Is lactose free milk safe ? (galactose may be toxic)

[Apple]

Lactose-free milk has been treated with lactase, which breaks down the lactose into simple sugars - glucose and galactose.

But then there is Galactosemia , the inability to metabolize Galactose. Galactose builds up in blood and organs , causing:

• jaundice (Yellow skin and whites of the eyes) , cataract , hepatosplenomegaly (enlarged spleen and liver), hypoglycemia, renal tubular dysfunction, muscle hypotonia (decreased tone and muscle strength), sepsis (presence of harmful bacteria and their toxins in tissues), Lethargy, poor weight gain, Irritability, brain damage.

Galactosemia should not be confused with lactose intolerance as galactosemia may be life-threatening.

What if lactose intolerance is a natural way of protection from excess of galactose ? And it may be good that in lactose intolerant people the lactose is handled by bacteria in our guts instead of being absorbed directly into blood in the form of galactose.
From this point of view lactose free milk may not be so good despite abscence of digestive issues since lactose-free milk bypasses digestion...

 

[ThunderSpank]

The same argument could be made for someone eating fruit or sucrose while lacking aldolase B which is responsible for proper fructose digestion.

Both situations are very rare and life threatening.

 

[rothko]

Wouldnt that be the same for non-lactose free milk then? You break lactose into its parts with lactase in the gut.

 

[Apple]

Wouldnt that be the same for non-lactose free milk then? You break lactose into its parts with lactase in the gut.

not exactly... most people are lactose malabsorbers, that means that lactose is digested and utilized by bacteria and only small amount of galactose gets into blood.

 

[Apple]

The same argument could be made for someone eating fruit or sucrose while lacking aldolase B which is responsible for proper fructose digestion.

Both situations are very rare and life threatening.

yep, fructose same as galactose can provoke cataracts when blood lacks certain enzymes... But still it might make sense to keep galactose level at bay so it doesn't accumulate with time. Lactose-free milk is a relatively new thing and there are no studies in this regard
Or to eat cheese instead since cheeses contain very low amount of these sugars...

 

[Apple]

in experiments on rats they usually induce cataract by feeding them with galactose

 

[Dolomite]

Several years ago I drank a lot of lactose free milk. At some point during that time I developed a cataract. I think it was from galactose but I will never know. I quit drinking all milk for several years. I recently tried a milk experiment where I started with only a teaspoon and over 20 days increased it. I did enjoy it but the estrogen in symptoms and losing hair made me stop. I was able to overcome the gut issues so maybe not all the lactose was going to the bacteria.

I worried about all that galactose, too, because if you don’t make enough lactase, maybe you don’t make enough of the enzyme necessary to break up the galactose, too.

I haven’t been to have my eyes checked since then but I know that eye has not recovered.

 

[Apple]

Several years ago I drank a lot of lactose free milk. At some point during that time I developed a cataract. I think it was from galactose but I will never know. I quit drinking all milk for several years. I recently tried a milk experiment where I started with only a teaspoon and over 20 days increased it. I did enjoy it but the estrogen in symptoms and losing hair made me stop. I was able to overcome the gut issues so maybe not all the lactose was going to the bacteria.

I worried about all that galactose, too, because if you don’t make enough lactase, maybe you don’t make enough of the enzyme necessary to break up the galactose, too.

I haven’t been to have my eyes checked since then but I know that eye has not recovered.

Wow....Thanks for sharing. I think as long as you are "lactose intolerant" and drink normal milk you are safe from galactosemia which is much worse. "Lactose intolerant" people usually produce small amount of lactase enzyme but lactose is converted only partially and most of it goes to bacteria and creates bulk.
I definitely will be carefull with lactose free milk from now on....I better continue with normal milk despite some farting.
I don't think it was ever studied because people usually don't drink milk in such amounts as Ray Peat followers.

They say there is no correlation between galactosemia and lactose intolerance. I think that the lack of Lactase enzyme secretion is a good thing actually. (sort of defensive mechanism against galactosemia )

 

[JudiBlueHen]

Wow....Thanks for sharing. I think as long as you are "lactose intolerant" and drink normal milk you are safe from galactosemia which is much worse. "Lactose intolerant" people usually produce small amount of lactase enzyme but lactose is converted only partially and most of it goes to bacteria and creates bulk.
I definitely will be carefull with lactose free milk from now on....I better continue with normal milk despite some farting.
I don't think it was ever studied because people usually don't drink milk in such amounts as Ray Peat followers.

They say there is no correlation between galactosemia and lactose intolerance. I think that the lack of Lactase enzyme secretion is a good thing actually. (sort of defensive mechanism against galactosemia )

Very helpful thread. I am genetically lactose-intolerant but don't really have a problem with regular milk - as long as it has some milkfat. Skim milk gives me diarrhea. I tried lactose-free milk for a while and also had a cataract that the doc wanted to remove at the time. But I stopped drinking lactose-free milk because it didn't seem right to me that it tasted so sweet. Now a year later, perhaps also coincidence, my cataract is decreasing and opthamologist said I mgiht not need cataract surgery for 3 more years.

 

[ecstatichamster]

Dr. Peat was asked about LF milk and said it is probably safe.

 

[Apple]

Very helpful thread. I am genetically lactose-intolerant but don't really have a problem with regular milk - as long as it has some milkfat. Skim milk gives me diarrhea. I tried lactose-free milk for a while and also had a cataract that the doc wanted to remove at the time. But I stopped drinking lactose-free milk because it didn't seem right to me that it tasted so sweet. Now a year later, perhaps also coincidence, my cataract is decreasing and opthamologist said I mgiht not need cataract surgery for 3 more years.

Cataract from galactose/galactitol can be reversed if treated early (by removing lactose-containing foods from diet) .

A recent 2000 study in Munich, Germany analyzed the activity levels of the GALE enzyme in various tissues and cells in patients with cataract. The experiment concluded that while patients with cataract seldom exhibited an acute decrease in GALE activity in blood cells, "the GALE activity in the lens of cataract patients was, on the other hand, significantly decreased".The extreme decrease in GALE activity in the lens of cataract patients seems to suggest an irrefutable connection between Type III galactosemia and cataract development.
As it turns out, the lens is a favorable site for galactose accumulation. The lens phosphorylates galactose at a relatively slow pace in comparison to other tissues.

Dr. Peat was asked about LF milk and said it is probably safe.

LF milk is like a processed food...too pure. It doesn't give me any digestive issues but gives me some anxiety.
Dr. Peat doestn't drink LF milk otherwise he would end up with constipation.

 

[amd]

Aren't the bacteria in the gut doing the same job as the enzyme in breaking a disaccharide?

You also get the gut distension from the gas produced by the bacterial action (serotonin).

RP site: "galactose is also called cerebrose, brain sugar"

---

Absorption of Monosaccharides
http://www.vivo.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_sugars.html

"Glucose and galactose are taken into the enterocyte by cotransport with sodium using the same transporter."

"Absorption of glucose entails transport from the intestinal lumen, across the epithelium and into blood. The transporter that carries glucose and galactose into the enterocyte is the sodium-dependent hexose transporter, known more formally as SGLUT-1."

---

Is Dietary Milk Intake Associated with Cataract Extraction History in Older Adults? An Analysis from the US Population
https://www.hindawi.com/journals/joph/2020/2562875/

Several mechanisms, such as oxidative and osmotic stress, mediate cataract development. In states of oxidative stress, the production of free radicals exceeds the tissue’s elimination capacity, resulting in the deposition of alpha-crystallin and impairment of lens transparency. In osmotic stress states, excess sugars (e.g., galactose) are converted to their sugar alcohol counterparts (e.g., galactitol), the accumulation of which disturbs water and electrolyte homeostatic mechanisms necessary to maintain tissue transparency [1]. This osmotic imbalance is believed to underlie the early development of cataract in inborn disorders of galactose metabolism, such as galactokinase deficiency and galactosemia [2]. In addition to the direct osmotic damage caused by its accumulation, recent evidence suggests that galactose could accelerate lens epithelial cell senescence in vitro, possibly by impairing autophagy and mitochondrial function [3]. The accumulation of sugar alcohols is also believed to play a role in hyperglycemia- and diabetes-induced cataracts [4].

Because of the modulatory role of diet in disease outcomes, and the cataractogenic potential of galactose, researchers speculated that long-term dietary intake of galactose might be associated with senile cataract formation [5]. In human diet, the major source of galactose is lactose in milk and dairy products. To date, the effect of dietary milk consumption on cataract development remains controversial. Early reports from regions of Asia concluded that possible links exist [5, 6]. However, recent investigations in European and Mediterranean populations were less conclusive [7, 8]. In this study, we examined the relationship between indicators of dietary milk exposure and cataract extraction history in a nationally representative sample of the American population.
...
However, more recent studies have found no such association between milk intake and cataract risk. For example, case-control studies did not find a significant difference in cataract [7] or cataract extraction risk [20] based on milk and dairy product consumption. Likewise, a recently published prospective study of adult Mediterranean subjects with high cardiovascular risk found no association between cataract incidence and total dairy products intake, including milk [8]. These findings are consistent with what we observed in this large, population-based study. We attempted to examine the possibility that individuals with consistently higher lactose levels accrue greater damage over long years of milk consumption [21] and found it to be insignificant. We also explored the possibility of such an effect being specifically related to consumption in the early years of a participant’s life (i.e., 5–35 years) and similarly found no significant association.

A possible explanation for the lack of direct association is that hypergalactosemia alone may be insufficient to cause damage to the lens in healthy individuals. As some empirical evidence suggests, immediate susceptibility combined with high-galactose intake is needed to affect the lens. This notion is consistent with the synergistic effect observed when two cataractogenic factors are introduced simultaneously in an animal model [22]. For example, an investigation of the effect of high milk intake in Sprague-Dawley rats showed that the presence of underlying damage to the lens (e.g., by naphthalene) led to significant susceptibility to injury by excessive milk intake [23]. This notion is also in line with previous clinical observations suggesting that high lactose intake was related to cataract risk in subjects with low activity of galactose-metabolic enzymes, but not when high levels of enzymatic activity were present [24].

We also found no clear association between the quartiles of current daily milk or total dairy intake and cataract history, a finding which is similar to that reported in a case-control study examining a Greek sample [7]. Possibly, because the nutritional profile of milk is rich with various nutrients, some components may “neutralize” the cataractogenic effects of lactose/galactose. For example, in one experiment, coadministering whey along with purified lactose in rats inhibited the formation of cataract that was otherwise observed when fed purified lactose alone [25]. Moreover, consistent intake of milk may replace other less healthy dietary behaviors/patterns that could otherwise increase the risk of cataract [26].

Interestingly, we did find a significant reduction in cataract history risk when assessing milk intake on a continuous scale. While it is less often encountered in the literature, a protective effect of dairy is reported occasionally with a specific dairy product [8, 20] or, less commonly, for a specific cataract type [27]. In the recent study examining Mediterranean adults, skimmed yogurt intake (but not milk or other types of dairy products) was associated with reduced cataract risk [8]. The authors postulated that this protection could be mediated by reduction in cardiovascular risk factors, such as diabetes, or inflammation. Nonetheless, other dairy products, including milk, examined in the same populations failed to show any association with cataract risk [8, 20]. Hence, the possibility of the observed effect being coincidental cannot be ruled out.

As alluded to earlier, there are interesting discrepancies between findings from older vs. more recent reports regarding the association between milk intake and cataract. Multiple factors could have played a role. References to data stemming from animal experimentation were common [14, 23, 25], but these models required notably high intake of lactose (25–70% of total dietary intake) that is unlikely to be applicable to the human diet [5]. Besides, different indicators of milk exposure were historically used to assess this relationship in humans. For example, one approach was to examine expression of galactosemic enzymes in RBCs and correlate it with cataract [28, 29]. Another approach was geographic segregation of milk consumption, lactose malabsorption, and cataract prevalence [5]. In the latter approach, the concordance found in the segregation of regions of high milk consumption and lactose absorption with high cataract incidence may be appealing, but one must exercise caution to avoid assigning group-level indicators to individual-level outcomes (i.e., ecological bias) [30].

Nonetheless, this study has some limitations. Because the milk-related indicators were self-reported, there is a potential for recall bias. In addition, indicators and outcomes were collected cross-sectionally, and thus, causality of any observed findings could not have been established. Another limitation is that the subtypes of cataracts in the studied participants were unknown. Previous reports suggested the presence of links between cortical cataract formation and osmotic stress, particularly at the initial stages [32]. On the other hand, this link seems to be less relevant to the age-related nuclear cataracts, which are largely oxidative stress-driven [32]. Therefore, a slight association of milk consumption with certain subtypes of cataract cannot be ruled out [6]. Also, the indicators of early-life consumption covered the regularity of milk consumption without the exact amounts. Finally, the focus of indicators used in this study was on the intake amounts and consistency. In conceptual terms, factors affecting serum lactose/galactose (and galactitol) levels would be the amount and consistency of milk consumption, intestinal lactase activity, and galactose absorption [33]. In turn, factors modulating intralenticular galactose levels (and cataract risk) include serum galactose levels, diffusion rate across aqueous humor and lens capsule, activity of galactose pathway enzymes [2, 24], and activity of enzymes of sugar alcohol metabolism within lens tissue [1, 2]. Therefore, from a holistic perspective, examining the sequence of factors in this pathway from lactose intake to intralenticular galactose levels would be necessary to better understand its relationship with cataract risk in the general population. While such investigation would be cost-prohibitive at the population level, further focused investigations that use this strategy are encouraged.

​

5. Conclusion​

While the link may be more relevant to susceptible individuals, milk consumption does not appear to be associated with the development of age-related cataract in the general population.

 

[Apple]

Aren't the bacteria in the gut doing the same job as the enzyme in breaking a disaccharide?

You also get the gut distension from the gas produced by the bacterial action (serotonin).

RP site: "galactose is also called cerebrose, brain sugar"

As I understand the bacteria consume/utilize lactose as energy source instead of just breaking it and releasing simple sugars.
Even if monosaccharides are released by bacteria it probably happens in colon. But glucose, fructose, and galactose are absorbed across the membrane of the small intestine.
The large intestine can absorb only minute amounts of glucose, fructose, galactose and xylose.

On the other hand cheeses contain only residues of sugars

 

[amd]

The breaking of the dissacharide into monosaccharides before ingestion makes them available to the small intestine, avoiding the gut distension (gas).

Lactic acid bacteria produce lactic acid (D-lactic acid vs L-lactic acid) instead of gas.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463488/
Meanwhile other bifidobacteria can be involved in cross-feeding with butyrate-producing bacteria either by releasing oligo- and mono-saccharides from complex substrates, or via the utilization of acidic fermentation products.14

The study in my previous post might be a good read.

As I understand the bacteria consume/utilize lactose as energy source instead of just breaking it and releasing disaccharides.
Even if monosaccharides are released by bacteria it probably happens in colon. But glucose, fructose, and galactose are absorbed across the membrane of the small intestine.
The large intestine (of rats) can absorb only minute amounts of glucose, fructose, galactose and xylose.

On the other hand cheeses contain only residues of sugars

 

[xeliex]

I remember studying galactosemia as a very rare genetic disease discovered shortly after a baby's birth.

Galactosemia - About the Disease - Genetic and Rare Diseases Information Center

Find symptoms and other information about Galactosemia.

rarediseases.info.nih.gov

 

[Apple]

I remember studying galactosemia as a very rare genetic disease discovered shortly after a baby's birth.

Galactosemia - About the Disease - Genetic and Rare Diseases Information Center

Find symptoms and other information about Galactosemia.

rarediseases.info.nih.gov

That's right. But there is also a study showing a decreased activity of galactosemic enzymes with age that may result in cataract.

Presenile cataract formation and decreased activity of galactosemic enzymes - PubMed

One hundred forty-seven patients, 144 with advanced cataract formation, had determinations of erythrocyte galactokinase and galactose-1-phosphate uridyl transferase performed. Significant reduction (more than 2 SDs) of one of these enzymes was found in 47.4% of patients 50 years old or less with...

pubmed.ncbi.nlm.nih.gov

 

[amd]

That study is from 1980, one of the findings in the other more recent study is the discrepancy in results when comparing older studies with recent ones.

---

Following on the statement at RP site ("galactose is also called cerebrose, brain sugar"):

Cerebrosides is the common name for a group of glycosphingolipids called monoglycosylceramides which are important components in animal muscle and nerve cell membranes.

They consist of a ceramide with a single sugar residue at the 1-hydroxyl moiety. The sugar residue can be either glucose or galactose; the two major types are therefore called glucocerebrosides (a.k.a. glucosylceramides) and galactocerebrosides (a.k.a. galactosylceramides). Galactocerebrosides are typically found in neural tissue, while glucocerebrosides are found in other tissues.

 

[Apple]

Pointing out that breaking the lactose before consumption avoids the gut distension and facilitates digestion.

Lactic acid bacteria produce lactic acid (D-lactic acid vs L-lactic acid) instead of gas.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463488/
Meanwhile other bifidobacteria can be involved in cross-feeding with butyrate-producing bacteria either by releasing oligo- and mono-saccharides from complex substrates, or via the utilization of acidic fermentation products.14

The study in my previous post might be a good read.

it is not very clear how much galactose/galactitol would be in fermented milk. I guess it is much less than in Lactose free milk.
Interstingly, skimmed yogurt intake (but not milk or other types of dairy products) was associated with reduced cataract risk. (kind of against Peat)

That study is from 1980, one of the findings in the other more recent study is the discrepancy in results when comparing older studies with recent ones.

yes, those studies have limitations but are not rulled out.

2 persons on this thread already said that milk consumption coincided with onset of cataract.

 

[amd]

Excess galactitol forms in the lens of the eye, if you suffer from galactokinase deficiency (a form of galactosemia), this is not about galactitol in fermented milk.

About yogurt intake ..

"The authors postulated that this protection could be mediated by reduction in cardiovascular risk factors, such as diabetes, or inflammation. Nonetheless, other dairy products, including milk, examined in the same populations failed to show any association with cataract risk [8, 20]. Hence, the possibility of the observed effect being coincidental cannot be ruled out." (from study posted above)

Is not about ruling out old studies, in other situations we "prefer" older studies because of the corruption, but is about the compelling points stated in that study, which people need to read with attention.

Also, galactose has other uses in the body (as stated above).

---

Epimerase Deficiency Galactosemia (Type III)
https://www.ncbi.nlm.nih.gov/books/NBK51671/

Management.​

Treatment of manifestations: The common acute and potentially lethal symptoms of generalized epimerase deficiency galactosemia are prevented or corrected by a galactose/lactose-restricted diet.

Note: Affected individuals may require trace environmental sources of galactose: infants should be fed a formula (e.g., soy formula) that contains trace levels of galactose or lactose.

---

The Adult Galactosemic Phenotype
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3641771/

"Yet galactosemia remains a disease that is incompletely treated by diet as evidenced by the common occurrence of central nervous system problems in both sexes (Waggoner et al 1990) and primary ovarian insufficiency (POI) in women (Kaufman et al 1981; Rubio-Gozalbo et al. 2010).

Neuroimaging studies confirm poor myelination, scattered white matter abnormalities, cerebral atrophy, and cerebellar atrophy in some patients, as well as abnormalities in glucose uptake of metabolism in many brain regions (Dubroff et al. 2008)."

---

Galactosemia Test
https://www.uofmhealth.org/health-library/hw7694

"A galactosemia test is a blood or urine test that checks for enzymes that are needed to change galactose into glucose, a sugar that your body uses for energy. A person with galactosemia doesn't have one of these enzymes, so high levels of galactose build up in the blood or urine."

it is not very clear how much galactose/galactitol would be in fermented milk. I guess it is much less than in Lactose free milk.
Interstingly, skimmed yogurt intake (but not milk or other types of dairy products) was associated with reduced cataract risk. (kind of against Peat)

yes, those studies have limitations but are not rulled out.

2 persons on this thread already said that milk consumption coincided with onset of cataract.

 

[Apple]

Excess galactitol forms in the lens of the eye, if you suffer from galactokinase deficiency (a form of galactosemia), this is not about galactitol in fermented milk.

My concern is rather about lactose free milk (where lactose is already broken down to Galactose and Glucose). We may get overload of Galactose if we drink it a lot and frequently.
Eye lens is a favorable site for galactose accumulation.
If we drink normal milk lactose first is treated by lactase enzyme so it will be a slower digestion process compared to drinking galactose directly.
Also significant portion of lactose is utilized by bacteria which also takes some time before Galactose amount can reach a critical level in blood.
Don't forget , in their experiments on rats they feed them with Galactose to induce cataract