Blueberries and Strawberries Reduce Heart Attack Risk in Middle-Aged Women
January 28, 2013
By Dr. Mercola
When it comes to fruit, berries are among the healthiest variety to choose, as they are densely packed with a variety of potent phytochemicals and fiber while at the same time being relatively low in sugar.
Blueberries and strawberries, in particular, have recently been highlighted by Harvard researchers as ‘superfoods’ for heart health.
Reduce Your Heart Attack Risk by Eating Berries
Women who eat more than three servings per week of blueberries and strawberries had a 32 percent lower risk of having a heart attack, according to new research.1 The benefit was due to flavonoids in the berries known as anthocyanins, which are antioxidants that give these fruits their characteristic red and purple hues.
Anthocyanins are known to benefit the endothelial lining of the circulatory system, possibly preventing plaque buildup in arteries as well as promoting healthy blood pressure. Other research has shown these antioxidants to protect against heart disease by reducing oxidative stress and inflammation, while enhancing capillary strength and inhibiting platelet formation.2 Researchers have further noted:3
“Epidemiological studies suggest that increased consumption of anthocyanins lowers the risk of cardiovascular disease (CVD), the most common cause of mortality among men and women.
Anthocyanins frequently interact with other phytochemicals, exhibiting synergistic biological effects but making contributions from individual components difficult to decipher. Over the past 2 decades, many peer-reviewed publications have demonstrated that in addition to their noted in vitro antioxidant activity, anthocyanins may regulate different signaling pathways involved in the development of CVD.”
Processed Foods Containing Anthocyanin-Rich Fruits May Not Have the Same Benefit
If you want to get the health benefits of antioxidant flavonoids like anthocyanins, it appears fresh berries may be among the best source. Many processed food manufacturers – baby foods in particular – have attempted to cash in on their growing popularity among the health conscious by adding blueberries and other anthocyanin-rich fruits to their products.
Aside from berries, other anthocyanin-rich foods include eggplant, red cabbage, red leaf lettuce, red radish, and plums. But be very careful when purchasing processed foods with these beneficial fruits as one study found that in processed foods in which anthocyanins were added as raw materials, such as canned foods, breads, cereals and baby foods, the anthocyanins could no longer be detected. This was likely due to their poor stability and possible destruction during processing. Researchers said:4
“ACNs were barely detected in baby foods prepared from fruits high in anthocyanins such as blueberries. In some foods that may contain a mixture of berries and fruits, such as baby foods, the amount of ACN-containing berry added may be so low that the ACNs were unable to be detected.”
Please be Careful With Your Fruit Consumption...
Fruit can be immensely beneficial to your health, as it’s a natural source of fiber, vitamins and antioxidants. But it also contains fructose, the metabolism of which causes most of the same toxic effects as ethanol, such as visceral adiposity (belly fat), insulin resistance and metabolic syndrome. When consumed excessively, fructose may actually be more damaging to your health than alcohol, having over 70 documented adverse effects.
The main offenders in this category are not whole, natural organic fruits, but added sugars that Americans are consuming in an "alarming number" on a daily basis. Soda, fruit juice, and high-fructose corn syrup in processed foods is likely to contribute far more to your daily fructose load than an apple or a handful of berries...
An appropriate amount of fructose is no more than 25 grams per day, but if you're overweight or at risk of (or have) heart disease, cancer, or type 2 diabetes, then you're probably better off cutting that down to 10-15 grams per day, including the fructose that comes from fruit. Another way to determine just how strict you need to be in regard to fruit consumption is to check your uric acid levels.
Some people may be able to process fructose more efficiently than others, and the key to assess this susceptibility to fructose-induced adverse health effects lies in evaluating your uric acid levels. The higher your uric acid, the more sensitive you are to the effects of fructose. The safest range of uric acid appears to be between 3 and 5.5 milligrams per deciliter (mg/dl), and there appears to be a steady relationship between uric acid levels and blood pressure and cardiovascular risk, even down to the range of 3 to 4 mg/dl.
If your levels are outside the healthy ranges listed above, then I strongly suggest you listen to your body's biochemical feedback and reduce your fructose consumption, including that from fruit, until your uric acid levels normalize. I've also included a chart below of fructose levels in fruit to give you an idea of what 25 grams of fructose a day looks like.
What are 10 of the Healthiest Fruits You Can Eat?
If your fruit consumption only consists of apples, oranges and bananas, you’re missing out on some of the healthiest fruits out there!
Blueberries, strawberries, raspberries, blackberries, cranberries... unless you overeat them, it is hard to go wrong with berries, as they contain powerful phytochemicals such as ellagic acid that provide antioxidant protection, as well as directly inhibit the DNA binding of certain carcinogens. Berries are also excellent sources of vitamin C, carotenes, zinc, potassium, iron, calcium and magnesium; they’re high in fiber and low in sugar.
Coconuts are among the most nutritionally dense foods on the planet and have been a dietary staple for millennia. Coconut, especially its oil, is a powerful destroyer of all kinds of microbes, from viruses to bacteria, from fungi to protozoa, many of which can harm your health. Over 50% of its fat is contains an immune-boosting fat called lauric acid that has been shown to stimulate weight loss, support heart health and healthy thyroid function, and more.
Coconut water, on the other hand, is a better sports hydration drink than ANY of the commercially available sugary sports drinks, and is both sterile and an isotonic beverage, meaning it has the same electrolyte consistency of human blood, which enabled medics in the Pacific Theater in World War II to use it as an emergency substitute for blood plasma.
Avocados are a very low fructose fruit and only have two grams of carbohydrates per avocado. They are rich in heart-healthy monounsaturated fat, which is easily burned for energy, and contain more than twice as much potassium as a banana. Avocados are also good sources of folate, dietary fiber, vitamin C, vitamin E, riboflavin and vitamin B6. I eat a whole avocado nearly every day.
Like berries, watermelon is loaded with phytochemicals, including lycopene, beta-carotene, and citrulline. When citrulline is consumed, it is converted to arginine. Arginine is an amino acid that has beneficial effects on your heart and circulatory system, as well as your immune system. Arginine boosts nitric oxide, which relaxes blood vessels, leading to another beneficial side benefit of watermelon... a Viagra-like effect without the hazards of a toxic drug! Arginine also helps the urea cycle by removing ammonia and other toxic compounds from your body.
The primary source of this fruit's benefits is its antioxidant content, particularly ellagitannin compounds like punicalagins and punicalins, which account for about half of the pomegranate's antioxidant ability. The juice and pulp of pomegranates have previously been studied for their potential heart- and joint-health benefits.
One mango will give you about half of your recommended daily allowance of both vitamins A and C, as well as some B vitamins, polyphenols and beta-carotene. Mangoes contain calcium, iron and potassium, are a good source of phosphorus, selenium, folate and zinc, and even contain 17 of the 20 amino acids that make up the human body.
Rich in antioxidants like carotenes, vitamin C and flavonoids, papaya is also useful for digestion, as it contains papain, an enzyme that helps with digestion by breaking down proteins. Papaya also has plant compounds that support your immune system, provide anti-inflammatory effects and may provide protection against cancer. It’s also a rich source of minerals, potassium and magnesium.
Pineapple contains an enzyme, bromelain, which aids digestion, reduces inflammation and swelling and may have anti-cancer effects. Rich in antioxidants like vitamin C, pineapple also provides immune support and is an excellent source of manganese, thiamin and riboflavin, which are important for energy production.
Rich in phytonutrients that appear to protect human DNA from free-radical damage, kiwi is also an excellent source of antioxidant vitamins C and E, and beta-carotene. Kiwi is also a good source of fiber, potassium, magnesium, copper and phosphorous.
Cherries contain powerful compounds like anthocyanins and bioflavonoids, which are known to fight inflammation and may help lower your uric acid levels and risk of gout. Bioflavonoids in cherries may reduce the activity of the enzymes Cyclooxyygenase-1 and – 2, which helps to reduce inflammatory processes associated with arthritis and gout in the body. Queritrin – a flavonoid – is also rich in cherries, and has been found to be a potent anticancer agent. Cherries also contain ellagic acid, a naturally occurring plant phenolic known as an anti-carcinogenic/anti-mutagenic compound.
Important Shopper’s Guide: Fruits You Should Buy Organic...
If possible, it’s best to buy all of your produce organic in order to reduce your exposure to pesticides. If you need to pick and choose, however, the Environmental Working Group has compiled a shopper’s guide to help.5 The following fruits have been found to contain the most and least toxic pesticide residues:
Most Contaminated Fruits (Buy These Fruits Organic)
Least Contaminated Fruits (OK to Buy Conventional)