According to an expert consensus statement from the European Atherosclerosis Society,
at the recommended daily intake of 2 grams of plant steriles a day, the available evidence
does not suggest any adverse effect associated with long-term intake.
An evidence from animal cell studies suggests a protective role of plant sterile intake
and risk of certain cancers.
Human population studies have also found a protective effect of dietary phytosterol intake
Those who consume the most at a 37% lower risk of cancer, but where are phytosterols found?
Healthy foods like nuts and seeds.
Even just a single ounce of nuts a day associated with less cardiovascular risk and a lower
risk of dying from cancer and from dying from all causes put together, so phytosterols
may just be a marker for healthy food intake, but it's also possible that phytosterols
made to be one of the reasons nuts and seeds are so good for us.
There's a new class of anti-cancer agents known as histone deacetylase inhibitors available
for the low-low cost of $38,000 a month, but in terms of the most potent, naturally
occurring such inhibitors reported to date phytosterols may fit the bill.
Perhaps one of the reasons healthy plant foods are so good for us.
Most marketing surveillance studies are said to have given phytosterols a clean bill of
health based on thousands of consumers, but the study was done by the company that sells
those products so I don't take much comfort from it.
There's a concern that plant sterols could reduce the absorption of certain fat soluble
They don't seem to impact concentrations of blood levels of vitamins A, D or K, but they
can drop vitamin E levels by about 10%.
The main concern, though, has been about the loss of crot noise like beta-carotene.
One modeling study suggests that if margins became 100% fortified with phytosterols, the
incidence of night blindness, difficulty seeing in dim light, may increase as much as
19,000 every year, whereas that would also result in 1,000 not getting heart disease.
Since night blindness is considered a relatively minor visual disturbance, the benefits of
fortification might clearly outweigh the punitive risk, but there's no need to have any
risk at all because the relatively small suppression of plasma crot noise levels can
be countered by just eating more fruits and vegetables.
The problem with fortifying something like margarine with phytosterols is that people make
cook with it, and that could cause the plant sterols to oxidize into phytosterol oxidation
We know cholesterol oxidation products are particularly bad, but we aren't sure about
oxidized phytosterols.
We don't know enough about what happens when we heat them, so better safe than sorry.
Don't cook with phytosterol fortified products.
There was a concerning finding in rats where phytosterols were found to make their red blood
cells more fragile, but in mice, the opposite was found.
Their red blood cells became less fragile, and in hamsters, there didn't seem to be any
So, are we more like rats, mice, or hamsters?
Now the amount of plant sterols researchers used in the rats was like 50 times higher
than you'd see in people, but you really don't know what normal amounts can do until
you put it to the test, and it turns out that doesn't appear to be an issue.
There is, however, a rare genetic condition, called phytosterolemia, where people end up
with extremely high levels of phytosterols in their blood and end up with horrific heart
disease even as kids.
At the same mutations that allow for the increased absorption of phytosterols also allow
for the increased absorption of cholesterol.
So these enforcement kids end up with cholesterol levels in the 700s, and no wonder they're
dying of heart attacks.
So when those who just genetically end up with high levels of phytosterols in their blood
streams have higher rates of cardiovascular disease, it's not necessarily because plant
sterols increase the risk of coronary heart disease, as some had feared, but rather because
those people are also sucking up extra regular cholesterol.
These genetic variations in sterile transporters result in increased blood levels of phytosterols,
increased intestinal cholesterol absorption, and subsequent result in higher LDL.
In fact, that's how we estimate how good people are at absorbing cholesterol, but you're
seeing how many plants sterols they have in their blood.
So people with lots of phytosterols in their blood also have markedly elevated LDL cholesterol
no wonder they're at risk for heart disease.
However, this increase in cholesterol absorption doesn't fully explain the increased risk.
So it's possible that phytosterols may indeed contribute directly to heart disease, raising
questions about the safety of supplementing food with phytosterols for the purpose of cardiovascular
But the risk in LDL achieved by the consumption of phytosterol enriched foods is 20 to 40 times
greater than the increase in phytosterols in the blood.
Thus phytosterols would need to cost 20 to 40 times more as they're oscarosis than cholesterol
that cancel out their positive effect in cholesterol reduction, yet there's no apparent evidence
In fact, at the levels we get in our blood from consuming a few grams of plants there
all today, there is no association with cardiovascular events in population studies, so that's how you
get these assurances that phytosterols are safe.