Unravelling the BCO1 Gene: Your Pathway from Beta-Carotene to Functional Vitamin A

1. Introduction: The Colourful World of Beta-Carotene

Imagine a world painted in vibrant hues of orange, yellow, and red. These are the colours of beta-carotene, nature’s own pigment and a precursor to something our bodies can’t do without – vitamin A. But what bridges the gap between consuming beta-carotene in foods like sweet potatoes and carrots, and reaping the benefits of vitamin A? Enter the BCO1 gene, a crucial player in this colourful transformation.

Vitamin A and beta carotene are two distinct substances. Vitamin A is an essential nutrient that supports various aspects of our health, including vision and immune function. On the other hand, beta carotene is a compound that can be converted into vitamin A by our bodies. It is naturally present in foods such as carrots and sweet potatoes. Unlike vitamin A, which is readily usable by our bodies, beta carotene requires conversion into vitamin A before it can be utilized.

Beta carotene and retinol are two forms of vitamin A that our bodies need to stay healthy. They’re both important, but they come from different places.

Beta Carotene:

This is a type of plant pigment called a carotenoid, which gives fruits and vegetables their bright colours. Our bodies can turn beta carotene into vitamin A. Here are some good sources:

Here are some examples of vegetables and fruits:

Carrots
Sweet Potatoes
Spinach
Kale
Butternut Squash
Cantaloupe

Retinol:

Retinol is the active form of vitamin A that comes from animal sources. Your body can use it directly. Here’s where you can find it:

Eggs
Dairy Products
Fish
Liver

Remember, getting too much vitamin A can be harmful, so it’s all about balance. Eating a variety of these foods can help you get the right amount of vitamin A.

The body has a feedback loop. When there’s more retinoic acid, it makes less BCO1 enzyme. This means the body turns less beta-carotene into retinal. [source]

2. What is the BCO1 Gene?

The BCO1 gene is your body’s natural converter, transforming beta-carotene into vitamin A, an essential nutrient for vision, immune function, and skin health. It’s like having a personal alchemist inside you, turning orange-coloured vegetables into gold for your health. However, not everyone’s BCO1 gene works with the same efficiency, which can be fascinating or frustrating, depending on your DNA blueprint.

The BCMO1 enzyme is also responsible for transforming carotenoids like lycopene.

Lycopene, which gives a rich red hue, can be found in foods such as tomatoes, watermelons, and papayas.

Changes in the genes that affect beta-carotene conversion may impact the body’s interaction with lycopene. A study involving men with prostate cancer hinted at a potential association between genetic variations in BCMO1 and the influence of lycopene from the diet. [source]

3. BCMO1 Gene Variants and You

Variations in the BCO1 gene can affect how well your body performs this vital conversion. Some people have a version that’s turbo-charged, making the most out of every carrot stick they munch on. Others might find their gene works more like a leisurely Sunday driver, taking its sweet time to produce vitamin A. This is where DNA tests step into the limelight, offering personalized insights into your unique genetic makeup.

Impact on Beta-Carotene Conversion: Individuals with a T allele at both rs12934922 and rs7501331 show a 69% lower conversion rate of beta-carotene to retinol. Those with just one T allele at rs7501331 experience a 32% reduction in conversion. [source]

rs7501331
TT
Decreased ability to convert Beta-Caroten into the active form of Vitamin A – Retinal. Lower Lutein levels. Single T allele decreases the conversion rate by 32%. PMID: 19103647, PMID: 21091228, PMID: 30801647. More impact if combined with T on rs12934922

rs12934922
TT
Decreased ability to convert Beta-Caroten into the active form of Vitamin A – Retinal. Increased risk of atherosclerosis with poor diet PMID: 19103647, PMID: 30896431, PMID: 30801647. More impact if combined with T allele on rs7501331

Less influential variations slightly reduce the conversion of beta-carotene into the retinol form of vitamin A. These may hold greater significance if you possess two copies of the variation or if you have a combination of all the variations mentioned below.

rs6420424
AA
Compared to G allele, A alelle = decreased ability to convert Beta-Caroten into the active form of Vitamin A – Retinal. This variant is less impactful than the 2 variants listed above PMID: 22113863

rs6564851
GG
Decreased ability to convert Beta-Caroten into the active form of Vitamin A – Retinal. This variant is less impactful then rs7501331 and rs12934922. PMID: 22113863

4. The Impact of BCO1 on Health

A well-functioning BCO1 gene means you’re likely getting plenty of vitamin A, but if your gene is less efficient, you might need to pay extra attention to your diet or consider supplements. After all, vitamin A isn’t just about seeing the world in high definition; it’s also about keeping your immune system in tip-top shape and your skin as resilient as a superhero’s.

Consuming too much beta carotene can lead to a condition known as carotenemia, in which your skin turns orange. Beta carotene is a pigment found in plants that gives yellow and orange fruits and vegetables their colour. It’s a type of carotenoid and acts as a precursor to vitamin A in your body, which means it can be converted into vitamin A as needed.

When you consume an excessive amount of beta carotene, your body cannot convert it to vitamin A quickly enough. The surplus circulates in your bloodstream and is deposited in the outermost layer of skin. This accumulation then imparts an orange hue to your skin, particularly noticeable on the palms of the hands and soles of the feet. However, it’s important to note that while carotenemia can make you look somewhat like a carrot, it’s generally considered harmless. The condition is reversible simply by reducing your intake of beta carotene.

Moreover, it’s worth noting that carotenemia doesn’t affect everyone equally. Factors like metabolic rate, digestive health, and overall diet can influence how much beta carotene your body absorbs and how quickly it’s converted into vitamin A. In addition, individuals with hypothyroidism or diabetes may be more prone to carotenemia, as these conditions can slow down the conversion process. It’s also notable that despite the change in skin colour, carotenemia does not cause any damage to the skin itself; there’s no irritation or discomfort associated with the condition other than the visible discoloration.

If you suspect you have carotenemia, it’s advisable to consult with a healthcare provider. They might suggest dietary adjustments or conduct tests to ensure there are no underlying health issues. Remember that vitamin A is crucial for vision, immune function, and skin health, but like many things, it should be consumed in moderation.

Too much beta-carotene might not be as harmless as it seems, according to research.

Let’s look at the evidence, though it’s important to note that the findings aren’t final.

Higher levels of beta-carotene have been linked to reduced overall death rates. This could mean that eating lots of fruits and vegetables might help people live longer.[source]

Risks of Cancer Death Increase: Some significant research, however, suggests that beta-carotene supplements could lead to a higher chance of dying from certain cancers.

In a study with more than 18,000 participants, including smokers and those exposed to asbestos, half were given beta-carotene and vitamin A, while the other half got a placebo. The supplement group saw their lung cancer risk go up by 46%, leading researchers to halt the study to prevent further harm.[source][source]

Another investigation found similar risks with beta-carotene supplements, particularly for smokers, who faced an increased risk of lung cancer.[source]

Supporting these findings, smaller studies also found:

Smokers taking 20 – 30 mg/day of beta-carotene had a higher chance of developing lung cancer.[source]
There was a slight rise in bladder cancer risk with beta-carotene supplementation.[source]

Why Might High Beta-Carotene Intake Be Risky?

Research indicates that at high doses, carotenoids may become harmful. Beta-carotene can turn into substances that damage the mitochondria, the energy centres of cells.[source]

Animal research also shows that while a small amount of beta-carotene can be beneficial after a heart attack, larger doses are not helpful and could even be damaging.[source]

Furthermore, high doses of beta-carotene led to lung cancer in animals subjected to cigarette smoke by interfering with the active form of vitamin A.[source] Surprisingly, excessive beta-carotene can both act as a cell-damaging agent and reduce vitamin A levels.

Potential Link Between Beta-Carotene Supplementation and Increased Cardiovascular Disease Risk:

Studies investigating the effects of supplemental beta-carotene on cardiovascular disease have revealed a noteworthy association with a slight increase in cardiovascular disease mortality and stroke.(https://www.jacc.org/doi/full/10.1016/j.jacc.2022.09.048)[source]

Furthermore, an analysis examining the risk of cardiovascular mortality based on serum β-carotene concentrations discovered that individuals in the highest quartile of levels faced more than double the risk of cardiovascular mortality.[source]

It is important to note that these epidemiological studies do not establish causation definitively. While it is theorized that β-carotene may exhibit pro-oxidant effects under specific circumstances, it is also plausible that individuals diagnosed with heart disease are more inclined to begin taking multi-vitamins containing beta-carotene or consuming substantial amounts of carrot juice.

Other health effects:

The BCMO1 gene produces Vitamin A, which is important for various functions in the body including brain health, immune system function, skin health, eye health, teeth and bone health, and hormone formation. Vitamin A helps protect the eyes and skin from UV damage, reducing the risk of skin cancer [source].

Vitamin A also plays a role in thyroid hormone and vitamin D function. It may have benefits for obesity as well [source].

In terms of brain function, Vitamin A is crucial for memory formation. Deficiency in Vitamin A can disrupt the body’s internal clock, leading to circadian dysrhythmia [source].

Vitamin A is necessary for the proper functioning of Vitamin D and thyroid hormones. It activates certain receptors that are required for these hormones to work effectively. In simple terms, if there is a deficiency in Vitamin A, taking Vitamin D alone may not have much impact because adequate Vitamin A is needed for it to work properly [source].

Vitamin A plays a role in the anti-inflammatory function by influencing the immune system. It promotes an increase in Th2 immune response, which is associated with reducing inflammation. At the same time, it decreases the activity of Th1 and Th17 immune responses, which are involved in promoting inflammation. This modulation of immune responses by vitamin A helps to maintain a balanced immune system and prevent excessive inflammation. In particular, vitamin A is crucial for supporting the immune system in the gut, where it contributes to the overall anti-inflammatory function. [source]

In animals, Vitamin A deficiency has been linked to lower adrenal hormone production and abnormal cortisol levels. Supplementing with Vitamin A can help normalize cortisol levels [source].

There have been studies suggesting that Vitamin A might benefit obesity by increasing fat burning in mice, but results in humans have been inconsistent [source].

Vitamin A plays a central role in increasing neuroplasticity and neurogenesis, which are important for brain health. It is critical for the hippocampus and hypothalamus, which control memory and wakefulness, respectively. Deficiency in Vitamin A can lead to cognitive dysfunction [source].

Vitamin A is also important for maintaining a normal circadian rhythm. Animals fed a Vitamin A-deficient diet have disrupted circadian rhythms, which can lead to cognitive dysfunction and altered antioxidant production [source].

In addition to daily rhythms, retinoic acid (a form of Vitamin A) is also important for seasonal rhythms [source].

Vitamin A is essential for the function of beta cells in the pancreas, which release insulin to regulate blood glucose levels. Deficiency in Vitamin A can lead to high blood glucose levels [source].

Sources:

5. Enhancing Vitamin A Absorption/ Optimise BCMO1

There’s a hack – adding a dash of healthy fats to your meals can boost absorption of your Vitamin A, making more room for the conversion of Beta-carotene into Retinol. Think olive oil drizzled over roasted sweet potatoes or a handful of nuts alongside your pumpkin soup.

Even with BCMO1 variants that reduce enzyme production, eating fruits and vegetables is beneficial. Studies confirm high intake reduces lung cancer risk independent of enzyme activity, offering vitamin A and other nutrients.[source]

For those who embrace plant-based eating, the journey to meet your vitamin A needs hinges on the body’s ability to transform beta-carotene into usable retinol. If you find yourself less adept at this conversion and your diet isn’t particularly rich in beta-carotene, it might be wise to amp up your intake of veggies that are bursting with this nutrient.

Bear in mind, though, that there’s a twist: our bodies tend to scale back on converting beta-carotene as we up the ante on its dietary intake. This curious diminishing return has been backed by scientific studies.[source]

If you’re pondering an alternative route, vegan-friendly vitamin A supplements do exist. One such option is retinyl palmitate crafted from soy oil – a boon for those committed to a vegan lifestyle.[source]

Alcohol can make it harder for your gut to take in Vitamin A from the food you eat. Plus, it can increase how fast your body gets rid of Vitamin A. So, not only are you not getting enough Vitamin A into your body, but you’re also losing what you already have faster.

Alcohol can also mess with how Vitamin A is stored and moved around in your body. It can break down the vitamin before your body gets to use it, and that’s not good because you need Vitamin A for lots of essential stuff.

BCMO1 is controlled by PPARgamma. This means that PPARgamma is a main factor that controls BCMO1 and other genes. Knowing how this works can help create new treatments for issues like vitamin A shortage.

PPARgamma is a type of protein in our bodies. It helps control how our cells work and can affect things like inflammation and metabolism.

Genes related to PPARgamma function are listed under the Immune system section of your report.

FAD and NADPH are critical cofactors essential for mitochondrial health and energy production. They support biochemical reactions, particularly oxidative phosphorylation, necessary for cellular vitality. FAD and NAD, deriving from vitamins B2 and B3, are vital for the BCMO1 gene function, underscoring the importance of maintaining mitochondrial health.

Given their central role in energy production and metabolism, maintaining the health of these organelles is indeed paramount for the wellbeing of every cell in our body. It is therefore imperative to continually monitor and address B2 and B3 vitamin levels, along with ensuring that iron and flavonoid intake is at an optimal level for promoting robust mitochondrial functionality and, consequently, overall health and vitality.

Flavonoids — natural compounds found abundantly in fruits, vegetables, grains, bark, roots, stems, flowers, tea, and wine — can significantly influence human health, including the support of mitochondrial activities. Among their many roles, they are known to promote the activity of BCMO1 (Beta-Carotene Monooxygenase 1), an important enzyme involved in the metabolism of beta-carotene into Vitamin A. This activity is not only pertinent to vision and eye health but also impacts other biological functions tied to cellular health and immunity.

Iron plays a crucial role in promoting the function of the BCMO1 gene. Research studies have shown that iron deficiency can negatively impact the expression and activity of BCMO1 (B-carotene 15,15′-monooxygenase), which is responsible for converting dietary beta-carotene into vitamin A. This finding highlights the importance of maintaining adequate iron levels for optimal BCMO1 gene function.

Reference:

1. von Lintig J, et al. Iron-dependent remodeling of retinoids by BCO1 enables mammalian vision. FASEB J. 2010;24(2):617-626.

Enhance the power of vitamin A with vitamin D:

Emerging research suggests that an imbalance between vitamin A and vitamin D levels may contribute to the development of osteoporosis.[source]. To safeguard against this, it is crucial to prioritize daily sun exposure if you are not supplementing with vitamin D. Additionally, when monitoring your vitamin A levels, it is equally important to assess your vitamin D levels simultaneously.

Warning: Exercise Caution with Excessive Vitamin A Intake

It is recommended to adhere to the upper daily limit of 10,000 IU of retinol-based vitamin A supplementation. This guideline aims to prevent any potential adverse effects on your health. If you have any concerns or queries regarding the suitability of a particular supplement or dosage for your individual needs, it is advisable to consult with your healthcare provider.

Pregnancy Advisory: It is crucial to note that high doses of vitamin A have been linked to an increased risk of birth defects. Therefore, if you are planning to conceive, it is imperative to discuss the use of vitamin A supplements with your doctor beforehand. Their guidance will help ensure the safety and well-being of both you and your baby.

6. Conclusion: Embrace Your Genetic Uniqueness

Your BCO1 gene is as unique as you are, and understanding it can unlock new ways to optimize your health. Whether you’re a beta-carotene converting champ or someone who needs a little extra help, embracing your genetic makeup is the first step towards a healthier you.

Q/A Section

Q: Can everyone convert beta-carotene to vitamin A efficiently?

A: No, the efficiency of converting beta-carotene to vitamin A varies due to differences in the BCO1 gene. DNA tests can provide insight into how well your body makes this conversion.

Q: Does a less efficient BCO1 gene mean I’ll have a vitamin A deficiency?

A: Not necessarily. While a less efficient BCO1 gene can affect conversion rates, a balanced diet and proper nutrition can help maintain adequate vitamin A levels.

Q: How can I improve my vitamin A absorption if I have a less efficient BCO1 gene?

A: Combining beta-carotene-rich foods with healthy fats can enhance absorption.

Q: Are there any other factors that can affect vitamin A absorption?

A: Yes, certain medical conditions such as Crohn’s disease or celiac disease can impair vitamin A absorption. Additionally, alcohol consumption and certain medications can also interfere with absorption. It’s important to discuss any concerns with a healthcare professional.

Q: What is retinol?

A: Retinol is a form of vitamin A that is found in animal products. It plays a crucial role in various bodily functions, including vision, immune function, and cell growth.

Q: Can retinol be obtained from supplements?

A: Yes, retinol supplements are available and can be used to meet the body’s vitamin A needs. However, it’s important to follow recommended dosage guidelines and consult with a healthcare professional before starting any new supplement regimen.

Q: Can taking too much retinol be harmful?

A: Yes, excessive intake of retinol can lead to vitamin A toxicity, also known as hypervitaminosis A. This can cause symptoms such as nausea, dizziness, blurred vision, and even liver damage. It’s important to avoid exceeding the recommended daily intake of retinol.

Q: Can beta-carotene supplements lead to vitamin A overdose?

A: Unlike retinol, beta-carotene is not associated with the same level of risk of toxicity as retinol. However, high doses of beta-carotene may cause a harmless condition called carotenemia, which can result in yellowing of the skin.

Q: Is there a link between beta-carotene and cancer?

A: Research has shown mixed results regarding the relationship between beta-carotene and cancer. Some studies suggest that high levels of beta-carotene from food sources may be associated with a reduced risk of certain cancers. However, other studies, particularly those involving smokers, have indicated that high-dose beta-carotene supplements might increase the risk of lung cancer. It is essential to consider individual risk factors and consult with a healthcare provider for personalized advice.

Q: Is it better to get vitamin A from food or supplements?

A: It is generally recommended to obtain vitamin A from a balanced diet that includes a variety of foods rich in beta-carotene and retinol. Whole foods provide additional nutrients and fiber that are beneficial for overall health. However, in certain cases where dietary intake is insufficient, supplements may be necessary under the guidance of a healthcare professional.