Common Anti-Nutrients

1.

Tea

Tea contains the compound tannin which can decrease the availability to the body of the mineral iron (Fe) ingested in food. For example, if tea is taken together with cereal e.g. as a breakfast meal, it may considerably decrease the body's absorption of the iron contained in the cereal. Tea - not just coffee - also contains caffeine which has both a stimulant and a diuretic effect. Depending on its strength, tea may contain up to around 4% caffeine, which is one reason why some people prefer not to drink either tea or coffee in the few hours before bedtime.

2.

Coffee

Coffee contains caffeine which has both a stimulant and a diuretic effect.

Excessive consumption of caffeine can adversely affect the absorption of some important vitamins and minerals including:

• iron (Fe)
• magnesium (Mg)
• zinc (Zn)
• potassium (K), and other minerals - as well as some B vitamins including
• Vitamin B₇ (also known as vitamin H, coenzyme R, and biotin) and
• Vitamin B₈ (inositol).

The effect is highest if caffeine is consumed with food.
See the effects of caffeine on the body.

3.

Alcohol

Nutrients in alcoholic drinks ?

Alcohol itself provides only energy to the body; it does not include other nutrients such as vitamins, minerals, amino acids etc.. However, alcoholic drinks often include a mixture of elements and compounds in solution or suspension and sometimes also light gases (e.g. sparkling wines). Hence alcoholic drinks that include fruit juices might include some vitamins (from the juice) and alcoholic drinks derived from grains might contain nutrients from their source, e.g. some beers contain vitamin B₂ (riboflavin) and vitamin B₃ (niacin).

Effect of alcohol on nutritional requirements:

• Alcohols are stimulants and so affect the body's metabolism, increasing metabolic rate.
• Significant consumption of alcohol increases the body's requirement for vitamin A, the group of B vitamins and vitamin C.
• Significant consumption of alcohol decreases the body's ability to make use of the mineral zinc (Zn) and some B-vitamins, including vitamin B₃ (niacin) and vitamin B₉ (folic acid).
• Consumption of large amounts of alcohol affect the liver and reduce the amount of vitamin A that it can store.

4.

Carbonated soft drinks

Carbonated soft drinks contain a wide variety of ingredients depending on particular drink (brand, flavour, etc.). Typically these can include:

• Caffeine - up to around 20mg per 100ml of drink (so more than 20mg per typical 330ml can). See above re. coffee for more about the possible effects of caffeine.
• Citric acid (which can either be extracted from citrus fruits or manufactured in laboratories from other reactants) or orthophosphoric acid (H₃PO₄) are commonly used to maintain the sugar in the drink in suspension, i.e. to prevent it from crystallizing. Such acids can erode the hard outer (tooth enamel) layer of teeth. If consumed in excessive quantities these acids may also affect appetite and the functions of the stomach.

5.

Tranquillisers (Tranquilizers, Am)

Tranquillisers slow the body's metabolic rate and depress appetite.

Metabolic rate concerns the amount of energy required by the body to perform its various functions incl. maintaining the body itself and performing external functions e.g. sports and daily tasks. If the body requires less energy then fewer calories from energy-providing foods such as sugary snacks are appropriate. However, sufficient nutrients incl. vitamins, minerals and amino acids are still needed. A reduced appetite can lead to undernutrition in some circumstances.

6.

Antibiotics

Antibiotics that are ingested (as opposed to e.g. applied topically to an infected area of skin) destroy either specific or a range of micro-organisms in the gastrointestinal tract - according to the type of antibiotics taken.
However, some of the micro-organisms in the digestive system play important roles, incl.:

• in the break-down of foodstuffs (digestion)
• the absorption by the body of useful chemical substances that have been released by the breakdown of foodstuffs in the gastrointestinal tract
• the synthesis of compounds needed by the body from the chemicals released from foodstuffs, e.g. the body's production of certain vitamins and other organic compounds.

Use of 'broad-spectrum antibiotics' can therefore adversely affect the efficiency of the digestive system by temporarily* depriving it of some useful micro-organisms. *Unless the antibiotics are taken long-term the effect is usually temporary because the balance of micro-organisms within the gastrointestinal tract usually re-establishes itself in time.

Due to the situation explained above and because some antibiotics can also interfere with the activity within the body of certain vitamins and minerals, people who are taking antibiotics for a long period of time might therefore be encouraged to pay particular attention to their requirements for and levels of vitamin B₅ (also called pantothenic acid and pantothenate), vitamin B₇ (also called Biotin, Coenzyme R, and vitamin H), and vitamin C.

7.

Cigarette Smoking

Cigarette smoking involves the intake of many anti-nutrients, see e.g. chemicals in cigarettes. The combined effect of these chemicals on the body is a huge subject involving the many diseases considered to be caused or exacerbated by smoking. The 'anti-nutrient effects' of smoking are just one small aspect of the large subject of 'the health effects of smoking'.

Cigarette Smoking and Vitamin C: Studies have shown that the more a person smokes, the lower his or her level of vitamin C is likely to be (after other possibly relevant factors have been taken into account). As some data (incl. e.g. "The influence of smoking on vitamin C status in adults" Ref. http://1.usa.gov/xuVp5L) suggests that the inverse relationship between smoking and serum vitamin C levels is independent of dietary intake (of Vit C), it seems that one or more of the many chemicals in cigarettes acts to reduce the amounts of available vitamin C in the body, increasing the amount of vitamin C that a person who smokes would need to consume to keep his or her body adequately supplied with vitamin C. Indications are that the more someone smokes the greater the amount of extra vitamin C he or she is likely to require.

In addition to their need for additional vitamin C, cigarette smokers are also likely to need more vitamin B₂ (riboflavin), vitamin B₆ (pyridoxine) and vitamin B₁₂ (cyanocobalamin).

8.

Medication

The anti-nutrient effects of medication depend on the substances contained in the medication. Examples of 'medication' sources of anti-nutrients mentioned elsewhere in this table include tranquillisers, antibiotics and the contraceptive pill (which may be prescribed for some reasons other than the prevention of pregnancy).

In general the nutritional impact, if any, of prescribed or of-the-shelf medication should be made known to the person taking it - either by the prescriber and/or the packaging and information leaflet with the product. However, physicians do not always have as much time as they would like and often have to impart a lot of information to patients as clearly as possible. People also do not always take the time to study packaging thoroughly. It makes sense to fully appreciate the known effects, including any 'side-effects' mentioned in connection with whatever medication one uses and, if appropriate, to adjust one's diet or supplements accordingly.

9.

The Contraceptive Pill

The contraceptive pill is reported to interfere with the uptake and activity of certain vitamins and minerals. Users might therefore be encouraged to pay particular attention to their requirements for and levels of vitamin B₂, vitamin B₉ (Folic Acid) and vitamin E.

10.

Stress

'Stress' is a state of the body whose origin is psychological yet some of whose effects are physically observable and, in some cases, measurable.