No part of the body responds quicker to good nutrition than the brain, and a series of new studies show how quality supplements can give you the boost you’ve been looking for in a matter of weeks — helping you to think sharper, quicker, and better than ever.

Start with the second letter of the alphabet — B vitamins.

In one of the studies, men given a high-dose B complex for 33 days improved on tests measuring mood, stress, and cognitive performance, and reported being less “mentally tired” after taking those tests.

The study was on men, but I have no doubt the benefits would apply to women as well because B vitamins such as B6, B12, and folate have proven time and again to help protect the brain.

But they’re also water soluble, which means your body doesn’t store them. They literally go right through you — in your mouth and out your urine, which is why it’s not enough to get them only some of the time.

You need to make sure you get them every single day.

Along with those B vitamins, be sure to take a quality multi — because another recent study found that women who took them for nine weeks had a boost in multitasking abilities.

More specifically, they had improved accuracy and faster responses while multitasking… and, as a bonus, they had lower levels of the inflammation marker homocysteine.

Again, there’s no reason these benefits wouldn’t apply to men and women alike. Just make sure your multivitamin comes from a maker you trust, and not the local dollar store.

And while you’re at it, be sure to take some fish oil. The omega-3 fatty acids are great for the brain, especially DHA. In one recent study, adults who took between 1 and 2 grams of DHA a day saw improvements in blood flow in the brain while engaged in cognitive tasks.

Of course, none of these supplements are miracle pills. They’re not going to magically undo the damage of an unhealthy lifestyle, but they’re an important part of the big picture — both in the short term and over the long haul.

Your own needs will depend on your diet, lifestyle, and even genetic factors that might make it more difficult for you to hold onto certain nutrients. A holistic doctor can run some tests to help you figure you which ones you need, how much you need, and the best way to get them.

Hello, gut.

But there’s one place you want as fat as can be, and that’s right inside your skull. Your brain is actually 60 percent fat — and the most critical fats of all when it comes to brain health are the omega-3 fatty acids found in fish oil.

Now, a new study confirms just how important those fats are for your thinker: People with the lowest levels have aging, shrinking brains and problems remembering what they had for breakfast.

Since the most prominent fat in your brain is DHA, the study of 1,575 dementia-free seniors also finds that it’s the most important one for brain health. The 25 percent with the lowest blood levels of DHA had the smallest brain volumes.

And, yes — when it comes to brains, bigger is definitely better.

Younger is better, too. And while you can’t turn back the clock, your brain can get old before its time — and seniors with the lowest DHA levels had brains that seemed two years older, according to the study in Neurology.

That’s what’s going on inside the head.

Out in the real world, seniors with the lowest omega-3 levels did worse on just about every test thrown their way — including tests on visual memory as well as executive functions such as problem-solving, multitasking, and abstract thought.

Along with charging your thinking cap, omega-3 fatty acids can also help slash your risk of heart problems, stroke, macular degeneration, and more. They can even lower your risk of gum disease.

But let’s stick to the brain today.

In addition to those omega-3s, be sure to get plenty of B vitamins. Studies have shown that seniors who get high levels of B6, B12 and folate have bigger brains, better memory, and more overall protection from dementia’s top risk factors.

You can read more about that B vitamin and dementia link right here.

Meats tend to be richest in B vitamins, but the best way to get what your brain needs is with a quality B complex from a trusted vitamin maker.

Similarly, you can get omega-3 fatty acids from a diet rich in fatty fish — but since most people don’t eat nearly enough salmon, herring, and anchovies, add an omega-3 supplement to your shopping list if you’re not taking one already.

For one more way to power up your grey matter, keep reading.

It’s the brain–and while we all lose a little grey matter as we age, too much shrinkage has been linked to dementia.

Now, a new study finds that the loss of brain mass found in Alzheimer’s patients might actually be detectable up to a decade before the telltale signs of the disease appear.

Researchers looked at two groups of 33 healthy people in their 70s who were given MRI scans of the regions of the brain associated with Alzheimer’s disease, and then tracked for between 8 and 11 years.

The researchers say 55 percent of the 11 people who had the lowest MRI measurements eventually developed Alzheimer’s disease… versus none of the nine people with the highest measurements and just 20 percent of those with normal readings, according to the study in Neurology.

A similar study in 2009 found that people with smaller hippocampal volumes and faster shrinkage rates were between two and four times more likely to develop dementia than people with larger hippocampal volumes and slower rates of shrinkage.

Like I said earlier, all brains shrink with age–so don’t worry about the normal loss of volume, which is about half a percent a year in seniors.

More than that, however, and you still don’t have to accept dementia as your fate. In fact, you might even be able to slow that shrinkage with ordinary B vitamins.

Researchers found that a patented blend of folate, B12 and B6 slowed the rate of brain shrinkage by an average of 30 percent when compared to a placebo in a study of 168 seniors who suffered from mild cognitive impairment.

The patients who had the highest levels of the inflammation marker homocysteine had an even greater benefit, with the B blend lowering their shrinkage rates by 53 percent. (Read about that here.)

Brain shrinkage isn’t the only dementia warning sign to watch for–another new study finds that people who lose the ability to detect lies and sarcasm may actually suffer from frontotemporal dementia, a form of the disease that affects about 5 percent of all dementia patients.

Researchers from U.C. San Francisco asked 175 older adults–half of whom had some form of dementia–to watch videos of two people speaking, one of whom occasionally lied or used sarcasm.

While the patients without dementia had no problems picking up on it, the ones who showed signs of frontotemporal dementia missed it.

Two messages from this: First, if someone in your life starts missing sarcasm and lies, it may be time to bring them to a specialist.

And second, if they do have this form of dementia, they may be especially prone to scams and con artists–so keep a close eye on them and their finances.

The latest research suggests that women can dramatically lower their risk of colorectal cancer by simply getting more folate. In fact, folate can decrease your risk by nearly two- thirds!

The South Korean study followed more than 1,000 patients. Nearly 600 of them were colorectal cancer patients, while just over 500 of them were healthy. And the researchers found that while drinking, smoking, a sedentary lifestyle, and a family history of the disease all played a role, the healthy women had more folate.

Women who got more than 300 micrograms of folate each day were 64 percent less likely to get the disease than women who got less than 200 micrograms daily, according to the study, published in the European Journal of Clinical Nutrition.

There’s been a shocking rise in the number of colorectal cancers in South Korea – with a six-fold jump in deaths over the past 25 years.

Researchers there believe the rapid switch to a more Western diet may be behind those horrifying stats – and if they’re right, what does that say about us? After all, colorectal cancer is the third most commonly diagnosed cancer – and the third most common cause of cancer deaths – here in the United States for men and women alike.

It doesn’t take a huge leap to make the connection between our diets and these cancers – after all, fresh vegetables have fallen out of favor as prepackaged convenience meals take over the dinner table.

And those fresh vegetables that should be on the table with every meal – especially the folate-rich leafy greens like spinach – have practically become exotic fare. Even when we do eat them, we tend to sauté the nutrients right out of the food.

The good news is, this is an easy enough habit to change. Eat more fresh vegetables, raw or lightly cooked, or take a folate supplement.

The bad news is strictly for the men – while there are lots of other great reasons for you to make sure you get enough folate, colorectal cancer prevention isn’t one of them. The researchers found the benefit applies only to women.

Sorry guys – but eat your spinach anyway. Popeye says so.