SAMA HOOLE: Calcium absorption from spinach: about 5% due to oxalates. Calcium absorption from dairy: 30-35%.

Calcium absorption from spinach: about 5% due to oxalates.

Calcium absorption from dairy: 30-35%.

You'd need to eat 16 cups of spinach to get the bioavailable calcium in one glass of milk.

Nutritional databases don't tell you this.

— Sama Hoole (@SamaHoole) October 13, 2025

SAMA HOOLE: Oxalate crystal formation isn't just kidney stones.

Oxalate crystal formation isn't just kidney stones. It's:

Joint pain and stiffness
Muscle pain and weakness
Vision issues
Digestive problems
Chronic fatigue
Depression and brain fog

That spinach salad is a full-body assault weapon.

— Sama Hoole (@SamaHoole) September 23, 2025

SAMA HOOLE: Superfoods with the highest oxalate content

The superfoods with the highest oxalate content:

Spinach: 750mg per cup
Rhubarb: 860mg per cup
Beets: 250mg per cup
Nuts: 200mg per serving

A "safe" daily limit is 40-50mg.

One spinach salad = 15 days worth of oxalates.

Maybe avoid these if you don't like kidney stones.

— Sama Hoole (@SamaHoole) September 21, 2025

Was Popeye the Sailor man trying to give us kidney stones? 

Whole Foods Using Fake Organic Foods from China?

I sold to Whole Foods 20 years ago and caught them charging triple for my fruit and labeling it organic while they knew that I was a conventional grower. I cut them off immediately.
Unfortunately, this just doesn’t happen from China. It happens all the time
I’ve caught and…

— Christine Davis (@DavisPeachFarm) March 6, 2025

10 FOODS PROVEN TO TRIGGER KIDNEY STONES

from Activebeat

Your kidneys play a vital role when it comes to filtering waste out of the body. Each day, these organs on either side of the spine, filter more than 200 quarts of blood and 2 quarts of waste products before it’s flushed out of the body via urination.

Obviously, healthy kidneys are essential for proper detoxification. However, certain foods can cause kidney stones and keep these organs from functioning optimally. Here are ten foods that encourage kidney stone development…

1. Excessive Caffeine

Too much caffeine—in the form of coffee, tea, and soda—can stress out the kidneys and lead to the development of kidney stones due to higher calcium levels in the urine, and even kidney failure due to the stimulant qualities that can cause organ exhaustion.

Too much of anything truly is bad for you.  One of the reasons why cups of coffee with saucer look appealing is because the amount of coffee is small.  It's not a large cup, say, from Starbucks or Pete's Coffee.  One guy in a forum I subscribe to advocated 6 to 8 eggs, cooked but as close to raw as possible, to restore nerve and hormonal communication between organs.  Okay, sounds good.  Cholesterol can do that, but there seemed to be little consideration for the amount of protein consumed in such large quantities of eggs.  Moderation really is the best rule of thumb, even if it is moderation in those things that are bad for you.  I love my coffee.  I like it at different times of the day, not just in the morning.  I tend to drink coffee in the morning to warm me up not wake me up.  Once I am up I don't need a stimulant; I generally need warmth.  Later in the day, I like the occasional cup of coffee for taste.  I love the taste.  But I do have to be careful drinking too many cups a day.  It has an aging and drying effect, particularly if the excess coffee consumption is exhausting my kidneys.

When in Denver this past summer, I was drinking a brand called DazBog.  I liked it because it had a deeper, richer coffee taste.  At times it did taste like burnt cigarette ashes but it was still good.  I liked it better than Starbucks, which even their dark roast cannot match to the richness and depth of DazBog.  I wished I drank better-tasting coffee.  For the longest time I was drinking instant coffee from Whole Foods that wasn't bad.

2. Rhubarb

If kidney stones are hereditary, you should steer clear of foods that contain oxalates (the material that makes up the actual stones). Rhubarb is one food that’s particularly high in oxalates.

On oxalates, the verdict is still out:

The formation of kidney stones containing oxalate is an area of controversy in clinical nutrition with respect to dietary restriction of oxalate. About 80% of kidney stones formed by adults in the U.S. are calcium oxalate stones. It is not clear from the research, however, that restriction of dietary oxalate helps prevent formation of calcium oxalate stones in individuals who have previously formed such stones. Since intake of dietary oxalate accounts for only 10-15% of the oxalate that is found in the urine of individuals who form calcium oxalate stones, many researchers believe that dietary restriction cannot significantly reduce risk of stone formation. 

In addition to the above observation, recent research studies have shown that intake of protein, calcium, and water influence calcium oxalate affect stone formation as much as, or more than intake of oxalate. Finally, some foods that have traditionally been assumed to increase stone formation because of their oxalate content (like black tea) actually appear in more recent research to have a preventive effect. For all of the above reasons, when healthcare providers recommend restriction of dietary oxalates to prevent calcium oxalate stone formation in individuals who have previously formed stones, they often suggest "limiting" or "reducing" oxalate intake rather than setting a specific milligram amount that should not be exceeded. "Reduce as much as can be tolerated" is another way that recommendations are often stated.

3. Artificial Sweetener

You probably use artificial sweetener in your coffee as opposed to sugar in order to cut calories. And maybe you opt for diet soda for the same reason. However, studies show that non-caloric sweeteners impair kidney function if consumed long term. So it’s best to opt for natural sweeteners like honey, stevia or agave instead.

Aspartame, which exists in a few artificial sweeteners, is the worst food you can put into your system.  Find out why.

4. Meat

Animal proteins are also linked to kidney stones and organ damage. And those who consume a high-protein diet put particular stress on their kidneys because protein waste is difficult to eliminate form the body efficiently. Meat is also high in uric acid, a common cause of kidney stones.

5. Sardines

If you’re prone to kidney stones, you’ll also want to curb your diet of any foods that are high in purines (an organic compound that boosts aroma). Sardines are extremely guilty of purine content so don’t pop that can top.

6. Salt

A healthy amount of sodium in your diet is necessary for healthy fluid levels. However, adding salt to your diet—via the salt shaker or processed foods—encourage water retention retaining water, meaning excess sodium isn’t flushed out of the body and the kidneys and blood pressure are put in jeopardy.

7. Carbonated Drinks

Carbonated drinks (i.e., soda, energy drinks, and certain bottled juices) will heighten the risk of developing kidney stones and even put you at risk for kidney disease. As an alternative, if you can’t drink your water plain, use frozen berries, slices of citrus, or a splash of natural cranberry or pomegranate juice.

8. Some Leafy Greens

We’ve already discussed that kidney stones form due to a build-up of calcium oxalate. And those with a high level of the chemical compound in their urine are more prone to stones. That’s why it’s vital to stay clear of some leafy greens—such as spinach, okra, and Swiss chard.

9. Dairy Foods

We eat dairy products because they are high in calcium to build strong bones. However, for those prone to kidney stones, calcium is not a friend. In fact, it increases the excretion of calcium in the urine, making waste elimination more difficult and encouraging kidney stones to form.

10. Processed Foods

Most processed foods, like that bag of chips you’re eating, contain genetically modified ingredients—such as corn, soy, rice, and canola—to protect crops from pests resistance and herbicides. However, these products impair healthy kidney and liver function, encouraging kidney stones to form.