Vitamin A is a fat-soluble vitamin that is good for healthy vision, skin, bones and other tissues in the body. Vitamin A often works as an antioxidant, fighting cell damage, but it also has many other uses.
There are two types of vitamin A. Preformed vitamin A, also called retinol, is found in animal products. Good sources are fortified milk, eggs, meat, cheese, liver, halibut fish oil, cream and kidneys.
Pro-vitamin A is found in plant-based foods such as fruits and vegetables, according to the U.S. National Library of Medicine (NLM). The most common type of pro-vitamin A is beta-carotene, a carotenoid that produces dark pigments in plant foods. Beta-carotene can be found in these brightly colored foods: Cantaloupe, Pink grapefruit, Apricots, Carrots, Pumpkin, Sweet potatoes, Winter squash, Dark green, leafy vegetables, Broccoli.
Retinol not only creates the pigments in the retina of the eye, according to NLM, but also is integral for good vision, especially night vision, and overall eye health. An age-related eye disease study by the National Eye Institute found that taking high levels of antioxidants, such as vitamin A, along with zinc, may reduce the risk of developing advanced age-related macular degeneration by about 25 percent. Age-related macular degeneration is the most common cause of loss of vision in the older population, said Ross.
Vitamin A also helps skin grow and repair skin.
vitamin A helps in the the formation and maintenance of teeth, bones, soft tissue, white blood cells, the immune system and mucus membranes.
Beta-carotene also acts as an antioxidant, protecting cells from free radical damage.
Around 250,000 to 500,000 children around the world with vitamin A deficiency become blind every year. Half of those children die within 12 months of losing their sight, according to the World Health Organization.
Symptoms of a severe deficiency are
Vitamin A dosage is tricky. Too little can make a person more susceptible to disease and vision problems while too much can create many problems, as well. The recommended dietary intakes for vitamin A depend on age, gender and reproductive status. The Dietary Reference Intakes (DRI) for adult women is 700 micrograms (mcg) and for adult men it is 900 mcg per day.
“Overdose of Vitamin A is absolutely a plausible scenario given its fat soluble nature, and it has been associated with a diverse set of symptoms ranging from skin and hair loss to neurologic problems, to gastrointestinal complains. In addition, liver injury has been described in situations of long term excess,” said Greuner.
“Ketogenic” is a term for a low-carb diet (like the Atkins diet). The idea is for you to get more calories from protein and fat and less from carbohydrates. You cut back most on the carbs that are easy to digest, like sugar, soda, pastries, and white bread.
How It Works
When you eat less than 50 grams of carbs a day, your body eventually runs out of fuel (blood sugar) it can use quickly. This typically takes 3 to 4 days. Then you’ll start to break down protein and fat for energy, which can make you lose weight. This is called ketosis. It’s important to note that the ketogenic diet is a short term diet that’s focussed on weight loss rather than the pursuit of health benefits.
Who Uses It?
People use a ketogenic diet most often to lose weight, but it can help manage certain medical conditions, like epilepsy, too. It also may help people with heart disease, certain brain diseases, and even acne, but there needs to be more research in those areas. Talk with your doctor first to find out if it’s safe for you to try a ketogenic diet, especially if you have type 1 diabetes.
A ketogenic diet may help you lose more weight in the first 3 to 6 months than some other diets. This may be because it takes more calories to change fat into energy than it does to change carbs into energy. It’s also possible that a high-fat, high-protein diet satisfies you more, so you eat less, but that hasn’t been proved yet.
Insulin is a hormone that lets your body use or store sugar as fuel. Ketogenic diets make you burn through this fuel quickly, so you don’t need to store it. This means your body needs — and makes — less insulin. Those lower levels may help protect you against some kinds of cancer or even slow the growth of cancer cells. More research is needed on this, though.
It seems strange that a diet that calls for more fat can raise “good” cholesterol and lower “bad” cholesterol, but ketogenic diets are linked to just that. It may be because the lower levels of insulin that result from these diets can stop your body from making more cholesterol. That means you’re less likely to have high blood pressure, hardened arteries, heart failure, and other heart conditions. It’s unclear, however; how long these effects last.
Carbohydrates have been linked to this skin condition, so cutting down on them may help. And the drop in insulin that a ketogenic diet can trigger may also help stop acne breakouts. (Insulin can cause your body to make other hormones that bring on outbreaks.) Still, more research is needed to determine exactly how much effect, if any, the diet actually has on acne.
Low-carb diets seem to help keep your blood sugar lower and more predictable than other diets. But when your body burns fat for energy, it makes compounds called ketones. If you have diabetes, particularly type 1, too many ketones in your blood can make you sick. So it’s very important to work with your doctor on any changes in your diet.
Ketogenic diets have helped control seizures caused by this condition since the 1920s. But again, it’s important to work with your doctor to figure out what’s right for you or your child.
Other Nervous System Disorders
These affect your brain and spine, as well as the nerves that link them together. Epilepsy is one, but others may be helped by a ketogenic diet as well, including Alzheimer’s disease, Parkinson’s disease, and sleep disorders. Scientists aren’t sure why, but it may be that the ketones your body makes when it breaks down fat for energy help protect your brain cells from damage.
Polycystic Ovary Syndrome
This is when a woman’s ovaries get larger than they should be and small fluid-filled sacs form around the eggs. High levels of insulin can cause it. Ketogenic diets, which lower both the amount of insulin you make and the amount you need, may help treat it, along with other lifestyle changes, like exercise and weight loss.
A ketogenic diet may help endurance athletes — runners and cyclists, for example — when they train. Over time, it helps your muscle-to-fat ratio and raises the amount of oxygen your body is able to use when it’s working hard. But while it might help in training, it may not work as well as other diets for peak performance.
The more common ones aren’t usually serious: You might have constipation, mild low blood sugar, or indigestion. Much less often, low-carb diets can lead to kidney stones or high levels of acid in your body (acidosis). Other side effects can include the “keto flu,” which may include headache, weakness, and irritability; bad breath; and fatugue.
Diet With Care
When your body burns its stores of fat, it can be hard on your kidneys. And starting a ketogenic diet — or going back to a normal diet afterward — can be tricky if you’re obese because of other health issues you’re likely to have, like diabetes, a heart condition, or high blood pressure. If you have any of these conditions, make diet changes slowly and only with the guidance of your doctor.
Tiger nuts may promote a healthy digestion in various ways.
For starters, they are high in insoluble fiber, which passes through your gut without being digested. Insoluble fiber adds bulk to your stools and helps food move through your gut easily, reducing the likelihood of constipation (1, 6Trusted Source).
Tiger nuts are also presumed to contain resistant starch, a type of fiber that can feed the friendly bacteria in your gut, helping your digestion run smoothly (7).
Moreover, tiger nuts may contain enzymes, such as catalases, lipases and amylases, which help break down foods in your gut, relieving gas, indigestion and diarrhea (7).
Keep in mind that the high fiber content of tiger nuts may initially cause unpleasant gas or bloating. Those interested in trying them should increase their portions gradually.
Animal studies show that tiger nut extract may help reduce blood sugar levels. This may, in large part, be due to the high fiber content of the tubers which may slow down the absorption of sugar in the gut (5).
Moreover, test-tube studies show that tiger nut extract may inhibit the action of carb-digesting enzymes in your gut.
As a result, less sugar may be absorbed from your gut in a way similar to the action of some blood-sugar-lowering diabetic medications. This is thought to potentially lower blood sugar levels, though more research in humans is needed (11Trusted Source).
Diets rich in monounsaturated fats are linked to lower levels of “bad” LDL cholesterol and higher levels of “good” HDL cholesterol. They are also associated with a lower risk of heart attack, stroke and death from heart disease (15Trusted Source, 16Trusted Source).
What’s more, tiger nuts are rich in the amino acid arginine. Arginine can promote heart health because your body can use it to make nitric oxide, a compound that helps arteries and veins dilate, hence lowering blood pressure (17Trusted Source, 18Trusted Source).
Research also links tiger nuts to better blood circulation and a lower likelihood of blood clots — both of which can reduce your risk of heart disease (7).
Tiger nuts may contribute to a stronger immune system.
In one test-tube study, tiger nut extracts were tested against several types of bacteria that can infect humans. The extract was effective against E. coli, Staphylococcus and Salmonella bacteria (19Trusted Source).
Another cell study found similar results. The researchers added that tiger nut extracts might also be effective at fighting antibiotic-resistant bacterial infections (20Trusted Source).
However, more studies are needed before strong conclusions can be drawn.