Food Intake and Health Risks Quiz

Food Intake and Health Risks

• Food intake can lead to health risks.
• These risks are categorized into microbiological and toxicological risks.
• Microbiological risks can result in infection or intoxication.
• Toxicological risks can cause general toxicity, carcinogenesis, mutagenesis, or teratogenesis.
• Toxicological risks can also include hormones and microbial pathogens.

Food Composition

• Food is a mixture of chemicals.
• Nutrients comprise the majority (99.9%) of food.
• Toxins, contaminants, and additives can also be present.
• The presence of these various components can pose a risk.

Natural Toxins

• Natural toxins are naturally present in plants and animals.
• Long-term ingestion of these toxins can lead to health problems.
• Many natural toxins, notably those in plant-derived foods, trigger allergic reactions.

Toxins in Food: Types of Risk

• General toxicity: instant death or illness.
• Carcinogenic: cancer-causing.
• Mutagenic: DNA-altering.
• Teratogenic: birth defect-inducing.
• Hormones: hormonal disruption.
• Microbial pathogens: infection-causing organisms.

Natural Toxins in Plant Foods

• Endogenous plant toxins include cyanogenic glycosides, glucosinolates, acetylcholinesterase inhibitors, biogenic amines, and central stimulants.
• Natural contaminants involve mixing edible plants with toxic ones and contamination from animal ingestion of toxins. Microbial toxins are also a concern.

Antinutrient Compounds

• Plants, fungi, and bacteria produce low and high molecular weight compounds.
• These compounds act as defense mechanisms against various stresses, including herbivores, insects, pathogens, and environmental conditions.
• The presence of these compounds can limit nutrient absorption (anti-nutritional effects).

Major Antinutrients in Plants

• Oxalates, goitrogens, lectins (including phytohemagglutinins), protease inhibitors, fatty derivatives, and amylase inhibitors are examples of major antinutrients in plants.
• Toxic amino acids are also found in protein sources.

Flavonoids

• High quantities of flavonoids can act as antinutrients.

Tannins

• Tannins are found in fruits, tea, coffee, cocoa, grapes, and wine.
• Tannins can inhibit mineral absorption (e.g., iron), potentially leading to anemia.
• Consuming high amounts of tannins can cause gastrointestinal irritation, kidney irritation, and liver damage.

Toxic Amino Acids in Proteins

• Certain toxic amino acids found in plant foliage and seeds play a role in determining the nutritional value of tropical legumes.
• These amino acids act as antagonists to essential amino acids.
• Mimosine (or leucenol) is an example of a toxic amino acid.

Saponins

• These compounds have antinutritional effects, impacting fat metabolism, blood counts, and potentially causing depression.
• Food sources include peas, soybeans, and various herbs.
• Although saponins may have health benefits, such as positive effects on cholesterol, cancer, and immune functions, their high consumption could be detrimental.

Glucosides

• Glucosides are a significant category of secondary metabolites and chiefly affect the blood and circulatory system.
• They are not inherently poisonous but can release cyanide under acidic conditions.
• Cyanogenic glucosides are common in plants.

Cyanogenic Glucosides

• Cyanogenic glucosides are widespread in various plant species (over 1000).
• These compounds release cyanide through hydrolysis.
• Leguminous plants (like linseed, lima beans, kidney beans, bamboo shoots) and Rosaceae fruits (like bitter almonds, peaches, and apricots) contain significant amounts of these compounds.

Food/Plant Toxin Contents

• Plants like lima beans, almonds, sorghum, cassava, peas, and beans have different cyanide (HCN) levels.
• Manioc (cassava) varieties have differing HCN levels from bitter to sweet types.
• Almonds, apricots, and peaches (Rosaceae family) also contain HCN.
• Glycoalkaloids like solanine are present in potatoes.

Potato Glycoalkaloids

• Potatoes are a crucial crop worldwide.
• Solanine, a glycoalkaloid, is present in the entire potato plant.
• Peeling potatoes removes a large percentage of the solanine.
• Exposure to light increases the potato's solanine concentration.

Protease Inhibitors

• Protease inhibitors are mainly present in legumes but also occur in other plants like potatoes and cereals.
• They may be present in animal products as well.

Substances Binding Minerals

• Phytic acid and phytates (compounds) are mineral chelating agents, forming complexes with iron, copper, and zinc.
• These bind to enzymes (peptidase like pepsin).
• This hinders the absorption of minerals and can affect starch digestibility.

Natural Plant Contaminants

• Sources of contamination involve mixing edible plants with toxic ones or animal ingestion of toxins, followed by contamination of animal products (such as milk and fish).
• Micro-organisms can also cause contamination.

Mycotoxins

• Mycotoxins, often produced by molds like Aspergillus, Penicillium, and Fusarium, are a concern.
• They are stable and can persist during food processing.
• Contamination directly affects food safety.
• Aflatoxins are prevalent in nuts, peanuts, corn, and cottonseed oil, particularly aflatoxin B, which is the most harmful and carcinogenic.