Thursday, July 16, 2026

Is the Ecological Crisis now becoming mainstream - breaking through the Corporate Media firewall?

 New UN conference on how the oceans are under severe threat and in crisis

The Highseas Treaty is now ratified by 92 countries - protects areas of the ocean... shares commercial benefits of ocean species....plastic pollution transformation mechanism.... 

‘OUR ECONOMY WILL COLLAPSE’- why Britain’s heatwaves are going to get worse 

First heat and now wildfire smoke has taken over the outside environment - I stopped my outdoor work this week until Friday - people are planning on things clearing up by Friday but I'm not so sure....

The wildfires will definitely still be going into September according to the foresters....

 

 

Wednesday, July 15, 2026

The primary bond market from Fed FREE bank Reverses is always a lower percentage rate than the secondary market: Steve Keen

 https://www.youtube.com/watch?v=vyLnDop6Ux4

Mixing up the primary and secondary bond markets.... the banks are getting an asset in the primary market  - an asset that gets NO interest... and so the government offers to trade those "reserves" for a secondary market. The yield on the reserves is less than the yield on bonds.  You can't trade reserves.

It's the rate on reserves versus the primary market (not the secondary market) - the government sets the rate on reserves. The government will always buy bonds since they're a better return rate than the reserves.

leading up to the 2008 financial crisis there was no interest rate on reserves....  

 

 

the fact that the on the primary market the funds that are used to buy the bonds are created by the deficit itself. So the government spends more than it gets back in taxation that creates reserves. Those are the funds that are used to buy initial bonds in an auction.
 10% of GDP as reserves were created from QE but only .1% were sold each day in the primary market... 
 
there's 100 times as many reserves outstanding as actually needed to buy the bonds that are on offer. And because the bonds offer a higher yield than can be traded, everybody will who who can bid will bid. There'll be overs subscribed bids. This is the standard situation.

 Yes, quantitative easing (QE) directly increases the reserve accounts that commercial banks hold at the central bank 

That will affect the price of  bonds on the secondary market, but that is nothing to do with the primary market.

  Effective March 26, 2020, the Board reduced reserve requirement ratios to zero percent. This action effectively eliminated reserve requirements for all depository institutions. Consequently, all funds banks hold on deposit are technically excess reserves, currently totaling over $3 trillion

 Interest on Reserve Balances (IORB): The Fed pays interest on these excess funds, which serves as a primary tool to establish a floor under the federal funds rate

 Yes, during Quantitative Easing (QE), the Federal Reserve effectively provided the banking system with vast amounts of "free reserves." [1]

During QE, the Fed creates digital money to purchase long-term assets (like Treasury bonds and Mortgage-Backed Securities) from financial institutions. When the Fed buys these assets, it credits the seller's commercial bank with an equivalent amount of new, digital central bank reserves. Because these reserves are created out of thin air to pay for the assets, they act as free reserves injected directly into the banking system

For the most part, central banks weren’t actually “printing money”.  Rather they were buying longer-term bonds paying 2% interest with newly issued interest bearing reserves, which at the time paid almost no interest at all. Central banks were essentially operating the world’s largest hedge funds. Borrowing short-term at low rates and lending long-term at a higher rate. 

 https://www.econlib.org/time-to-pay-the-piper/

 Banks, considered together, have no choice but to hold the reserves QE has force-fed into the system. Compelling them to do it for nothing would be a form of financial repression which may impair banks’ ability to lend. It would “transfer the costs [of rising rates] to the banking sector,” Sir Paul Tucker, a former deputy governor of the Bank of England, told parliament in 2021.

 The current interest rate banks earn on reserve balances (IORB) parked at the Federal Reserve is 3.65%.

 Back in 2007, short-term interest rates in the US were about 5% and thus banks held only a tiny amount of excess reserves.  Today, excess reserves are now roughly 1000-fold higher than before the Fed began paying IOR in 2008. .. 

 Central banks determine the nominal stock of reserves, while the commercial banking system determines the real stock of reserves.  

To be sure, central banks can induce commercial banks to hold a very large stock of reserves—even in real terms—if they are willing to pay sufficient IOR.  But if you assume that no interest would be paid on most bank reserves, why would banks choose to hold large a real stock of excess reserves?

If all banks simultaneously tried to get rid of excess reserves, this would lead to changes in the prices of goods, services, and assets.  Eventually, the price level would rise high enough so that banks were holding their desired real stock of reserves.  But when you consider that excess reserves in America are roughly 1000-fold higher than in 2007, the required price level increase would presumably be very large. ...

 The commercial banks acquire “free” legal reserves, yet the bankers protested that they didn’t earn any interest on their balances in the Federal Reserve Banks.
Given bankable opportunities (and the Federal Government is the largest creditworthy borrower providing zero risk-weighted assets), on the basis of these newly acquired free reserves, the commercial banks created a multiple volume of credit and money. And, through this money, they acquired a concomitant volume of additional earnings assets.
How much was this multiple expansion of money, credit, and bank earning assets? Thanks to fractional reserve banking (an essential characteristic of commercial banking) for every dollar of legal reserves pumped into the member banks by the Fed, the banking system acquired about $206:1 (c. 2006), dollars in earning assets through credit creation.

 https://talkmarkets.com/article/bank-reserves-and-loans-the-fed-is-pushing-on-a-string?post=64407

  The Fed is anxious to spark more lending/borrowing, and it has lowered interest rates to near-zero and made it easy for banks to build reserves--two things that in previous eras would have sparked increased borrowing.

Commercial banks acquire earning assets through the creation of new money. When commercial banks make loans to or buy securities from the nonbank public new money- demand deposits are created in the banking system.
The aggregate lending capacity of the payment’s System is determined by the monetary policy of Federal Reserve Authorities. It is in no way dependent on the savings practices of the public.

 https://fred.stlouisfed.org/graph/?g=UheC

 

 The real interest rate is the true cost of borrowing or the actual yield on savings after adjusting for inflation. It represents your true change in purchasing power. If a savings account pays 5% and inflation is 3%, your real interest rate is 2%

FFR (Federal Funds Rate) is the interest rate banks charge each other to borrow or lend reserve balances overnight. The rate banks earn on funds held directly at the Federal Reserve is called IORB (Interest on Reserve Balances). The Fed uses the IORB to anchor the FFR. [1, 2, 3]
The distinction operates as follows:
  • Federal Funds Rate (FFR): The rate commercial banks charge each other in the private market for overnight loans of reserves.
  • Interest on Reserve Balances (IORB): The rate the Fed pays banks for keeping their money in reserve at the central bank
ZLB (Zero Lower Bound) is the macroeconomic concept that short-term nominal interest rates cannot realistically fall below zero. It limits a central bank's ability to stimulate the economy during a recession because people and banks would rather hold cash (which yields 0%) than accept a negative return. [1, 2]
It is closely related to, but distinct from, the Interest on Reserve Balances (IORB) or Interest on Excess Reserves (IOER). While the ZLB refers to the "zero floor" limit for monetary policy, the IORB is the actual positive interest rate central banks (like the Federal Reserve) pay to commercial banks on the reserve funds

 The Federal Reserve provided central banks and commercial banks with trillions of dollars in excess reserve deposits, reaching peak excess reserves of roughly $4.2 trillion in late 2021. These massive reserve balances were created as the direct liability counterpart to the Fed's quantitative easing (QE) asset purchases

  • Great Recession (2008-2014): Initial large-scale asset purchases caused bank reserves at the Fed to surge to around $2.8 trillion, which unexpectedly became trapped as excess reserves rather than immediately entering the broader money supply. [1]
  • COVID-19 Pandemic (2020-2022): The Fed purchased approximately $4.6 trillion in securities, boosting peak reserve balances to an all-time high of roughly $4.2 trillion
  •  Since then, the Fed has utilized quantitative tightening (QT) to shrink its balance sheet and reduce these overall reserve deposits to around $3 trillion, which the Fed considers the baseline for an "ample reserves" monetary policy framework

     https://www.minneapolisfed.org/article/2015/should-we-worry-about-excess-reserves

      the nation’s fractional banking system allows banks to convert excess reserves held at the Federal Reserve into bank loans at about a 10-to-1 ratio. Banks might engage in such conversion if they believe other banks are about to do so, in a manner similar to a bank run that generates a self-fulfilling prophecy.

     Policymakers could guard against this inflationary possibility by the Fed selling financial assets it acquired during quantitative easing or by Congress significantly raising reserve requirements.

     So, 60 percent of the entire monetary base is now in the form of excess reserves compared to roughly 0 percent precrisis.

      Since each dollar of bank deposit requires approximately only 10 cents of required reserves at the Fed, then each dollar of excess reserves can be converted by banks into 10 dollars of deposits. That is, for every dollar in excess reserves, a bank can lend 10 dollars to businesses or households and still meet its required reserve ratio.

     Thus, if every dollar of excess reserves were converted into new loans at a ratio of 10 to one, the $2.4 trillion in excess reserves would become $24 trillion in new loans, and M2 liquidity would rise from $12 trillion to $36 trillion, a tripling of M2.

     The U.S. M2 money supply is currently at $23.05 trillion. This metric reflects a 5.58% year-over-year increase.

      a central bank that commits to pay a given nominal interest rate on excess reserves, but where banks are free to convert these excess reserves to loans at any time.1 Within this setting, we consider two scenarios: In the first, households, firms and banks all expect inflation to be low. In this scenario, the interest rate offered by the Fed is sufficiently high relative to the interest rate banks could get by loaning out their excess reserves to induce the banks to leave the excess reserves at the Fed.

     In the second scenario, households, firms and banks all expect inflation to be high. Given this expectation, households and firms will be willing to pay higher interest rates to banks for loans since they expect to pay back in cheaper dollars. In this situation, the Fed’s interest rate on excess reserves is no longer high enough to induce banks to leave their reserves at the Fed, and when banks convert their excess reserves to loans, they create extra liquidity that generates higher inflation. Thus, the expectation of higher inflation induces the reality of higher inflation.

     One possible solution would be for the Fed to severely reduce its balance sheet by selling to banks the financial assets it acquired during its quantitative-easing episodes. This would automatically lower the banks’ excess reserves.

    In exchange for the newly created bank reserves injected into the financial system, the Federal Reserve acquired two primary types of financial assets: [1]
    • Treasury Securities: The Fed purchased large quantities of U.S. government debt (such as Treasury bonds and notes) to lower long-term interest rates. [1, 2, 3]
    • Mortgage-Backed Securities (MBS): The Fed also bought MBSs issued by government-sponsored enterprises and federal agencies

     By digitally creating these central bank reserves, the Fed effectively swapped the public's or financial institutions' longer-term, interest-bearing securities for highly liquid, cash-like reserve balances. 

     Another potential solution is for Congress to make the policy and legal changes necessary to convert excess reserves into required reserves by dramatically increasing required reserve ratios, perhaps to 100 percent (and possibly compensating banks by paying adequate interest on these reserves).2 In a separate paper (Chari and Phelan 2014), V. V. Chari and I consider the costs and benefits of implementing a 100 percent reserve requirement and argue that the costs of such a requirement shrink as communications technologies improve, with the usual and oft-cited benefit that bank runs are eliminated. 

    The Federal Reserve sets the required reserve ratio for all depository institutions at 0%. Because there are no required reserves, banks are not legally required to hold a minimum against customer deposits. Any reserves a bank holds at the Fed are considered excess reserves. [1, 2, 3]
    The U.S. central bank dropped reserve requirements to zero percent in March 2020 as part of its pandemic response and continues to operate under an "abundant-reserve" framework. Instead of forcing banks to keep a portion of deposits on hand, the Fed manages the money supply and influences short-term interest rates by paying interest on the reserve balances banks choose to keep with them

     https://www.youtube.com/watch?v=HDmXLWH2p9E

     

     https://www.youtube.com/watch?v=MLzncbEc63M

     So the discount rate is the ceiling of the primary market difference to the reserve interest rate.

     The discount rate (or primary credit rate) acts as the upper bound or ceiling for short-term interbank lending. Because the Federal Reserve lends directly to eligible financial institutions, no bank would logically pay a higher rate to borrow reserves on the primary market than the Fed charges at its discount window

     https://fredblog.stlouisfed.org/2024/04/rates-related-to-monetary-policy/

  • Floor: The Interest on Reserve Balances (IORB) or Overnight Reverse Repurchase (ON RRP) rate
  •  

  • the federal discount rate is a key emergency backstop to prevent bank failures.
  • Secondary credit has an interest rate set above the primary discount rate for troubled banks.
  • The discount rate is set by the Fed's board of governors, unlike the market-set federal funds rate.
  • The Fed prefers banks to monitor each other's credit risk by borrowing at the lower federal funds rate.
  •  Essentially 100% of the Treasury securities purchased by the Federal Reserve for Quantitative Easing (QE) are sourced from Primary Dealers

     

    Primary Dealers

    ASL Capital Markets Inc.

    Bank of Montreal, Chicago Branch

    Bank of Nova Scotia, New York Agency

    BNP Paribas Securities Corp.

    Barclays Capital Inc.

    BofA Securities, Inc.

    Cantor Fitzgerald & Co.

    Citigroup Global Markets Inc.

    Daiwa Capital Markets America Inc.

    Deutsche Bank Securities Inc.

    Goldman Sachs & Co. LLC

    HSBC Securities (USA) Inc.

    Jefferies LLC

    J.P. Morgan Securities LLC

    Mizuho Securities USA LLC

    Morgan Stanley & Co. LLC

    MUFG Securities Americas Inc.

    NatWest Markets Securities Inc.

    Nomura Securities International, Inc.

    RBC Capital Markets, LLC

    Santander US Capital Markets LLC

    SMBC Nikko Securities America, Inc.

    Societe Generale, New York Branch

    TD Securities (USA) LLC

    UBS Securities LLC.

    Wells Fargo Securities, LLC

     https://www.federalreserve.gov/econres/notes/feds-notes/who-buys-treasuries-when-the-fed-reduces-its-holdings-20240614.html

     

     

     

     

     

     

     

     

     

     

     

    the difference btwn the AVERAGE income ($80K) and MEDIAN income ($50K) in the U.S. is the real secret: Radhika Desai

     https://www.youtube.com/watch?v=knSzS6MjZPA

     

    12 xylitol Dental mints a day!! Dr. Ellie Phillips says plaque forming bacteria are killed off by Xylitol as a fake feeding frenzy

     Dr. Ellie Phillip's teeth care 5 step system video

     1) Zellie's Xylitol gum or mints... (on waking up, after eating - let the xylitol work in for at least one hour, and after brushing/washing)...

    02. CloSYS Prerinse

    CloSYS will prepare your teeth for brushing. This pH neutral rinse ensures that brushing teeth does not occur in an acidic mouth and therefore easily damage teeth.

    03. Crest Cavity Protection Regular Paste

    Crest Cavity Protection Regular Paste has an active ingredient of sodium fluoride at optimal concentration (not stannous fluoride). This paste has the proper abrasion and no glycerine. Stannous fluoride: Dr. Phillips does not recommend stannous fluoride (often found in plaque-control and sensitive-teeth formulas). She states it can irritate the mouth, cause sores, and be too harsh on gum tissues

    04. Listerine

    Listerine is an effective rinse that targets the bacteria that cause plaque build up and gingivitis with three active ingredients: eucalyptus essential oil, menthol essential oil, and thymol essential oil.

    05. ACT Anticavity Rinse

    ACT is a very dilute but extremely effective sodium fluoride solution. It helps prevent and reverse cavities, strengthen teeth, reduce sensitivity, and leaves your breath fresh.

     .55 g of xylitol per  mint. Dentists recommend consuming 6g to 10g daily across 3 to 5 exposures for maximum dental benefits...I just ordered HALF a year's supply of Xylitol spearmints based on eating 12 per day! I'm very excited about this.

    Skip Dental Cleanings vid - no plaque buildup means no tartar means no cavities 

    https://zellies.com/products/spearmint-xylitol-dental-mints 

    Probably should have read the reviews but I'm a big fan of spearmint...

     Zellie's Spearmint Dental Mints are a minty, sweet treat that are amazing for your teeth! Your mouth will feel clean and refreshed after each mint.

    INGREDIENTS: Xylitol, Natural Spearmint Flavor, Magnesium Stearate.

    Pick the size that works best for you. Or mix-and-match sizes to be sure you have Zellie's wherever your day takes you.

    MADE IN CANADA

     Enjoy Zellie's throughout the day for fresher breath and healthier teeth.

    Studies show 6 to 10 grams of xylitol daily, in frequent small doses, helps support oral health.

    Suggested Use: Dissolve Zellie's mints in your mouth directly after meals, snacks and drinks.

     Zellie’s mints are sweetened with tooth-friendly xylitol and each mint contains 0.55 grams of xylitol.

     Yes, Dr. Ellie Phillips does not just work for Zellie's; she is the founder and creator of the brand Zellie's Mints & Gum. She is a dentist and oral health educator who crafted the products with plant-based xylitol to protect teeth and improve oral hygiene

     https://drellie.com/tag/zellies-complete-mouth-care-system/

     White strips and whitening rinses may whiten teeth at first – but your teeth will quickly stain again, and possibly be fragile and break or become porous and sensitive.

    Unfortunatley whitening products are not safe for you, or your teeth. I never suggest whitening rinses or toothpaste. Most whitening products are very acidic (a pH as low as 1.5). If you have weak or porous teeth – these products wreck havok on them. Dark or yellowing teeth need protection from acidity – not acidity! Use the Zellies Complete Mouth Care System to restore tooth enamel strength, and it will safely make your teeth look shiny, smooth, brighter and whiter in a few months.

    https://drellie.com/2012/06/15/the-dark-side-of-whitening/ 

     Hydrogen peroxide itself is a weak acid, so it temporarily lowers the pH of your mouth during use. However, it actually kills bacteria and helps break up bacterial plaque rather than feeding them...Peroxides can do harm to teeth, particularly young teeth. 

    The color may even out at first but the tooth will be more damaged, often sensitive and may even die. (see “The Dark Side of Whitening” for more info on why whitening is so damaging).

    Bleaching may seem like a “quick fix” but your teeth can end up with worse staining in the future, sensitivity and even gum recession. The best approach to stop, prevent or reverse white spots is to use the system of xylitol and rinses that I recommend.

     When Streptococcus mutans (the primary bacteria responsible for cavities) feeds on sugars (especially sucrose),

    As the bacteria digest the sugar, they excrete corrosive lactic acid. This continuous acid production drops the pH of your mouth below 5.5, which causes the minerals in your tooth enamel to dissolve and eventually leads to cavities 

    https://repo.odmu.edu.ua/xmlui/bitstream/handle/123456789/16986/Adamiv.pdf?sequence=1&isAllowed=y 

      This polyol has a significant antiplaque effect on teeth surface and can
    reduce the gingival inflammation; it is being used as a preventive agent for dental caries due to decreasing the growth levels of pathogenic Streptococcus mutans and Streptococcus sangui at the very early stages. Xylitol can bind with calcium ion leading to consequent remineralization of teeth enamel; it is also able to prevent osteoporosis.

     Xylitol decreases the growth of bacteria. S. mutans carry the xylitol sugar inside the cell during an energy-consuming cycle, and this phenomenon is responsible for inhibition of growth and, ultimately, inhibition of plaque (Alves et al. 2013). 

    https://link.springer.com/content/pdf/10.1186/s12866-020-01867-8.pdf 

     The inhibitory effect of polyols was more pronounced in the early stages of
    biofilm formation but affected also the measured total amount of formed biofilm. Effects seen in the real-time
    biofilm assay were only partially explained by changes in CFU values and polysaccharide amounts in the biofilms. Both
    xylitol and erythritol inhibited real-time biofilm formation by all the nine tested S. mutans strains. Sensitivity of the strains
    to inhibition varied: some were more sensitive to xylitol and some to erythritol. Xylitol also modified the expression levels
    of gbpB, gtfB, gtfC and gtfD genes that are important in polysaccharide-mediated adherence of S. mutans.
    Conclusion: The erythritol- and xylitol- induced inhibition of biofilm formation was only partly explained by decrease in
    the number of viable S. mutans cells or the amount of polysaccharides in the biofilm matrix, suggesting that in addition
    to reduced proliferation also the matrix composition and thereby the surface attachment quality of biofilm matrix may be
    altered by the polyols.

    xylitol inhibits the growth of S. mutans via a futile
    xylitol-5-phosphate cycle. The inhibition is related to the
    PEP:PTS activity, resulting in ‘starvation’ of the cells
    [31]. At the ten-hour time point we noted markedly
    lower amounts of RNA isolated from bacteria growing
    in biofilms exposed to xylitol compared to RNA from
    similar numbers of live bacteria from control biofilms,
    which may reflect the xylitol-induced ‘starvation’ of the
    bacteria in the xylitol biofilm. Our results thus suggest
    that growth inhibition may contribute to biofilm inhib-
    ition at the early stages, and even though the number of
    viable bacteria is not reduced in later stages, their pro-
    tein synthesis may be impaired.

    https://pmc.ncbi.nlm.nih.gov/articles/PMC7224268/ 

     the first study that shows significantly higher impact of S. mutans in microbial population of mouth microflora on caries development than sugar consumption and oral hygiene. Accordingly, S. mutans screening program should be more highlighted in preventive strategies.

    Health benefits of xylitol

    A Gasmi Benahmed, A Gasmi, M Arshad… - Applied Microbiology …, 2020 - Springer
    … due to decreasing the growth levels of pathogenic Streptococcus mutans and Streptococcus
    sangui at the very early stages. Xylitol can bind with calcium ion leading to consequent …Cite Cited by 245 Related articles All 14 versions

    Xylitol and erythritol inhibit real-time biofilm formation of Streptococcus mutans

    V Loimaranta, D Mazurel, D Deng, E Söderling - BMC microbiology, 2020 - Springer
    xylitol decreases the number of cariogenic streptococci in dental plaque. In vitro biofilm models
    to study the mechanism of xylitol … of xylitol on biofilm formation by Streptococcus mutans. …Cite Cited by 81 Related articles All 15 versions

    Transport and Phosphorylation of Xylitol by a Fructose Phosphotransferase System in Streptococcus mutans

    L Trahan, M Bareil, L Gauthier, C Vadeboncoeur - Caries Research, 1985 - karger.com
    … -preventive agent xylitol interferes with the growth of Streptococcus mutans. It was found that
    the xylitolsensitive strain of S. mutans 27352 (serotype g) and LG 1(serotype c) took up 14C-…Cite Cited by 176 Related articles All 5 versions

    Growth Inhibition of Streptococcus mutans with Low Xylitol Concentrations

    EM Söderling, TC Ekman, TJ Taipale - Current microbiology, 2008 - Springer
    … 0.1% and 1% xylitol. Our results suggest that low xylitol concentrations of 0.1% (6.6 mM)
    could inhibit mutans streptococci in vivo but even lower xylitol concentrations may be inhibitory. …Cite Cited by 88 Related articles All 13 versions

    Mutans streptococci dose response to xylitol chewing gum

    P Milgrom, KA Ly, MC Roberts… - Journal of dental …, 2006 - journals.sagepub.com
    … of xylitol used and the changes in mutans streptococci levels in plaque and saliva. Reductions
    in mutans streptococci levels … The earlier reduction in plaque mutans streptococci levels is …Cite Cited by 264 Related articles All 14 versions

    Influence of sucrose and xylitol on an early Streptococcus mutans biofilm in a dental simulator

    KM Salli, SD Forssten, SJ Lahtinen… - Archives of oral biology, 2016 - Elsevier
    … The effects of sucrose, xylitol, and their combination on three strains of Streptococcus
    mutans and one strain of Streptococcus sobrinus were studied using a dental simulator. …Cite Cited by 74 Related articles All 6 versions

     Xylitol is not a left-handed sugar. It is a naturally occurring "right-handed" sugar alcohol. While the human body cannot fully digest it, it is still partially absorbed, which gives it about 40% fewer calories than table sugar, rather than being entirely calorie-free.
    Cheese raises oral pH—despite being acidic itself—because the physical act of chewing stimulates a rush of alkaline saliva, which washes away and buffers acids in the mouth. Additionally, compounds like casein protein and calcium coat the teeth, creating a protective shield that prevents enamel erosion and neutralizes harmful bacteria. [1, 2, 3, 4]
    While cheese contains lactic acid, its primary effect on your teeth and mouth is highly protective. The mechanism breaks down into three specific actions: [1, 2]
    • Spikes Saliva Production: Chewing firm, dense cheese triggers a rapid increase in saliva flow. Saliva is naturally alkaline and contains bicarbonates that neutralize and wash away the acids produced by plaque. [1, 2, 3, 4, 5]
    • Elevates pH for up to 30 Minutes: Studies have shown that consuming just a small portion of cheese causes the pH of dental plaque to rise. It typically keeps the mouth in a basic/neutral state for over half an hour. [1, 2, 3, 4]
    • Releases Protective Minerals: Cheese is packed with calcium and phosphate. These minerals stick to tooth enamel, helping to remineralize areas weakened by acids and preventing cavities