Drinking at least five glasses of water a day can reduce the risk of heart attack by 40%

This is a fascinating and important topic, as heart disease is a leading cause of death worldwide. In this article, I will explain what the scientific evidence says about this claim, what are the benefits of drinking water for your heart health, and how much water you should drink each day. Let’s get started!

What is the evidence for drinking water and heart attack risk?

The claim that drinking at least five glasses of water a day can reduce the risk of heart attack by 40% comes from a study published in 2002 in the American Journal of Epidemiology. The researchers analyzed data from 8,280 men and 12,017 women who participated in the Adventist Health Study, a large cohort study of Seventh-day Adventists in California. The participants were followed for six years and their water intake and incidence of fatal and nonfatal heart attacks were recorded.

The results showed that after adjusting for other factors, such as age, smoking, physical activity, body mass index, and dietary habits, the men who drank five or more glasses of water per day had a 46% lower risk of dying from a heart attack than those who drank two or fewer glasses per day. The women who drank five or more glasses of water per day had a 59% lower risk of dying from a heart attack than those who drank two or fewer glasses per day. The researchers also found that drinking other fluids, such as coffee, tea, juice, milk, or alcohol, did not have the same protective effect as water.

How does water protect the heart?

The exact mechanism by which water protects the heart is not fully understood, but there are some possible explanations. One is that water helps lower blood viscosity, which means it makes the blood thinner and less sticky. This can improve blood flow and prevent blood clots that can cause heart attacks. Another is that water helps lower blood pressure, which is a major risk factor for heart disease. Water can also help regulate body temperature and prevent dehydration, which can stress the heart and impair its function.

What are the other benefits of drinking water?

Drinking water has many other benefits for your health besides reducing your risk of heart disease. Some of these benefits include:

It lubricates your joints and cushions your organs and tissues.
It delivers oxygen and nutrients to your cells and removes waste products.
It supports your digestion and prevents constipation.
It boosts your skin health and beauty.
It enhances your brain function and mood.
It helps you control your appetite and weight.
It prevents infections and supports your immune system.

How much water should you drink each day?

There is no universal answer to how much water you should drink each day, as it depends on many factors, such as your age, gender, activity level, health status, and environmental conditions. However, some general guidelines can help you estimate your daily fluid needs.

The U.S. National Academies of Sciences, Engineering, and Medicine recommend that an adequate daily fluid intake is about 15.5 cups (3.7 liters) for men and about 11.5 cups (2.7 liters) for women. These amounts include fluids from water, other beverages, and food. About 20% of your daily fluid intake usually comes from food, especially fruits and vegetables that have high water content.

You may need to drink more or less water depending on how much you sweat, whether you have a fever or diarrhea, whether you are pregnant or breastfeeding, whether you have any medical conditions that affect your fluid balance, such as kidney disease or heart failure, and whether you take any medications that make you retain or lose water.

The best way to tell if you are drinking enough water is to check your urine color and frequency. If you are well-hydrated, your urine will be pale yellow or clear, and you will urinate about four to eight times a day. If you are dehydrated, your urine will be dark yellow or brown, and you will urinate less often.

What are some tips to drink more water?

If you find it hard to drink enough water every day, here are some tips to help you increase your intake:

Carry a reusable water bottle with you wherever you go and refill it throughout the day.
Drink a glass of water before each meal and snack.
Add some flavor to your water with a slice of lemon, lime, cucumber, or mint.
Drink water instead of sugary drinks, such as soda, juice, or sports drinks.
Drink water before, during, and after exercise.
Drink water when you wake up and before you go to bed.
Set a reminder on your phone or computer to drink water every hour.
Track your water intake using an app or a journal.

FAQs

Q1: Can drinking too much water be harmful?

A1: Drinking too much water can cause a rare but serious condition called hyponatremia, which means low sodium levels in the blood. Sodium is an electrolyte that helps balance the amount of water in and around the cells. When you drink too much water, your kidneys cannot flush out the excess water, and the sodium in your blood becomes diluted. This can cause the cells to swell and lead to symptoms such as headache, nausea, vomiting, confusion, seizures, coma, and even death.

Hyponatremia can occur in people who drink excessive amounts of water in a short period of time, such as athletes or people who use drugs like ecstasy. It can also occur in people who have certain medical conditions that affect their ability to excrete water, such as kidney disease, heart failure, liver cirrhosis, or syndrome of inappropriate antidiuretic hormone secretion (SIADH).

To prevent hyponatremia, you should drink water according to your thirst and avoid drinking more than 1 liter per hour. You should also monitor your urine color and frequency and seek medical attention if you experience any signs of hyponatremia.

Q2: What are the signs and symptoms of dehydration?

A2: Dehydration occurs when you lose more fluid than you take in, and your body does not have enough water to carry out its normal functions. Dehydration can be mild, moderate, or severe depending on how much fluid is lost. Some common signs and symptoms of dehydration include:

Thirst
Dry mouth, lips, and eyes
Dark yellow or brown urine
Few or no tears when crying
Sunken eyes and cheeks
Lightheadedness or dizziness
Fatigue or weakness
Headache
Muscle cramps
Rapid heartbeat or breathing
Irritability or confusion
Fainting

Dehydration can be caused by various factors, such as vomiting, diarrhea, fever, excessive sweating, burns, diabetes, kidney disease, alcohol consumption, or not drinking enough water. Dehydration can lead to serious complications, such as heat exhaustion, heat stroke, urinary tract infections, kidney stones, kidney failure, seizures, low blood volume shock (hypovolemic shock), and coma.

To prevent dehydration, you should drink enough water every day according to your thirst and activity level. You should also replace lost fluids and electrolytes when you are sick or exercising. You should seek medical attention if you have severe dehydration or if you have any signs of heat-related illness.

Q3: Does drinking water help you lose weight?

A3: Drinking water can help you lose weight by increasing your metabolism, suppressing your appetite, and reducing your calorie intake. Several studies have shown that drinking water can boost your metabolic rate by 24–30% for up to 1.5 hours after drinking it . This means that drinking 2 liters of water per day can increase your energy expenditure by up to 96 calories per day.

Drinking water can also help you feel full and reduce your hunger. One study found that drinking 500 ml of water before each meal resulted in a 44% greater weight loss over 12 weeks compared with a control group . Another study found that drinking 500 ml of water before breakfast reduced the amount of calories consumed by 13% .

Drinking water can also replace high-calorie beverages, such as soda, juice, or alcohol, that can contribute to weight gain. One study estimated that replacing one serving of a sugar-sweetened drink with water per day can reduce your daily calorie intake by 200 calories and lower your risk of obesity by 7% .

However, drinking water alone is not enough to lose weight. You also need to eat a balanced diet that is rich in protein, fiber, healthy fats, vitamins, and minerals, and low in added sugars, refined grains, and processed foods. You also need to exercise regularly and get enough sleep and stress management. Drinking water can support your weight loss efforts, but it is not a magic bullet.

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