Beef Liver Supplements Lack Evidence and Carry Toxin Risks
A Beef-Blood Trial Deflates a Popular Theory
The closest test to date comes from a recent clinical trial, and its result challenges a popular assumption about iron pills. Mamadou Bah at the London School of Hygiene & Tropical Medicine and his colleagues randomly assigned around 200 babies in the Gambia, where iron deficiency is common, to receive either a haem-iron supplement made from beef blood or a standard iron supplement of ferrous sulphate. A fieldworker gave each baby the assigned dose every day for twelve weeks. The proportion of babies with anaemia — a blood condition marked by low iron — dropped from about 85 per cent to 45 per cent in both groups. The haem-iron supplement did not improve iron levels any more than the standard supplement, for reasons that were unclear. Even at the end, nearly half of the babies remained anaemic. The trial did not use beef liver; it used beef blood. It is, however, the closest approximation to a test of beef-liver supplements that exists.
The theoretical case for beef-liver supplements rests on a distinction between two kinds of iron. Haem iron occurs naturally in blood, meat and organ meats like liver. It consists of iron bound to a ring-shaped molecule called haem. Non-haem iron is unbound iron that occurs in salt form. It is found in plant foods like legumes, nuts and leafy green vegetables — including spinach, the vegetable Popeye made famous. Ordinary iron supplements have traditionally been made with non-haem iron, usually ferrous sulphate or ferrous fumarate. Both forms are absorbed in the small intestine, but each uses a separate pathway, and the uptake differs. SENTENCE: Some studies have found that they cause less constipation and diarrhoea than traditional non-haem iron tablets.
CORRECTION: Once absorbed, haem iron is broken down so that the iron can be released and used. This absorption advantage is one reason meat eaters are less likely to become iron deficient than vegetarians or vegans.
From that theory follows a confident prediction. Beef-liver supplements are made from dried, powdered beef livers, and they are rich in haem iron. So they should be better at increasing iron levels than traditional non-haem iron tablets. But the prediction remains an assumption, because no clinical trials have actually been done to confirm it. The marketing has raced ahead of the evidence. The supplements come in trendy-looking bottles featuring pictures of cows and terms like “grass fed”. They cost significantly more than standard tablets. They are meant to be more effective at raising iron levels and gentler on the gut. The pitch resonates with anyone who has struggled with ordinary iron pills. When I was pregnant, my iron levels plummeted, as is often the case. I started taking iron tablets, but they did not increase my iron as much as needed and left me uncomfortably backed up. This is a common story, and it spurs some people with low iron to try beef-liver supplements.
The Gambia results are a warning against treating haem-iron supplements as magical cures. Yet these products may still hold one advantage. Some studies have found that they cause less constipation and diarrhoea than traditional non-haem iron tablets. People who suffer those gut problems may find them genuinely beneficial. That is exactly the group I was in during pregnancy. It is also the group the supplement marketing speaks to most directly.
The Liver That Exposes What Cattle Absorb
Beyond the question of effectiveness lies a question of safety. A major concern is that beef livers can be contaminated with toxic heavy metals. The reason sits in the organ’s job description. The liver’s task is to capture toxins from the blood and try to excrete them. SENTENCE: What a cow’s liver holds, therefore, is a record of what that cow absorbed.
CORRECTION: What a cow’s liver holds, therefore, is a record of what that cow absorbed.
The problem was recently demonstrated in Egypt, where beef liver is a popular delicacy. A team led by Heba Mostafa El-Ghareb at Mansoura University collected 300 raw beef livers from marketplaces around the city of Mansoura. [1] All of the livers had been imported from the United States. [1] The team tested every single one. The majority contained levels of mercury, lead and arsenic that exceeded the maximum permissible limits recommended by many international agencies.
Does the same contamination reach the supplements on the shelf? SENTENCE: The question stays open.
CORRECTION: The question stays open. SENTENCE: The liver’s task is to capture toxins from the blood and try to excrete them.
CORRECTION:
There is another reason for caution. SENTENCE: The majority contained levels of mercury, lead and arsenic that exceeded the maximum permissible limits recommended by many international agencies.
CORRECTION: The link concerns haem iron, which is precisely the compound these supplements are built around. The finding sits uneasily next to the cow pictures and “grass fed” labels on the bottles.
From Nobel Prize to a Global Iron Gap
Beef liver is not only a source of iron. It is also rich in other valuable nutrients like vitamin A and vitamin B12. The organ has an unusual medical pedigree. The 1934 Nobel prize in medicine was awarded to a team of US doctors who discovered that people with pernicious anaemia — a cause of vitamin B12 deficiency — could be treated by eating daily beef liver. It was a Nobel-winning demonstration that a single food could act as a treatment.
The current craze is part of a wider pro-beef movement, and it has a powerful patron. US health secretary Robert F. Kennedy Jr eats beef every day, usually twice. He even cooked his Thanksgiving turkey in beef fat. The movement reaches far beyond liver capsules. Other trending beef products include beef-tallow moisturisers and shampoos, collagen supplements made from beef hides, and bone broth from beef bones. Beef, in short, is being repackaged from tail to snout.
So what should a shopper do when facing a bottle of beef-liver capsules? At this stage, there is not enough evidence to say whether beef-liver supplements really are better than traditional iron supplements. It comes down to personal preference. Since finishing having children, I have been able to get my iron levels back on track through diet. I have friends with low iron who swear by beef-liver supplements for getting their iron levels up without the unpleasant gut blockages. For them, the beefy price tag is worth it.
The personal choice, however, sits on top of a global problem. It is certainly worth trying to find better ways to treat iron deficiencies. Iron deficiency is common in people who are menstruating or pregnant, and in people who cannot afford or choose not to eat meat. Iron is particularly important as a component of haemoglobin, the substance that carries oxygen in the blood. Haemoglobin is made from haem iron and globular proteins. Low iron can cause fatigue, headaches, dizziness, shortness of breath and pale skin. It can impair children’s growth and cognitive development. About a quarter of people worldwide are estimated to be anaemic, with low-income countries worst affected.