The Role of Cholesterol in Human Health and Diet

Cholesterol is a dietary lipid found exclusively in animal products, absent in the plant kingdom. This compound, though non-essential as a nutrient, plays a crucial role in the body's biochemistry. The human body, particularly the liver, synthesizes sufficient cholesterol to meet physiological needs, ensuring its availability without dietary intake. The liver not only manufactures cholesterol but also regulates its release and retrieval from the bloodstream, maintaining balance and preventing excess accumulation.

Cholesterol differs from triglycerides in that it does not provide energy. Instead, it serves as a fundamental structural component of cell membranes, contributing to their fluidity and integrity. This structural role is vital for the proper functioning of cells, impacting processes such as hormone production, vitamin D synthesis, and the formation of bile acids necessary for fat digestion.

Recent studies on dietary cholesterol have primarily focused on its relationship with intestinal cancer, specifically colon tumors. While research outcomes have been inconsistent, a significant portion of the data suggests a potential link between high dietary cholesterol intake and the development of colon cancer. This association underscores the need for a balanced diet, considering both the benefits and risks of cholesterol consumption. Understanding these dynamics is essential for developing dietary guidelines that promote health while minimizing disease risk.
The Role of Cholesterol in Human Health and Diet

Understanding the Role of Dietary Fats in Health

Fats, essential components of our diet, are primarily derived from animal or vegetable food sources. Despite their varied origins, all fats share a common structural feature: they are composed of carbon, hydrogen, and oxygen molecules. However, dietary fats often carry a negative reputation due to their association with heart disease and cancer. This reputation, while sometimes justified, oversimplifies the complex role that dietary fats play in health and disease.

Certain fats are essential for proper growth and the maintenance of health, and their absence can lead to specific deficiency diseases. For instance, omega-3 and omega-6 fatty acids are crucial for brain function and cell growth. Conversely, excessive consumption of particular types of fats, such as saturated fats and trans fats, significantly increases the risk of chronic diseases. Diets high in these fats are linked to heart disease and arterial issues, which remain the leading cause of death among adults in the United States and Canada.

Obesity is another major health risk associated with high-fat diets. The high energy density of fatty foods often leads to an excess caloric intake, resulting in weight gain and obesity. Obesity, in turn, is linked to numerous health problems, including type 2 diabetes mellitus and hypertension. Both conditions place significant stress on the circulatory system, and a high intake of dietary fats can exacerbate this by contributing to the development of atherosclerosis, a condition characterized by the hardening and narrowing of the arteries.

The most important lipids in our food supply are triglycerides and cholesterol, which, despite being chemically distinct, share the characteristic of being insoluble in water. Triglycerides, commonly referred to as fats, oils, grease, shortening, lard, tallow, suet, and ghee, are transported to various fat depots in the body, such as muscles, breasts, and the insulating fat layer under the skin. These stored fats serve as a critical energy reserve, which the body taps into when available fuel from food runs low.

Cholesterol, another dietary lipid, is found exclusively in animal products and does not exist in the plant kingdom. While cholesterol is often vilified, it is essential for the formation of cell membranes and the production of certain hormones and vitamin D. However, excessive cholesterol, particularly low-density lipoprotein (LDL) cholesterol, can lead to plaque buildup in arteries, increasing the risk of heart disease.

In conclusion, while fats are often viewed negatively due to their association with various health issues, they are an essential part of the diet, required for many bodily functions. It is the type and quantity of fat consumed that determines its impact on health. A balanced intake of healthy fats, such as unsaturated fats found in fish, nuts, and olive oil, along with a reduced intake of harmful fats, can help maintain overall health and prevent chronic diseases.
Understanding the Role of Dietary Fats in Health

Phenylketonuria Diet Management

Phenylketonuria (PKU) is a rare genetic disorder caused by the absence of an enzyme called phenylalanine hydroxylase (PAH), which is vital for converting the amino acid phenylalanine into tyrosine. This condition falls under the category of inborn errors of metabolism. Typically, PKU is detected shortly after birth through routine screening tests.

Individuals with PKU face significant challenges due to their inability to metabolize phenylalanine effectively. If they consume foods high in phenylalanine, it can accumulate in the body and lead to severe cognitive impairment and potentially brain damage.

A critical component of managing PKU is strict dietary control, particularly limiting the intake of phenylalanine. One prominent source of concern for PKU patients is aspartame, an artificial sweetener composed of aspartic acid and phenylalanine. When aspartame is ingested, it breaks down in the digestive system, releasing phenylalanine, which cannot be properly processed by individuals with PKU.

Common food products containing aspartame include carbonated beverages, drink mixes, gelatin desserts, pudding mixes, and cold cereals. While these products are generally considered safe for the general population, they can pose serious health risks for those with PKU.

The avoidance of aspartame-containing products is crucial for individuals with PKU to prevent adverse health consequences. Ongoing education and awareness are essential to ensure that PKU patients and their caregivers are well-informed about which foods and beverages to avoid.

In conclusion, individuals diagnosed with PKU must remain vigilant in managing their diet to mitigate the risks associated with phenylalanine accumulation. Avoiding aspartame-containing products is a necessary and practical step towards safeguarding their health and well-being.
Phenylketonuria Diet Management

Healthy diet and nutrition during pregnancy

Both the quality and quantity of the diet during pregnancy critically influence the health of the mother and her unborn child.  The most common nutritional concern of women during pregnancy is excessive weight gain.

They need to be encouraged to maintain a healthy diet and sufficient exercise throughout pregnancy. Inappropriate weight gain can place the newborn at greater risk for infection, illness, disabilities, and even death.

Women with eating disorders are often underweight at conception, increasing the risk of delivering a low birth-weight infant.

Some women experience pica (persistent eating of foods that have not nutrient value). Nonfood items most commonly craved and consumed by pregnant women with pica include ice or freezer frost, laundry starch or cornstarch.

Pica behavior may lessen the nutritional level of the mother and her fetus since the mother may not eat nutritious foods in sufficient quantity, which can lead to poor weight gain, low birth weight and intrauterine growth retardation.

Also, the substance that the woman is eating may have harmful effects to the maternal fetal unit. As part of preconception counseling, as well as good health practice during pregnancy and lactation, women should avoid alcohol, smoking, recreational or illegal drug use and take only those medications approved by her physician.

Women who drink 2 – 3 cups of coffee each day have a daily caffeine intake about 300 mg. Caffeine decreases the absorption of iron, which has a direct effect in the maternal fetal unit. During pregnancy, the caffeine has long been suspected of causing adverse effects in pregnant women because it increase heart rate, acts as a diuretic, and stimulate the central nervous system. Caffeine consumption during pregnancy may lead to caffeine withdrawal symptoms in new born.

Aspartame (found in some artificial sweeteners) contains the amino acid phenylalanine and should be avoided by pregnant women because high levels of phenylalanine can lead to impaired fetal brain development and result in mental retardation.  It also aggravates the stress response in the brain, making the women even more prone to nervousness. Women with a metabolic disorder called phenylketonuria (PKU) should avoid it.
Healthy diet and nutrition during pregnancy 

The best food for healthy diet

Great food and a healthy diet means enjoying full flavor and invigorating meals while relishing the fresh, simple and unadulterated.

Apples: Apples have good amounts of soluble and insoluble dietary fiber as well as vitamin C. They contain many phytonutrients, such as quercetin, catechins, phloridzin and chlorogenic acid that act as antioxidants. The pulp and sin of apples contain flavonoids.

Almonds: Almonds have a high concentration of protein and nutrients and are a good source of vitamin E, calcium, zinc, potassium, magnesium and iron. Most of the fat in almonds is monounsaturated fat, which can help lower cholesterol levels when substituted for other fats. Most almonds are considered low sodium, with less than 140 milligrams of sodium an ounce.

Broccoli: Broccoli is rich in magnesium and vitamin C, which is known to help fight infections and viruses and is considered to be one of the most powerful immunity boosters available. Vitamin C also promotes the production of interferon, and antibody that blocks viruses and infections from getting deep into cells. 

Blueberries: Blueberries are a good source of vitamin C. They are a rich, low-calorie source of fiber, antioxidants and phytonutrients. Regular intake of blueberries may improve short-term memory and reduce the cellular damage associated with aging. Research has shown that blueberries may help prevent urinary tract infection by increasing the acidity of urine, which helps destroy bacteria and by preventing bacteria from colonizing on the bladder walls.

Red beans: Small red, pinto and dark red kidney varieties -- are an excellent low-fat source of antioxidants, protein, dietary fiber and copper. They’re also a good source of iron, magnesium, phosphorus, potassium and thiamin.

Wild salmon: Wild salmon is a great source of protein and contains minerals such as iodine, potassium and zinc. It also contains omega-3 fats o the ultimate anti-ageing nutrient as a major source component of brain and nerve tissue. Omega 3 fats also beneficial for good eyesight.

Spinach: The A and C vitamins in spinach plus fiber, folic acid, magnesium and other nutrients help control cancer, especially colon, lung and breast cancer.

Sweet potatoes: The deep orange-yellow color of sweet potatoes tells you that they’re high in beta-carotene. Sweet potatoes are also high in vitamin C and a good source of fiber, vitamin B-6 and potassium. And, they’re fat-free and relatively low in calories.

Vegetable juice: Fresh vegetable juice supplies concentrated amounts of enzymes and other vital nutrients that help body return to balance faster. Tomato juice, and vegetable juices which include tomatoes, are good sources of lycopene, an antioxidant that may reduce the risk of heart attack and certain types of cancer. Be sure to select the low-sodium varieties.
The best food for healthy diet

Folic acid in human body

The term ‘folic acid’ refers specifically to pteroylmonoglutamic acid which reference to the pteroic acid and glutamate moieties.

Folic acid is required for the formation of blood cells by the bone marrow and is involved in the formation of the blood pigment hemoglobin.

During pregnancy folic acid helps create red blood cells for the increased blood volume required by the mother, fetus and placenta.

asparagus

It is also required for the synthesis of some amino acids. Deficiency symptoms involve pernicious anemia.

Scientific experiments have revealed that folic acid deficiencies cause DNA damage resembling the DNA damage in cancer cells.

Folic acid is found in liver, dried beans, peas, lentils, orange, whole-wheat products, asparagus, beets, broccoli, Brussels sprouts and spinach.
Folic acid in human body 

Diet with calcium-rich foods

A calcium-rich diet is recommended for all individuals a part of a healthful, well balanced diet.

Consuming calcium-rich foods daily will help minimize resorption of calcium from the bones and thus promote dense, strong bones.

Calcium is found salmon (with bones), sardines, seafood and dark green leafy vegetables. Milk and dairy products are the primary source of calcium in the North American diet.

Other calcium-rich foods include almonds, asparagus, blackstrap molasses, brewer’s yeast, broccoli, buttermilk, cabbage, carobs, cheese, collards, dandelion green, dulse, figs, filberts, goat’s milk, kale, kelp, milk, mustard greens, oats, prunes, sesame seeds, soybeans tofu, turnip greens, watercress, whey and yogurt.

There are many herbs contains calcium.  This include alfalfa, burdock root, cayenne, chamomile, chickweed, chicory, dandelion, mullein, nettle, oat straw, paprika, parsley, peppermint, plantain, raspberry leaves,  eyebright, fennel seed, fenugreek, flaxseed, hops, horsetails, kelp, lemongrass, red clover, rose hips, shepherd’s purse, violet leaves, yarrow, and yellow dock.

Besides the many supplements or antacids that provide calcium, many food manufacturers have been adding calcium to their foods as well.

Consumption of food with high in protein, fat and/or sugar affects calcium uptake. The average American diets of meats, refined grains and soft drinks leads to increase excretion of calcium.

Consuming alcoholic beverages, coffee, junk foods, excess salt, and/or white flour also leads to the loss of calcium by the body.

Calcium may be poorly absorbed from foods rich in oxalic acid. Oxalic acid can be found in almonds, beet greens, cashews, chard, cocoa, soybeans and spinach. Oxalic acid known as oxalate, is the most potent inhibitor of calcium absorption by binding with it in the intestines and producing insoluble salts that cannot be absorbed.

The normal consumption of foods containing oxalic acids should not pose a problem, but overindulgence in these foods inhibits the absorption of calcium.

Oxalic acid can also combine with calcium to form calcium-oxalate kidney stones. However, that taking magnesium and potassium supplements can prevent the formation of this types of stone.
Diet with calcium-rich foods

Causes of vitamin K deficiency

Human intake of vitamin K comes from two main sources - diets and synthesis from intestinal bacteria. A primary deficiency of vitamin K is rare, but a secondary deficiency may occur in two circumstances.

First when fat absorption falters and second some drugs disrupt vitamin K’s synthesis. Vitamin K deficiencies can be caused by a variety of factors. These include:

*Not consuming enough of vitamin K from one's diet can contribute to a deficiency. Dietary vitamin K is highest in leafy green vegetables such as lettuce, kale, broccoli and collard greens.

*A diet with high intakes of salicylates can block vitamin K. Salicylates are found in foods such as nuts, fruits, spices and mints. Blocking vitamin K can "thin" the blood - it basically keeps blood from coagulating. 

*Prolonged use of some antibiotics decreases the intestinal flora that produce vitamin K, depleting vitamin K store. Antibiotics destroy not only harmful digestive tract bacteria, but also the beneficial intestinal bacteria that is needed to create vitamin K. Sulfonamides and broad-spectrum antibiotic drugs can virtually sterilize the lumen of the intestine, thus removing an important source do vitamin K for most animals.

Certain antibiotics such as cephalosporins that contain an N-methyl thiotetrazol ring, interfere directly with vitamin K activity.

*Candida (systemic yeast) infections have been linked to vitamin K deficiencies. An overgrowth of candida albicans or other kinds of yeast can crowd out the helpful bacteria in the digestive tract that make vitamin K.

*Lipid malabsorption. Diseases of the gastrointestinal tract, biliary stasis, liver disease, cystic fibrosis, celiac disease and Ascaris infection can interfere, with the enteric absorption of vitamin K.

*Ingestion of high-dose aspirin, high dose vitamin E, warfarin or other anticoagulants is a common cause of vitamin K deficiency, either from decreased absorption or vitamin antagonism.
Causes of vitamin K deficiency

Balance diet during pregnancy

Pregnancy is a period of increasing nutritional demands associated with the growth of fetus and placenta; growth of maternal tissues, notably uterus and breasts; and increase in the volume of circulating blood and fat stores.

During pregnancy, the fetus’ cells and physiological capacities are developing. Therefore, women need to eat a well balance diet that has sufficient calories and represents a variety of food groups. They need to be encouraged to maintain a healthy diet and sufficient exercise throughout pregnancy.

A pregnant woman directly influences the nutritional status of her baby, and she must be sure her diet contains adequate nutrients for herself and for her baby.

Some women experience pica (persistent eating of foods that have not nutrient value). Pica behavior may lessen the nutritional level of the mother and her fetus since the mother may not eat nutritious foods in sufficient quantity, which can lead to poor weight gain, low birth weight and intrauterine growth retardation.

Also, the substance that the woman is eating may have harmful effects to the maternal fetal unit.

Pregnant women should increase their intake of essential nutrients and calories. For example to satisfy the protein demand of pregnancy, WHO recommends a total diet daily intake of .52-.57 g/kg.

Fat is more energy dense than carbohydrate or protein. Recent evident suggest that omega-3 fatty acids consumed during pregnancy are beneficial to cognitive development in infancy and childhood.

Pregnant women should consume 25-30% of their daily energy as fatty acids and they requiring 2500 kcal/day would need to consume 69-83 total grams fats daily.

They will need extra iron and may require additional vitamin and mineral supplementation.   A pregnant woman needs iron to satisfy the demand created by the growth of fetus, placenta and red cell mass during pregnancy and also the blood loss expected at the time of parturition.
Balance diet during pregnancy

Human body composition

Human body is composed of various tissues and numerous body cavities filled with body fluid.

Around 1850s, Justus von Liebig found that the human body contains many substances present in food and that body fluids contain more sodium and less potassium than tissues.

The average human body contains about 20 % of fat, 15% protein, much smaller amounts of carbohydrate (perhaps I %) and large amounts of water.

Although fat is found primarily in adipose tissue, intracellular triglyceride pools are also observed in liver, skeletal muscle and other organs, particularly in pathological conditions such as hepatic steatosis and various forms of lipidosis.

Human body also contains substantial amounts of the “major minerals,” from calcium and phosphorus down to sulfur and magnesium as well as trace quantities of most elements.

The water content of the human body is never higher than at birth – about 70% of a term newborn infant’s weight may be water.

By adulthood, body water content is generally 56 to 64%. As the water content of the extracellular fluid is by and large controlled hormonally, the greatest influence upon tissue water content remains the ration of skeletal muscle to adipose tissue.

The human diet reflects this compositional need, and consists of large quantities of water containing, proteinaceous, fatty, and carbohydrate foods, as well as others rich in the minerals.
Human body composition 

Salt in human diet

The introduction of salt in significant quantities to the human diet is probably linked to two of its properties:
*Its ability to remove moisture from foods, thus increase their osmotic pressure and making them less likely to spoil,

*Its ability to increase the palatability of savory foods.

The substance we call salt is the chemical compound sodium chloride. Salt also contains small amounts of other trace elements including calcium, magnesium and iodine.

Human evolved in a low sat diet of no more than 20 to 40 mmol sodium per day, and became adapted to the physiologic conservation of the limited salt naturally present in foods and not for excretion of a sodium load some 10 to 20 higher than the physiologic need.

Adults usually consume about 10g of salt a day, but there are enormous variations. A high intake of salt may contribute to the development of hypertension or high blood pressure in some individuals.

Salt in the diet comes mainly from processed foods such as crisps, nuts, cheese, pickled vegetables, sauces and smoked foods.

It is also added to food during preparation, cooking and at the table. Small quantity occurs naturally in some foods. Nobody is quite sure exactly how much salt we need to eat, but it is relatively small amount.

Most of the salt in the diet of contemporary industrialized populations is found in processed foods, added by manufacturers during production for a range of reasons, including taste enhancement, texture and preservation.
Salt in human diet

Fatty acids – the simplest of lipids

Fats or lipids consists of numerous chemical compounds, including monoglycerides, diglycerides, triglycerides, phosphatides, cerebrosides, sterols, terpenes, fatty alcohols,  and fatty acids.

The fatty acids, the simplest of the lipids, are defined as monocarboxylic acids that tend to be more soluble in organic solvents than in water. They are a hydrocarbon with a methyl group at one end and carboxyl group at the other.

Some naturally occurring saturated fatty acids:
Butyric
Caproic
Caprylic
Capric
Lauric
Myristic
Palmitic
Stearic
Arachidic
Behedic
Lignoceric

The human body needs fatty acids and it can make all but two of them –linoleic acid (the 18-carbon omega-6 fatty acid) and linolenic acid (the 18 carbon omega-3 fatty acid).

Fatty acids are classified according to the number of double bonds they possess. It can be saturated, monounsaturated or polyunsaturated and are essential for energetic, metabolic and structural activities.

Some naturally occurring unsaturated fatty acids:
Monoenoic: Palmitoleic, Oleic
Dienoic: Linoleic
Trienoic: Linolenic
Tetraenoic: Arachidonic

Palmitic acid and stearic acid are by far the most commonly occurring and widely distributed of the saturated fatty acids whereas oleic acid and linolenic acid are the most prevalent of the unsaturated.

These four fatty acids account for over 90% of the fatty acids in the average American diet. Fatty acids of shorter chain length are for the most part minor constituents of plants and animal fats.

However, butyric acid and myristic acid occur in milk fat in large amounts and about 60% of the fatty acid in coconut oil consists of lauric acid and fatty acids of shorter chain length.

Highly unsaturated fatty acids are essential for cellular functions of many differentiated tissues in humans of all ages.

They are mostly incorporated in membrane phospholipids and serve as a structural component of the phospholipid membranes in tissues throughout the body.
Fatty acids – the simplest of lipids

Carbohydrate group of food

Carbohydrates are polyhydroxy aldehydes, ketones, alcohols, acids, their simple derivatives and their polymers having linkages of the acetal type. Most carbohydrates conform to the general formula (CH2O)n, but the classification of carbohydrates includes compounds that are not true hydrates as the names implies. 

For example, deoxyribose contains 5 carbon atoms, 10 hydrogen, but only 4 oxygen rather than 5 as is customary for pentose. Moreover, some compounds that are properly classified as carbohydrates in terms of chemical properties contain nitrogen or sulfur addition to carbon, hydrogen, and oxygen.

Carbohydrate biosynthesis in plants starting from carbon disaccharide and water with the help of light energy i.e. photosynthesis is the basis for the existence of all other organisms which depend on the intake of organic substance with food.

The major carbohydrate containing foods in the human diet are: cereal, sweeteners, root crops, pulses, vegetables, fruit, and milk products. Carbohydrates play a major role in human diets, comprising some 40-75% of energy intake. Their nutritional energy value amounts to 17 kJ/g or kcal/g. Their most important nutritional property is digestibility in the small intestine.

Carbohydrates can be classified based on their chemical structure and/or based on their physiological effects. There are three main groups, monosaccharide, or simple sugars; oligosaccharides, of which the most prevalent in nature are the disaccharides; and polysaccharides the most complex of the carbohydrates. 

Defining carbohydrates by chemical structure, does not take into account their physiological differing response, such as differences in satiety value, gastric emptying times and effects on glucose and insulin levels.

Starch is by far the most important source of carbohydrates in the human diet amounting to approximately 50% of total carbohydrate in the United States, but often as much as 75% total carbohydrates in some of the developing countries.

Many starches do not have the functional properties needed to impart or maintain desired qualities on food products. As a result, some starches have been modified to obtain the functional properties required. These type modified starches, also known as derivates.

Sucrose ranks next in important comprising about 25% of carbohydrates intake. In the last 70 years the intake of complex carbohydrates in the diet of United States has decreased, and the intake of sucrose has markedly increased.
Carbohydrate group of food

The importance of calcium in human body

Calcium is a divalent cation and is the most abundant mineral in the human body. Calcium quantity to be found in an adult’s body is approx 1, 5 kilos. It accounts for roughly 40% of total mineral mass and about 1,5% of total body mass. Calcium is a very potent mineral, fulfilling different tasks in human bodies.

Calcium plays an important role in many biological processes. The most important of its functions relate to: mineralization of the bone tissue (bones and teeth), maintaining the cardiac rhythm, coagulating the blood, regulating the acid-basic equilibrium.

Calcium intake is very beneficial for patients that suffer from acute or chronic convulsions, osteoporosis, concentration disorders, headaches, allergies etc.

Parathyroid hormone restores blood calcium in one of several ways. It can increased the amount of calcium absorbed in the small intestine. It can also stimulate bone destruction.

Calcium levels are also influenced by vitamin D. Vitamin D is available in some foods and also produced in skin when it is exposed to sunlight.

Calcium deficiency leads to anemia, osteoporosis, dental cavities, irregular menses, severe headaches, sexual problems, emotional disorders, sleep disorders (insomnia) and many other dysfunctions.

Calcium nutrition has become a concern for many individuals because of the increased incidence of osteoporosis as human life expectancy continues to increase.

Nutritionally, calcium is found in many foods, but the major spruce in most human diets is dairy products.

In milk, a predominant class of protein is the caseins. Its function is to solubulize calcium phosphate micrograules by surrounding them in a micellar structure, providing an important mineral nutrient in liquid form.
The importance of calcium in human body

Type of fats in Food

For more than two decades, fats have been in the lime light. Some fat diet is essential for good health, but too much fat, especially saturated fat and trans-fat, increases the risks of choric diseases.

Culinary experts provide flavorful ways to use sensible amounts of fat in food prep. And the food industry has launched many fat-modified products: “reduced fat,” “0 grams trans-fat,” and “with omega 3s.”

Foods that derive less than 30 percent of their calories from fat are low fat. Foods that derive 30-50 percent of their calories from fat are moderate. Foods that derive more than 50 percent of their calories from fat are high.

All the fats in food are combinations of fatty acids. Nutritionists characterize fatty acids as saturated fatty acids , monounsaturated fatty acids, depending in how many hydrogen atoms are attached to the carbon atoms in the chain.

Not surprisingly, many consumers hear the message and consider the “fat facts” as they buy and prepare food.

Evidence indicates that a diet high in saturated fats, trans fat and cholesterol increases increase total blood cholesterol and LDL cholesterol and therefore the risk of heart disease.

Managing excess calories is also harder with high fat eating. There may be a link to some cancers, too.

As science reveals more, it’s also becoming clear that the links between the different types of fat and health are more complex than once thought.

For example olive oil is a monounsaturated fat. Its fatty acids lower blood cholesterol, They lower the LDL cholesterol and increase the HDL cholesterol.

A saturated fat such as butter, has mostly saturated fatty acids. Saturated fats are less solid at room temperature and get harder when chilled.

Type of fats in Food