Food Sources High In Sulfur

Sulphur is a mineral that is found in all living organisms, whether that be plants, animals or humans. Recent research has looked into the importance of sulphur in our nutritional intake, and several benefits have been identified. This article will explain what roles sulphur plays in our body, what food sources are rich in this mineral, and explain its different health benefits. 

Introduction

Sulphur is an element that is vital in the human body, as it plays important roles in essential bodily functions like protein synthesis (aka the production of protein molecules), as well as metabolic and catalytic activities.¹ The latter refer to mechanisms that speed up the chemical reactions of enzymes that happen during metabolism.² 

Sulphur can be found in a variety of food sources, and can also be taken in the form of a vitamin supplement. Incorporating this element in your daily diet has been shown to improve overall health, as well as skin, hair and nail growth.³ Overconsumption of sulphur, however, has been linked to increased risks of heart disease or medical issues.⁴ 

Sulphur and Its Role in the Body

Essential role of sulphur in various bodily functions

There are many scientific terms that explain how and why sulphur is important in our bodily functions, but let’s keep it simple. Sulphur, from both organic (food) and non-organic sources, is associated with amino-acid-containing protein-rich foods. Examples of the latter are eggs, meat or fish.

Sulphur plays a role in maintaining the shape of these amino acids, which allows them to do what they need to do in the body.⁵ This includes protein synthesis, or the creation of protein molecules, which is an essential part of the growth and repair of our body. This includes muscle recovery, reduction of joint pain and more.⁶

Sulphur’s contribution to skin, hair and nail health

Sulphur is also a key factor in skin, hair and nail health. The hair is mainly composed of a protein called keratin, which is especially rich in cysteine, a sulphur-containing amino acid. Keratin strengthens the hair and prevents breakage, heat damage and frizz.

Sulphur supplementation has been shown to help with dandruff. Similarly, nails contain alpha-keratin, which is also dependent on sulphur-induced protein synthesis. This protein plays a protective role for our nails, strengthening them and making them more rigid.³

Lastly, incorporating sulphur in our daily diet has also been shown to have anti-ageing effects on the skin. Additionally, many creams and lotions aimed to treat skin conditions, such as acne, also contain sulfur.⁷ 

Sulphur’s role in detoxification and antioxidant defence

There are several antioxidant systems in the body that contain sulphur, for example, glutathione or thioredoxin. These can effectively combat reactive oxygen or nitrogen species. Increased levels of the latter in the body leads to oxidative stress, causing toxicity and damaging the cells in our body. The sulphur-rich antioxidants detoxify these areas and treat this oxidative stress. In addition, it also plays a preventative role as it helps maintain the correct balance of reactive oxygen/nitrogen species.⁸ 

Sulphur-rich Foods

There are no recommended daily intake guidelines for sulphur, but to ensure adequate intake, you should include the following food sources in your diet.

Cruciferous vegetables

Cruciferous vegetables such as cabbage, broccoli, cauliflower and Brussels sprouts contain high amounts of sulphur and do not tend to lose this amount after cutting or cooking. Half a cup of raw cabbage, for example, contains about 90 milligrams of sulfur.⁵

Allium vegetables

Allium vegetables, for example garlic and onions, are also rich in sulphur compounds and have been proven to be beneficial for overall health. Sulphur is what gives these alliums their unique flavour, and is also what induces tears when cutting an onion. The sulphur content is highest when raw, and reduces when heated up.⁹

Eggs

Have you ever found that dark green rings form around your egg yolks when you hard-boil your eggs? This is because of their sulphur content. The highest proportion of sulphur is found in the egg whites. In addition, it is sulphur that gives any protein supplements that egg-like smell.⁵ Other protein sources such as dairy and meat are also rich in sulphur. 

Legumes

Legumes such as beans (kidney beans, black beans, soybeans, etc.), chickpeas and lentils are also recognised as sulphur-rich food sources.⁵ 

Fish and seafood

Fish and seafood, such as crab, mussels or salmon contain high levels of protein and are rich in sulphur. This can also be the cause of unpleasant odours coming from seafood.¹⁰

Nuts and seeds 

Finally, nuts and seeds also contain high levels of sulphur. For example, sesame seeds contain up to 1200 milligrams per 100-gram portion, and 100 grams of peanuts gets you about 820 milligrams.¹¹

Cooking and preservation methods

As mentioned, many of the sulphur-containing food sources lose some of their mineral content with cutting and cooking. However, most vegetables and other foods mentioned above are usually cooked before being consumed, so what is the best way of preparation?

Studies have found that the least amount of minerals are lost when steaming (especially in the case of cruciferous vegetables), as well as microwaving or blanching. In contrast, using a stir-fry or frying method causes bigger losses of sulphur content.¹²

Several industrial processes have been put in place in the food production industry with the aim of containing sulphur in food sources as much as possible. Drying, whether that be by thermal or non-thermal techniques, is an effective method of food preservation. It has been shown to reduce sulphur percentage, but this reduction is minimal.¹³ 

Sulphur-containing compounds and health benefits

Glucosinolates in cruciferous vegetables and their anti-cancer properties

Cruciferous vegetables are mostly known for their high content of glucosinolates, which are sulphur-rich compounds.¹⁴ These play important roles in the immune system and overall health. In addition, it is believed that the consumption of glucosinolates can decrease the damage caused by carcinogenic chemicals.

For example, it was found that lower consumption of cruciferous vegetables was linked to a higher risk of colon cancer in adults. Increasing this intake reduced the risk. The mechanism through which glucosinolates prevent and combat cancer is not completely clear, but three ideas have been put forward.

Firstly, the compounds are believed to enhance detoxification, which protects our cells against environmental toxins. Next, they are believed to reduce cancer growth by arresting and inducing the destruction of cancer cells. Lastly, glucosinolates are thought to modulate epigenetic marks, which play a role in the protection against carcinogens.⁹

Allicin in garlic and its potential cardiovascular benefits

Allicin is a sulphur-rich compound that can be found in many allium vegetables, mainly in garlic. It can get absorbed through the cell membrane without causing any damage due to its hydrophobic properties, and can then cause multiple pharmacological effects that are beneficial to the cardiovascular system. The compound can cause various protective effects, as well as antioxidant benefits on the cardiovascular system.¹⁵

Methionine in eggs and its role in protein synthesis

Methionine is a sulphur-rich amino acid that is essential to the human body. It plays an important role in protein synthesis, acting as an antioxidant, stabilising the protein structure, helping with the recognition of specific protein sequences and more.¹⁶ Protein synthesis is a vital process in the body, as essential functions that keep us alive cannot be performed without proteins. 

Cysteine in legumes and its antioxidant properties

Cysteines are particularly important in the synthesis of antioxidants like glutathione. Legumes have a particularly high cysteine content compared to other sulphur-rich food sources, so incorporating these in your diet will have many benefits.¹⁷ Antioxidants reduce oxidative stress, help prevent disease, support eye and brain function, reduce inflammation and improve overall health.⁸

Dietary considerations and benefits

Maintaining an overall balanced diet should ensure that you consume enough sulphur to benefit from its actions. This includes stronger nails, healthier hair, slower ageing of your skin, reduced joint pain, and a stronger immune system. But what are the consequences of a deficiency in sulphur?

It has been shown that in plants, reduced sulphur levels lead to smaller and less healthy crops. In humans, symptoms caused by sulphur deficiencies are less clear, and it is also very rare. Some suggest that a lack of sulphur can eventually lead to protein deficiency in the body, which can cause all sorts of complications.

These include decreased immune function and muscle mass, prolonged and poor healing capacities, skin fragility and just decreased overall health.¹⁸ In the rare case of a deficiency, there are multiple sulphur supplements that can be taken. However, before consuming these it is important to consult with a healthcare professional to ensure they are safe to use. There is not much information about the overconsumption of sulphur supplements, but it may lead to uncomfortable symptoms like nausea or diarrhoea.¹⁹ 

Summary

Sulphur is a mineral found in many food sources that is vital to us. It is mainly an important compound in protein synthesis, a process that is essential to the building, repairing and maintaining of our body. Additionally, incorporating enough sulphur in our diets helps with nail, skin and hair health, and protects our body against toxic chemicals and illness. Incorporating foods such as cruciferous vegetables, alliums, nuts, fish, eggs and more in your diet will ensure that you consume the correct amount of sulphur. In the rare case of deficiency, sulphur supplements can also be taken. However, if you make sure to eat a healthy, well-balanced diet, this should not be necessary.