500 sodium for special groups
https://healthyeating.sfgate.com/usda-guidelines-sodium-intake-7839.html
21 FDA Recommendations: 2300 mg sodium, 1500 mg sodium for special groups
https://healthyeating.sfgate.com/fda-recommended-sodium-intake-1873.html
22 CDC Recommendations: 2300 mg sodium
https://www.cdc.gov/salt/pdfs/sodium_dietary_guidelines.pdf
23 Salt Reduction Initiatives around the World
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0130247
24 Dietary Guidelines in Singapore http://apjcn.nhri.org.tw/server/APJCN/20/3/472.pdf
25 Prevalence of Hypertension in Singapore
http://www.myheart.org.sg/article/about-the-heart-and-heart-disease/statistics/risk-factors/77
26 Strategies to reduce dietary sodium intake
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3612540/
27 How to reduce sodium in Chinese food
https://healthyeating.sfgate.com/reduce-sodium-chinese-food-5965.html
28 Tips for a lower salt diet
https://www.nhs.uk/live-well/eat-well/tips-for-a-lower-salt-diet/
29 Nine Surprisingly simple ways to reduce sodium intake
30 Top 19 tips for reducing salt in your diet
https://www.kidney.org/news/ekidney/june10/Salt_june10
VIDEOS
1 How three brothers created Irvins https://www.youtube.com/watch?v=QvhQNKzqKoM
2. How does sodium raise your blood pressure? https://www.youtube.com/watch?v=27olccGHjbY
3 How salty food raises the blood pressure https://www.youtube.com/watch?v=1NL76UKUfRE
4 Irvins Salted Egg Potato Chips Review https://www.youtube.com/watch?v=ys_pkCSMqRQ
5 Irvins Salted Egg Potato Chips Review (Indonesian) https://www.youtube.com/watch?v=nvnmpeNUj3w
Dangerously Addictive is written by Kenneth Lyen
25 September 2018, revised 27 April 2020